"Ekbletomys"
"Ekbletomys" | |
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Side view of the holotype skull | |
Scientific classification (unresolved) | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Cricetidae |
Subfamily: | Sigmodontinae |
Tribe: | Oryzomyini |
Genus: | †"Ekbletomys" Ray, 1962 (unavailable name)
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Species: | †"E. nasuta"
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Binomial name | |
†"Ekbletomys nasuta (Ray, 1962) (unavailable name)
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Location of endemic
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"Ekbletomys hypenemus" is an extinct[1] oryzomyine rodent from the islands of Antigua and Barbuda, Lesser Antilles. It was described as the only species of the subgenus "Ekbletomys" of genus Oryzomys in a 1962 Ph.D. thesis, but that name is not available under the International Code of Zoological Nomenclature and the species remains formally unnamed. It is currently referred to as "Ekbletomys hypenemus" in the absence of a formally available name.[2] The species is now thought to be extinct, but association with introduced Rattus indicates that it survived until before[clarification needed] 1500 BCE on Antigua.[citation needed]
It is known from abundant skeletal elements, which document it as the largest known oryzomyine, on par with
Taxonomy
Remains of "Ekbletomys" were first found on Barbuda in the summer of 1958[3] and subsequently on Antigua in 1961. In his 1962 Ph.D. thesis at Harvard University, paleontologist Clayton E. Ray described them as a new species, Oryzomys hypenemus, which he considered distinctive enough to merit its own subgenus, Ekbletomys. The specific name, hypenemus, is derived from ύπηνεμος (hypênemos), which means "leeward" in Ancient Greek and refers to the species' distribution in the Leeward Islands, and the subgeneric name, Ekbletomys, combines Ancient Greek εκβλητος (ekblêtos) "cast up" and μυς (mus) "mouse", referring to the way "Ekbletomys" probably reached its islands.[4] Because Ray's thesis does not meet the definition of a "published work" in the International Code of Zoological Nomenclature,[5] both new names proposed by Ray are not available and cannot be used in formal zoological nomenclature. The name has rarely been used in the literature on Antillean oryzomyines since, and no formal description has been published; thus, the animal still lacks a formally available name.[6]
Large oryzomyines from Antigua and Barbuda have been reported in several subsequent studies, but these did not explicitly refer the material to Ray's "Oryzomys hypenemus". New material has come from Indian Creek and Burma's Quarry on Antigua and from Indiantown Trail and Sufferers on Barbuda.
Description
"Ekbletomys" is known from numerous bones from Barbuda, including over a hundred
The Barbudan material, and particularly the skulls, shows a number of features distinctive enough for an oryzomyine to persuade Ray to allocate it to its own subgenus and species. The front part of the skull is short and broad. The
Measurement | UF 2816 | UF 2815 | UF 2814 I | UF 2951 E |
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Greatest skull length (without nasals) | 60.4 | – | – | – |
Length of diastema[fn 2] |
18.3 | 17.3 | – | – |
Length of incisive foramen | 6.5 | 5.9 | – | – |
Width of palate between first molars | 6.2 | 5.5 | – | – |
Minimum interorbital breadth | 7.1 | 8.3 | 8.1 | 8.3 |
Crown length of upper molars | 10.3, 10.2 | 10.4, – | – | –, 10.2 |
As "Ekbletomys" and Megalomys audreyae are from the same island, a close relation between the two would be expected,[13] but the two differ so much that Ray declared any special relationship between the genus Megalomys and "Ekbletomys" to be "out of the question".[14] In all measurements that could be examined, M. audreyae, which is known only from an upper incisor and a lower jaw with the first molar missing, falls far outside the range of variation of "Ekbletomys"[15] and in addition, it differs in the shape of the folds of the molars, which are broader than in "Ekbletomys", and in the more elongate form of the lower third molar.[14]
More complete material is available for the two Megalomys species known to have survived into historic times, M. desmarestii and
Ray considered "Ekbletomys" to be most closely related to
Distribution and habitat
"Ekbletomys hypenemus" is known from material from two small limestone caves at
In order to colonize Barbuda and Antigua, "Ekbletomys" must have reached the islands through overwater dispersal, probably by means of
Footnotes
References
- ^ Ray, 1962, table 10
- ^ Turvey, 2009, unnumbered table
- ^ Auffenberg, 1958, p. 248
- ^ Ray, 1962
- ^ International Code of Zoological Nomenclature, 1999, Art. 8. http://www.iczn.org/iczn/index.jsp Archived 2009-05-24 at the Wayback Machine
- ^ a b Turvey, 2009, unnumbered table, note 20
- ^ Steadman et al., 1984; Watters et al., 1984; Pregill et al., 1988, 1994
- ^ Pregill et al., 1988, p. 22
- ^ Ray, 1962, pp. 112–115
- ^ a b Ray, 1962, p. 107
- ^ Ray, 1962, pp. 107, 116–117
- ^ Ray, 1962, table 11
- ^ Ray, 1962, p. 164
- ^ a b Ray, 1962, p. 165
- ^ Ray, 1962, table 33
- ^ Ray, 1962, p. 120
- ^ Ray, 1962, p. 121
- ^ a b Ray, 1962, p. 124
- ^ Ray, 1962, p. 127
- ^ Ray, 1962, pp. 165–166
- ^ Ray, 1962, p. 167
- ^ Ray, 1962, p. 109; Pregill et al., 1994, pp. 16–17
- ^ Ray, 1962, pp. 109–110
- ^ Ray, 1962, p. 110
- ^ Ray, 1962, table 10; Frost, 2009, Uetz et al., 2009, Peterson, 1992, Simmons, 2005, for nomenclature
- ^ Ray, 1962, p. 112
- ^ Ray, 1962, pp. 176–185
- ^ Ray, 1962, p. 188
- ^ Ray, 1962, p. 189
Literature cited
- Auffenberg, W. 1958. A small fossil herpetofauna from Barbuda, Leeward Islands, with the description of a new species of Hyla. Quarterly Journal of the Florida Academy of Sciences 21(3):248–254.
- Frost, D.R. 2009. Amphibian Species of the World: an online reference. Version 5.3 (12 February 2009). Available at http://research.amnh.org/herpetology/amphibia/. American Museum of Natural History, New York, USA.
- Peterson, A.P. 2002. Zoonomen Nomenclatural data. Available at http://www.zoonomen.net. Accessed September 11, 2009.
- Pregill, G.K., Steadman, D.W., Olson, S.L. and Grady, F.V. 1988. Late Holocene fossil vertebrates from Burma Quarry, Antigua, Lesser Antilles. Smithsonian Contributions to Paleobiology 463:1–27.
- Pregill, G.K., Steadman, D.W. and Watters, D.R. 1994. Late Quaternary vertebrate faunas of the Lesser Antilles: historical components of Caribbean biogeography. Bulletin of Carnegie Museum of Natural History 30:1–51.
- Ray, C. E. 1962. The Oryzomyine Rodents of the Antillean Subregion. Doctor of Philosophy thesis, Harvard University, 211 pp.
- Simmons, N.B. 2005. Order Chiroptera. Pp. 312–529 in Wilson, D.E. and Reeder, D.M. (eds.). Mammal Species of the World: a taxonomic and geographic reference. 3rd ed. Baltimore: The Johns Hopkins University Press, 2 vols., 2142 pp. ISBN 978-0-8018-8221-0
- Steadman, D.W., Pregill, G.K. and Olson, S.L. 1984. Fossil vertebrates from Antigua, Lesser Antilles: Evidence for late Holocene human-caused extinctions in the West Indies. Proceedings of the National Academy of Sciences 81:4448–4451.
- Turvey, S.T. 2009. Holocene Extinctions. Oxford University Press US, 359 pp. ISBN 978-0-19-953509-5
- Uetz, P., et al. 2009. The Reptile Database. Available at http://www.reptile-database.org. Accessed September 11, 2009.
- Watters, D.R., Reitz, E.J., Steadman, D.W. and Pregill, G.K. 1984. Vertebrates from archaeological sites on Barbuda, West Indies. Annals of Carnegie Museum 53(13):383–412.
- Wing, E.S., Hoffman, C.A., Jr. and Ray, C.E. 1968. Vertebrate remains from Indian sites on Antigua, West Indies. Caribbean Journal of Science 8(3–4):123–139.