Oryzomys hypenemus
Encyclopedia
"Ekbletomys hypenemus" is an extinct
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. The species is now thought to be extinct, but association with introduced Rattus indicates that it survived until after 1500 CE on Antigua.
It is known from abundant skeletal elements, which document it as the largest known oryzomyine, on par with Megalomys desmarestii, another Antillean endemic. Its morphological features indicate that it is distinct from Megalomys
, which includes various other Antillean oryzomyines, and derives from a separate colonization of the Lesser Antilles by oryzomyines. In the original description, it was placed close to a species now placed in Nephelomys
, but its relationships have not been studied since.
, 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. Because Ray's thesis does not meet the definition of a "published work" in the International Code of Zoological Nomenclature
, 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.
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. These studies referred the Antigua and Barbuda material to "Undescribed species B", which is also known from archeological material on Guadeloupe
, Montserrat
and Marie-Galante
. In addition to this large species, other, smaller oryzomyines may also have occurred on Antigua; two species of oryzomyine were also formerly present on Barbuda.
and tibiofibulae (bones of the hindlimb), four substantial cranium (skull) fragments, one of which was designated by Ray as the holotype
, and various others. At the time of Ray's writing, the material from Antigua had not yet been completely sorted out, and consequently the description is based mainly on specimens from Barbuda.
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 interorbital region
of the skull (located between the eyes) is narrower than that of any other oryzomyine. The squamosal (back) roots of the zygomatic arch
es (cheekbones) are oriented perpendicular to the main axis of the skull. The incisive foramina
(openings in the palate
between the incisor
s and the molar
s) are extremely short. The molars are large. The palate is short, extending barely beyond the third molar. The anterocone (front cusp) of the first upper molar is divided by a marked anteromedian flexus. The length of the holotype skull is larger than that of all specimens but one of Megalomys desmarestii, indicating that "Ekbletomys" is among the largest oryzomyine species known.
As "Ekbletomys" and Megalomys audreyae
are from the same island, a close relation between the two would be expected, but the two differ so much that Ray declared any special relationship between the genus Megalomys
and "Ekbletomys" to be "out of the question". 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" 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.
More complete material is available for the two Megalomys species known to have survived into historic times, M. desmarestii and M. luciae. M. desmarestii is about as large as "Ekbletomys" and M. luciae is slightly smaller. In sharp contrast to the relatively narrow interorbital in "Ekbletomys", these two taxa show a very broad interorbital. Also, "Ekbletomys" shows a relatively large zygomatic breadth of the skull, whereas the relative value is at the lower end of the variation among oryzomyines in Megalomys. The hamular process of the squamosal
bone is much longer and more slender in "Ekbletomys. Megalomys also has relatively short incisive foramina, but not nearly as short as those in "Ekbletomys". Although overall skull length is about equal in both species, molars of Megalomys are smaller than those of "Ekbletomys" and incisors are larger, reflecting relatively large molars and slender incisors in "Ekbletomys" and the reverse in Megalomys.
Ray considered "Ekbletomys" to be most closely related to Oryzomys albigularis, a species which at the time encompassed virtually all forms now placed in the genus Nephelomys
. The two agree in their robust skull with short incisive foramina, a broad braincase, a similarly formed interorbital, supraorbital crests situated close together near the middle of the skull, and presence of an anteromedian flexus on the upper first molar. Ray suggested that the origin of "Ekbletomys" lies in a continental ancestor similar to Nephelomys.
and from a site named Mill Reef in the far east of Antigua
, also in Antigua and Barbuda, which has not been described in detail. In both Barbuda caves, the "Ekbletomys" material was found in red to yellow unconsolidated sediments on the cave floor which were partially overlain by a darker sediment that yielded the introduced Rattus, indicating deposition after the first European contact around 1500. These sediments are probably ancient owl pellets deposited by a Burrowing Owl
(Athene cunicularia) and they also yielded the frog Eleutherodactylus johnstonei; the lizards Thecadactylus rapicauda, Ameiva griswoldi
, and Anolis leachii; the birds Puffinus lherminieri, Zenaida aurita, Columbina passerina, Tiaris bicolor, and an unidentified fringillid; and the bats Mormoops blainvillei, Brachyphylla cavernarum, Natalus stramineus, Tadarida brasiliensis, and Molossus molossus. The deposits that included "Ekbletomys" are probably very late Quaternary, but pre-Columbian
, and the Antigua material ranges in age from about 2500 BCE to post-Columbian.
In order to colonize Barbuda and Antigua, "Ekbletomys" must have reached the islands through overwater dispersal, probably by means of rafting
. Ray thought it improbable that the ancestor of the animal reached the islands through repeated overwater dispersal (island hopping
) from mainland South America along the Lesser Antilles all the way to Barbuda. Even when sea levels dropped during the Pleistocene
, the animal would still have been required to overcome seven water barriers, a series of voyages "no less wondrous than those of Sindbad." Instead, he argued that the animal reached the islands directly on a raft from mainland South America, probably from one of the continent's large rivers.
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
oryzomyine
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of family Cricetidae. It includes about 120 species in about thirty genera, distributed from the eastern United States to the southernmost parts of South America, including many offshore islands...
rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
from the islands of Antigua
Antigua
Antigua , also known as Waladli, is an island in the West Indies, in the Leeward Islands in the Caribbean region, the main island of the country of Antigua and Barbuda. Antigua means "ancient" in Spanish and was named by Christopher Columbus after an icon in Seville Cathedral, Santa Maria de la...
and Barbuda
Barbuda
Barbuda is an island in the Eastern Caribbean, and forms part of the state of Antigua and Barbuda. It has a population of about 1,500, most of whom live in the town of Codrington.-Location:...
, Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...
. It was described as the only species of the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
"Ekbletomys" of genus Oryzomys
Oryzomys
Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat of the United States and O. couesi of Mexico and Central America—are widespread; the six others have...
in a 1962 Ph.D. thesis, but that name is not available
Unavailable name
In zoological nomenclature, an unavailable name is a name that does not conform to the rules of the International Code of Zoological Nomenclature and that therefore is not available for use as a valid name for a taxon...
under the International Code of Zoological Nomenclature
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
and the species remains formally unnamed. It is currently referred to as "Ekbletomys hypenemus" in the absence of a formally available name. The species is now thought to be extinct, but association with introduced Rattus indicates that it survived until after 1500 CE on Antigua.
It is known from abundant skeletal elements, which document it as the largest known oryzomyine, on par with Megalomys desmarestii, another Antillean endemic. Its morphological features indicate that it is distinct from Megalomys
Megalomys
Megalomys is a genus of rodent in the family Cricetidae, part of the tribe Oryzomyini. The genus contains four large rodents from various Caribbean islands, all of which are now extinct. The last species to survive was M...
, which includes various other Antillean oryzomyines, and derives from a separate colonization of the Lesser Antilles by oryzomyines. In the original description, it was placed close to a species now placed in Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
, but its relationships have not been studied since.
Taxonomy
Remains of "Ekbletomys" were first found on Barbuda in the summer of 1958 and subsequently on Antigua in 1961. In his 1962 Ph.D. thesis at Harvard UniversityHarvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
, paleontologist Clayton E. Ray described them as a new species, Oryzomys hypenemus, which he considered distinctive enough to merit its own subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
, Ekbletomys. The specific name, hypenemus, is derived from ύπηνεμος (hypênemos), which means "leeward" in Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
and refers to the species' distribution in the Leeward Islands
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...
, 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. Because Ray's thesis does not meet the definition of a "published work" in the International Code of Zoological Nomenclature
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
, 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.
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. These studies referred the Antigua and Barbuda material to "Undescribed species B", which is also known from archeological material on Guadeloupe
Guadeloupe
Guadeloupe is an archipelago located in the Leeward Islands, in the Lesser Antilles, with a land area of 1,628 square kilometres and a population of 400,000. It is the first overseas region of France, consisting of a single overseas department. As with the other overseas departments, Guadeloupe...
, Montserrat
Montserrat
Montserrat is a British overseas territory located in the Leeward Islands, part of the chain of islands called the Lesser Antilles in the West Indies. This island measures approximately long and wide, giving of coastline...
and Marie-Galante
Marie-Galante
Marie-Galante is an island of the Caribbean Sea located at the south of Guadeloupe and at north of Dominica. Marie-Galante is a dependence of Guadeloupe which is a french overseas department....
. In addition to this large species, other, smaller oryzomyines may also have occurred on Antigua; two species of oryzomyine were also formerly present on Barbuda.
Description
"Ekbletomys" is known from numerous bones from Barbuda, including over a hundred femoraFemur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
and tibiofibulae (bones of the hindlimb), four substantial cranium (skull) fragments, one of which was designated by Ray as the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, and various others. At the time of Ray's writing, the material from Antigua had not yet been completely sorted out, and consequently the description is based mainly on specimens from Barbuda.
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 interorbital region
Interorbital region
The interorbital region of the skull is located between the eyes, anterior to the braincase. The form of the interorbital region may exhibit significant variation between taxonomic groups....
of the skull (located between the eyes) is narrower than that of any other oryzomyine. The squamosal (back) roots of the zygomatic arch
Zygomatic arch
The zygomatic arch or cheek bone is formed by the zygomatic process of temporal bone and the temporal process of the zygomatic bone , the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process...
es (cheekbones) are oriented perpendicular to the main axis of the skull. The incisive foramina
Incisive foramen
The fossa incisiva is an opening in the bone of the oral hard palate where blood vessels and nerves may pass. There are four of these openings in the incisive fossa.-Formation:...
(openings in the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
between the incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s and the molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
s) are extremely short. The molars are large. The palate is short, extending barely beyond the third molar. The anterocone (front cusp) of the first upper molar is divided by a marked anteromedian flexus. The length of the holotype skull is larger than that of all specimens but one of Megalomys desmarestii, indicating that "Ekbletomys" is among the largest oryzomyine species known.
| Measurement | UF 2816 | UF 2815 | UF 2814 I | UF 2951 E |
|---|---|---|---|---|
| Greatest skull length (without nasals) | 60.4 | – | – | – |
| Length of diastema Diastema (dentistry) Diastema is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars.-In humans:... The toothless space between the incisors and the molars. |
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
Megalomys audreyae
Megalomys audreyae, known as the Barbudan Muskrat or the Barbuda giant rice-rat, is an extinct oryzomyine rodent from Barbuda in the Lesser Antilles. Described on the basis of a single mandible with the first molar missing and an isolated upper incisor, both of uncertain but Quaternary age, it is...
are from the same island, a close relation between the two would be expected, but the two differ so much that Ray declared any special relationship between the genus Megalomys
Megalomys
Megalomys is a genus of rodent in the family Cricetidae, part of the tribe Oryzomyini. The genus contains four large rodents from various Caribbean islands, all of which are now extinct. The last species to survive was M...
and "Ekbletomys" to be "out of the question". 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" 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.
More complete material is available for the two Megalomys species known to have survived into historic times, M. desmarestii and M. luciae. M. desmarestii is about as large as "Ekbletomys" and M. luciae is slightly smaller. In sharp contrast to the relatively narrow interorbital in "Ekbletomys", these two taxa show a very broad interorbital. Also, "Ekbletomys" shows a relatively large zygomatic breadth of the skull, whereas the relative value is at the lower end of the variation among oryzomyines in Megalomys. The hamular process of the squamosal
Squamosal
The squamosal is a bone of the head of higher vertebrates. It is the principal component of the cheek region in the skull, lying below the temporal series and otic notch and bounded anteriorly by postorbital. Posteriorly, the squamosal articulates with the posterior elements of the palatal complex,...
bone is much longer and more slender in "Ekbletomys. Megalomys also has relatively short incisive foramina, but not nearly as short as those in "Ekbletomys". Although overall skull length is about equal in both species, molars of Megalomys are smaller than those of "Ekbletomys" and incisors are larger, reflecting relatively large molars and slender incisors in "Ekbletomys" and the reverse in Megalomys.
Ray considered "Ekbletomys" to be most closely related to Oryzomys albigularis, a species which at the time encompassed virtually all forms now placed in the genus Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
. The two agree in their robust skull with short incisive foramina, a broad braincase, a similarly formed interorbital, supraorbital crests situated close together near the middle of the skull, and presence of an anteromedian flexus on the upper first molar. Ray suggested that the origin of "Ekbletomys" lies in a continental ancestor similar to Nephelomys.
Distribution and habitat
"Ekbletomys hypenemus" is known from material from two small limestone caves at Two Foot Bay at the eastern side of the island of Barbuda, Antigua and BarbudaAntigua and Barbuda
Antigua and Barbuda is a twin-island nation lying between the Caribbean Sea and the Atlantic Ocean. It consists of two major inhabited islands, Antigua and Barbuda, and a number of smaller islands...
and from a site named Mill Reef in the far east of Antigua
Antigua
Antigua , also known as Waladli, is an island in the West Indies, in the Leeward Islands in the Caribbean region, the main island of the country of Antigua and Barbuda. Antigua means "ancient" in Spanish and was named by Christopher Columbus after an icon in Seville Cathedral, Santa Maria de la...
, also in Antigua and Barbuda, which has not been described in detail. In both Barbuda caves, the "Ekbletomys" material was found in red to yellow unconsolidated sediments on the cave floor which were partially overlain by a darker sediment that yielded the introduced Rattus, indicating deposition after the first European contact around 1500. These sediments are probably ancient owl pellets deposited by a Burrowing Owl
Burrowing Owl
The Burrowing Owl is a tiny but long-legged owl found throughout open landscapes of North and South America. Burrowing Owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation. They nest and roost in burrows, such as those excavated...
(Athene cunicularia) and they also yielded the frog Eleutherodactylus johnstonei; the lizards Thecadactylus rapicauda, Ameiva griswoldi
Ameiva griswoldi
Griswold's Ameiva is a species of lizard in the genus Ameiva. It is endemic to the Caribbean nation of Antigua and Barbuda, where it is found on both islands. It is also known as the Antiguan Ameiva or the Antiguan Ground Lizard.It is common on Barbuda, and more common on the offshore islands of...
, and Anolis leachii; the birds Puffinus lherminieri, Zenaida aurita, Columbina passerina, Tiaris bicolor, and an unidentified fringillid; and the bats Mormoops blainvillei, Brachyphylla cavernarum, Natalus stramineus, Tadarida brasiliensis, and Molossus molossus. The deposits that included "Ekbletomys" are probably very late Quaternary, but pre-Columbian
Columbian Exchange
The Columbian Exchange was a dramatically widespread exchange of animals, plants, culture, human populations , communicable disease, and ideas between the Eastern and Western hemispheres . It was one of the most significant events concerning ecology, agriculture, and culture in all of human history...
, and the Antigua material ranges in age from about 2500 BCE to post-Columbian.
In order to colonize Barbuda and Antigua, "Ekbletomys" must have reached the islands through overwater dispersal, probably by means of rafting
Rafting event
Oceanic dispersal is a type of biological dispersal that occurs when organisms transfer from one land mass to another by way of a sea crossing on large clumps of floating vegetation. Such matted clumps of vegetation are often seen floating down major rivers in the tropics and washing out to sea,...
. Ray thought it improbable that the ancestor of the animal reached the islands through repeated overwater dispersal (island hopping
Island hopping
Island hopping is a term that refers to the means of crossing an ocean by a series of shorter journeys between islands, as opposed to a single journey directly across the ocean to the destination.- Forms :...
) from mainland South America along the Lesser Antilles all the way to Barbuda. Even when sea levels dropped during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, the animal would still have been required to overcome seven water barriers, a series of voyages "no less wondrous than those of Sindbad." Instead, he argued that the animal reached the islands directly on a raft from mainland South America, probably from one of the continent's large rivers.
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 the 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.