A Late Triassic Vertebrate Paleontology Extravaganza - ‘Late Triassic Terrestrial Biotas and the Rise of Dinosaurs’ Special Issue

It's out. The special volume in Earth and Environmental Science Transactions of the Royal Society of Edinburgh on Late Triassic Terrestrial Biotas and the Rise of Dinosaurs. These papers stem from the Society of Vertebrate Paleontology Symposium at the 2009 annual meeting in Bristol, U. K.  I've included a list of the papers and their abstracts below. There is an amazing amount of information here on Late Triassic vertebrates and early dinosaurs.  It will take me awhile to get through the papers, but for now I'd like to say it is an honor to be included in this volume.  I think Randy, Richard, Max, and the staff of EESTRSE did an excellent job in the production of this volume and I hope everyone who has an interest in Late Triassic terrestrial biotas enjoys the volume and finds the papers interesting and useful.

Issue cover featuring artwork by Jeff Martz.

Table of Contents - Volume 101 - Special Issue 3-4 (Late Triassic Terrestrial Biotas and the Rise of Dinosaurs)

1) Butler, R. J., Irmis, R. B., and M. C. Langer. Preface to ‘Late Triassic Terrestrial Biotas and the Rise of Dinosaurs’ Special Issue.

Abstract - The early Mesozoic records an important transition in the history of the Earth’s terrestrial ecosystems. As they recovered from the largest known mass extinction (the end-Permian event), organisms in these ecosystems transitioned to new forms that eventually evolved into the classic Mesozoic biotas, and laid the foundations for many groups still flourishing today (Fraser 2006; Irmis & Whiteside 2010; Sues & Fraser 2010). All of this was set against a backdrop of dynamic climatic and physical events that shaped these biotas. This early Mesozoic terrestrial transition reached its culmination in many ways during the Late Triassic, when ecosystems had largely recovered from the end-Permian extinction, but had not yet been affected by the end-Triassic mass extinction (Fraser & Sues this volume). Thus, we see a combination of taxa, with some groups that would not survive the end of the Triassic living alongside early representatives of lineages that flourished later in the Mesozoic (e.g., Fraser 2006; Irmis et al. 2007; Brusatte et al. 2008; Sues & Fraser 2010, this volume) and in some cases are still diverse today. Just one example of this transition, recorded during the Late Triassic, is the origin and diversification of non-avian dinosaurs, the iconic representatives of Mesozoic terrestrial ecosystems (Brusatte et al. 2010; Langer et al. 2010). Although small and rare components of their respective biotas when they first evolved ∼231 Ma, dinosaurs were abundant and had a near-worldwide distribution by the beginning of the Jurassic Period (∼201·3 Ma).

2) Fraser, N. C., and H. D. Sues. The beginning of the ‘Age of Dinosaurs’: a brief overview of terrestrial biotic changes during the Triassic.

Abstract - The first appearance of dinosaurs during the early Late Triassic coincided with marked faunal changes in terrestrial ecosystems. Most of the major groups of extant tetrapods (or their proximate sister-taxa), including mammaliaforms, crocodyliform archosaurs, lepidosaurs and turtles, also first appeared in the fossil record during the Late Triassic. On the other hand, a number of Palaeozoic ‘holdovers’, such as procolophonid parareptiles, dicynodont therapsids and many groups of temnospondyls, vanished near or at the end of the Triassic. The tempo and mode of this faunal turnover have long been debated, but there has been growing acceptance of a rather sudden event, although the precise dating of such an event remains controversial. However, new discoveries have cast doubt on this assumption. The persistence of non-dinosaurian dinosauromorphs alongside dinosaurs well into Norian times hints at a more protracted turnover. New data on Triassic insect assemblages indicate that turnover among insects may also have been more protracted and possibly not co-incident with the faunal changes among tetrapods. Future work directed toward improved absolute age assessments for major faunal assemblages will be critical for a better understanding of the transition from therapsid-dominated to dinosaur-dominated communities during the early Mesozoic.

3) Olsen, P. E., Kent, D. V., and J. H. Whiteside. Implications of the Newark Supergroup-based astrochronology and geomagnetic polarity time scale (Newark-APTS) for the tempo and mode of the early diversification of the Dinosauria.

Abstract - The Newark-APTS established a high-resolution framework for the Late Triassic and Early Jurassic. Palaeomagnetic polarity correlations to marine sections show that stage-level correlations of continental sequences were off by as much as 10 million years. New U–Pb ages show the new correlations and the Newark basin astrochronology to be accurate. Correlation of Newark-APTS to the Chinle Formation/Dockum Group, Glen Canyon Group, Fleming Fjord Formation and Ischigualasto Formation led to the following conclusions: (1) there are no unequivocal Carnian-age dinosaurs; (2) the Norian Age was characterised by a slowly increasing saurischian diversity but no unequivocal ornithischians; (3) there was profound Norian and Rhaetian continental provinciality; (4) the classic Chinle-, Germanic- and Los Colorados-type assemblages may have persisted to the close of the Rhaetian; (5) the distinct genus-level biotic transition traditionally correlated with the marine Carnian–Norian is in fact mid-Norian in age and within published error of the Manicouagan impact; (6) the end-Triassic marine and continental extinctions as seen in eastern North America were contemporaneous; and (7) compared to Triassic communities, Hettangian and Sinemurian age terrestrial communities were nearly globally homogenous and of low diversity. Consequently, the complex emerging picture of dinosaur diversification demands biostratigraphically-independent geochronologies in each of the faunally-important regions.

4) Parker, W. G., and J. W. Martz. The Late Triassic (Norian) Adamanian–Revueltian tetrapod faunal transition in the Chinle Formation of Petrified Forest National Park, Arizona.

Abstract - Recent stratigraphic revisions of the Upper Triassic Chinle Formation of Petrified Forest National Park, in conjunction with precise and accurate documentation of fossil tetrapod occurrences, clarified the local biostratigraphy, with regional and global implications. A significant overlap between Adamanian and Revueltian faunas is rejected, as is the validity of the Lamyan sub-land vertebrate faunachron. The Adamanian–Revueltian boundary can be precisely placed within the lower Jim Camp Wash beds of the Sonsela Member and thus does not occur at the hypothesised Tr-4 unconformity. This mid-Norian faunal turnover, may coincide with a floral turnover, based on palynology studies and also on sedimentological evidence of increasing aridity. Available age constraints bracketing the turnover horizon are consistent with the age of the Manicouagan impact event. The rise of dinosaurs in western North America did not correspond to the Adamanian–Revueltian transition, and overall dinosauromorph diversity seems to have remained at a constant level across it. The paucity of detailed Late Triassic vertebrate biostratigraphic data and radioisotopic dates makes it currently impossible to either support or reject the existence of globally synchronous Late Triassic extinctions for tetrapods.

5) Sulej, T., Bronowicz, R., Tałanda, M., and G. Niedźwiedzki. A new dicynodont–archosaur assemblage from the Late Triassic (Carnian) of Poland.

Abstract - This paper reports a new assemblage from the Late Triassic (mid–late Carnian) at Woźniki near Częstochowa (Poland). The Woźniki vertebrate assemblage is similar to that of Lisowice–Lipie Śląskie, a new locality bearing vertebrates from latest Triassic (latest Norian–early Rhaetian) strata of southern Poland, in the presence of dicynodonts, shark spines, plagiosaurs and a cyclotosaur, but conchostracans and bivalves are similar to those from the Krasiejów site (late Carnian). The most complete specimen from Woźniki belongs to a dicynodont, and consists of cranial and postcranial bones of a single individual. It demonstrates that large dicynodonts were part of the Late Triassic vertebrate assemblage in Central Europe. Numerous tetrapod tracks and traces are associated with skeletal fossils at Woźniki.

6) Nesbitt, S. J., Liu, J., and C. Li. A sail-backed suchian from the Heshanggou Formation (Early Triassic: Olenekian) of China.

Abstract - The two major lineages of extant archosaurs, crocodylians and avians, diverged in the Triassic, but the details and timing of this event are incompletely understood. Fragmentary and phylogenetically uninformative specimens, in addition to poor temporal constraints on rock units from the Early and Middle Triassic, typify obstacles in identifying early archosaurs. This paper re-describes the partial skeleton of the only known specimen of Xilousuchus sapingensis Wu, 1981 from the Early Triassic Heshanggou Formation in north-central China. Originally assigned to the non-archosaurian archosauriform clade Proterosuchidae, an extensive phylogenetic analysis posits X. sapingensis as a crown-group archosaur within Suchia, thus making this taxon the unequivocally oldest known member of Archosauria. The age and phylogenetic position of X. sapingensis indicate that many archosaurs, including all major clades of non-archosaurian archosauriforms, the avianline, ornithosuchids, aetosaurs and paracrocodylomorph lineages, must have diverged by the end of the Early Triassic. X. sapingensis is part of a possible clade of sail-backed poposauroids that were common components of archosaur assemblages during the Early to Middle Triassic.

7) Benton, M. J., and A. D. Walker. Saltopus, a dinosauriform from the Upper Triassic of Scotland.

Abstract - Saltopus elginensis, reported in 1910 from the yellow sandstones of the Lossiemouth Sandstone Formation (Late Triassic) of Morayshire, NE Scotland, has long been controversial. It was described first as a theropod dinosaur, but others disagreed. Reanalysis of the type, and only, specimen using casts from the natural rock moulds, as well as X-rays and CT scans, has revealed new anatomical data not available to previous researchers. Saltopus was a small, 800–1000 mm-long biped, whose tail made up more than half its length. It is an avemetatarsalian because it has elongated and tightly bunched metatarsals, the tibia is longer than the femur, the calcaneal tuber is rudimentary or absent, and metatarsal II is equal to or longer than metatarsal IV; a unique assemblage of characters diagnosing this clade. Saltopus is a dinosauromorph on the basis of the reduced fingers IV and V, the saddle-shaped dorsal margin of the iliac blade, and the articulation of sacral rib 1 close to the front of the iliac blade. Saltopus is a dinosauriform on the basis of the trochanteric shelf and lesser trochanter on the proximal end of the femur, the waisted sacral ribs, and perhaps the rod-like and straight pubis. However, it lacks all apomorphies of Dinosauria, retaining for example the primitive condition of two sacral vertebrae. Cladistic analyses place Saltopus within Dinosauromorpha and Dinosauriformes, and between the basal dinosauriform Pseudolagosuchus and the derived clade consisting of Silesauridae and Dinosauria, so making it one of a radiation of small pre-dinosaurian bipedal archosaurs in the Triassic found so far in North and South America and in Europe.

8) Langer, M. C., Bittencourt, J. S., and C. L. Schultz. A reassessment of the basal dinosaur Guaibasaurus candelariensis, from the Late Triassic Caturrita Formation of south Brazil.

Abstract - The dinosaur record of the Santa Maria beds of Rio Grande do Sul (Mid–Late Triassic; south Brazil) includes the herrerasaur Staurikosaurus pricei, and two basal members of the sauropodomorph lineage: Saturnalia tupiniquim and Unaysaurus tolentinoi. The most enigmatic of the saurischian taxa is, however, Guaibasaurus candelariensis, previously regarded as either a basal theropod or a basal sauropodomorph. This study provides a detailed anatomical revision of all specimens originally referred to G. candelariensis by Bonaparte and co-authors, including its type-series and a more recently excavated partial postcranium. Although coming from different sites, these specimens share a unique combination of traits, and at least one possible autapomorphic feature of the pelvis, which support the inclusivity and uniqueness of the species. G. candelariensis was a medium-sized (nearly 2 m long) biped with an intriguing mix of plesiomorphic and derived (eusaurischian/theropod) features. Phylogenetic studies reveal weak support for the nesting of G. candelariensis within Theropoda, but this affinity is bolstered by various traits it shares with neotheropods. The Norian age of G. candelariensis corroborates previous studies that suggest the continuous radiation of more basal dinosauromorphs until the end of the Triassic, after the appearance of the three main dinosaur clades.

9) Novas, F. E., Ezcurra, M. D., Chatterjee, S., and T. S. Kutty. New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of Central India.

Abstract - The beginning of dinosaur evolution is currently known based on a handful of highly informative Gondwanan outcrops of Ischigualastian age (late Carnian–early Norian). The richest Triassic dinosaur records of the southern continents are those of South America and South Africa, with taxonomically diverse faunas, whereas faunas from India and central Africa are more poorly known. Here, the known diversity of Gondwanan Triassic dinosaurs is increased with new specimens from central India, which allow a more comprehensive characterisation of these dinosaur assemblages. Five dinosauriform specimens are reported from the probable late Norian–earliest Rhaetian Upper Maleri Formation, including two new sauropodomorph species, the non-plateosaurian Nambalia roychowdhurii and the plateosaurian Jaklapallisaurus asymmetrica, a guaibasaurid and two basal dinosauriforms. The Lower Dharmaram Formation, probably latest Norian–Rhaetian in age, includes basal sauropodomorph and neotheropod remains, providing the second record of a Triassic Gondwanan neotheropod. The currently available evidence suggests that the oldest known Gondwanan dinosaur assemblages (Ischigualastian) were not homogeneous, but more diverse in South America than in India. In addition, the Upper Maleri and Lower Dharmaram dinosaur assemblages resemble purported coeval South American and European beds in the presence of basal sauropodomorphs. Accordingly, the current available evidence of the Triassic beds of the Pranhita–Godavari Basin suggests that dinosaurs increased in diversity and abundance during the late Norian to Rhaetian in this region of Gondwana.

10) Porro, L. B., Butler, R. J., Barrett, P. M., Moore-Fay, S., and R. L. Abel. New heterodontosaurid specimens from the Lower Jurassic of southern Africa and the early ornithischian dinosaur radiation.

Abstract - Heterodontosaurids are poorly understood early ornithischian dinosaurs with extensive geographic and stratigraphic ranges. The group is best known from the Lower Jurassic upper ‘Stormberg Group’ (upper Elliot and Clarens formations) of southern Africa, previously represented by at least three distinct species and ten described specimens. This paper describes four additional heterodontosaurid specimens from southern Africa. A partial skull of a large individual of Heterodontosaurus tucki (NM QR 1788) is approximately 70 longer than that of the type specimen of Heterodontosaurus, and provides new information on allometric changes in mandibular morphology during growth in this taxon. It is the largest known heterodontosaurid cranial specimen, representing an individual approximately 1·75 metres in length, and perhaps 10 kg in body mass. NHMUK R14161 is a partial skull that appears to differ from all other heterodontosaurids on the basis of the proportions of the dentaries, and may represent an unnamed new taxon. Two additional partial skulls (NHMUK RU C68, NHMUK RU69) are referred to cf. Lycorhinus. At least four, and possibly five or more, heterodontosaurid species are present in the upper ‘Stormberg’. This high diversity may have been achieved by dietary niche partitioning, and suggests an adaptive radiation of small-bodied ornithischians following the end Triassic extinctions.

11) Brusatte, S. L., Benton, M. J., Lloyd, G. T., Ruta, M., and S. C. Wang. Macroevolutionary patterns in the evolutionary radiation of archosaurs (Tetrapoda: Diapsida).

Abstract - The rise of archosaurs during the Triassic and Early Jurassic has been treated as a classic example of an evolutionary radiation in the fossil record. This paper reviews published studies and provides new data on archosaur lineage origination, diversity and lineage evolution, morphological disparity, rates of morphological character change, and faunal abundance during the Triassic–Early Jurassic. The fundamental archosaur lineages originated early in the Triassic, in concert with the highest rates of character change. Disparity and diversity peaked later, during the Norian, but the most significant increase in disparity occurred before maximum diversity. Archosaurs were rare components of Early–Middle Triassic faunas, but were more abundant in the Late Triassic and pre-eminent globally by the Early Jurassic. The archosaur radiation was a drawn-out event and major components such as diversity and abundance were discordant from each other. Crurotarsans (crocodile-line archosaurs) were more disparate, diverse, and abundant than avemetatarsalians (bird-line archosaurs, including dinosaurs) during the Late Triassic, but these roles were reversed in the Early Jurassic. There is no strong evidence that dinosaurs outcompeted or gradually eclipsed crurotarsans during the Late Triassic. Instead, crurotarsan diversity decreased precipitously by the end-Triassic extinction, which helped usher in the age of dinosaurian dominance. 



12) Barrett, P. M., Butler, R. J., and S. J. Nesbitt. The roles of herbivory and omnivory in early dinosaur evolution.

Abstract - Herbivorous and omnivorous dinosaurs were rare during the Carnian stage of the Late Triassic. By contrast, the succeeding Norian stage witnessed the rapid diversification of sauropodomorphs and the rise of the clade to ecological dominance. Ornithischians, by contrast, remained relatively rare components of dinosaur assemblages until much later in the Mesozoic. The causes underlying the differential success of ornithischians and sauropodomorphs remain unclear, but might be related to trophic specialisation. Sauropodomorphs replaced an established herbivore guild consisting of rhynchosaurs, aetosaurs and basal synapsids, but this faunal turnover appears to have been opportunistic and cannot be easily attributed to either competitive interactions or responses to floral change. Consideration of diversity patterns and relative abundance suggests that the ability to eat plants might have been a major factor promoting sauropodomorph success, but that it was less important in the early evolution of Ornithischia. On the basis of current evidence it is difficult to determine the diet of the ancestral dinosaur and scenarios in which omnivory or carnivory represent the basal condition appear equally likely.

13) Irmis, R. B. Evaluating hypotheses for the early diversification of dinosaurs.

Abstract - Many hypotheses have been proposed for the rise of dinosaurs, but their early diversification remains poorly understood. This paper examines the occurrences, species diversity and abundance of early dinosaurs at both regional and global scales to determine patterns of their early evolutionary history. Four main patterns are clear: (1) sauropodomorph dinosaurs became abundant during the late Norian–Rhaetian of Gondwana and Europe; (2) Triassic dinosaurs of North America have low species diversity and abundance until the beginning of the Jurassic; (3) sauropodomorphs and ornithischians are absent in the Triassic of North America; and (4) ornithischian dinosaurs maintain low species diversity, relative abundance and small body size until the Early Jurassic. No one hypothesis fully explains these data. There is no evidence for a Carnian–Norian extinction event, but sauropodomorphs did become abundant during the Norian in some assemblages. No clear connection exists between palaeoenvironment and early dinosaur diversity, but environmental stress at the Triassic–Jurassic boundary is consistent with changes in North American dinosaur assemblages. Elevated growth rates in dinosaurs are consistent with the gradual phyletic increase in body size. This study demonstrates that early dinosaur diversification was a complex process that was geographically diachronous and probably had several causes.

New Triassic Dinosaur Papers from the Proceedings of the Third Gondwanan Dinosaur Symposium

Most of you are probably aware that the Proceedings of the Third Gondwanan Dinosaur Symposium have just been published in the journal Anais da Academia Brasileira de Ciências. There are numerous papers here, three of which pertain to the Triassic.  You can view and download all of the papers from the following link:
http://www.scielo.br/scielo.php?script=sci_issuetoc&pid=0001-376520110001&ln

I have listed the relevent Triassic dinosaur papers below.

Bittencourt, J. S., and M. C. Langer. 2011. Mesozoic dinosaurs from Brazil and their biogeographic implications. Anais da Academia Brasileira de Ciências 83:23-60.

Abstract - The record of dinosaur body-fossils in the Brazilian Mesozoic is restricted to the Triassic of Rio Grande do Sul and Cretaceous of various parts of the country. This includes 21 named species, two of which were regarded as nomina dubia, and 19 consensually assigned to Dinosauria. Additional eight supraspecific taxa have been identified based on fragmentary specimens and numerous dinosaur footprints known in Brazil. In fact, most Brazilian specimens related to dinosaurs are composed of isolated teeth and vertebrae. Despite the increase of fieldwork during the last decade, there are still no dinosaur body-fossils of Jurassic age and the evidence of ornithischians in Brazil is very limited. Dinosaur faunas from this country are generally correlated with those from other parts of Gondwana throughout the Mesozoic. During the Late Triassic, there is a close correspondence to Argentina and other south-Pangaea areas. Mid-Cretaceous faunas of northeastern Brazil resemble those of coeval deposits of North Africa and Argentina. Southern hemisphere spinosaurids are restricted to Africa and Brazil, whereas abelisaurids are still unknown in the Early Cretaceous of the latter. Late Cretaceous dinosaur assemblages of south-central Brazil are endemic only to genus or, more conspicuously, to species level, sharing closely related taxa with Argentina, Madagascar, Indo-Pakistan and, to a lesser degree, continental Africa.

and two new papers on Staurikosaurus, one of which was previously mentioned here.

Grillo, O. N., and S. A. K. Azevedo. 2011. Pelvic and hind limb musculature of Staurikosaurus pricei (Dinosauria: Saurischia). Anais da Academia Brasileira de Ciências 83:73-98.

Abstract - The study of pelvic and hind limb bones and muscles in basal dinosaurs is important for understanding the early evolution of bipedal locomotion in the group. The use of data from both extant and extinct taxa placed into a phylogenetic context allowed to make well-supported inferences concerning most of the hind limb musculature of the basal saurischian Staurikosaurus pricei Colbert, 1970 (Santa Maria Formation, Late Triassic of Rio Grande do Sul, Brazil). Two large concavities in the lateral surface of the ilium represent the origin of the muscles iliotrochantericus caudalis plus iliofemoralis externus (in the anterior concavity) and iliofibularis (in the posterior concavity). Muscle ambiens has only one head and originates from the pubic tubercle. The origin of puboischiofemoralis internus 1 possibly corresponds to a fossa in the ventral margin of the preacetabular iliac process. This could represent an intermediate stage prior to the origin of a true preacetabular fossa. Muscles caudofemorales longus et brevis were likely well developed, and Staurikosaurus is unique in bearing a posteriorly projected surface for the origin of caudofemoralis brevis.

Triassic Literature Recap - 2010

It's time again to list all of the literature published on Triassic vertebrate paleontology in 2010.  Most of these papers were announced on this site; however, some slipped through the cracks.  Even with those inclusions this list is not entirely exhaustive given the sheer volume of work out there and the plethora of scientific journals. 

Temnospondyl studies cooled off a little in 2010 compared with past years, while synapsids and pterosaurs remained hot.  Permo-Triassic and end Triassic extinction interval studies continue on a rapid pace. In the world of dinosaurs we had a new herrerrasaur, Sanjuansaurus, and found out that Azendohsaurus was not.  I'm always thrilled when new aetosaur papers our published and in 2010 we had a new species of Stagonolepis, an armor histology study, two papers on Typothorax, and a revision of Lucasuchus hunti.  Amazingly there were actually two new papers this year dealing with phytosaurs, including a new taxon from the Petrified Forest.  The most prominent Triassic reference this year, however, was the new book, "Triassic Life on Land: The great transition" by Hans Sues and Nick Fraser.  I encourage all Triassophiles who have not yet picked up this book to do so.

In 2009 the most prolific Triassic author for vertebrate paleontology papers was Cesar Schultz with six papers.  This year it is Spencer Lucas with eight. Sterling Nesbitt is right behind with six.  Let's hope 2011 is as productive for Triassic research as the past years.

Abdala, F., and Ribeiro, A.M. 2010. Distribution and diversity patterns of Triassic cynodonts (Therapsida, Cynodontia) in Gondwana. Palaeogeography, Palaeoclimatology, Palaeoecology 286:202-217.


Alcober, O. A., and Martinez, R. N. 2010. A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic of Ischigualasto Formation of northwestern Argentina. ZooKeys 63: 55-81.

Allington-Jones, L., Braddy, S. J., and Trueman, C. N. 2010. Palaeoenvironmental implications of the ichnology and geochemistry of the Westbury Formation (Rhaetian), Westburyon- Severn, South-West England. Palaeontology 53:491-506.

Benson, R. B. J., Butler, R. J., Lindgren, J., and Smith, A. S. 2010. Mesozoic marine tetrapod diversity: mass extinctions and temporal heterogeneity in geological megabiases affecting vertebrates. Proceedings of the Royal Society, Series B 277:820-834.

Benton, M. J. 2010. Archosaur remains from the Otter Sandstone Formation (Middle Triassic, late Anisian) of Devon, southern UK. Proceedings of the Geologists' Association (early online), doi:10.1016/j.pgeola.2010.08.004.

Bonaparte, J. F., Schultz, C. L., and M. B. Soares. 2010. Pterosauria from the Late Triassic of Southern Brazil, pp. 63-71 in Bandyopadhyay, S. (ed.), New Aspects of Mesozoic Biodiversity, Lecture Notes in Earth Sciences 132, Springer-Verlag Berlin/ Heidelberg, DOI: 10.1007/978-3-642-10311-7

Botha-Brink, J., and Angielczyk, K. D. 2010. Do extraordinarily high growth rates in Permo-Triassic dicynodonts (Therapsida, Anomodontia) explain theic success before and after the end-Permian extinction? Zoological Journal of the Linnean Society 160: 341-365.

Böttcher, R. 2010. Description of the shark egg capsule Palaeoxyris friessi n. sp. From the Ladinian (Middle Triassic) of SW Germany and discussion of all known egg capsules from the Triassic of the Germanic Basin. Palaeodiversity 3: 123–139.

Brinkmann, W., Romano, C., Bucher, H,. Ware, D., and Jenks, J. 2010. Palaeobiogeography and stratigraphy of advanced gnathostomian fishes (Chondrichthyes and Osteichthyes) in the Early Triassic and from selected Anisian Localities (Report 1863-2009). Zentrallblatt fur Geologie und Palaontologie Teil II, Heft, 5/6: 765-812.

Brusatte, S. L., Niedzwiedzki, G., and Butler, R. J. 2010. Footprints pull origin and disversification of dinosaur stem lineage deep into the Early Triassic. Proceedings of the Royal Society, Series B., published on line, 7pp.

Brusatte, S. L., Benton, M. J., Desojo, J. B., Langer, M. C. 2010. The higher-level phylogeny of Archosauria (Tetrapoda: Diapsida). Journal of Systematic Palaeontology 8:3-47.

Brusatte, S. J., Nesbitt, S. J., Irmis, R. B., Butler, R. J., Benton, M. J., and Norell, M. A. 2010. The origin and early radiation of dinosaurs. Earth-Science Reviews 101:68-100.

Budziszewska-Karwowska, E., Bujok, A., and Sadlok, G. 2010. Bite marks on an Upper Triassic dicynodontid tibia from Zawiercie, Krakow-Czestochowa upland, Southern Poland. Palaios 25: 415-421.

Buchwitz, M. and S. Voigt. 2010. Peculiar carapace structure of a Triassic chroniosuchian implies evolutionary shift in trunk flexibility. Journal of Vertebrate Paleontology 30:1697-1708.

Cerda, I. A., and J. B. Desojo. 2010: Dermal armour histology of aetosaurs (Archosauria: Pseudosuchia), from the Upper Triassic of Argentina and Brazil. Lethaia, DOI: 10.1111/j.1502-3931.2010.00252.x.

Cisneros, J. C., and Ruta, M. 2010. Morphological diversity and biogeography of procolophonids (Amniota: Parareptilia). Journal of Systematic Palaeontology 8:607-625.

Cisneros, J. C., Cabral, U. G., Beer, F de, Damiani, R., and Fortier D. C. 2010 Spondarthritis in the Triassic. PLoS ONE 5, 5 pp.

Deenen, M. H. L., Ruhl, M., Bonis, N. R., Krigsman, W., Kuerschner, W. M. Reitsma, M., and van Bergen, M. J. 2010. A new chronology for the end-Triassic mass extinction. Earth and Planetary Sciences Letters 291: 113-125.

Dias-Da-Silva, S., and Milner, A. R. 2010. The pustulated temnospondyl revisited-a plagiosternine plagiosaurid from the Lower Triassic of Brazil. Acta Palaeontlogica Polonica 55: 561-563.

Diedrich, C. J. 2010. Palaeoecology of Placodus gigas (Reptilia) and other placodontids -- Middle Triassic macroalgae feeders in the Germanic basin of central Europe--and evidence for convergent evolution with Sirenia. Palaeogeography, Palaeoclimatology, Palaeoecology 285:287-306.

Ezcurra, M. D. 2010. Biogeography of Triassic tetrapods: evidence for provincialism and driven sympatric cladogensis in the early evolution of modern tetrapod lineages. Proceedings of the Royal Society, Series B 277:2547-2552.

Ezcurra, M. D. 2010. A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny. Journal of Systematic Paleontology 8: 371-425.

Ezcurra, M. D., Lecuona, A., and Martinelli, A. 2010. A new basal archosauriform diapsid from the Lower Triassic of Argentina. Journal of Vertebrate Paleontology 30: 1433-1450.

Fischer, J., Axsmith, B. J., and Ash, S. R. 2010. First unequivocal record of the hybodont shark egg capsule Palaeoxyris in the Mesozoic of North America: Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 255: 327-344.

Flynn, J. J., Nesbitt, S. J., Parrish, M., Raniovohartmanana, L., and Wyss, A. R. 2010. A new species of Azendohsaurus (Diapaida: Archosauromorpha) from the Triassic Isalo Group of Southwestern Madagascar: cranium and mandible. Palaeontology 53:660-688.

Fröbisch, J., Angiekczyk, K. D., and Sidor, C. A. 2010. The Triassic dicynodont Kombuisia (Synapsida, Anomodontia) from Antarctica, a refuge from the terrestrial Permian-Triassic mass extinction. Naturwissenschaften 97: 187-196.

Gand, G., De la Horra, R., Galan-Abellan, B., Lopez-Gomez, J., Barrenechea, J. F., Arche, A., and Isabel Benito, M. 2010. New ichnites from the Middle Triassic of the Iberian Ranges (Spain): paleonenvironmental and paleogeographical implications: Historical Biology 22: 40-56.

Gao, K.-Q., Fox, R. C., Zhou, C.-F., and Li, D.-Q. 2010. A new nomammalian eucynodont (Synapsida: Therapsida) from the Triassic of Northern Gansu Province, China, and its biostratigraphic and biogeographic lmplications. American Museum Novitates 3685, 25pp.

Giordano, N., Rigo, M., Ciarapica G. & Bertinelli A. 2010. New biostratigraphical constraints for the Norian ⁄Rhaetian boundary: data from Lagonegro Basin, Southern Apennines, Italy. Lethaia, 10.1111/j.1502-3931.2010.00219.x.

Green, J. L., Schweitzer, M. H., and Lamm, E.-T. 2010. Limb bone histology and growth in Placerias hesternus (Therapsida: Anomodontia) from the Upper Triassic of North America. Palaeontology 53: 347-364.

Heckert, A. B., Lucas, S. G., Rinehart, L. F., Celeskey, M. D., Spielmann, J. A., and Hunt, A. P. 2010. Articulated skeletons of the aetosaur Typothorax coccinarum Cope (Archosauria: Stagonolepididae) from the Upper Triassic Bull Canyon Formation (Revueltian: Early-Mid Norian), eastern New Mexico, USA. Journal of Vertebrate Paleontology 30: 619-642.

Hu, S.-x,. Zhang, Q.-y., Chen, Z.-Q., Zhou, C.-y., Lü, T., Xie, T., Wen, W., Huang, J. -y., and M. J. Benton, 2010. The Luoping biota: exceptional preservation, and new evidence on the Triassic recovery from end-Permian mass extinction. Proceedings of the Royal Society: B (advance online publication) doi: 10.1098/rspb.2010.2235

Irmis, R. B., and Whiteside, J. H., 2010. Newly integrated approaches to studying Late Triassic terrestrial ecosystems. Palaios 25: 689-691.

Irmis, R. B., Martz, J. W., Parker, W. G., and Nesbitt, S. J. 2010. Re-evaluating the correlation between Late Triassic terrestrial vertebrate biostratigraphy and the GSSP-defined marine stages. Albertiana 38:40-52.

Jaisnoski, S. G., Rayfield, E. J., and Chinsamy, A. 2010. Mechanics of the scarf premaxilla-nasal suture in the snout of Lystrosaurus. Journal of Vertebrate Palaeontology 30:1283-1288.

Kammerer, C. F., Flynn, J. J., Ranivoharimanana, L. and A. R. Wyss. 2010. The first record of a probainognathian (Cynodontia: Chiniquodontidae) from the Triassic of Madagascar. Journal of Vertebrate Paleontology 30:1889-1894.

Kemp, T. 2010. New Perspectives on the Evolution of Late Palaeozoic and Mesozoic Terrestrial Tetrapods; pp. 1-26 in S. Bandyopadhyay (ed.), New Aspects of Mesozoic Biodiversity, Lecture Notes in Earth Sciences 132, DOI 10.1007/978-3-642-10311-7

Kimmig, J., and G. Arp. 2010. Phytosaur remains from the Norian Arnstadt Formation (Leine Valley, Germany), with reference to European phytosaur habitats. Palaeodiversity 3: 215–224.

Klein, N. 2010. Long bone histology of sauropterygia from the Lower Muschelkalk of the Germanic Basin Provides unexpected implications for phylgeny. PLoS ONE 5, 25 pp.

Klein, H., and Lucas, S. G. 2010. Tetrapod footprints - their use in biostratigraphy and biochronology of the Triassic; pp. 419-446 in Lucas, S.G. (ed.) The Triassic Timescale, Geological Society of London, Special Publications.

Klein, H., and Lucas, S. G. 2010. The Triassic footprint record of crocodylomorphs-a critical re-evaluation. New Mexico Museum of Natural History and Science Bulletin 51:55-60.

Klein, H., Voigt, S., Hminna, A., Saber, H., Schneider, J., and D. Hmich. 2010. Early Triassic Archosaur-Dominated Footprint Assemblage from the Argana Basin (Western High Atlas, Morocco). Ichnos 17:1–13. DOI: 10.1080/10420940.2010.510030

Langer, M. C. , Montefeltro, F. C. , Hone, D. E. , Whatley, R. and C. L. Schultz. 2010. On Fodonyx spenceri and a new rhynchosaur from the Middle Triassic of Devon. Journal of Vertebrate Paleontology 30:1884 -1888.

Liu, J., and Sues, H.-D. 2010. Dentition and tooth replacement of Boreogomphodon (Cynodontia: Traversodontidae) from the Upper Triassic of North Carolina, USA. Vertebrata PalAsiatica 40: 169-184.

Liu, J., and Olsen, P. 2010. The phylogenetic relationships of Eucynodontia (Amniota: Synapsada). Journal of Mammal Evolution 17: 151-176.

Liutkus, C. M., Beard, J. S., Fraser, N. C., and Ragland, P. C. 2010. Use of fine-scale stratigraphy and chemostratigraphy to evaluate conditions of deposition and preservation of a Triassic Lagerstätte, south-central Virginia. Journal of Paleolimnology 44: 645-666.

Lopez-Arbarello, A., Rauhut, O.W.M, and E. Cerdeno. 2010. The Triassic fish faunas of the Cuyana Basin, western Argentina. Palaeontology 53:249-276.

Lucas, S. G., Spielmann, J. A., Klein, H., and Lerner, A. J. 2010. Ichnology of the Upper Triassic (Apachean) Redonda Formation, east-central New Mexico. New Mexico Museum of Natural History and Science Bulletin 47:1-74.

Lucas, S. G., Rinehart, L. F., Krainer, K., Spielmann, J. A., and A. B. Heckert. 2010. Taphonomy of the Lamy amphibian quarry: A Late Triassic bonebed in New Mexico, U.S.A. Palaeogeography, Palaeoclimatology, Palaeoecology 298:388–398.

Lyson, T. R., Bever, G. S., Bhullar, B. S., Joyce, W. G., and Gauthier, J. G. 2010. Transitional fossils and the origin of turtles. Biology Letters, published on line, 4pp.

Maisch, M. W. and Kapitzke, M. 2010. A presumably marine phytosaur (Reptilia: Archosauria) from the pre-planorbis beds (Hettangian) of England. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 257: 373–379.

Mallison, H. 2010. The digital Plateosaurus 1: body mass, mass distribution and posture assessd using CAD and CAE on a digitally mounted complete skeleton. Palaeontologia Electronica 13.2.8A.

Mallison, H. 2010. The digital Plateosaurus II: An assessment of the range of motion of the limbs and vertebral column and of previous reconstructions using a digital skeletal mount. Acata Palaeontologica Polonica 55: 433-458.

Mannion, P. D., and Upchurch, P. 2010. Completeness metrics and the quality of the sauropodomorph fossil record through geological and historical time. Paleobiology 36:283-302.

Marsicano, C.A., Mancuso, A.C., Palma, R.M., and Krapovickas, V. 2010. Tetrapod tracks in a marginal lacustrine setting (Middle Triassic, Argentina): taphonomy and significance. Palaeogeography, Palaeoclimatology, Palaeoecology 291:388-399.

Martin, T., Sun, G., and Mosbrugger, V. 2010. Triassic-Jurassic biodiversity, ecosystems, and climate in the Junggar Basin, Xinjinag, northwest China. Palaeobiodiveristy and Palaeoenvironments 90:171-173.

Martinelli, A. G. 2010. On the postcanine dentition of Pascualgnathus polanskii Bonaparte (Cynodontia, Traversodontidae) from the Middle Triassic of Argentina. Geobios 43:629–638.

Mitchell, J. S., Heckert, A. B., and H.-D. Sues. 2010. Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”. Naturwissenschaften 97:1117-1121.

Modesto, S. P., and Botha-Brink, J. 2010. A burrow cast with Lystrosaurus skeletal remains from the Lower Triassic of South Africa. Palaios 25: 274-281.

Modesto, S. P., Scott, D. M., Botha-Brink, J, and Reisz, R. R. 2010. A new and unusual procolophonid parareptile from the Lower Triassic Katberg Formation of South Africa. Journal of Vertebrate Paleontology 30: 715-723.

Mukherjee, D., Ray, S., and Sengupta, D. P. 2010. Preliminary observations on the bone microstucture, growth patterns, and life habits of some Triassic temnospondyls from India. Journal of Vertebrate Paleontology 30: 78-93.

Nesbitt, S. J., and D. W. E. Hone. 2010. An external mandibular fenestra and other archosauriform character states in basal pterosaurs. Palaeodiversity 3: 225–233.

Nesbitt, S. J., Sidor, C. A., Irmis, R. B., Angielcyzk, K. D., Smith, R. M. H., and Tsuji, L. A. 2010. Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira. Nature 464: 95-98.

Nicolas, M., and Rubidge, B. S. 2010. Changes in Permo-Triassic terrestrial tetrapod ecological representation in the Beaufort Group (Karoo Supergroup) of South Africa. Lethaia 43: 45-59.

Novikov, I. V. 2010. New data on Trematosauroid Labyrinthodonts of Eastern Europe: 2. Trematosaurus galae sp. nov.: cranial morphology. Paleontological Journal 44: 457-467.

de Oliveira, T. V., Sores, M. B., and Schultz, C. L. 2010. Trucidocynodon riograndensis gen. nov. et sp. nov. (Eucynodontia), a new cynodont from the Brazilian Upper Triassic (Santa Maria Formation). Zootaxa 2382, 71pp.

Osi, A. 2010: Feeding-related characters in basal pterosaurs: implications for jaw mechanism, dental function and diet. Lethaia, DOI: 10.1111/j.1502-3931.2010.00230.x.

Padian, K., Li, C., and Pchelnikova, J. 2010. The trackmaker of Apatopus (Late Triassic, North America): Implications for the evolution of archosaur stance and gait. Palaeontology 53: 175-189.

Parker, W. G., and Martz, J. W. 2010. Using positional homology in aetosaur (Archosauria: Pseudosuchia) osteoderms to evaluate the taxonomic status of Lucasuchus hunti. Journal of Vertebrate Paleontology 30: 1100-1108.

Piechowski, R., and Dzik, J. 2010. The axial skeleton of Silesaurus opolensis. Journal of Vertebrate Paleontology 30: 1127-1141.

Ray, S., Bandyopadhyay, S., and R. Appana. 2010. Bone Histology of a Kannemeyeriid Dicynodont Wadiasaurus: Palaeobiological Implications; pp. 73-89 in S. Bandyopadhyay (ed.), New Aspects of Mesozoic Biodiversity, Lecture Notes in Earth Sciences 132, DOI 10.1007/978-3-642-10311-7

Renesto, S. 2010. A new specimen of Nothosaurus from the Latest Anisian (Middle Triassic) Besano Formation (Grenzbitumenzone) of Italy: Rivista Italiana di Paleontologia e Stratigrafia 116: 245-260.

Renesto, S., Spielmann, J. A., Lucas, S. G., and Spagnoli, G. T. 2010. The taxonomy and paleobiology of the Late Triassic (Carnian-Norian: Adamanian-Apachean) drepanosaurs (Diapsida: Archosauromorpha: Drepanosauromorpha). New Mexico Museum of Natural History and Science Bulletin 46:1-81.

Rieppel, O., Jiang, D.-Y., Fraser, N. C., Hao, W.-C., Motani, R., Sun, Y.-L., and Sun, Z.-Y. 2010. Tanystropheus cf. T. longobardicus from the Early Late Triassic of Guizhou Province, Southwestern China. Journal of Vertebrate Paleontology 30: 1082-1089.

Rowe, T. B., Sues, H.-D., and R. Reisz. 2010. Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon. Proceedings of the Royal Society B, First Cite. doi:10.1098/rspb.2010.1867

Saila, L. K. 2010. Osteology of Leptopleuron lacertinum Owen, a procolophonoid parareptile from the Upper Triassic of Scotland, with remarks on ontogeny, ecology and affinities. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 101, 1–25.


Sanchez, S., Germain, D., De Ricqles, A., Abourachid, A., Goussard, F. and Tafforeau, P. 2010. Limb-bone histology of temnospondyls: implications for understanding the diversification of palaeoecologies and patterns of locomotion of Permo-Triassic tetrapods. Journal of Evolutionary Biology, early online. doi:10.1111/j.1420-9101.2010.02081.x

Santucci, V. L., and Kirkland, J. I. 2010. An overview of National Park Service Paleontological Resources from the Parks and Mounuments in Utah; pp. 589-623 in Sprinkel, D. A,. Chidsey, T. C., and Anderson, P. B. (eds.), Geology of Utah’s Parks and Monuments, Utah Geological Association Publication 28.

Scheyer, T. M. 2010. New interpretation of the postcranial skeleton and overall body shape of the placodont Cymodus hildegradis Peyer, 1931 (Reptilia, Sauropterygia). Palaentologia Electronica 13.2.15A.

Schoch, R. R., Voigt, S., and Buchwitz, M. 2010. A chroniosuchid from the Triassic of Kyrgyzstan and analysis of chroniosuchian relationships. Zoological Journal of the Linnean Society 160:515-530.

Schoch, R. R., Nesbitt, S., Müller, J., Lucas, S. G., and Boy, J. A., 2010. The reptile assemblage from the Moenkopi Formation (Middle Triassic) of New Mexico. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 255: 345-369.

Spielmann, J. A., and Lucas, S. G. 2010. Typothorax coccinarum (Archosauria: Stagonolepididae) from the Upper Triassic (Revueltian) Petrified Forest Formation, El Puertocito, Canon del Cobre, Rio Arriba County, New Mexico. New Mexico Museum of Natural History and Science Bulletin 49: 221-229.

Stocker, M. R. 2010. A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Late Triassic (Norian) Sonsela Member (Chinle Formation) in Arizona, and a critical reevaluation of Leptosuchus Case, 1922. Palaeontology 53: 997-1022.

Sues, H.-D., and N. C. Fraser. 2010. Triassic life on land: The Great Transition. Columbia University Press, New York, 229p.

Sues, H.-D., and Hopson, J. A. 2010. Anatomy and phylogenetic relationships of Boreogomphodon jeffersoni (Cynodontia: Gomphodontia) from the Upper Triassic of Virginia. Journal of Vertebrate Paleontology 30: 1202-1220.

Sulej, T. 2010. The skull of an early Late Triassic aetosaur and the evolution of the stagonolepidid archosaurian reptiles. Zoological Journal of the Linnean Society 158:860-881.

Sullivan, C. 2010. The role of the calcaneal 'heel' as a propulsive lever in basal archosaurs and extant monitor lizards. Journal of Vertebrate Paleontology 30: 1422-1432.

Tanimoto, M., Utsunomiya, S., and Fujimoto, T. 2010. Osteichthyan teeth from the Early Triassic Taho Formation of Ehime Prefecture, Southwest Japan. Konseki 33: 49-52.

Tintori, A., Sun, Z.-Y., Lombardo, C., Jiang, D.-Y., Sun, Y.-L., and Hao, W.-C., 2010. A new basal neopterygian from the Middle Triassic of Luoping County (South China). Rivista Italiana di Paleontologia e Stratigrafia 116 (2).

Tourania, A., Benaouissa, N.,Gand, G., Bourquinc, S., Jalil, N.-E., Broutind,J., Battail, B., Germaine, D., Khaldounea, F., Soumaya, S., Steyere, J. S., and R. . 2010. Evidence of an Early Triassic age (Olenekian) in Argana Basin (High Atlas, Morocco) based on new chirotherioidtraces. Comptes Rendus Palevol, early online.

Trotteyn, M. J. and J. A. Haro. 2010. The braincase of a specimen of Proterochampsa Reig (Archosauriformes: Proterochampsidae) from the Late Triassic of Argentina. Paläontologische Zeitschrift. Published on-line May 11 2010. DOI 10.1007/s12542-010-0068-7

Witzmann, F., Scholz, H., Mueller, J., and N. Kardjilov. 2010. Sculpture and vascularization of dermal bones, and the implications for the physiology of basal tetrapods. Zoological Journal of the Linnean Society 160:302-340.

Zhao, L.-J., Sato, T., Liu, J., Li, C., and X.-C. Wu. 2010. A new skeleton of Miodentosaurus brevis (Diapsida:Thalattosauria) with a further study of the taxon. Vertebrata PalAsiatica 48:1-10.

New Triassic Insect from Kyrgystan and a New Species of Palaeoxyris from Germany

Béthoux, O., Voigt, S., and J. W. Schneider. 2010. A Triassic palaeodictyopteran from Kyrgyzstan. Palaeodiversity 3: 9–13.

Abstract - A specimen belonging to the species reliquia n. sp. is described from the Dzaylyaucho locality (Madygen, Kyrgyzstan; late Middle to early Late Triassic). It is interpreted as a palaeodictyopteran. It is therefore the latest occurrence of this group, previously considered as extinct during Middle to earliest Late Permian.

Böttcher, R. 2010. Description of the shark egg capsule Palaeoxyris friessi n. sp. From the Ladinian (Middle Triassic) of SW Germany and discussion of all known egg capsules from the Triassic of the Germanic Basin. Palaeodiversity 3: 123–139.
Abstract - The new shark egg capsule Palaeoxyris friessi n. sp. is described from the Hauptsandstein of the Lower Keuper (Erfurt Formation, Ladinian, Middle Triassic). The type and only specimen is complete and remarkably well preserved. With a length of 27 cm it is the longest complete Palaeoxyris egg capsule known so far. It is interpreted as an egg capsule of the hybodontid sharks Polyacrodus polycyphus or cf. Polyacrodus keuperianus. The capsule is associated with a rich flora, the brackish water bivalve Unionites and conchostracans, but other vertebrate remains were absent. All known records of Triassic and Lower Jurassic egg capsules from the Germanic Basin and their potential producers are discussed. All of the capsules have been found in deltaic or prodeltaic deposits.

Two New Cynodont Papers from the Middle Triassic of Gondwana

The first paper is a short note so there is no abstract.


Kammerer, C. F., Flynn, J. J., Ranivoharimanana, L. and A. R. Wyss. 2010. The first record of a probainognathian (Cynodontia: Chiniquodontidae) from the Triassic of Madagascar. Journal of Vertebrate Paleontology 30:1889-1894. DOI: 10.1080/02724634.2010.520784

Note: The authors state that this specimen is probably Middle Triassic in age, but could possibly be as young as Carnian.


Martinelli, A. G. 2010. On the postcanine dentition of Pascualgnathus polanskii Bonaparte (Cynodontia, Traversodontidae) from the Middle Triassic of Argentina. Geobios 43:629–638


Abstract - The dental morphology of Pascualgnathus polanskii Bonaparte (Therapsida, Eucynodontia, Traversodontidae), from the Middle Triassic Río Seco de la Quebrada Formation (Puesto Viejo Group, Argentina), is described and compared with that of other basal traversodontid cynodonts. Albeit Pascualgnathus is frequently used in phylogenetic analyses, neither a detailed description nor drawings of its postcanines have been published so far. The upper postcanines of Pascualgnathus are transversely wide, rectangular in occlusal view, with a lingual cusp connected to the transverse ridge which is located in the center of the crown, and one main labial cusp followed by one posterior labial, both forming the labial margin. The lower postcanines, mostly worn out in the known specimens, are quadrangular until pc6 and then they are rectangular with the major axis anteroposteriorly oriented. They have a tall mesial border, possibly constituted by one labial and one lingual cusp, and a transverse ridge. After comparisons, the number of cusps in the sectorial, labial border of the upper gomphodont teeth, frequently used in phylogenetic analyses, would not necessary implies real homologies. For example, postcanine morphologies with one or more cusps anterior to the main labial cusp would not be homologous to morphologies with one or more cusps posterior to the main labial cusp, while resulting in a similar count of labial cusps.

New Triassic Paper in PloS ONE

Klein, N. 2010. Long Bone Histology of Sauropterygia from the Lower Muschelkalk of the Germanic Basin Provides Unexpected Implications for Phylogeny. PLoS ONE 5(7): e11613. doi:10.1371/journal.pone.0011613

Abstract

Background

Sauropterygia is an abundant and successful group of Triassic marine reptiles. Phylogenetic relationships of Triassic Sauropterygia have always been unstable and recently questioned. Although specimens occur in high numbers, the main problems are rareness of diagnostic material from the Germanic Basin and uniformity of postcranial morphology of eosauropterygians. In the current paper, morphotypes of humeri along with their corresponding bone histologies for Lower to Middle Muschelkalk sauropterygians are described and interpreted for the first time in a phylogenetic context.

Methodology/Principal Findings

Nothosaurus shows a typical plesiomorphic lamellar-zonal bone type, but varying growth patterns and the occurrence of a new humerus morphotype point to a higher taxonomic diversity than was known. In contrast to the enormous morphological variability of eosauropterygian humeri not assigned to Nothosaurus, their long bone histology is relatively uniform and can be divided into two histotypes. Unexpectedly, both of these histotypes reveal abundant fibrolamellar bone throughout the cortex. This pushes the origin of fibrolamellar bone in Sauropterygia back from the Cretaceous to the early Middle Triassic (early Anisian). Histotype A is assigned to Cymatosaurus, a basal member of the Pistosauroidea, which includes the plesiosaurs as derived members. Histotype B is related to the pachypleurosaur Anarosaurus. Contrary to these new finds, the stratigraphically younger pachypleurosaur Neusticosaurus shows the plesiomorphic lamellar-zonal bone type and an incomplete endochondral ossification, like Nothosaurus.

Conclusions/Significance

Histological results hypothetically discussed in a phylogenetical context have a large impact on the current phylogenetic hypothesis of Sauropterygia, leaving the pachypleurosaurs polyphyletic. On the basis of histological data, Neusticosaurus would be related to Nothosaurus, whereas Anarosaurus would follow the pistosaur clade. Furthermore, the presence of fibrolamellar bone, which is accompanied with increased growth rates and presumably even with increased metabolic rates, already in Anarosaurus and Cymatosaurus can explain the success of the Pistosauroidea, the only sauropterygian group to survive into the Jurassic and give rise to the pelagic plesiosaur radiation.

Early Triassic Age for the Base of the Timezgadiwine Formation of Morocco

Tourania, A., Benaouissa, N.,Gand, G., Bourquinc, S., Jalil, N.-E., Broutind,J., Battail, B., Germaine, D., Khaldounea, F., Soumaya, S., Steyere,  J. S., and R. . 2010. Evidence of an Early Triassic age (Olenekian) in Argana Basin (High Atlas, Morocco)based on new chirotherioidtraces. Comptes Rendus Palevol, early online. 

Abstract - New chirotherioid traces (Synaptichnium, Chirotherium, Brachychirotherium, Isochirotherium), are described in the Argana Basin (High Atlas of Morocco). Seeing that these ichnotaxa are frequent in the Triassic, their occurrence in outcrops formerly mapped as Permian (T2Member) has required detailed sedimentological and paleontological studies of the fossiliferous site.These studies clearly show that theichnite-bearing strata belong actually to the T3 Member of the “regional Triassic”, i.e. lower member of the Timezgadiwine Formation, the age of which was, in fact, unknown up to now.The description of these ichnospecies and their statistical comparison with those of other Early and Middle Triassic areas, suggestan Olenekian age for this footprint site, and consequently for the T3. The trackmakers were Archosauriformes, some of which had autopodia less evolved than those of Anisian age. With Lepidosauria,they lived in a flood plain close to alluvial-fans.

New Triassic Papers in Rivista Italiana di Palaeontolgia e Stratigrafia.

There are a trio of Triassic papers in the new issue of Rivista Italiana di Paleontologia e Stratigrafia.

Renesto, S. 2010. A new specimen of Nothosaurus from the latest Anisian (Middle Triassic) Besano Formation (Grenzbitumenzone) of Italy. Rivista Italiana di Paleontologia e Stratigrafia 116(2).

Abstract - A nearly complete but disarticulated skeleton of a small sized nothosaur is described. The specimen was collected in 2003 from an outcrop of the Besano Formation (Grenzbitumenzone of Swiss authors) of latest Anisian (Middle Triassic) age, in the Monte San Giorgio Area, northern Italy. The osteology of the postcranial skeleton supports the assignment to the genus Nothosaurus, and also excludes its belonging to Nothosaurus giganteus/Paranothosaurus amsleri already known from coeval localities of the Besano Formation in the Swiss part of the Monte San Giorgio area. Despite the lack of most of the skull, which contains diagnostic characters at the species level for Nothosaurus, the few preserved cranial elements suggest similarities with N. juvenilis which skull, and only known part, is also of comparable size. This specimen is particularly significant because it improves the knowledge of the osteology of N. juvenilis and because the second Nothosaurus species, smaller than N. giganteus/P. amsleri, suggests coexistence of sympatric species characterized by size and, probably, trophic differentiation within the genus Nothosaurus in the Monte San Giorgio area as occurred in the coeval Germanic Basin.

Tintori, A., Sun, Z.-Y., Lombardo, C., Jiang, D.-Y., Sun, Y.-L., and Hao, W.-C., 2010. A new basal neopterygian from the Middle Triassic of Luoping County (South China). Rivista Italiana di Paleontologia e Stratigrafia 116 (2).



Abstract - A new taxon belonging to Neopterygians is described, based on very nicely preserved specimens from the rich vertebrate levels recently discovered in Luoping County, Yunnan Province, South China. This new assemblage dates to Pelsonian (Anisian, Middle Triassic), about the same age of the Panxian Fauna from the nearby Guizhou Province. The Luoping Fauna, yielding this new taxon, is turning out to be one of the most important fish faunas of the whole Middle Triassic and the oldest evidence of the fish radiation of this time span. This new genus of basal neopterygian shows unique derived characters, especially for the almost naked body, with a single row of urodermals covering the body lobe in the tail and a row of very small and thin scales bearing the lateral line canal along the flank. Also in the axial skeleton the new taxon shows peculiar characters such as the neural spines perfectly aligned to each paired neural arches and abdominal ribs well developed. Concerning skull bones, no suborbitals have been detected.
Stockar, R., and Kustatscher, E. 2010. The Ladinian flora from the Cassina Beds (Meride Limestone, Monte San Giorgio, Switzerland): preliminary results. Rivista Italiana di Paleontologia e Stratigrafia 116 (2).


Abstract - A newly opened excavation in the Cassina beds of the Lower Meride Limestone (Monte San Giorgio UNESCO WHL, Canton Ticino, Southern Alps) has yielded a small collection of Ladinian plant fossils, together with vertebrate (mostly fish) and invertebrate remains. The flora contains at least five species; conifer remains assignable to the genera Elatocladus, Voltzia and ?Pelourdea are the most common elements. A new species, Elatocladus cassinae n. sp., is formally described. Co-occurring with the conifers are seed ferns (Ptilozamites) and a few putative cycadalean remains (?Taeniopteris). Among the identified genera, only Voltzia has previously been reported from Monte San Giorgio. The fossils presented in this paper indicate that a diversified flora thrived in the region during the Ladinian. Floral composition and preservation patterns are suggestive of a taphonomically-biased record and a relatively far-away source area.

Enhanced Technique for Separating Microvertebrates from Matrix

The Journal of Paleontological Techniques is an online, open access journal dedicate to publishing papers on fossil preparation.  The latest offering is this paper by Mitchell and Heckert describing the use of sodium polytungstate filtration to separate some Upper Triassic microfossils from collected matrix. Although there are some serious caveats to using these chemicals (such as how the chemicals react with metal and glass...ouch), the results are promising and the set-up looks fairly easy.  You can download this article free from here.

Mitchell, J. S. and A. B. Heckert. 2010. The setup, use and efficacy of sodium polytungstate separation methodology with respect to microvertebrate remains. Journal of Paleontological Techniques, 7: 1-12.

Abstract - Concentrated deposits of small remains from vertebrates, termed microvertebrate sites or vertebrate microsites, are a unique and detailed source of information about the history of life. Collecting fossils from these sites, however, presents unique challenges. The most time consuming, and thus most deterring, aspect by far is the separation of the fossils from the sediment. This study attempts to quantify to what extent the use of sodium polytungstate (=sodium metatungstate, Na6H2W12O40, abbr. SPT) filtration increases fossil concentration, how quickly fossils sink in SPT solutions, and what is a good working density for SPT. We do this by generally following the methodology set out by previous authors, although with some substantial modifications, on an Upper Triassic deposit dominated by clay minerals and lithic fragments, as well as on a second, smaller quartz sand dominated microsite. We also provide a revised and detailed guide with our modifications to former practices and our recommendations to other workers interested in creating a SPT laboratory, including the strong advisory to work over thin plastic sheets, as SPT can react with metal and adheres strongly to glass when it crystallizes.

Our experiments have shown a significant improvement in fossil concentration (from ~2% of the clasts being fossils to ~19%) at the main site, with a sample from the other site showing the treated concentrate as 25% fossil. We have also found very few fossils in the float (<0.5%), but noticeable rates of fossil loss in SPT solutions above ~2.80 g/mL (up to 16%). Further, we have found that 2.75 g/mL is a good working density for several lithologies, as it is high enough to float most rock, low enough to sink most fossils, and low enough to be manageably maintained. SPT has, in processing one particularly rich site, saved many person-hours that otherwise would have been spent picking through less concentrated sediment.

My Thoughts on the Peer Review Process (Part 3) - Wait Until the Peer-reviewed Paper (a case study from the ongoing debate surrounding reports of Triassic nests from Arizona).

When I was working on my MS thesis at Northern Arizona University on aetosaurs, I was struck by the announced discovery of fossil "reptile nests" (Hasiotis and Martin, 1999) and the earliest records of many social insect nests including bees (e.g., Hasiotis et al., 1998).  It seemed possible that aetosaurs could have been the nest maker, and evidence from the site had also suggested some degree of parental care from whomever the nest maker was.  Likewise, I had been tossing around the idea of possible alternative food sources for aetosaurs and insects might just fit the bill, especially if there was evidence for social insect nests during the Late Triassic.  This early bee record also suggested that bees evolved before and separately from angiosperms.

Photograph of purported reptile nests from Petrified Forest National Park.  From Hasiotis and Martin, 1999.

 When I started working at the park one of the first sites my supervisor took me to was the site of these "reptile nests" as she was curious what another geologist/paleontologist would think of them.  Needless to say I was extremely disappointed.  Every geologist I have showed them to since agrees with my assessment, they are simply erosional potholes in a sandstone.  Visiting the site provides the detailed evidence for this determination.  Unfortunately this discovery resulted in much popular press and these "nests" even make into more recent research papers; however, no detailed rebuttal has yet been published.  Other nests attributed to aetosaurs have been described from the Triassic of Italy (Avanzini et al., 2007), but I have not been able to see these first hand to evaluate them.

[Note: I had forgotten about the rebuttal on the Petrified Forest 'nests' by Lucas and Hunt (2006)].

Purported "Bee's Nests" from Petrified Forest National Park.  NPS photo.

The bee's nest record, from a log in the Petrified Forest, was immediately criticized by entomologists (e.g., Grimaldi, 1999; Engel, 2001), arguing that these traces provide no signature evidence of bee activity.  Unlike the "reptile nests"; however, these must have been made by some type of organism, and beetles have been the most cited tracemaker.  Also unlike the 'reptile nests' there is a detailed rebuttal paper that provides good evidence that these traces are not bee's nests, but rather represent a new form of beetle trace (Lucas et al., 2010 - see abstract below).  Like the 'reptile nests' every person with an entomological background that I have shown these to agrees with this assessment and like the 'reptile nests' these story too received much popular press before a paper was published. 

The lesson here is that we should avoid oversensationalizing 'amazing' discoveries like these until peer reviewed papers describing them in detail are published in the relevant literature.  Failing to do so can cause long term misunderstandings regarding our fossil resources. This also happened in the case of Chindesaurus bryansmalli ("Gertie") which was hailed as the world's "earliest" dinosaur, a claim which still makes it in to occasional brochures and webpages about Petrified Forest National Park. 

It can be very tempting to get excited about the finds and want to make a big media splash, but in the end they cannot be considered valid or relevant until they pass the critical test of peer review. As I argued in a previous post, having these papers reviewed by qualified entomologists and geological colleagues can help avoid having your work criticized and/or not accepted by future workers. 

Having seen the specimens I believe that the Lucas et al's. interpretation has much merit; as do several other entomologists; however, it would appear that the debate is not entirely closed.  I do especially have to agree with the last quote in this news story.  I'd like to see more evidence for such a sensational claim.

Lucas, S. G., Minter, N. J., and A. P. Hunt.  2010. Re-evaluation of alleged bees' nests from the Upper Triassic of Arizona. Palaeogeography, Palaeoclimatology, Palaeoecology 286:194–201.

Abstract - Published records of supposed Triassic bees' nests are based on trace fossils in silicified wood and in sandstone in Upper Triassic strata of the Chinle Group in Petrified Forest National Park, Arizona. A critical, firsthand restudy of these trace fossils indicates that they lack diagnostic features of bees' nests, such as cells with smooth linings and spiral closure caps. Indeed, many of the observations claimed to identify these traces as bees' nests cannot be replicated. Instead, the putative Triassic bees' nests can be classified as: 1. Clavate borings in petrified wood, somewhat similar to Teredolites; these borings preferentially penetrate
heart-rot fungus (Polyporites) and are mostly likely larval chambers of wood-boring beetles. 2. Cylindrical,
vertical burrows in sandstone assignable to Skolithos; these are almost certainly arthropod produced. The
recognition that the Chinle Group trace fossils are not bees' nests eliminates them as evidence that decouples
bee origins from the Cretaceous origin of angiosperms. The Triassic trace fossils in silicified wood are also a
new and unique record of likely beetle borings in Triassic wood.

REFERENCES

Avanzini, M., Dalla Vecchia, F.M., Mietto, P., Piubelli, D., Preto, N., Rigo, M., and G. Roghi. 2007. A vertebrate nesting site in northeastern Italy reveals unexpectedly complex behavior for Late Carnian reptiles. Palaios 22:465-475.

Engel, M.S. 2001. A monograph of the Baltic amber bees and the evolution of the Apoidea (Hymenoptera). Bulletin of the American Museum of Natural History 259:1–192.

Grimaldi, D. 1999. The co-radiations of pollinating insects and angiosperms in the Cretaceous. Annals of the Missouri Botanical Garden 86, 373–406.

Hasiotis, S.T., and Martin, A., 1999, Probable reptile nests from the Upper Triassic Chinle Formation, Petrified Forest National Park, Arizona, in Santucci, V., and McClelland, L., eds., National Park Service, Paleontological Research, v. 4, p. 85–90.

Hasiotis, S.T., Dubiel, R.F., Kay, P.T., Demko, T.M., Kowalska, K., and D. McDaniel. 1998. Research update on hymenopteran nests and cocoons, Upper Triassic Chinle Formation, Petrified Forest National Park, Arizona. In: Santucci, V.L., McClelland, L. (Eds.), National Park Service Paleontological Research. Technical Report NPS/NRGRD/GRDTR-98/01, pp. 116–121.

Lucas, S.G., and Hunt, A.P. 2006. Reappraisal of 'reptile nests' from the Upper Triassic Chinle Group, Petrified Forest National Park, Arizona. New Mexico Museum of Natural History and Science Bulletin 37:155-159.

Lucas, S. G., Minter, N. J., and A. P. Hunt. 2010. Re-evaluation of alleged bees' nests from the Upper Triassic of Arizona. Palaeogeography, Palaeoclimatology, Palaeoecology 286:194–201.

New Book Available - The Triassic Timescale

Available now, Geological Society of London Special Publication 334, The Triassic Timescale, edited by S. G. Lucas.  The table of contents is listed below and you can find out more about the book and order it here.  The PDF of the introductory article is also available as a free download.  Note that in this introductory article Lucas rejects the recent long Norian hypothesis basing this rejection on vertebrate, pollen, and conchostracan biochronology.  For a detailed discussion of this I'll refer interested parties again to the recent paper by Irmis et al. (2010).

LUCAS, S. G. The Triassic timescale: an introduction.

LUCAS, S. G. The Triassic chronostratigraphic scale: history and status.

MUNDIL, R., PÁLFY, J., RENNE, P. R. & BRACK, P. The Triassic timescale: new constraints and a review of geochronological data.

HOUNSLOW, M. W. &MUTTONI, G. The geomagnetic polarity timescale for the Triassic: linkage to stage boundary definitions.

TANNER, L. H. The Triassic isotope record.

TANNER, L. H. Cyclostratigraphic record of the Triassic: a critical examination.

ORCHARD, M. J. Triassic conodonts and their role in stage boundary definition.

O’DOGHERTY, L., CARTER, E. S., GORIČAN, Š., & DUMITRICA, P. Triassic radiolarian biostratigraphy.

MCROBERTS, C. A. Biochronology of Triassic bivalves.

BALINI, M., LUCAS, S. G., JENKS, J. F. & SPIELMANN, J. A. Triassic ammonoid biostratigraphy: an overview.

KÜRSCHNER, W. M. & WALDEMAAR HERNGREEN, G. F. Triassic palynology of central and northwestern Europe: a review of palynofloral diversity patterns and biostratigraphic subdivisions.

CIRILLI, S. Upper Triassic–lowermost Jurassic palynology and palynostratigraphy: a review.

KOZUR, H. W. & WEEMS, R. E. The biostratigraphic importance of conchostracans in the continental Triassic of the northern hemisphere.

KLEIN, H. & LUCAS, S. G. Tetrapod footprints – their use in biostratigraphy and biochronology of the Triassic.

LUCAS, S. G. The Triassic timescale based on nonmarine tetrapod biostratigraphy and biochronology.

Re-evaluating Late Triassic Global Biostratigraphic Correlations

Irmis, R. B., Martz, J. W., Parker, W. G., and S. J. Nesbitt. 2010. Re-evaluating the correlation between Late Triassic terrestrial vertebrate biostratigraphy and the GSSP-defined marine stages. Albertiana 38:40-52.


A series of four land-vertebrate faunachrons have been proposed for biostratigraphical correlation of Upper Triassic non-marine strata, particularly in western North America but purportedly of global utility (Lucas, 1998). As these faunachrons are supposed to represent units of time it is necessary to tie them to the various stages of the Late Triassic, which are defined by marine fossils. Fortunately metoposaurs, phytosaurs, and aetosaurs have been found in both marine and non-marine strata and these have been used to provide ties to the marine scale (Lucas and Heckert, 2000).  To aid in this attempt, these often fragmentary specimens have been identified to the genus level and synonymy of numerous taxa have been proposed to "smooth" global correlations (e.g., Lucas, 1998; Lucas and Heckert, 2000).  Furthermore, first appearances of index taxa have been assumed to be synchronous across Pangea, allowing for hypothetical timing of major events in the Late Triassic such as the first appearance of groups such as the dinosaurs (Heckert and Lucas, 1999). 

In this paper we critically examine these taxonomic assignments and conclude that they, and thus the correlations they provide, are unsupported.  Furthermore, we argue that assuming the synchronous appearance of taxa globally masks potentially diachronous patterns of vertebrate dispersal.  This has already been supported by comparison of dates from the Ischigualasto (Argentina) and Chinle (western North America)Formations, which biostratigraphy considered to be time equivalents, but may be separated by as much as 10 million years (Furin et al., 2006; Irmis and Mundil, 2008).   Finally we argue that based on this detailed biostratigraphic frameworks must be constructed for particular regions and then correlated using independent methods such as radioisotopic dates. 

 To quote from the conclusions section "it is clear to us that the veracity of vertebrate biochronology as a means of correlating Upper Triassic strata has reached the present limits of its resolution, and has been compromised by controversial taxonomic practices and circular reasoning....To advance Late Triassic vertebrate biochronology, which has assumed an importance in chronostratigraphic correlation far in excess of its actual substance, must yield to other methods for understanding of Late Triassic vertebrate faunal change".

Albertiana is the official newsletter of the Subcommision on Triassic Stratigraphy and is published once a year.  More information and past issues can be downloaded from here.  Unfortunately, the current issue is not available on-line yet, but a PDF of this article can be obtained by e-mailing me or Randall Irmis.  Be advised that if we get many requests it may take a bit to respond to them all so please be patient.

The full abstract for the article is below:

Abstract - One of the main methods for correlating Late Triassic terrestrial strata is through the use of land-vertebrate faunachrons (LVFs). Use of LVFs is widespread because of their supposed global application and ability to be correlated with the marine stages of the timescale. New magnetostratigraphic and radioisotopic data indicate that the traditional correlation of Late Triassic LVFs requires revision, although some authors maintain that these original correlations are sound, and that the new correlations of the marine stages to the numerical timescale are in error. Here, we examine the available evidence for cross-correlation of Late Triassic LVFs with the marine stages and numerical timescale. We conclude that the biostratigraphic links between the LVFs and marine stages are not robust; they are based on nondiagnostic specimens and/or taxonomically controversial specimens, endemic taxa, and/or ambiguously correlated assemblage zones. Given the available data, new correlations of the LVFs, marine stages, and the numerical timescale using magnetostratigraphy and radioisotopic ages that support a “long Norian” are preferential to those using largely vertebrate biostratigraphy that support a “long Tuvalian.” We also outline a framework for improving the accuracy and relevance of Late Triassic vertebrate biostratigraphy going forward in the near future.

REFERENCES

Furin, S., Preto, N., Rigo, M., Roghi, G., Gianolla, P., Crowley, J. L., and S. A. Bowring. 2006. High-precision U-Pb zircon age from the Triassic of Italy: implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs. Geology 34: 1009-1012.

Heckert, A. B., and S. G. Lucas. 1999. Global correlation and chronology of Triassic theropods (Archosauria: Dinosauria). Albertiana 23:22-35. [Note: this article is identical to the one published by the same authors in the Gaia volume in 2000].

Irmis, R. and Mundil, R. 2008. New age constraints from the Chinle Formation revise global comparisons of Late Triassic vertebrate assemblages. Journal of Vertebrate Paleontology, 28 (3 Supplement): 95A.

Lucas, S. G. 1998. Global Triassic tetrapod biostratigraphy and biochronology. Palaeogeogeography, Palaeoclimatology, Palaeoecology143:345-382.

Lucas, S. G. and A. B. Heckert. 2000. Biochronological significance of Triassic nonmarine tetrapod records from marine strata. Albertiana 24: 30-36.

New Cynodont from the Upper Triassic of Brazil

This is a sizeable monograph containing a description of a new taxon of cynodont, Trucidocynodon riograndensis, from the Upper Triassic Santa Maria Formation of Brazil.  This paper includes a detailed phylogenetic analysis of the Cynodontia with 145 characters, and a detailed atlas depicting various character states used in the analysis.  The resulting tree does appear to be significantly different than the one recently published by Liu and Olsen (2010).  I don't study cynodonts so I cannot evaluate the phylogenetic, taxonomic, and descriptive work; however, it is maddening to see that the straigraphic section still considers the Ischigualasto Formation to be entirely Carnian in age ignoring much of the recent Triassic timescale revisions and studies showing good evidence that much of the Ischigulasto is actually Norian in age (Furin et al. 2006; Irmis and Mundil, 2008; Currie et al. 2009). Despite this, however, this still appears to be an impressive piece of work pending resolution of the differences with the Liu and Olsen study.

Oliveira, T. V., Soares, M. B. and C. L. Schultz. 2010. Trucidocynodon riograndensis gen. nov. et sp. nov. (Eucynodontia), a new cynodont from the Brazilian Upper Triassic (Santa Maria Formation). Zootaxa 2382:1–71.

Abstract - An almost complete skeleton of a new carnivorous cynodont from the Upper Triassic of Southern Brazil, Trucidocynodon riograndensis gen. nov. et sp. nov., is described. The new taxon is very similar to Ecteninion lunensis Martinez et al. 1996 from Upper Triassic of Argentina (Ischigualasto Formation). Both have an elongated skull, large pterygoid flanges, a well developed orbitosphenoid, a relatively short osseous secondary palate, greatly developed canines and sectorial postcanines with posteriorly directed cusps. However, the new taxon shows some differences relative to E. lunensis such as an open pterygoparoccipital foramen, the posterior opening of the post-temporal foramen enclosed by tabular and squamosal, and upper incisors with serrated cutting edges. The more remarkable features of the postcranium of T. riograndensis are the presence of 32 presacral vertebrae, a greater number than in most of non-mammaliaform cynodonts, the accentuated lumbarisation of the posterior trunk vertebrae and a remarkable morphological gradient in the caudal vertebrae; the femur and humerus show some interesting adaptations suggesting a more upright limb posture. The overall morphology of the astragalocalcaneal complex is similar to that of Diademodon and of the therocephalian Bauria.

REFERENCES

Currie, B. S., Colombi, C. E., Tabor, N. J., Shipman, T. C., and I. P. Montañez. 2009. Stratigraphy and architecture of the Upper Triassic Ischigualasto Formation, Ischigualasto Provincial Park, San Juan, Argentina, Journal of South American Earth Sciences 27:74-87. doi: 10.1016/j.jsames.2008.10.004

Furin, S., Preto, N., Rigo, M., Roghi, G., Gianolla, P., Crowley, J.L., and Bowring, S.A., 2006, High-precision U-Pb zircon age from the Triassic of Italy: Implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs: Geology, v. 34, p. 1009–1012, doi:10.1130/G22967A.1.


Irmis, R. B., and R. Mundil. 2008. New age constraints from the Chinle Formation resolve global comparisons of Late Triassic vertebrate assemblages. Journal of Vertebrate Paleontology 28:95A.

Liu, J., and P. Olsen. 2010. The Phylogenetic Relationships of Eucynodontia (Amniota: Synapsida). Journal of Mammalian Evolution. Published online April 13 2010. doi: 10.1007/s10914-010-9136-8

The Origin and Early Radiation of Dinosaurs

Finally this is out, although presently only as an accepted manuscript in Earth Science Reviews.  I was one of the reviewers for this paper and felt that it constitutes a very well written overview of early dinosaur work to the present, including many of the recent cool finds from the Chinle Formation of course.  I was reviewing this manuscript last year about the time another early dinosaur review paper came out by Max Langer and colleagues (not sure why this paper is so delayed) and feel that these papers are nice complements to each other.

[Note: after writing this I noticed that Brusatte et al. added a similarily worded paragraph to the end of the introduction.  I also noticed that they use the word "compliment" when they mean "complement".  See the difference here ;)].

Brusatte, S. L., Nesbitt, S. J., Irmis, R. B., Butler, R. J., Benton, M. J., and M. A. Norell. 2010. The origin and early radiation of dinosaurs. Earth Science Reviews. Early online. doi: 10.1016/j.earscirev.2010.04.001

Abstract - Dinosaurs were remarkably successful during the Mesozoic and one subgroup, birds, remain an important component of modern ecosystems. Although the extinction of non-avian dinosaurs at the end of the Cretaceous has been the subject of intense debate, comparatively little attention has been given to the origin and early evolution of dinosaurs during the Late Triassic and Early Jurassic, one of the most important evolutionary radiations in earth history. Our understanding of this keystone event has dramatically changed over the past 25 years, thanks to an influx of new fossil discoveries, reinterpretations of long-ignored specimens, and quantitative macroevolutionary analyses that synthesize anatomical and geological data. Here we provide an overview of the first 50 million years of dinosaur history, with a focus on the large-scale patterns that characterize the ascent of dinosaurs from a small, almost marginal group of reptiles in the Late Triassic to the pre-eminent terrestrial vertebrates of the Jurassic and Cretaceous. We provide both a biological and geological background for early dinosaur history. Dinosaurs are deeply nested among the archosaurian reptiles, diagnosed by only a small number of characters, and are subdivided into a number of major lineages. The first unequivocal dinosaurs are known from the late Carnian of South America, but the presence of their sister group in the Middle Triassic implies that dinosaurs possibly originated much earlier. The three major dinosaur lineages, theropods, sauropodomorphs, and ornithischians, are all known from the Triassic, when continents were joined into the supercontinent Pangaea and global climates were hot and arid. Although many researchers have long suggested that dinosaurs outcompeted other reptile groups during the Triassic, we argue that the ascent of dinosaurs was more of a matter of contingency and opportunism. Dinosaurs were overshadowed in most Late Triassic ecosystems by crocodile-line archosaurs and showed no signs of outcompeting their rivals. Instead, the rise of dinosaurs was a two-stage process, as dinosaurs expanded in taxonomic diversity, morphological disparity, and absolute faunal abundance only after the extinction of most crocodile-line reptiles and other groups.

Triassic Life on Land: The Great Transition

Finally!  After 10 days of waiting my copy of Hans Sues and Nick Fraser's new book on the Triassic was finally delivered (actually I've been waiting much longer, since I found out about this project AND it wasn't really 'delivered' I had to pick it up at the post office).  Unfortunately I'm in the middle of a term paper and several other projects so this is really bad timing, but I have taken a quick skim and it looks like it will be excellent reading.  This is a more technical treatise than the 2006 Dawn of the Dinosaurs book by Nick Fraser, but both are essential reading for Triasofiles.

Now I'm going to go do some more work so Hans and Nick will be forced to do an updated second edition next year ;). 

Sues, H.-D., and N. C. Fraser. 2010. Triassic life on land: The Great Transistion. Columbia University Press, New York, 229p.

P.S. Why is there no aetosaur on the cover?  Maybe it is hiding?

Sequence Stratigraphy of the Upper Triassic Succession in Algeria

Bourquin, S., Eschard, R., Hamouche, B.  High-resolution sequence stratigraphy of Upper Triassic succession (Carnian - Rhaetian) of the Zarzaitine outcrops (Algeria): a model of fluvio-lacustrine deposits, African Earth Sciences (2010), doi: 10.1016/j.jafrearsci.2010.04.003

Abstract - The detailed facies analysis of the Zarzaitine outcrops (Illizi Basin in the In Amenas area of Algeria) allows the depositional environment of the Upper Triassic succession to be defined: braided rivers within an arid and humid alluvial plain, low sinuosity rivers within a humid alluvial plain, lake deposits and marginal sabkha. The description of the outcrops helps to define three types of genetic units from a proximal to a distal depositional environment: fluvial, fluvial-lacustrine and lacustrine. The spatial and temporal evolutions of the genetic unit were characterised by five specific stages from dry to humid climate conditions, inducing sediment supply and lake-level variations. During the first two stages (stage 1 and 2) under a dry climate, the lake level was low and sediments mostly by-passed and poorly preserved. During stages 3 and 4, an increase in humidity and rainfall induced a rise in the lake-level and the development of vegetation, as well as a decrease in the sediment supply, although the sediment preservation were then at its maximum. The last stage (stage 5) marked the beginning of a decrease in the humidity, the minimum of sediment supply and the maximum of the lake level. Therefore, the recognition and the description of genetic units within this fluviallacustrine environment help to demonstrate the interaction between climate, sediment supply and lake-level variation, at the scale of these units. Six stratigraphic cycles have been recognised in the vertically stacked genetic units and can be grouped in three megacycles (denoted as I, II and III). The first megacycle, attributed to Carnian to early Norian, corresponds to the base of braided river systems with some ephemeral channels developed in an arid environment where some aeolian deposits were preserved. It evolved trough time to humid conditions favouring the development of extensive floodplain, associated with hydromorphic soils, and perennial lake environments. During the Carnian times and Norian, the Zarzaitine area was not connected to the Berkine basin northward, a Hercynian unconformity palaeorelief forming a drainage divide. According to the directions of the palaeocurrents, the sediment provenances were mostly from the southwest and the north. The connection with the Berkine basin only occurred during the upper part of the megacycle II deposition, characterised by fluvio-lacustrine environments. The maximum flooding of the megacycle I, Norian in age, could be correlated with the early Norian maximum flooding observed on the Saharan platform. The late Norian-Rhaetian second megacycle was mostly a lacustrine environment associated with extensive floodplain, with the development of a hydromorphic palaeosol with root imprints attributed to a warm and humid climate. The maximum flooding episode of this second megacycle could be
attributed to the major marine trangression recorded in Algeria, during the Rhaetian, and
could be correlated with a relative sea-level rise. A dolomitic level, attributed to sabkha
environments, marks the beginning of the retrogradational trend of the third cycle,
attributed to the Rhaetian-Liassic. The palaeocurrent of the upper part of megacycle II
and of the megacycle III were always oriented toward the northeast, attesting that the
relief was located to the southwest.