Open Paleo

Colossosauria

González Riga et al., 2019

Its genera lived 132.6–66.0 million years ago Early Cretaceous–Late Cretaceous
Early Cretaceous and Late Cretaceous stages

Colossosauria is a clade of titanosaur sauropod dinosaurs that lived in South America from the latest Early Cretaceous through the Late Cretaceous. Originally erected around Mendozasaurus, it is delimited in current usage as all titanosaurs closer to Patagotitan than to Saltasaurus, a framework that places it as the opposing branch to Saltasauroidea within the larger group Eutitanosauria. Its core subgroups are Lognkosauria, which includes some of the largest land animals ever known, and the smaller-bodied Rinconsauria, so the clade spans a wide range of body sizes. Depending on the phylogenetic analysis, it may also take in other similar titanosaurs and various unclassified forms on the stem toward either subgroup. Members are distinguished mainly by traits of the limb girdles and limbs, including a wide-gauge stance.

Diagnosis

  1. Eye-shaped (reniform) sternal plates with a strong lateral expansion
  2. Robust, transversely broad metacarpals forming a vertical colonnade
  3. Femur with a prominent lateral bulge below the greater trochanter
  4. Forelimb and hindlimb proportions indicating a wide-gauge stance

Clades within Colossosauria

Genera placed directly in Colossosauria

  • Austroposeidon Bandeira et al., 2016 Campanian–Maastrichtian (83.6–66.0 Ma)Brazilunder dispute
  • Bonitasaura Apesteguía, 2004 Santonian (85.7–83.6 Ma)Argentina
  • Chucarosaurus Agnolín et al., 2023 Cenomanian–Turonian (100.5–89.8 Ma)Argentina
  • Inawentu Filippi et al., 2024 Santonian (85.7–83.6 Ma)Argentina
  • Pitekunsaurus Filippi & Garrido, 2008 Campanian (83.6–72.2 Ma)Argentinaunder dispute
  • Volgatitan Averianov & Efimov, 2018 Hauterivian (132.6–125.8 Ma)Russia

References

  1. González Riga, B. J.; Lamanna, M. C.; Otero, A.; Ortiz David, L. D.; Kellner, A. W. A.; Ibiricu, L. M. (2019). An overview of the appendicular skeletal anatomy of South American titanosaurian sauropods, with definition of a newly recognized clade. Anais da Academia Brasileira de Ciências 91(suppl 2): e20180374. doi:10.1590/0001-3765201920180374

    Erected Colossosauria (originally defined by reference to Mendozasaurus).

    gonzálezriga2019a
  2. Carballido, J. L.; Otero, A.; Mannion, P. D.; Salgado, L.; Pérez Moreno, A. P. (2022). Titanosauria: a critical reappraisal of its systematics and the relevance of the South American record. South American Sauropodomorph Dinosaurs: Record, Diversity and Evolution 269-298. Springer International Publishing. doi:10.1007/978-3-030-95959-3_8

    Redefined Colossosauria (Patagotitan not Saltasaurus) as the Patagotitan-line stem of Eutitanosauria.

    carballido2022a