AetosaurAetosaurs (eɪˌɛtoʊˈsɔr) are heavily armored reptiles belonging to the extinct order Aetosauria (eɪˌɛtoʊˈsɔriə; from Greek, ἀετός (aetos, "eagle") and σαυρος (sauros, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates.
ThecodontiaThecodontia (meaning 'socket-teeth'), now considered an obsolete taxonomic grouping, was formerly used to describe a diverse "order" of early archosaurian reptiles that first appeared in the latest Permian period and flourished until the end of the Triassic period. All of them were built somewhat like crocodiles but with shorter skulls, more erect pose and usually somewhat lighter. The group includes the ancestors of dinosaurs, pterosaurs, and crocodilians, as well as a number of extinct forms that did not give rise to any descendants.
BipedalismBipedalism is a form of terrestrial locomotion where a tetrapod moves by means of its two rear (or lower) limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped ˈbaɪpɛd, meaning 'two feet' (from Latin bis 'double' and pes 'foot'). Types of bipedal movement include walking or running (a bipedal gait) and hopping. Several groups of modern species are habitual bipeds whose normal method of locomotion is two-legged.
ParaphylyIn taxonomy, a grouping is paraphyletic if it consists of the grouping's last common ancestor and most of its descendants, but excludes a few monophyletic subgroups. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies.
Pennsylvanian (geology)The Pennsylvanian (ˌpɛnsəlˈveɪni.ən , also known as Upper Carboniferous or Late Carboniferous) is, in the ICS geologic timescale, the younger of two subperiods (or upper of two subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S.
EuparkeriaEuparkeria (juːˌpɑːrkəˈriːə; meaning "Parker's good animal", named in honor of W. K. Parker) is an extinct genus of archosauriform reptile from the Triassic of South Africa. 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 archosauriforms in the fossil-rich Karoo Basin.
Michael BentonMichael James Benton (born 8 April 1956) is a British palaeontologist, and professor of vertebrate palaeontology in the School of Earth Sciences at the University of Bristol. His published work has mostly concentrated on the evolution of Triassic reptiles but he has also worked on extinction events and faunal changes in the fossil record. Benton was educated at Robert Gordon's College, the University of Aberdeen and Newcastle University where he was awarded a PhD in 1981.
DinosauromorphaDinosauromorpha is a clade of avemetatarsalian archosaurs (reptiles closer to birds than to crocodilians) that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include dinosauriforms and lagerpetids, with later formulations specifically excluding pterosaurs from the group. Birds are the only dinosauromorphs which survive to the present day. The name "Dinosauromorpha" was briefly coined by Michael J. Benton in 1985.
Bird anatomyBird anatomy, or the physiological structure of birds' bodies, shows many unique adaptations, mostly aiding flight. Birds have a light skeletal system and light but powerful musculature which, along with circulatory and respiratory systems capable of very high metabolic rates and oxygen supply, permit the bird to fly. The development of a beak has led to evolution of a specially adapted digestive system. Birds have many bones that are hollow (pneumatized) with criss-crossing struts or trusses for structural strength.
American alligatorThe American alligator (Alligator mississippiensis), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States. It is one of the two extant species in the genus Alligator, and is larger than the only other living alligator species, the Chinese alligator. Adult male American alligators measure in length, and can weigh up to , with unverified sizes of up to and weights of making it the second largest member of the family Alligatoridae, after the black caiman.
