Myocastor Explained

Myocastor is a genus of rodent that contains the living nutria (or coypu), as well as several fossil species.

Taxonomy

Due to similar cranial morphology, the nutria was once considered a close relative of the Caribbean hutias and placed together with them in the family Capromyidae.^[1] Later, it was more accepted to place it in its own family, the Myocastoridae.^[2] Recent molecular studies place them in the family Echimyidae, in the tribe Myocastorini.^{[3] [4] [5]}

Fossil record

Kerber et al. (2013) recognize the following species as valid:^[6]

• Myocastor columnaris (Middle Pleistocene)
• Myocastor obesus (Late Miocene)
• Myocastor paranensis (Late Miocene)

Other species described but no longer considered valid include Myocastor minor, Myocastor perditus, and Myocastor priscus.

Notes and References

1. Woods . C.A. . Howland . E.B. . Adaptive Radiation of Capromyid Rodents: Anatomy of the Masticatory Apparatus . Journal of Mammalogy . 1979 . 60 . 1 . 95–116 . 10.2307/1379762. 1379762 .
2. Book: Woods . C. A. . Mares. M. A.. Genoways. H. H.. Mammalian Biology in South America . University of Pittsburgh . 1982 . 377–392 . The history and classification of South American Hystricognath rodents: reflections on the far away and long ago . Pittsburgh .
3. Galewski. Thomas. Mauffrey. Jean-François. Leite. Yuri L. R.. Patton. James L.. Douzery. Emmanuel J. P.. 2005. Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach. Molecular Phylogenetics and Evolution. 34. 3. 601–615. 10.1016/j.ympev.2004.11.015. 15683932.
4. Upham. Nathan S.. Patterson. Bruce D.. 2012. Diversification and biogeography of the Neotropical caviomorph lineage Octodontoidea (Rodentia: Hystricognathi). Molecular Phylogenetics and Evolution. 63. 2. 417–429. 10.1016/j.ympev.2012.01.020. 22327013.
5. Fabre. Pierre-Henri. Upham. Nathan S.. Emmons. Louise H.. Justy. Fabienne. Leite. Yuri L. R.. Loss. Ana Carolina. Orlando. Ludovic. Tilak. Marie-Ka. Patterson. Bruce D.. Douzery. Emmanuel J. P.. 2017-03-01. Mitogenomic Phylogeny, Diversification, and Biogeography of South American Spiny Rats. Molecular Biology and Evolution. 34. 3. 613–633. 10.1093/molbev/msw261. 28025278. 0737-4038. free.
6. Kerber . L. . Late Quaternary fossil record of Myocastor Kerr, 1792 (Rodentia: Hystricognathi: Caviomorpha) from Brazil with taxonomical and environmental remarks . Quaternary International . 2013 . 1–12 .