Extinct clade of reptiles
Allokotosauria is a
monophyletic grouping of specialized herbivorous archosauromorphs was recovered by Sterling J. Nesbitt, John J. Flynn, Adam C. Pritchard, J. Michael Parrish, Lovasoa Ranivoharimanana and André R. Wyss in
2015. The name Allokotosauria is derived from
Greek meaning "strange reptiles" in reference to unexpected grouping of early archosauromorph with a high disparity of features typically associated with
herbivory.
History
Nesbitt et al. (2015) defined the group as a
Rhynchosaurus articeps. Therefore, Allokotosauria includes the families
Azendohsauridae and
Trilophosauridae by definition, as well as the potentially more
basal Pamelaria which is closer to them than to other early archosauromorphs.
Pamelaria is the earliest known allokotosaur, dating to the
Anisian of
India. Azendohsauridae is currently represented by a single genus
Azendohsaurus known from the
Ladinian to
Carnian of
Africa, while trilophosaurids are mostly known from the
Carnian to
Norian stages of
North America,
England and potentially
European Russia,
[1] though one member of the latter group,
Variodens inopinatus, is known from
Rhaetian.
[2] According to studies of
Arctosaurus material from
Cameron Island in Canada, the latter may have been an allokotosaurian because of the similarities with
Azendohsaurus due to the presence of a posterior ridge from the centrum to the diapophyses which extends from the diapophysis all the way to the posterior ventrolateral corner of the centrum. This ridge overhangs a deep groove in the lateral surface of the centrum.
[3]Description and phylogeny
Allokotosauria is most notably characterized by wrinkled side surface of orbital border of the
azendohsaurid instead.
[4]Sengupta et al. (2017) described a new azendohsaurid and recovered Pamelaria as an azendohsaurid.[5]
Pritchard and Nesbitt (2017) found support for the inclusion of Kuehneosauridae within Allokotosauria.[6]
References
