Dinosauromorpha is a clade of archosaurs that includes the clade Dinosauria (dinosaurs), and all animals more closely related to dinosaurs than to pterosaurs. Birds are the only surviving dinosauromorphs.
|Reconstructed skeleton of a Lagosuchus talampayensis|
The name was coined by Michael J. Benton in 1984. The first clade definitions were by Paul Sereno in 1991 who defined the concept as a node clade: the last common ancestor of Lagerpeton chanarensis, Marasuchus lilloensis, Pseudolagosuchus major and the Dinosauria (including Aves) and all its descendants.
Dinosauromorphs appeared by the Anisian stage of the Middle Triassic around 242 to 244 million years ago, splitting from other ornithodires. Early Triassic footprints reported in October 2010 from the Świętokrzyskie (Holy Cross) Mountains of Poland may belong to a dinosauromorph. If so, the origin of dinosauromorphs would be pushed back into the Early Olenekian, around 249 Ma. The oldest Polish footprints are from a small quadrupedal animal named Prorotodactylus, but footprints belonging to the ichnogenus Sphingopus that have been found from Early Anisian strata show that moderately large bipedal dinosauromorphs had appeared by 246 Ma. The tracks show that the dinosaur lineage appeared soon after the Permian-Triassic extinction event. Their age suggests that the rise of dinosaurs was slow and drawn out across much of the Triassic.
Basal forms include Saltopus, Marasuchus, the perhaps identical Lagosuchus, the lagerpetonids Lagerpeton from the Ladinian of Argentina and Dromomeron from the Norian of Arizona, New Mexico, and Texas (all in the United States), and the silesaurids, which include Silesaurus from the Carnian of Poland, Eucoelophysis from the Carnian-Norian of New Mexico, Lewisuchus and the perhaps identical Pseudolagosuchus from the Ladinian of Argentina, Sacisaurus from the Norian of Brazil, Technosaurus from the Carnian of Texas, Asilisaurus from the Anisian of Tanzania, and Diodorus from the Carnian(?) to Norian of Morocco.
Cladogram simplified after Nesbitt (2011):
Adeopapposaurus (meaning "far eating lizard", in reference to its long neck) is a genus of prosauropod dinosaur from the Early Jurassic Cañón del Colorado Formation of San Juan, Argentina. It was similar to Massospondylus. Four partial skeletons with two partial skulls are known.The type specimen, PVSJ568, includes a skull and most of a skeleton to just past the hips. The form of the bones at the tips of the upper and lower jaws suggests it had keratinous beaks. The fossils now named Adeopapposaurus were first thought to represent South American examples of Massospondylus; while this is no longer the case, Adeopapposaurus is classified as a massospondylid. Adeopapposaurus was described in 2009 by Ricardo N. Martínez. The type species is A. mognai, referring to the Mogna locality where it was found.Anchisauria
The Anchisauria were a clade of sauropodomorph dinosaurs that lived during the Late Triassic and Early Jurassic. The name Anchisauria was first used by Galton and Upchurch in the second edition of The Dinosauria. Galton and Upchurch assigned two families of dinosaurs to the Anchisauria: the Anchisauridae and the Melanorosauridae. The more common prosauropods Plateosaurus and Massospondylus were placed in the sister clade Plateosauria.
However, recent research indicates that Anchisaurus is closer to sauropods than traditional prosauropods; thus, Anchisauria would also include Sauropoda.The following cladogram simplified after an analysis presented by Blair McPhee and colleagues in 2014.Avemetatarsalia
Avemetatarsalia (meaning "bird metatarsals") is a clade name established by British palaeontologist Michael Benton in 1999 for all crown group archosaurs that are closer to birds than to crocodilians. An alternate name is Pan-Aves, or "all birds", in reference to its definition containing all animals, living or extinct, which are more closely related to birds than to crocodilians. Almost all avemetatarsalians are members of a similarly defined subgroup, Ornithodira. Ornithodira is defined as the last common ancestor of dinosaurs and pterosaurs, and all of its descendants.Members of this group include the Dinosauromorpha, Pterosauromorpha, the genus Scleromochlus, and Aphanosauria. Dinosauromorpha contains more basal forms, including Lagerpeton and Marasuchus, as well as more derived forms, including dinosaurs. Birds belong to the dinosaurs as members of the theropods. Pterosauromorpha contains Pterosauria, which were the first vertebrates capable of true flight. Aphanosauria is a Triassic group of gracile carnivorous quadrupeds which was recognized in 2017.Averostra
Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs that have a promaxillary fenestra (fenestra promaxillaris), an extra opening in the front outer side of the maxilla, the bone that makes up the upper jaw. Two groups of averostrans, the Ceratosauria and the Orionides, survived into the Cretaceous period. When the Cretaceous–Paleogene extinction event occurred, ceratosaurians and two groups of orionideans within the clade Coelurosauria, the Tyrannosauroidea and Maniraptoriformes, were still extant. Only one subgroup of maniraptoriformes, Aves, survived the extinction event and persisted to the present day.Avetheropoda
Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs.Cerapoda
Cerapoda ("ceratopsians and ornithopods") is a clade of the dinosaur order Ornithischia.Dinosauriformes
Dinosauriformes is a clade of archosaurian reptiles that include the dinosaurs and their most immediate relatives. All dinosauriformes are distinguished by several features, such as shortened forelimbs and a partially to fully perforated acetabulum, the hole in the hip socket traditionally used to define dinosaurs. The oldest known member is Asilisaurus, dating to about 245 million years ago in the Anisian age of the middle Triassic period.Echinodon
Echinodon (pronounced eh-KY-no-don) meaning "hedgehog tooth" in reference to the spines on its teeth (Ancient Greek: εχινος, romanized: echinos, lit. 'hedgehog', + ὀδών, odṓn, 'tooth'), occasionally known as Saurechinodon, is a genus of small European dinosaur of the early Cretaceous Period (Berriasian age), 140 million years ago.Jingshanosaurus
Jingshanosaurus (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period.Lagerpeton
Lagerpeton is a genus of basal dinosauromorph. First described by A. S. Romer in 1971, it includes only the species L. chanarensis. This species is incompletely known, with fossil specimens accounting for the pelvic girdle, hindlimbs and posterior presacral, sacral and anterior caudal vertebrae.Lagosuchus
Lagosuchus is a genus of small avemetatarsalian archosaurs from the middle Triassic period. It is generally thought to be closely related to dinosaurs, as a member of the Dinosauromorpha. Its fossils were found in the Chañares Formation of Argentina, the dating of which is uncertain; some sources date it to the Middle Triassic whilst others date it to the earliest Carnian.Neotheropoda
Neotheropoda (meaning "new theropods") is a clade that includes coelophysoids and more advanced theropod dinosaurs, and the only group of theropods who survived the Triassic–Jurassic extinction event. Yet all of the neotheropods became extinct during the early Jurassic period except for Averostra.Orionides
Orionides is a clade of tetanuran theropod dinosaurs from the Middle Jurassic to the Present. The clade includes most theropod dinosaurs, including birds.Orodrominae
Orodrominae is a subfamily of parksosaurid dinosaurs from the Cretaceous of North America and Asia.Plateosauridae
Plateosauridae is a family of plateosaurian sauropodomorphs from the Late Triassic of Europe. Although several dinosaurs have been classified as plateosaurids over the years, the family Plateosauridae is now restricted to Plateosaurus. In another study, Yates (2003) sunk Sellosaurus into Plateosaurus (as P. gracilis).Pseudolagosuchus
Pseudolagosuchus (meaning "false Lagosuchus") is a genus of dinosauromorph from the Middle Triassic (Ladinian) Chañares Formation of Argentina. It may be a junior synonym of Lewisuchus, but there is very little overlapping material. It was a small reptile which was probably about 1 meter (3.3 ft) long, 30 centimeters (1 ft) tall, and weighed approximately 2 kilograms (4.4 lb). It is known only from a pubis, a femur, a tibia, and vertebrae. Both Sterling Nesbitt, Christian Sidor et al. (2010) and Matthew Baron, David Norman and Paul Barrett (2017) treated this taxon as being synonymous with Lewisuchus.Saturnaliinae
Saturnaliinae is a clade of sauropodomorph dinosaurs found in Brazil and Argentina.
In 2010, Martin Ezcurra defined the subfamily Saturnaliinae for the clade containing Saturnalia and Chromogisaurus, which were found to be close relatives in several studies. While they are sometimes found to be a subgroup within the Guaibasauridae, other studies have found the saturnaliines to form an independent lineage at the very base of the sauropodomorph family tree. Langer and colleagues (2019) recovered Pampadromaeus and Panphagia as relatives of Saturnalia and Chromogisaurus, elevating Saturnaliinae to family rank as Saturnaliidae. They recovered Guaibasaurus as a basal theropod.Xixiposaurus
Xixiposaurus is a genus of prosauropod dinosaur which existed in what is now Lower Lufeng Formation, China during the lower Jurassic period. It was first named by Sekiya Toru in 2010 and the type species is Xixiposaurus suni.
Avemetatarsalians (Dinosauromorpha and relatives)