Neotheropoda

Skeletal mounts of Coelophysis bauri, copyright Firsfron.

Belongs within: Theropoda.
Contains: Ceratosauria, Tetanurae.

The Neotheropoda are a clade containing the greater part of the theropod dinosaurs, first appearing in the Late Triassic. Three main lineages are recognised within the Neotheropoda—the Coelophysoidea, Ceratosauria and Tetanurae—with most recent analyses placing the Coelophysoidea outside the clade formed by the other two. The Triassic Coelophysis bauri is one of the best known of all fossil dinosaurs, represented by a large number of specimens collected from the Ghost Ranch deposit in New Mexico.

Synapomorphies (from Novas et al. 2015): Nasal process of premaxilla with posterior tip that extending posterior to posterior tip of posterolateral premaxillary process; premaxilla-nasal suture on internarial bar W-shaped; maxillary antorbital fossa shallow, margins formed by low ridges, sharp rim may be present only in front of promaxillary foramen; depth of ventral antorbital fossa much greater than depth of maxilla below ventral margin of antorbital fossa; prefrontal ventral process short and subtriangular or absent; squamosal lateral surface of main body separated from ventral process by sub-horizontal shelf; basisphenoid recess present between basispenoid and basioccipital; dentary rostral end dorsally raised over distance of first three to four alveoli; enlarged, fang-like teeth in anterior part of dentary; pleurocoels in dorsal vertebrae present in anterior dorsals (‘pectorals’); more than three sacral vertebrae present; distal end of metacarpal I with strongly asymmetrical condyles, lateral condyle extending further distally than medial condyle; shaft of metacarpal III considerably more slender than metacarpal II (less than 70% of width of metacarpal II); third finger of manus shorter than second finger; ilium without tuberosity contacting preacetabular process with supraacetabular crest; iliac supraacetabular crest hood-like and extensive, extending laterally and also curving ventrally, to cover dorsal portion of acetabulum in lateral view; brevis fossa very strongly expanded posteriorly; dorsolateral trochanter on proximal femur reduced or absent; femur with mediodistal crest in distal end; ridge on lateral side of tibia for connection with fibula; tibial lateral malleolus tabular; tibia with ventral extension of lateral malleolus distinctly ventral to level of ventral margin of medial malleolus, separated by an inflexion; tibia with concave posterolateral surface of distal end; eeep groove on medial side of proximal end of fibula and medial side of fibula bearing distinct fossa; astragalus without proximally facing basin posterior to base of ascending process; metatarsal I not contacting ankle joint; shaft of metatarsal I contacting metatarsal II along its entire extension; metatarsal I length <50% metatarsal II length; distal articular surface of metatarsal IV taller dorsoplantarlly than broad mediolaterally.

<==Neotheropoda [Halticosaurinae, Paleotheropoda]
    |  i. s.: Dracoraptor hanigani BNB17
    |--+--Zupaysaurus rougieri Arcucci & Coria 2003 XC09, R05
    |  `--+--Dilophosaurus Welles 1970 NS15, TR04
    |     |    |--D. breedorum D07
    |     |    `--D. wetherilli (Welles 1954) [=Megalosaurus wetherilli] TR04
    |     `--+--Dracovenator regenti NS15, BNB17
    |        `--+--‘Dilophosaurus’ sinensis Hu 1993 NS15, TR04
    |           `--Averostra [Intertheropoda] XC09
    |               |--Ceratosauria XC09
    |               `--Tetanurae XC09
    `--Coelophysoidea XC09
         |  i. s.: Longosaurus Welles 1984 N85, TR04
         |           `--*L. longicollis (Cope 1887) [=Coelurus longicollis] TR04
         |         Lukousaurus Young 1948 N85, P88
         |         Avipes Huene 1932 N85, P88
         |         Dolichosuchus cristatus Huene 1932 N85, TR04
         |         Velocipes guerichi Huene 1932 (n. d.) N85, TR04
         |         Gojirasaurus Carpenter 1997 TR04
         |           `--G. quayi Carpenter 1997 TR04
         |         Camposaurus Hunt, Lucas et al. 1998 TR04
         |           `--C. arizonensis Hunt, Lucas et al. 1998 TR04
         |         Podokesaurus Talbot 1911 TR04 [Podokesauridae]
         |           `--P. holyokensis Talbot 1911 [=Coelophysis holyokensis] TR04
         |--Panguraptor lufengensis BNB17
         `--+--+--Procompsognathus Fraas 1913 [Procompsognathidae, Procompsognathinae] TR04
            |  |    `--P. triassicus Fraas 1913 TR04
            |  `--Coelophysidae [Coelophysinae] TR04
            |       |--Segisaurus Camp 1936 [Segisauridae] TR04
            |       |    `--S. halli Camp 1936 TR04
            |       |--Syntarsus Raath 1969 [incl. Megapnosaurus Ivie, Slipinsky & Wegrzynowicz 2001] TR04
            |       |    `--S. kayentakatae Rowe 1989 [=Megapnosaurus kayentakatae] TR04
            |       `--Coelophysis Cope 1889 XC09, TR04
            |            |--*C. bauri (Cope 1889) WU03, TR04 (see below for synonymy)
            |            `--C. rhodesiensis (Raath 1969) XC09, TR04 (see below for synonymy)
            `--+--Cryolophosaurus Hammer & Hickerson 1994 BNB17, HMC04
               |    `--C. ellioti Hammer & Hickerson 1994 HMC04
               |--Sinosaurus Young 1948 BNB17, G00
               |    `--S. triassicus BNB17
               `--Lophostropheus airelensis BNB17

*Coelophysis bauri (Cope 1889) WU03, TR04 [=Coelurus bauri TR04, Rioarribasaurus bauri TR04, Tanystrophaeus bauri TR04; incl. R. colberti Hunt & Lucas 1991 TR04, Syntarsus colberti TR04, Coelophysis longicollis N85, Coelophysis willistoni N85]

Coelophysis rhodesiensis (Raath 1969) XC09, TR04 [=Syntarsus rhodesiensis P88, Megapnosaurus rhodesiensis TR04]

*Type species of generic name indicated

REFERENCES

[BNB17] Baron, M. G., D. B. Norman & P. M. Barrett. 2017. A new hypothesis of dinosaur relationships and early dinosaur evolution. Nature 543: 501–506.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[G00] Gower, D. J. 2000. Rauisuchian archosaurs (Reptilia, Diapsida): an overview. Neues Jahrbuch für Geologie und Paläontologie—Abhandlungen 218 (3): 447–488.

[HMC04] Holtz, T. R., Jr, R. E. Molnar & P. J. Currie. 2004. Basal Tetanurae. In: Weishampel, D. B., P. Dodson & H. Osmólska (eds) The Dinosauria 2^nd ed. pp. 71–110. University of California Press: Berkeley.

[N85] Norman, D. 1985 (reprinted 2000). The Illustrated Encyclopedia of Dinosaurs. Salamander Books: London.

[NS15] Novas, F. E., L. Salgado, M. Suárez, F. L. Agnolin, M. D. Ezcurra, N. R. Chimento, R. de la Cruz, M. P. Isasi, A. O. Vargas & D. Rubilar-Rogers. 2015. An enigmatic plant-eating theropod from the Late Jurassic period of Chile. Nature 522: 331–334.

[P88] Paul, G. S. 1988. Predatory Dinosaurs of the World: A Complete Illustrated Guide. Simon & Schuster: New York.

[R05] Rauhut, O. W. M. 2005. Osteology and relationships of a new theropod dinosaur from the Middle Jurassic of Patagonia. Palaeontology 48 (1): 87–110.

[TR04] Tykoski, R. S., & T. Rowe. 2004. Ceratosauria. In: Weishampel, D. B., P. Dodson & H. Osmólska (eds) The Dinosauria 2^nd ed. pp. 47–70. University of California Press: Berkeley.

[WU03] Wilson, J. A., & P. Upchurch. 2003. A revision of Titanosaurus Lydekker (Dinosauria—Sauropoda), the first dinosaur genus with a ‘Gondwanan’ distribution. Journal of Systematic Palaeontology 1 (3): 125–160.

[XC09] Xu, X., J. M. Clark, J. Mo, J. Choiniere, C. A. Forster, G. M. Erickson, D. W. E. Hone, C. Sullivan, D. A. Eberth, S. Nesbitt, Q. Zhao, R. Hernandez, C.-K. Jia, F.-L. Han & Y. Guo. 2009. A Jurassic ceratosaur from China helps clarify avian digital homologies. Nature 459: 940–944.

Last updated: 11 July 2018.