Chondrichthyans have a long evolutionary history, reaching back over 450 million years.
Despite the longevity of the chondrichthyan fossil record, it is remarkably incomplete. This …

The concepts of platytrabia/platybasia and tropibasia/tropitrabia in gnathostomes are
reviewed. The terms platytrabia and tropitrabia refer to developmental states of the …

Morphological studies of fossil and extant shark teeth have typically been qualitative in
nature, with resulting taxonomic problems due to the complicated forms of heterodonty …

A diverse assemblage of chondrichthyans has recently been recognised from the Permian
(Late Leonardian) Kaibab Formation in and around Flagstaff, Arizona. Of this diverse …

The teeth of a well known late Palaeozoic cladodont chondrichthyan,“Cladodus”
occidentalis from Russia, USA, and England are restudied and a new generic name …

The Late Permian mass extinction occurring at 252.6±0.2 Ma is the most severe
Phanerozoic extinction event and was preceded and followed by additional disturbances …

The predominantly red bed sequence of Tiki Formation, representing a significant
lithostratigraphic unit of the South Rewa Gondwana Basin of India, is well known for its …

Two chondrichthyan assemblages of Late Mississippian/Early Pennsylvanian age are now
recognized from the western Grand Canyon of northern Arizona. The latest Serpukhovian …

A diverse microvertebrate fauna is described from the Virgin Hills and Napier formations,
Bugle Gap Limestone Canning Basin, Western Australia. Measured sections at horse Spring …

A Formação Irati, Permiano (Cisuraliano) da Bacia do Paraná, destaca-se por importantes
características geológicas e paleontológicas. Entre seus fósseis, os crustáceos e répteis …