Open Paleo

Isasicursor

Novas et al., 2019 ih-SAH-see-KUR-sor

Named after geologist Marcelo Pablo Isasi combined with Latin cursor (runner); meaning "Isasi's runner"

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Isasicursor is an extinct genus of elasmarian ornithopod dinosaurs known from the Late Cretaceous Chorrillo Formation of Santa Cruz Province, Argentina. The genus contains a single species, Isasicursor santacrucensis. It was a contemporary of the titanosaur sauropod Nullotitan, which was described in the same paper.

Diagnosis

  1. Ventrally arched sacrum
  2. Peg-and-socket articulation between first and second sacral vertebrae in ventral view
  3. Tibia with strongly proximally projected and thickened cnemial crest
  4. Lateral condyle of tibia with an additional anterolateral process
  5. Metatarsal II with proximally displaced collateral ligament pit on lateral surface

Species

Isasicursor santacrucensis Novas et al., 2019

Type species

Named for Santa Cruz Province, Argentina, where the fossil was discovered.

Holotype
MPM 21525 , Museo Padre Molina, Rio Gallegos
Material
Proximal end of left tibia
Horizon
upper Chorrillo Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Ornithopod site, Santa Cruz, Argentina Novas and colleagues (2019) place the holotype at their locality 5 without saying whether it falls on the La Anita or the neighboring Alta Vista farm.

References

  1. Novas, F.; Agnolin, F.; Rozadilla, S.; Aranciaga Rolando, A.; Brissón Egli, F.; Motta, M.; Cerroni, M.; Ezcurra, M.; Martinelli, A.; D´Angelo, J.; Álvarez-Herrera, G.; Gentil, A.; Bogan, S.; Chimento, N.; García Marsà, J. A.; Lo Coco, G.; Miquel, S.; Brito, F.; Vera, E.; Loinaze, V.; Fernandez, M.; Salgado, L. (2019). Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina. Revista del Museo Argentino de Ciencias Naturales 21: 217-293. Museo Argentino de Ciencia Naturales. doi:10.22179/revmacn.21.655 novas2019a
  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