Open Paleo

Thespesius

Leidy, 1856 thes-PEE-zhus Nomen dubium

From Greek thespesios, "wondrous" — means "wondrous one", named because of the colossal size of the remains

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

Thespesius is a dubious genus of hadrosaurid dinosaur from the late Maastrichtian-age Upper Cretaceous Lance Formation of South Dakota.

Species

Thespesius occidentalis Leidy, 1856 Nomen dubium

Type species

From Latin 'occidentalis' meaning 'western', referring to the western location of the discovery site in what was then the Nebraska Territory.

Syntypes
USNM 219, USNM 220, USNM 221 , National Museum of Natural History, Smithsonian Institution
Material
Two caudal vertebrae and first phalanx; vertebral bodies quadrately oval in outline with distinct articular processes for chevron bones; phalanx 5 inches long with transverse reniform proximal articulation
Horizon
Lance Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Grand River, South Dakota, United States

References

  1. Leidy, J. (1856). Notices of Extinct Vertebrata Discovered by Dr. F. V. Hayden, during the Expedition to the Sioux Country under the Command of Lieut. G. K. Warren. Proceedings of the Academy of Natural Sciences of Philadelphia 8: 311-312.

    Gives the syntypes as from the lowest member of the Lignite formation of Grand River, in what was then Nebraska Territory, without a closer locality.

    leidy1856a
  2. Horner, J. R.; Weishampel, D. B.; Forster, C. A. (2004). Hadrosauridae. The Dinosauria, Second Edition (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 438-463. University of California Press, Berkeley.

    Places the type material in South Dakota.

    horner2004a
  3. Prieto-Márquez, A.; Weishampel, D. B.; Horner, J. R. (2006). The dinosaur Hadrosaurus foulkii, from the Campanian of the East Coast of North America, with a reevaluation of the genus. Acta Palaeontologica Polonica 51(1): 77-98. Polska Akademia Nauk Instytut Paleobiologii (Institute of Paleobiology, Polish Academy of Sciences).

    Gives the syntypes as two caudal vertebrae and a phalanx from the Lance Formation, the source of the formation.

    prieto-márquez2006a
  4. Brett-Surman, M. K. (1989). A revision of the Hadrosauridae (Reptilia: Ornithischia) and their evolution during the Campanian and Maastrichtian. 1-272. Doctoral thesis, The George Washington University.

    Finds the type material undiagnostic even at subfamily level and the name a nomen dubium; notes that Lull and Wright (1942) moved the species referred to the genus to Anatosaurus.

    brett-surman1989a
  5. Lull, R. S.; Wright, N. E. (1942). Hadrosaurian Dinosaurs of North America. Geological Society of America Special Papers 40: 1-272. Geological Society of America. doi:10.1130/spe40-p1

    Moved the species referred to Thespesius into Anatosaurus.

    lull1942a