New Triassic Reptile Species Sonselasuchus cedrus Discovered in Arizona

Fossils from Petrified Forest Reveal New Archosaur from Late Triassic Era

Scientists have identified a previously unknown reptile species that lived roughly 225–201 million years ago during the Late Triassic . The discovery was made by palaeontologists from the University of Washington and the Burke Museum of Natural History and Culture . Fossil remains were unearthed in Petrified Forest National Park , a region famous for preserving prehistoric plants and animals. The newly described reptile has been named Sonselasuchus cedrus , offering new clues about the diversity of reptiles that existed alongside early dinosaurs.

Fossil Discovery in Arizona

Researchers discovered the fossils within rock layers in Arizona , an area known for its extensive Triassic fossil deposits. Field studies conducted since 2014 have recovered nearly 950 fossil specimens associated with this species. The abundance of remains allowed scientists to analyse skeletal features and reconstruct aspects of its anatomy, behaviour and evolutionary relationships.

Member of the Shuvosaurid Group

The reptile belongs to the Shuvosauridae , a lineage of reptiles related to early crocodilian ancestors within the broader Archosaurs . Members of this group displayed a bird-like body shape and superficially resembled Ornithomimids . Despite these similarities, shuvosaurids were not dinosaurs but belonged to a separate evolutionary branch of archosaurs.

Physical Characteristics and Movement

Researchers estimate that Sonselasuchus cedrus was approximately the size of a small dog , standing about 25 inches tall . Fossil limb bones indicate that juveniles likely moved on four legs, while adults may have adopted a bipedal stance as their hind limbs became stronger with growth. The reptile possessed several distinctive traits, including a toothless beak, hollow bones and large eye sockets , features that resemble those seen in certain dinosaur groups.

Exam-Focused Key Points

• Late Triassic Period: Approximately 237–201 million years ago .

• Petrified Forest National Park: Major fossil site known for Triassic plant and animal remains.

• Archosaurs: Group that includes modern birds and crocodiles as well as extinct reptiles.

• Shuvosaurids: Crocodile-related reptiles with bird-like body structures.

• The species Sonselasuchus cedrus helps explain reptile evolution before the dominance of dinosaurs.