Tetanurae

Skeletal mount of Monolophosaurus jiangi, copyright Kabacchi.

Belongs within: Neotheropoda.
Contains: Megalosauroidea, Allosauroidea, Coelurosauria.

The clade Tetanurae includes all theropods more closely related to birds than to Ceratosaurus. The name of the clade refers to the development of a stiffened tail; members of the clade are also characterised by the loss of an external fourth digit on the hand. The clade is first definitely recorded from the beginning of the Middle Jurassic (Rauhut 2005).

Most basal members of the Tetanurae are large carnivorous species, the 'carnosaurs' of earlier authors. However, Chilesaurus diegosuarezi from the Late Jurassic (Tithonian) of Chile is a smaller herbivorous form (Novas et al. 2015); this species could be described as superficially similar to one of the basal sauropodomorphs. Other basal tetanurans include Condorraptor currumili and Piatnitzkysaurus floresi from the Middle Jurassic (Callovian) of Argentinean Patagonia, and Marshosaurus bicentesimus from the Late Jurassic (Kimmeridgian) of Utah (Holtz et al. 2004; Rauhut 2005); Piatnitzkysaurus is known from a relatively complete skeleton whereas Condorraptor and Marshosaurus are known from more fragmentary remains. Monolophosaurus jiangi from the Middle Jurassic of China is also known from a complete skull and pelvis and much of the vertebral column; this species is characterised by a distinctive hollow crest along the dorsal midline of the skull (Holtz et al. 2004). The Allosauroidea and Coelurosauria are united in a clade Avetheropoda to the exclusion of megalosauroids by several features including the presence of palatine recesses, an expanded ectopterygoid, laterally displaced zygapophyses on the cervical vertebrae, a widely open ventral floor to the pelvic canal, and L-shaped haemal arches in at least the distal half of the tail (Holtz et al. 2004).

Synapomorphies (from Novas et al. 2015): Metacarpal I closely appressed to proximal half of metacarpal II; metacarpal IV absent; antitrochanter posterior to acetabulum absent or poorly developed; brevis fossa narrow and with subparallel margins; femur with ratio between maximum transverse width of the distal end and total length of the bone of 0.20-0.25; femoral head horizontally directed; well-developed extensor groove present on anterior side of distal femur; tibia with lateral condyle of the proximal end anteriorly displaced from the posterior margin of the medial condyle but well on the posterior half of the bone in proximal view; tibia with deep and broad notch separating the posterior condyles of the proximal end; ridge on lateral side of tibia for connection with fibula present and clearly separated from proximal articular surface.

<==Tetanurae [Allosaurinae, Avipoda, Carnosauria, Eustreptospondylidae, Eustreptospondylinae, Torvosauridae, Torvosauroidea]
    |--Chilesaurus Novas, Salgado et al. 2015 NS15
    |    `--*C. diegosuarezi Novas, Salgado et al. 2015 NS15
    `--+--+--Marshosaurus Madsen 1976 OES10, HMC04
       |  |    `--M. bicentesimus Madsen 1976 HMC04
       |  `--+--Condorraptor Rauhut 2005 NS15, R05
       |     |    `--*C. currumili Rauhut 2005 R05
       |     `--Piatnitzkysaurus Bonaparte 1979 NS15, HMC04
       |          `--P. floresi Bonaparte 1979 HMC04
       `--+--Megalosauroidea NS15
          `--+--Monolophosaurus Zhao & Currie 1993 NS15, HMC04
             |    `--M. jiangi Zhao & Currie 1993 HMC04
             `--Avetheropoda [Allosauria, Neotetanurae] HMC04
                  |  i. s.: Bahariasaurus Stromer 1934 HMC04
                  |           `--B. ingens Stromer 1934 HMC04
                  |         Ozraptor Long & Molnar 1998 HMC04
                  |           `--O. subotaii Long & Molnar 1998 HMC04
                  |         Quilmesaurus Coria 2001 HMC04
                  |           `--Q. curriei Coria 2001 HMC04
                  |         Shanyangosaurus Xue, Zhang & Bi 1996 HMC04
                  |           `--S. niupanggouensis Zue, Zhang & Bi 1996 HMC04
                  |         Valdoraptor Olshevsky 1991 HMC04
                  |           `--V. oweni (Lydekker 1889) [=Megalosaurus oweni] HMC04
                  |--Allosauroidea HMC04
                  `--Coelurosauria HMC04

Tetanurae incertae sedis:
  Becklespinax Olshevsky 1991 HMC04
    `--B. altispinax (Paul 1988) [=Acrocanthosaurus altispinax] HMC04
  Chilantaisaurus Hu 1964 HMC04
    |--C. sibiricus (Riabinin 1914) [=Allosaurus sibiricus] HMC04
    `--C. tashuikouensis Hu 1964 HMC04
  Kaijiangosaurus He 1984 HMC04
    `--K. lini He 1984 HMC04
  Kelmayisaurus Dong 1973 HMC04
    `--K. petrolicus Dong 1973 HMC04
  Sigilmassaurus Russell 1996 [Sigilmassauridae] HMC04
    `--S. brevicollis Russell 1996 HMC04
  ‘Zanclodon’ cambrensis Newton 1899 HMC04
  Chienkosaurus ceratosauroides (Young 1942) (n. d.) HMC04
  Chuandongocoelurus primitivus He 1984 (n. d.) HMC04
  Dandakosaurus indicus Yadagiri 1982 (n. d.) HMC04
  Embasaurus minax Riabinin 1931 (n. d.) HMC04
  Inosaurus tedreftensis Lapparent 1960 (n. d.) HMC04
  Betasuchus Huene 1932 (n. d.) HMC04
    `--*B. bredai (Seeley 1883) [=Megalosaurus bredai] HMC04
  Scrotum humanum Brookes 1763 (n. d.) HMC04
  Siamosaurus suteethorni Buffetaut & Ingavat 1986 (n. d.) HMC04
  Sinocoelurus fragilis Young 1942 (n. d.) HMC04
  Teinurosaurus Nopcsa 1928 HMC04, O69 [=Caudocoelus Huene 1932 HMC04]
    `--*T. sauvagei (Huene 1932) (n. d.) O69 [=*Caudocoelus sauvagei HMC04]
  Wakinosaurus satoi Okazaki 1992 (n. d.) HMC04
  Walgettosuchus woodwardi Huene 1932 (n. d.) [=Magnosaurus woodwardi] HMC04
  Szechuanosaurus Young 1942 HMC04, D07
    |--S. campi Young 1942 HMC04
    |--S. yandonensis Dong, Chang et al. 1978 HMC04
    `--S. zigongensis Gao 1993 HMC04
  Xuanhanosaurus Dong 1984 HMC04
    `--X. qilixiaensis Dong 1984 HMC04

*Type species of generic name indicated

REFERENCES

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

[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.

[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.

[OES10] Ortega, F., F. Escaso & J. L. Sanz. 2010. A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain. Nature 467: 203–206.

[O69] Ostrom, J. H. 1969. Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana. Bulletin of the Peabody Museum of Natural History 30: 1–165.

[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.

Last updated: 6 August 2017.