Alligator olseni

Olsen's alligator Temporal range: Early Miocene 20.4–16 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Forelimbs of Alligator olseni
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauromorpha
Clade:	Archosauriformes
Order:	Crocodilia
Family:	Alligatoridae
Subfamily:	Alligatorinae
Genus:	Alligator
Species:	†A. olseni
Binomial name
†Alligator olseni White, 1942

Alligator olseni (common name Olsen's Alligator, named after Russel Olsen) is an extinct species of alligator. They lived in the Early Miocene period, around 20.4–15.97 million years ago and possibly earlier.^[2] Their range was principally in what is now known as Florida, United States, and possibly extending into southeastern Texas.^[3][4] It is a small alligator with an estimated body length of 2.6 metres (8.5 ft).^[5]

Classification

Alligator olseni is a member of the subfamily Alligatorinae, within the larger family Alligatoridae. It is closely related to the living American alligator and Chinese alligator, as shown in the cladogram below:^[6][7]

Alligatoridae

Caimaninae Alligatorinae Ceratosuchus burdoshi† Hassiacosuchus haupti† Navajosuchus mooki† Wannaganosuchus brachymanus† Arambourgia gaudryi† Allognathosuchus polyodon† Allognathosuchus wartheni† Procaimanoidea kayi† Alligator Alligator prenasalis† Alligator mcgrewi† Alligator olseni† Alligator sinensis Chinese alligator Alligator thomsoni† Alligator mefferdi† Alligator mississippiensis American alligator

References

1. Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
2. T. E. White. 1942. A new alligator from the Miocene of Florida. Copeia 1942(1):3-7
3. "Alligator olseni". Florida Museum of Natural History. Retrieved 18 June 2016.
4. "Alligator olseni". Fossilworks. Retrieved 17 December 2021.
5. Ikejiri, T. (2010). Morphology of the Neurocentral Junction during Postnatal Growth of Alligator (Reptilia, Crocodylia) (PhD thesis). University of Michigan.
6. Hastings, A. K.; Bloch, J. I.; Jaramillo, C. A.; Rincon, A. F.; MacFadden, B. J. (2013). "Systematics and biogeography of crocodylians from the Miocene of Panama". Journal of Vertebrate Paleontology. 33 (2): 239. Bibcode:2013JVPal..33..239H. doi:10.1080/02724634.2012.713814. S2CID 83972694.
7. Brochu, C. A. (2011). "Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines". Zoological Journal of the Linnean Society. 163: S228 – S256. doi:10.1111/j.1096-3642.2011.00716.x.