Colognathidae

Colognathids
Temporal range: MiddleLate Triassic
Partial skull of Quasicolognathus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: incertae sedis
Family: Colognathidae
Sues, Kligman & Schoch, 2022
Type genus
Colognathus
Genera

Colognathidae is an extinct family of enigmatic reptiles. It contains two genera: Colognathus, known from the Late Triassic of the southwestern United States, and the older Quasicolognathus, known from the Middle Triassic of Germany. Both are known from fragmentary remains, mostly comprising tooth-bearing bones of the skull and isolated teeth. The phylogenetic affinities of these taxa have been historically complicated due to their unique anatomy and fragmentary nature; Colognathus was initially described as a unique fish,[1] with later researchers suggesting possible affinities with procolophonids,[2] lepidosauromorphs,[3] and archosauromorphs.[4] A 2022 review indicated that research on the relationships of colognathids was ongoing, but that affinities with osteichthyan fishes, procolophonids, and lepidosauromorphs were not supported.[5]

Colognathids are characterized by having transversely narrow snouts and unique dental anatomy, exhibiting pleurodont/acrodont implantation. There are only two or three large teeth in the maxilla and dentary (upper and lower tooth-bearing bones), leaving the front of the jaw edentulous (toothless). The posteriormost (further to the back) teeth are greatly enlarged.[5]

References

  1. ^ Case, E. C. (1928). "Indications of a cotylosaur and of a new form of fish from the Triassic beds of Texas, with remarks on the Shinarump Conglomerate". Journal of the Washington Academy of Sciences. 23 (1): 65. hdl:2027.42/48181.
  2. ^ Murry, Phillip A. (1986). "9. Vertebrate paleontology of the Dockum Group, western Texas and eastern New Mexico". In Padian, Kevin (ed.). The Beginning of the Age of Dinosaurs: Faunal change across the Triassic-Jurassic boundary. New York: Cambridge University Press. pp. 109–137. ISBN 978-0-521-30328-6.
  3. ^ Heckert, Andrew (2010). Biostratigraphic significance and redescription of the enigmatic vertebrate Colognathus obscurus from the Upper Triassic Chinle Group, southwestern USA. Society of Vertebrate Paleontology, 70th Annual Meeting. pp. 103A–104A.
  4. ^ Heckert, Andrew B.; Mitchell, Jonathon S.; Schneider, Vincent P.; Olsen, Paul E. "Diverse New Microvertebrate Assemblage from the Upper Triassic Cumnock Formation, Sanford Subbasin, North Carolina, USA". Journal of Paleontology. 86 (2): 368–390. doi:10.2307/41480198 (inactive 2026-02-08).{{cite journal}}: CS1 maint: DOI inactive as of February 2026 (link)
  5. ^ a b Sues, Hans-Dieter; Kligman, Ben T.; Schoch, Rainer R. (2022). "An unusual Colognathus-like reptile from the Middle Triassic (Ladinian) Erfurt Formation of Germany". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 303 (2): 227–238. doi:10.1127/njgpa/2022/1046. S2CID 246800490.