RIOJASAURUS
a plant-eating riojasaurid sauropodomorph dinosaur from the Late Triassic of Argentina.
Pronunciation: ree-YO-ha-SOR-us
Meaning: La Rioja lizard
Author/s: Bonaparte (
1969)
Synonyms: Strenusaurus procerus
First Discovery: La Rioja, Argentina
Discovery Chart Position: #214
Riojasaurus incertus
Etymology
Riojasaurus is derived from "La Rioja" (the Province in Argentina where its fossils were found) and the Greek "sauros" (lizard).
The
species epithet,
incertus, means "uncertain" in Latin.
Discovery
The first fossils of
Riojasaurus were discovered at La Esquina in the Los Colorados Formation, near Pagancilla, La Rioja Province, Argentina, during a José Bonaparte-led expedition of the Museo Argentino de Ciencias
Naturales and the Universidad Provincial de La Rioja, in 1966. They were described in 1969.
The
holotype (PVL 3808) is a large chunk of the skeleton, including but no skull material. A skull was discovered in 1986 during a trip by the same crew to the same area — attached to the articulated skeleton of hypodigm specimen (PULR 56) that was around 35% smaller than the holotype.
Riojasaurus also includes a headless partial skeleton (PVL 3663) from La Esquina that Bonaparte initially named
Strenusaurus procerus ("vigorous lizard") in his 1969 paper. But it was sunk as a junior synonym of
Riojasaurus by Bonaparte himself two years later.
Estimations
Timeline:
Era: Mesozoic
Epoch: Triassic
Stage: Norian
Age range: 227-209 mya
Stats:
Est. max. length: 6.5 meters
Est. max. hip height: 1.8 meters
Est. max. weight: 1.2 tons
Diet: Herbivore
References
• Bonaparte JF (1969) "Dos nuevas "faunas" de reptiles triásicos de Argentina" [Two new reptilian "faunas" of the Argentine Triassic].
Gondwana Stratigraphy, IUGS Symposium, Page 290-291
• Bonaparte JF 1971) "Los tetrapodos del sector superior de la Formacion Los Colorados, La Rioja, Argentina (Triásico Superior)" [The tetrapods of the upper part of the Los Colorados Formation, La Rioja, Argentina (Upper Triassic)].
Opera Lilloana 22: 1-183.
• Dodson P, Britt B, Carpenter K, Forster CA, Gillette DD, Norell MA, Olshevsky G, Parrish MJ, Weishampel DB (1994)
"
Riojasaurus". Page 41 in "
The Age of Dinosaurs".
• Bonaparte JF and Pumares JA (1995) "Notas sobre el primer craneo de
Riojasaurus incertus (Dinosauria, Prosauropoda, Melanorosauridae) del Triasico Superios de La Rioja, Argentina" [
Notes on the first skull and jaws of Riojasaurus incertus (Dinosauria, Prosauropoda, Melanorosauridae) of the Late Triassic of La Rioja, Argentina].
(English translation by Jeffrey A Wilson) 
• Paul GS (2010) "
The Princeton Field Guide to Dinosaurs".
Time stands still for no man, and research is ongoing. If you spot an error, or want to expand, edit or add a dinosaur, please use
this form. Go
here to contribute to our FAQ.
All dinos are GM free, and no herbivores were eaten during site construction!
To cite this page:
Atkinson, L.
"
RIOJASAURUS :: from DinoChecker's dinosaur archive".
‹
http://www.dinochecker.com/dinosaurs/RIOJASAURUS›. Web access: 06th Mar 2026.
