Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Mandibular dentition in the Late Triassic temnospondyl amphibian Metoposaurus

100%

Konietzko-Meier D., Wawro K.

Acta Palaeontologica Polonica

|

2007

|

tom 52

|

nr 1

The Temnospondyli are a large and diverse group of stemtetrapods (sensu Laurin and Reisz 1997) known from the Early Carboniferous to the Early Cretaceous; their remains have been found on all continents, from Greenland to Antarctica. The Metoposauridae are a short−ranging temnospondyl group recorded only from the Late Triassic; they are characterized by an anterior position of the orbits, a broad parasphenoid and a large quadrate foramen. However, unclear is the taxonomic value of the external location of tusks on the dentary. Our analysis of tooth rows in Metoposaurus diagnosticus krasiejowensis from the Triassic (Late Carnian) of Krasiejów (Silesia, SW Poland) shows that the external location of tusks on the dentary is not a synapomorphy for Metoposauridae but a character of great intraspecific variability. Variability of the arrangement of the internal tooth row on the upper jaw has also been observed.

2

Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus

100%

Sulej T.

Acta Palaeontologica Polonica

|

2002

|

tom 47

|

nr 3

Re−investigation of the skull roof in Metoposaurus diagnosticus from the German Middle Keuper revealed that in contrast to previous opinions, the lacrimal bone in this species enters the orbital margin.The same pattern is demonstrated by the skulls of a newly discovered metoposaur from the Keuper of Krasiejów in Poland.The difference in the shape of the parietal between the population from Krasiejów and the type population of Metoposaurus diagnosticus enables the discrimination of two separate subspecies within Metoposaurus diagnosticus.For the specimens from the Late Carnian of Drawno Beds at Krasiejów, Poland and its lateral equivalents Lehrberg Beds at Stuttgart−Sonnenberg and Kieselsandstein at Fichtenberg, Germany, a new chronosubspecies Metoposaurus diagnosticus krasiejowensis is erected.The new subspecies differs from the older nominal subspecies M. diagnosticus diagnosticus in having a shorter and wider prepineal part of the parietal.If one accepts that the nominal subspecies is the ancestor of M. krasiejowensisthe change in the shape of the parietal would be a reversal of the trend towards elongating postorbital part of the skull observed in ancestors of the metoposaurids.It seems that the skull development in ontogeny changed after the anterior shift of the orbits occurred in the phylogenetic history of the metoposaurids.The difference in ornamentation of the interclavicle between European Metoposaurus and North American genera is corroborated by Polish material.

3

A new large capitosaurid temnospondyl amphibian from the Early Triassic of Poland

80%

Sulej T., Niedzwiedzki G.

Acta Palaeontologica Polonica

|

2013

|

tom 58

|

nr 1

The Early Triassic record of the large capitosaurid amphibian genus Parotosuchus is supplemented by new material from fluvial deposits of Wióry, southern Poland, corresponding in age to the Detfurth Formation (Spathian, Late Olenekian) of the Germanic Basin. The skull of the new capitosaurid shows an “intermediate” morphology between that of Paroto− suchus helgolandicus from the Volpriehausen−Detfurth Formation (Smithian, Early Olenekian) of Germany and the slightly younger Parotosuchus orenburgensis from European Russia. These three species may represent an evolutionary lineage that underwent a progressive shifting of the jaw articulation anteriorly. The morphology of the Polish form is dis− tinct enough from other species of Parotosuchus to warrant erection of a new species. The very large mandible of Parot− osuchus ptaszynskii sp. nov. indicates that this was one of the largest tetrapod of the Early Triassic. Its prominent anatomi− cal features include a triangular retroarticular process and an elongated base of the hamate process.

4

The brachyopoid Hadrokkosaurus bradyi from the early Middle Triassic of Arizona, and a phylogenetic analysis of lower jaw characters in temnospondyl amphibians

80%

Ruta M., Bolt J. R.

Acta Palaeontologica Polonica

|

2008

|

tom 53

|

nr 4

The holotype of the brachyopoid temnospondyl Hadrokkosaurus bradyi, represented by a right lower jaw ramus, is re−examined based upon new data and revision of various morphological features. Additional fragmentary jaw material referred to this species is briefly described. Prominent features are a large postsymphyseal foramen that is anteriorly open, and prearticular and surangular buttresses for support of the articular. Brachyopoid characters include a long and robust postglenoid area formed by surangular and prearticular, anterior and posterior keels on at least some marginal dentary teeth, and subtriangular outline of the adductor fossa in dorsal view. Five features of the holotype ramus, long thought to be at odds with its brachyopoid or temnospondyl nature, are critically re−evaluated. A phylogenetic analysis of lower jaw characters in temnospondyls retrieves most of the clades found in more comprehensive data sets, but the statistical node support is low. Brachyopoids are monophyletic, with Hadrokkosaurus emerging as their most basal taxon.

Ograniczanie wyników

4 Acta Palaeontologica Polonica

2 Sulej T.

1 Bolt J. R.

1 Konietzko-Meier D.

1 Niedzwiedzki G.

1 Ruta M.

1 Wawro K.

1 2013

1 2008

1 2007

1 2002

Mandibular dentition in the Late Triassic temnospondyl amphibian Metoposaurus

Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus

A new large capitosaurid temnospondyl amphibian from the Early Triassic of Poland

The brachyopoid Hadrokkosaurus bradyi from the early Middle Triassic of Arizona, and a phylogenetic analysis of lower jaw characters in temnospondyl amphibians