Triassic

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Brusatte, S. L., Butler R. J., Mateus O., Steyer J. S., & Whiteside J. H. (2013).  Terrestrial vertebrates from the Late Triassic of Portugal: new records of temnospondyls and archosauriforms from a Pangaean rift sequence. 61st Symposium on Vertebrate Palaeontology and Comparative Anatomy. 15-16., Edinburgh Abstractbrusatte_et_al_2013_triassic_algarve_portugal_temnospondyls_svpca.org_years_2013_edinburgh_abstracts.pdf

The Late Triassic (ca. 237-201.5 million years ago) was a transitional interval in the evolution of terrestrial ecosystems, during which ‘modern’ clades such as archosaurs and mammals were radiating while ‘archaic’ groups such as temnospondyl amphibians and basal synapsids remained abundant. Little is known about the Triassic terrestrial (nonmarine) vertebrates of the Iberian Peninsula. The Algarve Basin of southern Portugal is an extensional rift basin formed during the breakup of Pangaea, which is filled with terrestrial, lacustrine, and marginal marine siliciclastics of the Grés de Silves Formation, interbedded with CAMP basalts that mark the end-Triassic extinction (radioisotopically dated to ~198-201.5 Ma). Since 2009, our field project in the Algarve has discovered numerous vertebrate specimens within the Grés de Silves, including a monodominant bonebed containing hundreds of specimens of metoposaurids, a peculiar group of temnospondyls that filled crocodile-like predatory niches in lacustrine and fluvial environments. These specimens appear to belong to a new species of Metoposaurus, similar to M. diagnosticus and M. krasiejowensis from central Europe but possessing several putative autapomorphies of the braincase and lower jaw. We also discovered a mandible of a phytosaur, the first specimen of these long-snouted, semi-aquatic archosauriforms from the Iberian Peninsula. These discoveries of characteristic Carnian Norian taxa indicate that the fossil-bearing portion of the Grés de Silves is Late Triassic in age, and provide further evidence that metoposaurids and phytosaurs commonly occurred together in low palaeolatitudes during this time.

Milàn, J., Clemmensen L. B., Adolfssen J. S., Estrup E. J., Frobøse N., Klein N., Mateus O., & Wings O. (2012).  A preliminary report on coprolites from the Late Triassic part of the Kap Stewart Formation, Jameson Land, East Greenland. New Mexico Museum of Natural History and Science, Bulletin. 57, 203-205. Abstractmilan_et_al_2012_greenland_coprolites_triassic.pdf

The basal part of the Triassic-Jurassic (Rhaetian-Sinemurian) Kap Stewart Formation, exposed at Jameson Land, East Greenland, yields an extensive coprolite collection from black, parallel-laminated mudstone (“paper shale”), representing an open lacustrine system. Preliminary investigations show three different types of coprolites: elongated cylindrical masses, composed of irregularly wrapped layers; elongated cylindrical masses with constriction marks; and spirally-coiled specimens.

Steyer, J. S., Mateus O., Butler R. J., Brusatte S. L., & Whiteside J. H. (2011).  A new metoposaurid (temnospondyl) bonebed from the Late Triassic of Portugal. 71st Annual Meeting of the Society of Vertebrate Paleontology. 200., Jan: Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology Abstractsteyer_mateus_et_al_2011_._a_new_metoposaurid_temnospondyl_bonebed_from_the_late_triassic_of_portugal_svp11abstracts.pdf

The end-Triassic extinction event (ETE), considered one of the ‘Big Five’ mass extinctions, marks a dividing line between early Mesozoic vertebrate assemblages, typically including abundant temnospondyls, basal synapsids and basal archosaurs, and ‘typical’ Mesozoic faunas dominated by dinosaurs, pterosaurs, crocodylomorphs, turtles and mammaliaforms.
Recent geochemical work has provided strong evidence that the ETE is synchronous with, and likely caused by, the emplacement of the Central Atlantic magmatic province (CAMP).
However, stratigraphic sections containing both terrestrial vertebrates and CAMP basalts are scarce, complicating attempts to examine terrestrial faunal changes during this extinction event. The Triassic–Jurassic Algarve Basin, southern Portugal, is an extensional rift basin

to-marginal marine red beds (the ‘Grés de Silves’ Group) interbedded with CAMP basalts.

bonebed from the interval ‘AB1’ of the Grés de Silves. Preliminary excavations yielded at least nine well-preserved temnospondyl individuals represented by partial to nearly complete skulls and disarticulated postcranial elements of juvenile to adult ages. Nearly all material appears to represent a single species of metoposaurid referable to the genus Metoposaurus, well known from the late Carnian–early Norian of Germany and Poland. A number of characters of the occiput and mandible suggest that the Algarve material may represent a new species. This new material provides new data on the diversity and paleogeographical distribution of the metoposaurids, a highly autapomorphic and peculiar group composed of large aquatic carnivores with a unique elongated but brevirostral skull. This taxon also provides

Horizon may be within or close to the late Carnian–early Norian. Additional bone-bearing horizons within the ‘Grés de Silves’ provide a rare opportunity to examine terrestrial faunal change in the lead-up to the ETE.