brodiei more closely related to hyperodapedontines than to Rhynchosaurus articeps. Hyperodapedon is the most commonly found tetrapod along the oldest dinosaur lineage which results in a broad biostratigraphic correlation. Rhynchosaurs are archosauromorph diapsids which is believed to Trilophosaurus, and sister group to Prolacertiformes and Archosauria. A cladistic analysis of Rhynchosauria reveals that Hyperodapedontinae is a major subgroup of the late Triassic. Stenaulorhynchus and Rhynchosaurus are close outgroups to Hyperdapedontinae during the middle Triassic. They share the synapomorphy of the dentary is well over half the length of the lower jaw. Rhynchosaurs were basal archosauromorphs that were herbivorous on dry land in Triassic Pangea. Some rare forms are Mesosuchus and Howesia. Hyperodapedon and Scaphonyx are included in the subfamily of Hyperodapedontinae. Hyperodapedontinae consist of Hyperodapedon huxleyi and Scaphonyx sulcognathus. Palaeoecology Hyperodapedon are commonly found in aeolian sand in Elgin, India, Brazil, and Argentina. They are a widely distributed tetrapod during the Upper Triassic and are present in locations where phytosaurs are absent. Hyperodapedon localities are found in the Popo Agie Formation in Wyoming that dates to the Otischalkian. They are also found in Scotland in the Lossiemouth Sandstone dating to the Adamanian, Maleri Formations in India, Pebbly Arkose Formation in Zimbabwe, Ischigualasto Formation in Argentina, and Santa Maria Formation in Brazil that vary between Otischalkian and Adamanian. Similarly, Rhynchosaurus is found in fluvial-intertidal deposits with desiccation along with aeolian deposits with common flash floods. Distribution Fossils of Hyperodapedon have been found in: Ischigualasto Formation, Argentina Caturrita and Santa Maria Formations, Brazil Lower Maleri and Tiki Formations, India Ruvuma, Tanzania Lossiemouth Sandstone, Scotland Popo Agie Formation, Wyoming, United States Pebbly Arkose Formation, Zimbabwe References External links Rhynchosaurs Prehistoric reptile genera Carnian genera Late Triassic reptiles of Africa Fossils of Tanzania Fossils of Zimbabwe Late Triassic reptiles of Asia Fossils of India Late Triassic reptiles of Europe Triassic Scotland Fossils of Scotland Late Triassic reptiles of North America Triassic United States Fossils of the United States Paleontology in Wyoming Late Triassic reptiles of South America Triassic Argentina Fossils of Argentina Ischigualasto Formation Triassic Brazil Fossils of Brazil Santa Maria Formation Paraná Basin Fossil taxa described in 1859 Taxa named by Thomas Henry Huxley