Living tetrapods owe their existence to a critical moment 360–340 million years ago when
their ancestors walked on land. Vertebrae are central to locomotion, yet systematic testing of …

abstract We introduce a spectacular new specimen of a Late Triassic stem crocodilian
identified as Poposaurus gracilis. It is part of a poorly known group, Poposauroidea, that …

Abstract Sea scorpions (Euchelicerata: Eurypterida) explored extreme limits of the aquatic
euchelicerate body plan, such that the group contains the largest known marine …

One of the rarest of marine reptiles is the mosasaur genus Globidens, characterized by a
massive, bulbous dentition. The rarity of the taxon, coupled with the bulbous dentition …

Extant and fossil crocodilians have long been divided into taxonomic and/or ecological
groups based on broad patterns of skull shape, particularly the relative length and width of …

Plesiosaurs were the longest-surviving group of secondarily marine tetrapods, comparable
in diversity to today's cetaceans. During their long evolutionary history, which spanned the …

The sauropterygian clade Plesiosauria arose in the Late Triassic and survived to the very
end of the Cretaceous. Plesiosauria evolved the greatest species diversity of any marine …

Current knowledge of plesiosaurs of clade Cryptoclidia is constrained by a lack of fossils
from outside the Oxford Clay deposits of England. Recent fieldwork in the Sundance …

Therizinosaurs are a group of herbivorous theropod dinosaurs from the Cretaceous of North
America and Asia, best known for their iconically large and elongate manual claws …

Teleosauroids were a successful group of semi-aquatic crocodylomorphs that were an
integral part of coastal marine/lagoonal faunas during the Jurassic. Their fossil record …