Abstract - Diverse tetrapod track assemblages with Scoyenia invertebrate traces were discovered in the Triassic Timezgadiouine and Bigoudine formations of the Argana Basin (Western High Atlas, Morocco). The ichnofossils occur in alluvial plain sandstones and mudstones of the Irohalène Member (T5) and Tadart Ouadou Member (T6) considered Carnian-Norian in age by vertebrate remains and palynomorphs. Tetrapod footprints are assigned to Apatopus, Atreipus-Grallator,Eubrontes isp., Parachirotherium, cf. Parachirotherium postchirotherioides, Rhynchosauroides ispp., and Synaptichnium isp. They can be referred to lepidosauromorph/ archosauromorph, basal archosaur, and dinosauromorph trackmakers. Apatopus represented by 11 tracks of a more than 4 m long trackway, is recorded for the first time outside of North America and Europe. The assemblage concurs with the proposed Late Triassic age of the track-bearing beds by the occurrence of Apatopus, Atreipus-Grallator, and Eubrontes. If this is accepted, the stratigraphic range of Synaptichnium and Parachirotherium, hitherto known only from Early or Middle Triassic deposits, has to be extended to the Carnian-Norian. The occurrence of Eubrontes in the Irohalene Member (T5) provides further evidence for large theropods in pre-Jurassic strata. All assemblages are referred to the Scoyenia ichnofacies indicating continental environments with alternating wet and dry conditions.
Showing posts with label Morocco. Show all posts
Showing posts with label Morocco. Show all posts
Diverse Tetrapod Track Assemblages from the Late Triassic of Morocco
Lagnaoui, A. Klein, H., Voigt, S., Hminna, A., Saber, H., Schneider, J. W., and R. Werneburg. 2012. Late Triassic Tetrapod-Dominated Ichnoassemblages from the Argana Basin (Western High Atlas, Morocco). Ichnos 19:238-253.
DOI:
10.1080/10420940.2012.718014
Abstract - Diverse tetrapod track assemblages with Scoyenia invertebrate traces were discovered in the Triassic Timezgadiouine and Bigoudine formations of the Argana Basin (Western High Atlas, Morocco). The ichnofossils occur in alluvial plain sandstones and mudstones of the Irohalène Member (T5) and Tadart Ouadou Member (T6) considered Carnian-Norian in age by vertebrate remains and palynomorphs. Tetrapod footprints are assigned to Apatopus, Atreipus-Grallator,Eubrontes isp., Parachirotherium, cf. Parachirotherium postchirotherioides, Rhynchosauroides ispp., and Synaptichnium isp. They can be referred to lepidosauromorph/ archosauromorph, basal archosaur, and dinosauromorph trackmakers. Apatopus represented by 11 tracks of a more than 4 m long trackway, is recorded for the first time outside of North America and Europe. The assemblage concurs with the proposed Late Triassic age of the track-bearing beds by the occurrence of Apatopus, Atreipus-Grallator, and Eubrontes. If this is accepted, the stratigraphic range of Synaptichnium and Parachirotherium, hitherto known only from Early or Middle Triassic deposits, has to be extended to the Carnian-Norian. The occurrence of Eubrontes in the Irohalene Member (T5) provides further evidence for large theropods in pre-Jurassic strata. All assemblages are referred to the Scoyenia ichnofacies indicating continental environments with alternating wet and dry conditions.
Abstract - Diverse tetrapod track assemblages with Scoyenia invertebrate traces were discovered in the Triassic Timezgadiouine and Bigoudine formations of the Argana Basin (Western High Atlas, Morocco). The ichnofossils occur in alluvial plain sandstones and mudstones of the Irohalène Member (T5) and Tadart Ouadou Member (T6) considered Carnian-Norian in age by vertebrate remains and palynomorphs. Tetrapod footprints are assigned to Apatopus, Atreipus-Grallator,Eubrontes isp., Parachirotherium, cf. Parachirotherium postchirotherioides, Rhynchosauroides ispp., and Synaptichnium isp. They can be referred to lepidosauromorph/ archosauromorph, basal archosaur, and dinosauromorph trackmakers. Apatopus represented by 11 tracks of a more than 4 m long trackway, is recorded for the first time outside of North America and Europe. The assemblage concurs with the proposed Late Triassic age of the track-bearing beds by the occurrence of Apatopus, Atreipus-Grallator, and Eubrontes. If this is accepted, the stratigraphic range of Synaptichnium and Parachirotherium, hitherto known only from Early or Middle Triassic deposits, has to be extended to the Carnian-Norian. The occurrence of Eubrontes in the Irohalene Member (T5) provides further evidence for large theropods in pre-Jurassic strata. All assemblages are referred to the Scoyenia ichnofacies indicating continental environments with alternating wet and dry conditions.
Complex Tetrapod Burrows from the Middle Triassic of Morocco
Too bad there are not any body fossils associated with this find....
Voigt, S., Schneider, J. W., Saber, H., Hminna, A., Lagnaoui, A., Klein, H., Brosig, A., and J. Fischer. 2011. Complex tetrapod burrows from Middle Triassic red beds of The Argana Basin (Western High Atlas, Morocco). Palaios 26:555-556.
Abstract - Although burrowing ability has been widespread in tetrapods for more than 300 million years, subsurface dwelling structures that indicate communal behavior are poorly evidenced from pre-Cenozoic strata. Here we present recently discovered tetrapod burrows from Middle Triassic red beds of the Argana Basin in central Morocco, whose complexity suggests an origin by gregarious animals. The well-preserved burrows occur in interbedded mudstones and sandstones interpreted as channel and overbank deposits of ephemeral, braided streams. All burrows originate from the top of thick-bedded sandstones and descend as moderately inclined (10°–30°), partially spiral tunnels to laterally extended, branched chambers in underlying mudstones. Tunnel segments are biconvex to planoconvex in cross section, up to 20 cm wide and 12 cm in maximum height and exhibit transverse scratch marks along the ceilings and sidewalls. Distinctive burrow characteristics include a laterally sinuous geometry (wavelength λ = 38–45 cm; amplitude A = 5–10 cm) of the tubelike passages and the presence of grouped alcoves in terminal chambers. We attribute the burrows to procolophonids or therapsids based on closely associated tetrapod tracks and the limited diameter of the excavations. Our findings represent the second oldest record of communal fossorial behavior by tetrapods and the oldest example from low-latitude areas. Beyond providing refuge from predators, these elaborate underground structures probably functioned as a buffer against diurnal or seasonal variations of air temperature and humidity in a semiarid habitat that was situated just north of the paleoequator.
Abstract - Although burrowing ability has been widespread in tetrapods for more than 300 million years, subsurface dwelling structures that indicate communal behavior are poorly evidenced from pre-Cenozoic strata. Here we present recently discovered tetrapod burrows from Middle Triassic red beds of the Argana Basin in central Morocco, whose complexity suggests an origin by gregarious animals. The well-preserved burrows occur in interbedded mudstones and sandstones interpreted as channel and overbank deposits of ephemeral, braided streams. All burrows originate from the top of thick-bedded sandstones and descend as moderately inclined (10°–30°), partially spiral tunnels to laterally extended, branched chambers in underlying mudstones. Tunnel segments are biconvex to planoconvex in cross section, up to 20 cm wide and 12 cm in maximum height and exhibit transverse scratch marks along the ceilings and sidewalls. Distinctive burrow characteristics include a laterally sinuous geometry (wavelength λ = 38–45 cm; amplitude A = 5–10 cm) of the tubelike passages and the presence of grouped alcoves in terminal chambers. We attribute the burrows to procolophonids or therapsids based on closely associated tetrapod tracks and the limited diameter of the excavations. Our findings represent the second oldest record of communal fossorial behavior by tetrapods and the oldest example from low-latitude areas. Beyond providing refuge from predators, these elaborate underground structures probably functioned as a buffer against diurnal or seasonal variations of air temperature and humidity in a semiarid habitat that was situated just north of the paleoequator.
Diodorus scytobrachion, A New Silesaurid from the Late Triassic of Morocco
I've had this paper in the queue for a bit as I still don't like the idea of online publishing of new taxon names at the "accepted manuscript" stage, but the knowledge of this proposed new taxon is increasingly widespead so I'll post the abstract and link here now. Silesaurids are amazingly cosmopolitan in their distribution and must have been significant members of various Triassic ecosystems, most likely filling the role later occupied by ornithischians.
I'm a big fan of the creative taxonomic name as well.
Kammerer, C. F., Nesbitt, S. J., and N. H. Shubin. In press. The first basal dinosauriform (Silesauridae) from the Late Triassic of Morocco. Acta Palaeontologica Polonica. doi: 10.4202/app.2011.0015
Abstract - Disarticulated material from the Late Triassic Timezgadiouine Formation in the Argana Basin of Morocco represents a new taxon of silesaurid dinosauromorph,
Diodorus scytobrachion gen. et sp. nov. D. scytobrachion can be distinguished from other silesaurids by the presence of anteriorly-canted teeth that decrease in size towards the anterior end of the dentary and a distinct lateral ridge running parallel to the dentary alveolar margin. In a phylogenetic analysis, D. scytobrachion is recovered as the sister taxon to the Brazilian Sacisaurus agudoensis, nested deep within Silesauridae. This new taxon provides further evidence of a near-cosmopolitan range for basal dinosauriforms in the Late Triassic and further demonstrates the disparity of dental morphologies within Silesauridae.
First Occurrence of a Middle Triassic Tetrapod Ichnofauna from Morocco
Klein, H., Voigt, S., Saber, H., Schneider, J. W., Hminna, A., Fischer, J., Lagnaoui, A., and A. Brosig. 2011. First occurrence of a Middle Triassic tetrapod ichnofauna from the Argana Basin (Western High Atlas, Morocco). Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication) doi:10.1016/j.palaeo.2011.05.021
Abstract - Footprints of Early Mesozoic terrestrial tetrapods are inadequately known from NW Africa despite pervasive and well-exposed continental strata of corresponding age in that region. Here, we report on the first occurrence of a tetrapod ichnofauna from the middle part of the Triassic Timezgadiouine Formation in the Argana Basin, Central Morocco that is outstanding in terms of abundance, preservation, and diversity. Footprints of this assemblage are assigned to the ichnotaxa Chirotherium barthii, Isochirotherium coureli, Synaptichnium isp., Atreipus–Grallator, Rotodactylus isp., Rhynchosauroides isp., and Procolophonichnium isp., suggesting early archosaurian, dinosauromorph, lepidosauromorph and possible therapsid or procolophonoid trackmakers. Based on comparison with the abundant record of Early Mesozoic vertebrate ichnofossils from Europe and North America, the ichnofauna presented here indicates a Middle Triassic (Anisian–Ladinian) age for the track-bearing horizon in the Argana Basin. Its clearly Euramerican affinity sheds light on the migration and dispersal of early archosaur-dominated tetrapod faunas considering that several ichnotaxa of the assemblage are documented from Africa for the first time.
As pointed out by Ben Creisler on the Dinosaur Mailing List, this paper is closely related to one published last year by many of the same authors.
Abstract - Footprints of Early Mesozoic terrestrial tetrapods are inadequately known from NW Africa despite pervasive and well-exposed continental strata of corresponding age in that region. Here, we report on the first occurrence of a tetrapod ichnofauna from the middle part of the Triassic Timezgadiouine Formation in the Argana Basin, Central Morocco that is outstanding in terms of abundance, preservation, and diversity. Footprints of this assemblage are assigned to the ichnotaxa Chirotherium barthii, Isochirotherium coureli, Synaptichnium isp., Atreipus–Grallator, Rotodactylus isp., Rhynchosauroides isp., and Procolophonichnium isp., suggesting early archosaurian, dinosauromorph, lepidosauromorph and possible therapsid or procolophonoid trackmakers. Based on comparison with the abundant record of Early Mesozoic vertebrate ichnofossils from Europe and North America, the ichnofauna presented here indicates a Middle Triassic (Anisian–Ladinian) age for the track-bearing horizon in the Argana Basin. Its clearly Euramerican affinity sheds light on the migration and dispersal of early archosaur-dominated tetrapod faunas considering that several ichnotaxa of the assemblage are documented from Africa for the first time.
As pointed out by Ben Creisler on the Dinosaur Mailing List, this paper is closely related to one published last year by many of the same authors.
Early Triassic Archosaur-dominated Footprint Assemblage from Morocco
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
Abstract - An assemblage of abundant and well-preserved tetrapod footprints has been discovered in the Tanamert Member (T3) of the Triassic Timezgadiouine Formation (Argana basin, western High Atlas, Morocco). It is the first fossil record from T3. Surfaces from different localities show a uniform tetrapod ichnofauna that consists of chirotherian and small lacertoid forms. The chirotherians are assigned to the plexus Protochirotherium—Synaptichnium, their trackmakers interpreted as basal archosaurs. The lacertoid imprints show close affinities with Rhynchosauroides and may reflect archosauromorphs or lepidosauromorphs. Protochirotherium—Synaptichnium assemblages are characteristic of the Early Triassic and were known previously only from units of this age in central Europe. Biostratigraphically, the European record implies a wide-spread pre-Anisian Protochirotherium—Synaptichnium dominated assemblage preceding the first appearance of Chirotherium barthii near the Olenekian-
Anisian boundary. The stratigraphic position of T3 between Late Permian (uppermost T2) and Middle Triassic (T4) and the European correlatives suggest an Early Triassic age of this unit. It is the first record of Early Triassic continental deposits in Morocco. The surfaces from T3 open up perspectives for further contributions to ecology, biogeography and locomotion of early archosaurs. Furthermore, excellent outcrops and quality of footprint preservation in the Argana basin offer a potential for clarification of ichnotaxonomic and biostratigraphic issues.
Abstract - An assemblage of abundant and well-preserved tetrapod footprints has been discovered in the Tanamert Member (T3) of the Triassic Timezgadiouine Formation (Argana basin, western High Atlas, Morocco). It is the first fossil record from T3. Surfaces from different localities show a uniform tetrapod ichnofauna that consists of chirotherian and small lacertoid forms. The chirotherians are assigned to the plexus Protochirotherium—Synaptichnium, their trackmakers interpreted as basal archosaurs. The lacertoid imprints show close affinities with Rhynchosauroides and may reflect archosauromorphs or lepidosauromorphs. Protochirotherium—Synaptichnium assemblages are characteristic of the Early Triassic and were known previously only from units of this age in central Europe. Biostratigraphically, the European record implies a wide-spread pre-Anisian Protochirotherium—Synaptichnium dominated assemblage preceding the first appearance of Chirotherium barthii near the Olenekian-
Anisian boundary. The stratigraphic position of T3 between Late Permian (uppermost T2) and Middle Triassic (T4) and the European correlatives suggest an Early Triassic age of this unit. It is the first record of Early Triassic continental deposits in Morocco. The surfaces from T3 open up perspectives for further contributions to ecology, biogeography and locomotion of early archosaurs. Furthermore, excellent outcrops and quality of footprint preservation in the Argana basin offer a potential for clarification of ichnotaxonomic and biostratigraphic issues.
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.
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.
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