Triassic United States

Hyperodapedon (from , 'above' and , 'pavement') is an extinct genus of rhynchosaur reptiles which lived during Late Triassic period. Like other rhynchosaurs, it was a heavily built archosauromorph, distantly related to archosaurs such as crocodilians and dinosaurs. Hyperodapedon in particular was part of the subfamily Hyperodapedontinae, a specialized rhynchosaurian subgroup with broad skulls, beaked snouts, and crushing tooth plates on the roof of the mouth.

Stagonolepis is an extinct genus of stagonolepidid aetosaur known from the Late Triassic (Carnian stage) Hassberge Formation of Germany, the Drawno Beds of Poland, and the Lossiemouth Sandstone of Scotland. Supposed fossils from North and South America have been placed into their own genera, Calyptosuchus and Aetosauroides, respectively.

Omphalosaurus (from the Greek root "Button Lizard", for their button-like teeth) is an extinct genus of marine reptile from the Early Triassic to Middle Triassic, thought to be in the order of Ichthyosauria. Most of what is known about Omphalosaurus is based on multiple jaw fragments, ribs, and vertebrae. Specimens of Omphalosaurus have been described from the western United States, Poland, Austria and the island of Spitsbergen off the northern coast of Norway.

Thalattoarchon is a genus of large, Middle Triassic predatory ichthyosaur from North America, containing the single species T. saurophagis. The taxon was described in 2013 from a single partial skeleton discovered in Nevada. The generic name, meaning "ruler of the seas", refers to its status as an apex predator, while the specific epithet, meaning "lizard eater", alludes to its carnivorous diet. As an ichthyosaur, Thalattoarchon had flippers for limbs and a fin on the tail. It is a large ichthyosaur, with an estimated length between . The animal has a long, slender body but with a proportional

major feature of the supercontinent