Krzyzanowskisaurus

Krzyzanowskisaurus
Temporal range: Late Triassic,
~221.5–201.6 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Clade: Eucrocopoda
Clade: Crurotarsi (?)
Genus: †Krzyzanowskisaurus
Heckert, 2005
Species:
†K. hunti
Binomial name
†Krzyzanowskisaurus hunti
(Heckert, 2002)
Synonyms

Krzyzanowskisaurus (meaning "Stan Krzyżanowski's lizard") is the name given to a genus of archosaur from the Late Triassic-aged Chinle Formation and it is a tooth taxon, based on fossils only of teeth (such as the holotype tooth NMMNH P-29357[1]) and these teeth have been found in the U.S. states of Arizona (including the type locality) and New Mexico.[2][1] The original report described it as a "probable ornithischian" and Heckert (2005) suggests that Krzyzanowskisaurus teeth have biostratigraphic utility as an index fossil of the St. Johnsian sub-LVF (land-vertebrate faunachron).[3]

The type species, Krzyzanowskisaurus hunti, was reevaluated by Heckert in 2005,[3] after previously being described by him as Revueltosaurus hunti in 2002.[4] The name was changed when it was discovered that the type species of Revueltosaurus, R. callenderi, was a pseudosuchian rather than an ornithischian dinosaur (Parker et al. 2005).[5] According to Heckert, "R." hunti displays an orithischian-like feature not present in R. callenderi (teeth possessing a cingulum), suggesting that it represents a new genus of early ornithischian. This was challenged by Irmis et al. (2006), who found that the cingulum differed from that in true early ornithischians, and noted that some teeth had been found with skull bones and osteoderms that matched those of Revueltosaurus.[6] Thus, they found that it was not a dinosaur, and provisionally retained it in Revueltosaurus;[6] it may once again be R. hunti.

  1. ^ a b "Galerie der Arten • Species Gallery : Kryzanowskisaurus hunti". Archived from the original on 26 October 2007. Retrieved 25 May 2022.
  2. ^ "Re: Krzyzanowskisaurus". Archived from the original on 2012-02-04. Retrieved 2006-04-19.
  3. ^ a b Heckert, A.B., (2005). Krzyzanowskisaurus, a new name for a probable ornithischian dinosaur from the Upper Triassic Chinle Group, Arizona and New Mexico, USA. New Mexico Museum of Natural History and Science Bulletin 29: 77-83.
  4. ^ A. B. Heckert. (2002). A revision of the Upper Triassic ornithischian dinosaur Revueltosaurus, with a description of a new species. Upper Triassic Stratigraphy and Palaeontology, New Mexico Museum of Natural History and Science Bulletin 21:253-266
  5. ^ Parker, W. G., R. B. Irmis, S.N. Nesbitt, J. W. Martz & L. S. Browne. (2005). The pseudosuchian Revueltosaurus callenderi and its implications for the diversity of early ornithischian dinosaurs. Proceedings of the Royal Society London B272 (1566): 963–969.
  6. ^ a b * Irmis, R.B., Parker, W.G., Nesbitt, S.J., and Liu, J. (2006). Early ornithischian dinosaurs: the Triassic record. Historical Biology, 19(1):3-22.