Search results
Results from the WOW.Com Content Network
Archosaurs quickly diversified in the aftermath of the Permian-Triassic mass extinction (~252 Ma), which wiped out most of the then-dominant therapsid competitors such as the gorgonopsians and anomodonts, and the subsequent arid Triassic climate allowed the more drought-resilient archosaurs (largely due to their uric acid-based urinary system ...
This left crocodilians and birds as the two surviving archosaur groups. [56] A series of phylogenetic analyses in the late 1980s and 1990s strongly supported the proposal of Gow (1975). [54] [57] [53] [58] [59] Tanystropheus, Macrocnemus, Protorosaurus, and Prolacerta were always placed as members of Archosauromorpha, closer to archosaurs than ...
Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles encompassing archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria. [3]
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.
Tanystropheidae is an extinct family of archosauromorph reptiles that lived throughout the Triassic Period, often considered to be "protorosaurs".They are characterized by their long, stiff necks formed from elongated cervical vertebrae with very long cervical ribs.
Traditionally, the order Thecodontia Owen, 1859 was divided into four suborders, the Proterosuchia (early primitive forms, another paraphyletic assemblage), Phytosauria (large crocodile-like semi-aquatic animals), the Aetosauria (armoured herbivores), and the Pseudosuchia, a wastebasket taxon intended to be paraphyletic to all later archosaurs (see e.g., Alfred Sherwood Romer's Vertebrate ...
Like other early archosaurs (and archosaur relatives such as Euparkeria), the femur (thigh bone) was slender and S-shaped. The femoral head was thin when seen from above, and its apex projected about 45 degrees between medially (inwards) and anteriorly (forwards). Most archosaurs had three tubera (bumps) on their flattened femoral head, one at ...
Euparkeria is close to the ancestry of Archosauria, the reptile group that includes crocodilians, pterosaurs, and dinosaurs (including birds). Fossils of Euparkeria , including nearly complete skeletons, have been recovered from the Cynognathus Assemblage Zone (CAZ, also known as the Burgersdorp Formation ), which hosts the oldest advanced ...