Sauropodomorpha

Skeletal reconstruction of Massospondylus carinatus, copyright Ballista.

Belongs within: Dinosauria.
Contains: Plateosauridae, Anchisauria, Sauropoda.

The Sauropodomorpha are a clade of often large herbivorous dinosaurs, the best-known members of which are the gigantic sauropods. Non-sauropod sauropodomorphs are commonly referred to as 'prosauropods' though the majority of analyses have not recognised them as a monophyletic clade. The earliest sauropodomorphs, such as Saturnalia tupiniquim and Panphagia protos, are known from the Late Triassic (Carnian) of South America. These were small forms, close to 1.5 metres in length. Guaibasaurus candelariensis is a slightly larger form represented by a partial postcranial skeleton from the Norian of Brazil that has been placed by various analyses as either a basal sauropodomorph or basal theropod.

Synapomorphies (from Baron et al. 2017): Premaxilla with posterodorsal process thin, bar-like, restricted to ventral border of external naris; external naris extending posteriorly to overlie maxilla; anterior margin of external naris posterior to midlength of premaxillary body; posterior margin of external naris posterior to first maxillary alveolus; anterior profile of maxilla with a strong inflection (notch) at base of ascending ramus, creating an anterior ramus with parallel dorsal and ventral margins; squamosal with ventral process narrower than one-quarter of its length; ventral ramus of squamosal forming more than half of caudal border of lower temporal fenestra; 18 or more dentary teeth present; premaxillary teeth with crown at least moderately expanded above root; maxillary/dentary tooth serrations present as enlarged and coarser (lower density) denticles; majority of maxillary and dentary teeth not recurved; anterior dentary teeth inclined anteriorly (procumbent); ten or more cervical vertebrae present; cervical vertebrae lacking prezygaodiapophyseal lamina; preacetabular process triangular and pointed; ischial shaft distally expanded into distinct ‘foot’ or 'boot'; tibia with posterolateral margin of distal end concave.

<==Sauropodomorpha [Plateosauria, Prosauropoda]
    |--+--Saturnalia Langer, Abdala et al. 1999 BNB17, GU04
    |  |    `--S. tupiniquim Langer, Abdala et al. 1999 GU04
    |  `--Chromogisaurus NS15
    |--Pampadromaeus barberenai BNB17
    `--+--Guaibasaurus Bonaparte, Ferigolo & Ribeiro 1999 BNB17, L04
       |    `--G. candelariensis Bonaparte, Ferigolo & Ribeiro 1999 L04
       |--Panphagia protos BNB17
       |--Pantydraco caducus BNB17
       |--Thecodontosaurus Riley & Stutchbury 1836 BNB17, GU04 [Thecodontosauridae]
       |    |--*T. antiquus Morris 1843 Y03
       |    |--T. caducus Yates 2003 Y03
       |    |--T. dubius Haughton 1924 (n. d.) GU04
       |    `--T. minor Haughton 1918 (n. d.) GU04
       `--+--Plateosauravus Huene 1932 NS15, GU04 [Plateosauravidae]
          |    `--*P. cullngworthi (Haughton 1924) (n. d.) [=Plateosaurus cullingworthi] GU04
          `--+--Plateosauridae BNB17
             `--+--+--Lufengosaurus Young 1941 BNB17, GU04
                |  |    |--L. changhduensis D07
                |  |    `--L. huenei Young 1941 [incl. L. magnus Young 1947] GU04
                |  `--Gyposaurus GU04
                |       |--G. capensis Broom 1911 (n. d.) GU04
                |       `--G. sinensis Young 1941 GU04 [=Anchisaurus capensis N85]
                `--+--Coloradisaurus Lambert 1983 BNB17, GU04 [incl. Coloradia Bonaparte 1978 GU04]
                   |    `--C. brevis (Bonaparte 1978) [=Coloradia brevis] GU04
                   `--+--Yunnanosaurus Young 1942 BNB17, GU04 [Yunnanosauridae]
                      |    `--Y. huangi Young 1942 [incl. Y. robustus Young 1951] GU04
                      `--+--+--Massospondylus Owen 1854 BNB17, GU04 [Massospondylidae]
                         |  |    |--M. browni Seeley 1895 (n. d.) GU04
                         |  |    |--M. carinatus Owen 1854 GU04
                         |  |    |--M. harriesi Broom 1911 (n. d.) GU04
                         |  |    |--M. hislopi Lydekker 1890 (n. d.) GU04
                         |  |    |--M. kaalea BNB17
                         |  |    `--M. schwarzi Haughton 1924 (n. d.) GU04
                         |  `--+--Leyesaurus marayensis NS15, BNB17
                         |     `--Adeopapposaurus NS15
                         `--+--Anchisauria BNB17
                            `--+--Aardonyx celestae BNB17
                               |--Pulanesaura eocollum BNB17
                               `--Sauropoda BNB17

Sauropodomorpha incertae sedis:
  Avalonianus sanfordi (Seeley 1898) (n. d.) N85, H79 [=Avalonia sanfordi H79]
  Clepsysaurus (n. d.) N85
  Dinosaurus (n. d.) N85
  Nyasasaurus parringtoni BNB17
  Orosauravus (n. d.) N85
  Palaeosauriscus (n. d.) N85
  Picrodon herveyi Seeley 1898 (n. d.) N85, H79
  Thotobolosaurus (n. d.) N85
  Gresslyosaurus GU04
    |--G. ingens Rütimeyer 1856 (n. d.) GU04
    |--G. plieningeri APS03
    |--G. robustus Huene 1907-1908 (n. d.) GU04
    `--G. torgeri Jaekel 1911 (n. d.) GU04
  Aetonyx palustris Broom 1911 (n. d.) GU04
  Dromicosaurus gracilis Hoepen 1920 (n. d.) GU04
  Hortalotarsus skirtopodus Seeley 1894 (n. d.) GU04
  Leptospondylus capensis Owen 1854 (n. d.) GU04
  Pachysauriscus Kuhn 1959 (n. d.) [incl. Pachysaurops Huene 1959] GU04
    `--*P. ajax (Huene 1907-1908) (n. d.) [=Pachysaurus ajax, *Pachysaurops ajax] GU04
  Pachyspondylus orpenii Owen 1854 (n. d.) GU04
  Yimenosaurus Bai, Yang & Wang 1990 GU04
    `--Y. youngi Bai, Yang & Wang 1990 GU04
  Fulengia Carroll & Galton 1977 GU04, E88
    `--F. youngi Carroll & Galton 1977 (n. d.) GU04
  Pachysaurus GU04
    |--P. giganteus Huene 1932 (n. d.) GU04
    |--P. magnus Huene 1907-1908 (n. d.) GU04
    |--P. reiningeri Huene 1907-1908 (n. d.) GU04
    `--P. wetzelianus Huene 1932 (n. d.) GU04
  Palaeosaurus fraserianus Cope 1878 (n. d.) GU04
  Strenusaurus procerus Bonaparte 1969 (n. d.) GU04
  Tawasaurus minor Young 1982 (n. d.) GU04
  ‘Teratosaurus’ minor Huene 1907-1908 (n. d.) GU04
  ‘Teratosaurus’ trossingensis Huene 1907-1908 (n. d.) GU04
  Ruehleia Galton 2001 NS15, GU04
    `--R. bedheimensis Galton 2001 GU04
  Jingshanosaurus Zhang & Yang 1995 GU04
    `--J. xinwaensis Zhang & Yang 1995 GU04
  Agrosaurus mcgillivrayi Seeley 1891 GU04
  Basutodon ferox Huene 1932 (n. d.) N85, H79

*Type species of generic name indicated

REFERENCES

[APS03] Allain, R., & X. Pereda Suberbiola. 2003. Dinosaurs of France. Comptes Rendus Palevol 2 (1): 27–44.

[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.

[E88] Evans, S. E. 1988. The early history and relationships of the Diapsida. In: Benton, M. J. (ed.) The Phylogeny and Classification of the Tetrapods vol. 1. Amphibians, Reptiles, Birds pp. 221–260. Clarendon Press: Oxford.

[GU04] Galton, P. M., & P. Upchurch. 2004. Prosauropoda. In: Weishampel, D. B., P. Dodson & H. Osmólska (eds) The Dinosauria 2^nd ed. pp. 232–258. University of California Press: Berkeley.

[H79] Heerden, J. van. 1979. The morphology and taxonomy of Euskelosaurus (Reptilia: Saurischia; late Triassic) from South Africa. Navorsinge van die Nasionale Museum 4: 21–84.

[L04] Langer, M. C. 2004. Basal Saurischia. In: Weishampel, D. B., P. Dodson & H. Osmólska (eds) The Dinosauria 2^nd ed. pp. 25–46. 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.

[Y03] Yates, A. M. 2003. A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs. Journal of Systematic Palaeontology 1: 1–42.

Last updated: 11 July 2018.