Neotheropoda (meaning "new theropods") is a
clade that includes
coelophysoid
Coelophysoidea were common dinosaurs of the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the ...
s and more advanced
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
dinosaurs, and is the only group of theropods that survived the
Triassic–Jurassic extinction event
The Triassic–Jurassic (Tr-J) extinction event, often called the end-Triassic extinction, marks the boundary between the Triassic and Jurassic periods, , and is one of the top five major extinction events of the Phanerozoic eon, profoundly affect ...
. All neotheropods became extinct by the end of the Early Jurassic (
Pliensbachian
The Pliensbachian is an age (geology), age of the geologic timescale and stage (stratigraphy), stage in the stratigraphic column. It is part of the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series an ...
) period except for
Averostra
Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs, namely Ceratosauria and Tetanurae, and represent the only group of post-Early Jurassic theropods. Both survived into the Cretaceous period. When the Cretaceous–Pa ...
.
Classification
Neotheropoda was named by
Robert T. Bakker in 1986 as a group including the relatively derived theropod subgroups
Ceratosauria
Ceratosaurs are members of the clade Ceratosauria, a group of dinosaurs defined as all theropods sharing a more recent common ancestor with ''Ceratosaurus'' than with birds. The oldest known ceratosaur, '' Saltriovenator'', dates to the earliest ...
and
Tetanurae
Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans ar ...
, and excluding
coelophysoids
Coelophysoidea were common dinosaurs of the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the ...
. However, most later researchers have used it to denote a broader group. Neotheropoda was first defined as a
clade by
Paul Sereno
Paul Callistus Sereno (born October 11, 1957) is a professor of paleontology at the University of Chicago and a National Geographic "explorer-in-residence" who has discovered several new dinosaur species on several continents, including at sites ...
in 1998 as ''
Coelophysis
''Coelophysis'' ( traditionally; or , as heard more commonly in recent decades) is an extinct genus of coelophysid theropod dinosaur that lived approximately 228 to 201.3 million years ago during the latter part of the Triassic Period fro ...
'' plus modern
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s, which includes almost all theropods except the most primitive species.
[Sereno, 1998. A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 210, 41-83.] Dilophosauridae was formerly considered a small clade within Neotheropoda, but was later considered to be
paraphyletic.
The following family tree illustrates a synthesis of the relationships of the early theropod groups compiled by Hendrickx ''et al.'' in 2015.
[Hendrickx, C., Hartman, S.A., & Mateus, O. (2015)]
An Overview of Non- Avian Theropod Discoveries and Classification
''PalArch’s Journal of Vertebrate Palaeontology'', 12(1): 1-73.
This second cladogram is based on the redescription of ''Dilophosaurus'' by Marsh and Rowe (2020).
This third cladogram is based on the larger analysis in the description of ''
Pendraig milnerae'' by Spiekman ''et al.'' 2021:
References
{{Taxonbar, from=Q145206
*
Late Triassic first appearances
Taxa named by Robert T. Bakker