Castor californicus

{{Speciesbox

| fossil_range = late Miocene to early Pleistocene

| genus = Castor

| species = californicus

| authority = Kellogg, 1911{{cite journal|last1=Kellogg|first1=Louise|title=A Fossil Beaver from the Kettleman Hills, California|journal=Bulletin of the Department of Geology|date=1911|volume=6|issue=17|pages=401–402|url=https://babel.hathitrust.org/cgi/pt?id=uc1.c034382348;view=1up;seq=495|publisher=University of California Publications}}

| extinct = yes

| synonyms =

†Castor accessor Hay, 1927{{cite book|last1=Hay|first1=Oliver P.|title=The Pleistocene of the Western Region of North America and its Vertebrated Animals|series=Carnegie Institution of Washington. Publication; no. 322B|date=1927|publisher=Carnegie Institution of Washington|pages=266–267|url=https://babel.hathitrust.org/cgi/pt?id=osu.32435009092347;view=1up;seq=274}}

| range_map = Castor californicus map.PNG

| range_map_caption = Sites of C. californicus finds

}}

File:Beaver (Castor californicus) 2016-10-13 2280.jpg

Castor californicus is an extinct species of beaver that lived in western North America from the end of the Miocene to the early Pleistocene.{{cite web | title = The Paleobiology Database - Castor californicus | date = | url = https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=44956 | access-date = 2007-09-30 }} Castor californicus was first discovered in the Kettleman Hills of California, United States. The species was similar to but larger than the extant North American beaver, C. canadensis.{{cite book | author = Kurtén, B. | author-link = Björn Kurtén | author2 = E. Anderson | name-list-style = amp | title = Pleistocene Mammals of North America | location = New York | publisher = Columbia University Press | year = 1980 | pages = 236–237 | isbn = 0-231-03733-3}}

Unlike other members of the Castor genus, Castor californicus possessed a total of three enamel folds, the folds of the internal enamel epithelium.{{Cite web |title=A fossil beaver from the Kettleman Hills, California, by Louise Kellogg {{!}} The Online Books Page |url=https://onlinebooks.library.upenn.edu/webbin/book/lookupid?key=ha100897771 |access-date=2023-10-24 |website=onlinebooks.library.upenn.edu}}

Phylogenetic characteristics

Castor californicus has been determined to be the earliest type of its genus to appear in North America.{{Citation needed|date=November 2023}}

Castor californicus is characterized by having short nasal passages. The backs of their skulls were quite wide in comparison to other members of the Castor genus. The coronoid process is more spread out. Their pterygoid muscles were on the larger side, and their neck muscles were broad. Due to these distinctions, Castor californicus had a slight physical advantage compared to Castor fiber, the extant European beaver. Each Castor californicus speciemn examined was slightly unique in its postcranial morphology. They had short femurs and elongated hind feet, which assisted them in moving with ease through water.{{Citation needed|date=March 2025}}

Compared to other species of beavers, Castor californicus had considerably wide metatarsals, which aided them in the swimming and digging process.{{Cite journal |last=Lubbers |first=Kelly E. |last2=Samuels |first2=Joshua X. |date=2023-09-02 |title=Comparison of Miocene to early Pleistocene-aged Castor californicus (Rodentia: Castoridae) to extant beavers and implications for the evolution of Castor in North America |url=https://palaeo-electronica.org/content/2023/3943-fossil-beaver-morphology |journal=Palaeontologia Electronica |language=English |volume=26 |issue=3 |pages=1–28 |doi=10.26879/1284 |issn=1094-8074|doi-access=free }} Castor californicus has three folds of the internal enamel epithelium, unlike other members of the Castor genus.

Castor californicus

Phylogenetic characteristics

References

Further reading