Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Palaeoenvironment and palaeoecology of three Cretaceous snakes: Pachyophis, Pachyrhachis, and Dinilysia

100%

Caldwell M. W., Albino A. M.

Acta Palaeontologica Polonica

|

2001

|

tom 46

|

nr 2

The palaeoecology of three Late Cretaceous snakes is evaluated. Pachyophis woodwardi Nopcsa, 1923 and Pachyrhachis problematicus Haas, 1979, are Cenomanian in age and are found in carbonate rocks deposited in marine inter-reef basin environments of the European and African Tethys Sea. Dinilysia patagonica Woodward, 1901, Coniacian in age, is considered closely allied to Living anilioid snakes, and is found in clastic rocks deposited in a terrestrial inter-dune basin environment in northern Patagonia, Argentina. All three snakes are known from well preserved and articulated specimens found in sediments where detailed sedimentological and taphonomic analyses are possible. Pachyophis and Pachyrhachis were laterally compressed, have pachyostotic ribs and vertebrae, and small, narrow heads. These two snakes are interpreted as aquatic predators living in and around the margins of reef mounds on a shallow water carbonate platform. Dinilysia was a large bodied snake with a relatively large head, and is interpreted here as a terrestrial predator that lived in a dry, interdune basin environment dominated by aeolian sedimentation. Sedimentary units preserve ichnological evidence of burrowing insects and rooting plants.

2

The oldest Brazilian snakes from the Cenomanian (early Late Cretaceous)

81%

Hsiou A. S., Albino A. M., Medeiros M. A., Santos R. A. B.

Acta Palaeontologica Polonica

|

2014

|

tom 59

|

nr 3

South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian– Campanian (Dinilysia), and Campanian–Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain systematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil.

3

Reappraisal of the south American Miocene snakes of the genus Colombophis, with description of a new species

81%

Hsiou A. S., Albino A. M., Ferigolo J.

Acta Palaeontologica Polonica

|

2010

|

tom 55

|

nr 3

365-379

A redescription of the extinct snake genus Colombophis is presented, on the basis of new specimens from the late Miocene of southwestern Brazilian Amazonia, and those previously reported for the middle Miocene of Colombia and Venezuela. The reappraisal of Colombophis allows the recognition of a new species,C. spinosussp. nov. The revised diagnosis of the genus is based on the midtrunk vertebrae, distinct from those of other snakes mainly in the features of the neural arch, position and shape of the neural spine, inclination of the zygapophyses, shape of the centrum, and development of the haemal keel. The affinities of Colombophis with “Anilioidea” are still unresolved; it is distinguished from all known extinct and extant “anilioids” due to its great vertebral size and the frequent presence of paracotylar foramina. The posterior paired apophyses of the haemal keel in some vertebrae, and the high neural spine of C. spinosus also contrast significantly with the “anilioid” genera, making the allocation of the genus into this probably paraphyletic group not well supported. Here, we recognized Colombophis as a basal alethinophidian of uncertain relationships.

Ograniczanie wyników

3 Acta Palaeontologica Polonica

3 Albino A. M.

2 Hsiou A. S.

1 Caldwell M. W.

1 Ferigolo J.

1 Medeiros M. A.

1 Santos R. A. B.

1 2014

1 2010

1 2001

Palaeoenvironment and palaeoecology of three Cretaceous snakes: Pachyophis, Pachyrhachis, and Dinilysia

The oldest Brazilian snakes from the Cenomanian (early Late Cretaceous)

Reappraisal of the south American Miocene snakes of the genus Colombophis, with description of a new species