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Coloradisaurus

Bonaparte, 1978 ko-lo-RAHD-i-SAWR-us

Named after the Los Colorados Formation in La Rioja Province, Argentina, where fossils were found, + Greek sauros ('lizard'), meaning 'Los Colorados lizard'.

227.3–205.7 million years ago Norian, Late Triassic
Late Triassic stages

Coloradisaurus is a genus of massospondylid sauropodomorph dinosaur. It lived during the Late Triassic period (Norian stage) in what is now La Rioja Province, Argentina. It is known from two specimens collected from the Los Colorados Formation of the Ischigualasto-Villa Unión Basin.

Diagnosis

  1. Antorbital region clearly shorter than in Plateosaurus-Lufengosaurus, with proportionally long frontals
  2. Antorbital fenestra partially beneath the orbit, with pronounced dorsal maxillary process
  3. Orbit proportionally large, with sclerotic ring
  4. Mandibular symphysis and posterior half of mandible shorter than in Plateosaurus
  5. Cervical vertebrae low and long, bearing long, thin cervical ribs
  6. Occipital region with forward inclination of the dorsal surface, more dorsally projected than in Plateosaurus

Species

Coloradisaurus brevis Bonaparte, 1978

Type species

From Latin 'brevis' meaning 'short', likely assigned by José F. Bonaparte to describe the relatively short skull compared to other dinosaurs from the same locality.

Holotype
PVL 3967 , Colección de Paleontologia de Vertebrados de la Fundación Instituto Miguel Lillo
Material
Nearly entire skull and mandible (somewhat distorted), articulated with first 3 vertebrae; 3 additional cervicals, 2 incomplete dorsals, 3 caudals; scapula, coracoids, fragmentary humerus; portions of radius and ulna; isolated carpals, incomplete metacarpus and manual phalanges; 1 complete astragalus and some pedal phalanges.
Horizon
upper Los Colorados Formation, Norian, Late Triassic , 227.3–205.7 million years ago
Locality
La Esquina, La Rioja, Argentina

Synonyms of the genus

Name Type Reason
Coloradia preoccupied Name preoccupied by Coloradia (Lepidoptera).

References

  1. Bonaparte, J. F. (1978). Coloradisaurus brevis n.g. et n.sp. (Saurischia Prosauropoda), dinosaurio Plateosauridae de la Formación Los Colorados, Triásico Superior de La Rioja, Argentina. Ameghiniana 15(3-4): 327-332. bonaparte1978a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b