Saturday 10 March 2012

A new Pterosaur from the Early Cretaceous of Brazil.

The Crato Formation is an Aptian (Early Cretaceous, about 180 million years old) fossil Lagerstätte (site where numerous well preserved fossils have been found) in the Araripe Basin of northeast Brazil. It was laid down in a shallow inland sea, where fine-grained limestones were deposited, and rapidly accreted round dead animals forming protective nodules in which soft tissue was often preserved. The Formation is noted for its well preserved insects and pterosaurs, but also produces large numbers of fish, amphibians, reptiles, plants and the occasional dinosaur.

In a paper in the journal Acta Palaeotologica Polonica in March 2012, Ross Elgin and Eberhard Frey of the Staatliches Museum für Naturkunde in Karlsruhe report the discovery of a new Pterosaur from the Nova Olinda Member; a finely laminated limestone at the base of the Crato Formation. The specimen is housed in the Staatliches Museum.

The new Crato Formation Pterosaur. (A) Photograph. (B) Interpretive drawing. From Ross & Frey (2012).

The new Pterosaur is not named to species level, as it lacks a head, the most important diagnostic feature in Pterosaurs. Ross and Frey consider it to be a member of the family Ornithocheiridae, due to its elongated cervical vertebrae. The specimen has particularly sharp claws on its hind feet, which Ross and Frey take to indicate it spent much of its life on the wing, since an animal which spent a lot of time foraging on the ground would be likely to have blunted claws.

The hindfoot (pes) of the new Pterosaur. (A₁) As found. (A₂) Reconstructed.