Spondylosoma

Spondylosoma (meaning "vertebra body") is a genus of archosaur of uncertain affinities from the late Ladinian-age Middle Triassic Lower Santa Maria Formation in Geopark of Paleorrota, Brazil. Recent studies have gone back and forth on its identity, suggesting rauisuchian or basal saurischian dinosaur. If it was a dinosaur, it would be the oldest.

History

Friedrich von Huene based the genus on a fragmentary postcranial skeleton held at the University of Tübingen. This skeleton includes two teeth, two cervical vertebrae, four dorsal vertebrae, three sacral vertebrae, scapulae, part of a humerus, part of a femur, and part of a pubis. At the time, he thought it was a prosauropod.^[1]

With the discovery of basal dinosaur Staurikosaurus, Spondylosoma drew attention as a possible relative. Authors have gone back and forth on the question, considering it either as a basal dinosaur, or as a "thecodont" or other basal archosaur. The two most recent papers to address it illustrate this clearly: in 2000, Peter Galton claimed that it lacks dinosaurian characteristics and was probably a rauisuchian,^[2] whereas in 2004 Max Langer disputed this and included Spondylosoma as a possible basal dinosaur similar to the herrerasaurs (but did not firmly rule out raisuchian affinities).^[3] This debate will probably continue until better remains are found and described.

References

v t e Fauna and Flora of Paleorrota Geopark Rio Grande do Sul Fauna Aetosaurs Stagonolepis Archosaurs Barberenachampsa nodosa Barberenasuchus brasiliensis Cerritosaurus Chanaresuchus Decuriasuchus Fitossauros Karamuru vorax Prestosuchus chiniquensis Procerosuchus Proterochampsa nodosa Protorosaurus Rauisuchus tiradentes Rhadinosuchus gracilis Spondylosoma Teyumbaita sulcognathus Teyuwasu Cynodonts Belesodon magnificus Brasilitherium Brasilodon Candelariodon Chiniquodon Charruodon Tetracuspidatus Exaeretodon riograndensis Gomphodontosuchus Brasiliensis Irajatherium hernadezi Luangwa Massetognathus Menadon Minicynodon Protheriodon estudianti Protuberum cabralensis Prozostrodon brasiliensis Riograndia Santacruzodon hopsoni Therioherpeton cargnini Traversodon Stahleckeri Dicynodonts Dinodontosaurus pedroanum Dinodontosaurus turpior Jachaleria candelariensis Stahleckeria Trucidocynodon Dinosaurs Staurikosaurus Guaibasaurus Pampadromaeus Sacisaurus Saturnalia tupiniquim Unaysaurus Mesosaurus Mesosaurus Pareiasaurus Provelosaurus brasiliensis Procolophons Candelaria barbouri Procolophon brasiliensis Procolophon pricei Procolophon trigoniceps Rhynchosaurs Hyperodapedon huenei Hyperodapedon mariensis Hyperodapedon sanjuanensis Temnospondylis Bageherpeton longignathus Sangaia lavinai Stereospondyli Insects Sanctipaulus mendesi Others Clevosaurus brasiliensis Dinocephalians Pampaphoneus biccai Soturnia caliodon Tiarajudens eccentricus Paleorrota's Flag. Dinotchê: The mascot Paleorrota. Flora Lycophytas Brasilodendron pedroanum Cyclodendron sp. Pteridospermatophytas Dicroidium odontopteroides Dicroidium zuberi Pteridophytas Asterotheca sp. Botrychiopsis plantianum Botrychiopsis valida Neomariopteris sp. Osmundites brasiliensis Pecopteris sp. Stephanophyllites sp. Sphenophytas Phyllotheca brevifolia Phyllotheca longifolia Sphenopteris sp. Neocalamites sp. Glossopteris Gangamopteris obovata Gangamopteris sulriograndensis Glossopteris angustifolia Glossopteris. brasiliensis Glossopteris browniana Glossopteris communisi Glossopteris indica Glossopteris occidentalis Cordaites Cordaites hislopii Kawizophyllum sp. Ginkgophytas Baieroxylon cicatricum Cheirophyllum speculare Chiropteris sp. Ginkgoites antarctica Sphenobaiera sp. Conifers Brachyphyllum sp. Buriadia sp. Cordaicarpus brasilianus Cordaicarpus cerronegrensisi Cordaicarpus fanatinensis Cordaicarpus truncata Coricladus quiteriensis Kaokoxylon zalesskyi Pagiophyllum sp. Samaropsis gigas Samaropsis kurtzii Samaropsis millaniana Samaropsis rigbyi Samaropsis seixasi Sommerxylon spiralosus Bennettitales Nilssonia sp. Williamsonia sp.