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 dorsoplantarly than broad mediolaterally.

<==Neotheropoda [Halticosaurinae, Paleotheropoda]
    |  i. s.: Dracoraptor haniganiBNB17
    |--+--Zupaysaurus rougieri Arcucci & Coria 2003XC09, R05
    |  `--+--Dilophosaurus Welles 1970NS15, TR04
    |     |    |--D. breedorumD07
    |     |    `--D. wetherilli (Welles 1954) [=Megalosaurus wetherilli]TR04
    |     `--+--Dracovenator regentiNS15, BNB17
    |        `--+--‘Dilophosaurus’ sinensis Hu 1993NS15, TR04
    |           `--Averostra [Intertheropoda]XC09
    |               |--CeratosauriaXC09
    |               `--TetanuraeXC09
    `--CoelophysoideaXC09
         |  i. s.: Longosaurus Welles 1984N85, TR04
         |           `--*L. longicollis (Cope 1887) [=Coelurus longicollis]TR04
         |         Lukousaurus Young 1948N85, P88
         |         Avipes Huene 1932N85, P88
         |         Dolichosuchus cristatus Huene 1932N85, TR04
         |         Velocipes guerichi Huene 1932 (n. d.)N85, TR04
         |         Gojirasaurus Carpenter 1997TR04
         |           `--G. quayi Carpenter 1997TR04
         |         Camposaurus Hunt, Lucas et al. 1998TR04
         |           `--C. arizonensis Hunt, Lucas et al. 1998TR04
         |         Podokesaurus Talbot 1911 [Podokesauridae]TR04
         |           `--P. holyokensis Talbot 1911 [=Coelophysis holyokensis]TR04
         |--Panguraptor lufengensisBNB17
         `--+--+--Lophostropheus airelensisBNB17
            |  |--Cryolophosaurus Hammer & Hickerson 1994BNB17, HMC04
            |  |    `--*C. ellioti Hammer & Hickerson 1994HH94
            |  `--Sinosaurus Young 1948BNB17, G00
            |       `--S. triassicusBNB17
            `--+--Procompsognathus Fraas 1913 [Procompsognathidae, Procompsognathinae]TR04
               |    `--P. triassicus Fraas 1913TR04
               `--Coelophysidae [Coelophysinae]TR04
                    |--Segisaurus Camp 1936 [Segisauridae]TR04
                    |    `--S. halli Camp 1936TR04
                    |--Syntarsus Raath 1969 [incl. Megapnosaurus Ivie, Slipinsky & Wegrzynowicz 2001]TR04
                    |    `--S. kayentakatae Rowe 1989TR04 [=Coelophysis kayentakataeP10, Megapnosaurus kayentakataeTR04]
                    `--Coelophysis Cope 1889XC09, TR04
                         |--*C. bauri (Cope 1889)WU03, TR04 (see below for synonymy)
                         `--C. rhodesiensis (Raath 1969)XC09, TR04 [=Syntarsus rhodesiensisP88, Megapnosaurus rhodesiensisTR04]

*Coelophysis bauri (Cope 1889)WU03, TR04 [=Coelurus bauriTR04, Rioarribasaurus bauriTR04, Tanystrophaeus bauriTR04; incl. R. colberti Hunt & Lucas 1991TR04, Syntarsus colbertiTR04, Coelophysis longicollisN85, Coelophysis willistoniN85]

*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.

[HH94] Hammer, W. R., & W. J. Hickerson. 1994. A crested theropod dinosaur from Antarctica. Science 264: 828–830.

[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 2nd ed. pp. 71–110. University of California Press: Berkeley.

[N85] Norman, D. 1985. 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.

[P10] Paul, G. S. 2010. Dinosaurs: A Field Guide. A & C Black.

[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 2nd 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.

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