Open Paleo

Muyelensaurus

Calvo et al., 2007 moo-YEH-len-SOR-us

Named after 'Muyelen', an indigenous name for the Colorado River in Argentina, combined with Greek 'sauros' (lizard); meaning 'Muyelen lizard'.

89.8–83.6 million years ago Coniacian–Santonian, Late Cretaceous
Late Cretaceous stages

Muyelensaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Argentina. It was more slender than other titanosaurs. Fossils have been recovered in the Neuquén province of Patagonia and were originally assigned to the Portezuelo Formation but further research showed that these layers belong to the Plottier Formation. The type species is M. pecheni. The name Muyelensaurus first appeared in a 2007 paper by Argentine paleontologists Jorge Calvo of the Universidad Nacional del Comahue and Bernardo González Riga of the Laboratorio de Paleovertebrados, and Brazilian paleontologist Juan Porfiri of the Universidade Federal do Rio de Janeiro.

Diagnosis

  1. Basal tubera diverge 70 degrees from each other
  2. Extensive, thin and concave medial lamina unites basal tubera ventrally
  3. Basioccipital condyle wider than proximal portion of basal tubera
  4. Posterior dorsal neural spines with large prespinal lamina reinforced by two small accessory laminae
  5. Distal end of pubic blade rectangular and medially thick

Species

Muyelensaurus pecheni Calvo et al., 2007

Type species

Named in honor of Dra. Ana María Pechen, head of the National University of Comahue (2002-2006), who supported the study of dinosaur fossils in Neuquén Province, Patagonia.

Holotype
MRS-PV 207 , Museo Argentino Urquiza, Rincón de los Sauces
Material
Braincase including partial frontal and parietal, basioccipital, incomplete basipterygoid process, supraoccipital, exoccipital, basisphenoid tubers, orbitosphenoids, and incomplete parasphenoids
Horizon
Plottier Formation, Coniacian–Santonian, Late Cretaceous , 89.8–83.6 million years ago
Locality
Loma del Lindero, Neuquén, Argentina

References

  1. Calvo, J. O.; González Riga, B. J.; Porfiri, J. D. (2007). A new titanosaur sauropod from the Late Cretaceous of Neuquén, Patagonia, Argentina. Arquivos do Museu Nacional, Rio de Janeiro 65(4): 485-504. calvo2007b
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b
  4. Bellardini, F.; Baiano, M. A.; Barrios, F.; Holgado, B.; Coria, R. A. (2018). New Titanosauria (Dinosauria, Sauropoda) remains from the Upper Cretaceous (Plottier Fm) of the southern Neuquén Basin (Patagonia, Argentina). Journal of Iberian Geology 44(1): 75-84. Springer Science and Business Media LLC. doi:10.1007/s41513-018-0047-5

    Assigns Muyelensaurus to the Plottier Formation against Calvo and colleagues, following Garrido's revision of the Neuquén Group.

    bellardini2018a