// Workers AI · dad joke modeWhat did the coronoid bone say? I've got a jaw-dropping story.
The coronoid is a bone present in the mandible of many non-mammalian vertebrates. It typically lies on the medial wall of each hemimandible.[1] Among its functions, it provides a lever arm for the attachment of jaw muscles.
Evolution
[edit]In some actinoperygian fishes, the coronoid occurs near the anterior tip of the mandible and bears teeth.[2]
The coronoid is present in most sauropsids and amphibians.[3]
In early synapsids, the bone was present; it was progressively reduced during the evolution of mammals, and is absent in modern mammals. Its function has been taken over by the coronoid process of the dentary.[1]
In some animals, including some salamanders and parareptiles, the coronoid bears teeth.[4][5]
In some species, including the parareptile Delorhynchus and the fish Polypterus, multiple coronoid ossifications are present on each side.[5]
References
[edit]- 1 2 Kardong, Kenneth (2015). Vertebrates: Comparative Anatomy, Function, Evolution (7th ed.). New York: McGraw-Hill. ISBN 978-0-07-802302-6.
{{cite book}}: CS1 maint: date and year (link) - ↑ Jollie, M. (1984). "Development of the head and pectoral skeleton of Polypterus with a note on scales (Pisces: Actinopterygii)". Journal of Zoology. 204 (4): 469–507. doi:10.1111/j.1469-7998.1984.tb02382.x. ISSN 1469-7998.
- ↑ Romer, A. S. (1956). Osteology of the Reptiles. Chicago: University of Chicago Press.
- ↑ Vassilieva, Anna B.; Smirnov, Sergei V. (2001). "Development and Morphology of the Dentition in the Asian Salamander, Ranodon sibiricus (Urodela: Hynobiidae)". Russian Journal of Herpetology. 8 (2): 105–116. doi:10.30906/1026-2296-2001-8-2-105-116. ISSN 1026-2296.
- 1 2 Haridy, Yara; Macdougall, Mark J; Reisz, Robert R (2018-11-01). "The lower jaw of the Early Permian parareptile Delorhynchus, first evidence of multiple denticulate coronoids in a reptile". Zoological Journal of the Linnean Society. 184 (3): 791–803. doi:10.1093/zoolinnean/zlx085. ISSN 0024-4082.