Martinelli, A. G., Francischini, H., Dentzien-Dias, P. C., Soares, M. B., and C. L. Schultz. 2016.
The oldest archosauromorph from South America: postcranial remains from the Guadalupian (mid-Permian) Rio do Rasto Formation (Paraná Basin), southern Brazil. Historical Biology.
DOI:10.1080/08912963.2015.1125897
http://www.tandfonline.com/doi/full/10.1080/08912963.2015.1125897
Abstract - In this contribution, we report a distal portion of a left humerus that likely belongs to an indeterminate basal archosauromorph from the Guadalupian (mid-Permian) Rio do Rastro Formation (Paraná Basin) of southern Brazil. A precise taxonomy of the fragmented and isolated humerus UFRGS-PV-0546-P is not warranted at generic nor familiar level but, likely, this specimen belongs to an Archosauromorpha due to the lack of both the entepicondylar and the ectepicondylar foramina. The narrow distal end of the humerus, the rounded radial and ulnar condyles, and the moderately developed supinator process with a shallow ectepicondylar groove (not notched) are features reminiscent of tanystropheids rather than that of other archosauromorphs. This material likely represents the first and oldest Permian archosauromorph from South America and indicates the presence of this lineage before the P/T boundary.
Showing posts with label Archosauromorphs. Show all posts
Showing posts with label Archosauromorphs. Show all posts
Morphology and Diversity of the Mandibular Symphysis of Archosauriforms
Excellent study that demonstrates changes in mandibular symphyses through individual clades; changes that appear to be influenced by changes in dental morphology, which presumably reflect differences in diet. This paper is part of the upcoming volume on early archosaurs.
Abstract: Archosauromorphs
radiated into numerous trophic niches during the Mesozoic, many of which were
accommodated by particular suites of cranial adaptations and feeding
behaviours. The mandibular symphysis, the joint linking the mandibles, is a
poorly understood craniomandibular joint that may offer significant insight
into skull function and feeding ecology. Using comparative data from extant
amniotes, we investigated the skeletal anatomy and osteological correlates of relevant
soft tissues in a survey of archosauromorph mandibular symphyses. Characters
were identified and their evolution mapped using a current phylogeny of archosauriforms
with the addition of non-archosauriform archosauromorphs. Extinct taxa with the
simple Class I condition (e.g. proterochampsids, ‘rauisuchians’), rugose Class
II (aetosaurs, protosuchians, silesaurids) and interdigitating Class III
symphyses (e.g. phytosaurs, crocodyliforms) and finally fused Class IV (avians)
build the joints in expected ways, although they differ in the contributions of
bony elements and Meckel’s cartilage. Optimization of the different classes of
symphyses across archosauromorph clades indicates that major iterative
transitions from plesiomorphic Class I to derived, rigid Class II–IV symphyses
occurred along the lines to phytosaurs, aetosaurs, a subset of poposauroids, crocodyliformes,
pterosaurs and birds. These transitions in symphyseal morphology also appear to
track changes in dentition and potentially diet.
Holliday, C. M., and S. J. Nesbitt.
2013. Morphology and diversity of the mandibular symphysis of archosauriforms In Nesbitt, S. J., Desojo, J. B. and R.
B. Irmis (eds) Anatomy, Phylogeny and Palaeobiology of Early Archosaurs and
their Kin. Geological Society, London, Special Publications, 379, http://dx.doi.org/10.1144/SP379.2
Osteohistology of Some Triassic Archosauromorphs
Botha-Brink, J., and R. M. H. Smith. 2011. Osteohistology of the Triassic archosauromorphs Prolacerta, Proterosuchus, Euparkeria, and Erythrosuchus from the Karoo Basin of South Africa. Journal of Vertebrate Paleontology 31:1238-1254. DOI:10.1080/02724634.2011.621797
Abstract - The South African non-archosauriform archosauromorph Prolacerta and the archosauriforms Proterosuchus, Erythrosuchus, and Euparkeria were important constituents of the Early to early Middle Triassic Karoo ecosystem following the end-Permian mass extinction. We present new data on the osteohistology of these stem archosaurs and provide insight into their paleobiology. Bone tissues of the Early Triassic Prolacerta contain a poorly defined fibro-lamellar complex, with parallel-fibered bone in some regions, whereas the contemporaneous Proterosuchus exhibits rapidly forming uninterrupted fibro-lamellar bone early in its ontogeny, which becomes slow forming lamellar-zonal bone with increasing age. The early Middle Triassic Erythrosuchus deposited highly vascularized, uninterrupted fibro-lamellar bone throughout ontogeny, whereas the growth of the contemporaneous Euparkeria was relatively slow and cyclical. When our data are combined with those of previous studies, preliminary results reveal that Early and Middle Triassic non-crown group archosauromorphs generally exhibit faster growth rates than many of those of the Late Triassic. Early rapid growth and rapid attainment of sexual maturity are consistent with life history expectations for taxa living in the unpredictable conditions following the end-Permian mass extinction. Further research with larger sample sizes will be required to determine the nature of the environmental pressures on these basal archosaurs.
New Record of Large Archosauromorphs from the Early Triassic of Antarctica
Smith, N. D., Crandall, J. R., Hellert, S. M., Hammer, W. R., and P. J. Makovicky. 2011. Anatomy and affinities of large archosauromorphs from the lower Fremouw Formation (Early Triassic) of Antarctica. Journal of Vertebrate Paleontology 31:784-797. DOI:10.1080/02724634.2011.586662
Abstract - The vertebrate assemblage of the lower Fremouw Formation has been studied for nearly 50 years, but many components remain poorly known. We describe a partial presacral vertebra and the distal end of a left humerus collected just above the Permian–Triassic boundary in the Shackleton Glacier region of the central Transantarctic Mountains. Our identification of these specimens as archosauromorphs that represent at least one taxon of large-bodied archosauriform increases the known reptile diversity of the Fremouw Formation considerably, and provides the first definitive evidence for the presence of Archosauriformes in the Early Triassic of Antarctica. These records increase faunal similarities between the lower Fremouw Formation and other Early Triassic assemblages. Although the lower Fremouw assemblage is typically considered a subset of the coeval Lystrosaurus Assemblage Zone (LAZ) of South Africa, the discrepancy in inferred body size between the Antarctic specimens and Proterosuchus fergusi, coupled with the fact that the LAZ of the Karoo Basin has been sampled much more thoroughly, suggests a real disparity in the maximum body size of apex carnivores between the lower Fremouw assemblage and the LAZ. The lower Fremouw specimens also demonstrate that one or more lineages of archosauriform had attained the large body size characteristic of later members of the clade very soon after the end-Permian mass extinction. This offers a point of contrast with the global pattern of post-extinction terrestrial communities, which are typified by a marked reduction in body size (the ‘Lilliput effect’).
Abstract - The vertebrate assemblage of the lower Fremouw Formation has been studied for nearly 50 years, but many components remain poorly known. We describe a partial presacral vertebra and the distal end of a left humerus collected just above the Permian–Triassic boundary in the Shackleton Glacier region of the central Transantarctic Mountains. Our identification of these specimens as archosauromorphs that represent at least one taxon of large-bodied archosauriform increases the known reptile diversity of the Fremouw Formation considerably, and provides the first definitive evidence for the presence of Archosauriformes in the Early Triassic of Antarctica. These records increase faunal similarities between the lower Fremouw Formation and other Early Triassic assemblages. Although the lower Fremouw assemblage is typically considered a subset of the coeval Lystrosaurus Assemblage Zone (LAZ) of South Africa, the discrepancy in inferred body size between the Antarctic specimens and Proterosuchus fergusi, coupled with the fact that the LAZ of the Karoo Basin has been sampled much more thoroughly, suggests a real disparity in the maximum body size of apex carnivores between the lower Fremouw assemblage and the LAZ. The lower Fremouw specimens also demonstrate that one or more lineages of archosauriform had attained the large body size characteristic of later members of the clade very soon after the end-Permian mass extinction. This offers a point of contrast with the global pattern of post-extinction terrestrial communities, which are typified by a marked reduction in body size (the ‘Lilliput effect’).
New Tanystropheids from the Early Triassic of Europe
I don't have access to this article, only the abstract.
Sennikov, A.G. 2011. New Tanystropheids (Reptilia: Archosauromorpha) from the Triassic of Europe. Palaeontological Journal 45:95-104. DOI: 10.1134/S0031030111010151
Abstract—A new prolacertilian species and genus, Augustaburiania vatagini gen. et sp. nov. (Reptilia: Archosauromorpha), from the Lower Triassic of the Don River Basin is described. It is the first representative of the Tanystropheidae in the Eastern Europe and the world oldest member of this family. Another new genus (Protanystropheus gen. nov.) from Central and Western Europe is also established. The diversity, systematics, phylogeny, evolution, and stratigraphic and geographical distribution of prolacertilians are discussed. The ecological role of prolacertilians in Early Triassic communities and adaptation to marine environments are analyzed.
Sennikov, A.G. 2011. New Tanystropheids (Reptilia: Archosauromorpha) from the Triassic of Europe. Palaeontological Journal 45:95-104. DOI: 10.1134/S0031030111010151
Abstract—A new prolacertilian species and genus, Augustaburiania vatagini gen. et sp. nov. (Reptilia: Archosauromorpha), from the Lower Triassic of the Don River Basin is described. It is the first representative of the Tanystropheidae in the Eastern Europe and the world oldest member of this family. Another new genus (Protanystropheus gen. nov.) from Central and Western Europe is also established. The diversity, systematics, phylogeny, evolution, and stratigraphic and geographical distribution of prolacertilians are discussed. The ecological role of prolacertilians in Early Triassic communities and adaptation to marine environments are analyzed.
New Volume on the Early Triassic Vertebrates from Karst Deposits at Czatkowice, Poland
The most recent issue (10 papers) of Palaeontologia Polonica (Volume 65, dated 2009) is dedicated to describing the vertebrate faunal assemblage a Czatkowice Poland. The issue is open access and available at the Palaeontologia Polonica website.
MARIUSZ PASZKOWSKI
The Early Triassic karst of Czatkowice 1, southern Poland
ELIZABETH COOK and CLIVE TRUEMAN
Taphonomy and geochemistry of a vertebrate microremains assemblage from the Early Triassic karst deposits at Czatkowice 1, southern Poland
MIKHAIL A. SHISHKIN and TOMASZ SULEJ
The Early Triassic temnospondyls of the Czatkowice 1 tetrapod assemblage
SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA
The Early Triassic stem−frog Czatkobatrachus from Poland
MAGDALENA BORSUK−BIAŁYNICKA and MARIUSZ LUBKA
Procolophonids from the Early Triassic of Poland
SUSAN E. EVANS
An early kuehneosaurid reptile (Reptilia: Diapsida) from the Early Triassic of Poland
SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA
A small lepidosauromorph reptile from the Early Triassic of Poland
MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS
A long−necked archosauromorph from the Early Triassic of Poland
MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS
Cranial and mandibular osteology of the Early Triassic archosauriform Osmolskina czatkowicensis from Poland
MAGDALENA BORSUK−BIAŁYNICKA and ANDRIEJ G. SENNIKOV
Archosauriform postcranial remains from the Early Triassic karst deposits of southern Poland
MARIUSZ PASZKOWSKI
The Early Triassic karst of Czatkowice 1, southern Poland
ELIZABETH COOK and CLIVE TRUEMAN
Taphonomy and geochemistry of a vertebrate microremains assemblage from the Early Triassic karst deposits at Czatkowice 1, southern Poland
MIKHAIL A. SHISHKIN and TOMASZ SULEJ
The Early Triassic temnospondyls of the Czatkowice 1 tetrapod assemblage
SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA
The Early Triassic stem−frog Czatkobatrachus from Poland
MAGDALENA BORSUK−BIAŁYNICKA and MARIUSZ LUBKA
Procolophonids from the Early Triassic of Poland
SUSAN E. EVANS
An early kuehneosaurid reptile (Reptilia: Diapsida) from the Early Triassic of Poland
SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA
A small lepidosauromorph reptile from the Early Triassic of Poland
MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS
A long−necked archosauromorph from the Early Triassic of Poland
MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS
Cranial and mandibular osteology of the Early Triassic archosauriform Osmolskina czatkowicensis from Poland
MAGDALENA BORSUK−BIAŁYNICKA and ANDRIEJ G. SENNIKOV
Archosauriform postcranial remains from the Early Triassic karst deposits of southern Poland
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