Agathaeromys
Encyclopedia
Agathaeromys is an extinct genus of oryzomyine
rodents from the Pleistocene
of Bonaire, West Indies. Two species are known, which differ in size and some details of tooth morphology. The larger A. donovani, the type species
, is known from hundreds of teeth, found in four localities that are probably 900,000 to 540,000 years old. A. praeuniversitatis, the smaller species, is known from 35 teeth found in a single fossil site, which is probably 540,000 to 230,000 years old.
Although material of Agathaeromys was first described in 1959, the genus was not formally named and diagnosed until 2010. It probably belongs to "clade D" within the oryzomyine group, together with many other island-dwelling species. The molars
of both species possess several accessory crests in addition to the main cusps
. In addition to some differences in features of the chewing surface of the molars, A. donovani has more roots on its lower molars than does A. praeuniversitatis.
, Megalomys curazensis
. Hooijer described a few fossil teeth and jaws from Fontein, Bonaire, as an indeterminate species of Thomasomys
("Thomasomys sp.") and considered them to be similar to species now placed in Delomys
. In his 1974 monograph on the geology of the ABC islands (Aruba
, Bonaire, and Curaçao—three Dutch
islands off northwestern Venezuela
), Paul Henri de Buisonjé listed Thomasomys sp. from additional fossil sites on Bonaire and additionally mentioned Oryzomys sp. from a different Bonaire site, Seroe Grandi. Although the Bonaire material represented one of the few fossil records of Thomasomys, it was only rarely mentioned in the literature.
In 2010, Jelle Zijlstra, Anneke Madern, and Lars van den Hoek Ostende reviewed the material. They considered it unlikely that the Bonaire "Thomasomys" would belong to the southern Brazilian genus Delomys or to Thomasomys, which occurs only in the mountains of the Andes. Using a cladistic
analysis of the Sigmodontinae
, they provided evidence that the Bonaire material belonged to the tribe Oryzomyini
, rather than Thomasomyini (which includes Thomasomys). They carried out another cladistic analysis focused on Oryzomyini, which suggested that the Bonaire "Thomasomys" and the material from Seroe Grandi (De Buisonjé's "Oryzomys sp.") were closely related, but distinct from any recognized oryzomyine genus. Therefore, they named a new oryzomyine genus, Agathaeromys, with two species: Agathaeromys donovani (type species
) for the material previously identified as Thomasomys; and Agathaeromys praeuniversitatis for the material from Seroe Grandi. The name Agathaeromys combines the Greek words "good", "air", and "mouse", referring to the name of the island of Bonaire and to the "fresh air" that contributions by Marcelo Weksler and colleagues brought to the classification of Oryzomyini. The name donovani honors Stephen Donovan for his contributions to the scientific knowledge of the Caribbean and praeuniversitatis refers to Leiden University
's Pre-University College, which provided an opportunity for Zijlstra to participate in the project that led to the identification of Agathaeromys.
Although Zijlstra and colleagues could not precisely determine the position of Agathaeromys within Oryzomyini, their results suggest that it occupies a position near the base of "clade D", one of the major subgroups of Oryzomyini. This clade contains a number of species only occurring on islands—including members of Aegialomys
, Agathaeromys, Megalomys
, Nesoryzomys
, Noronhomys, Oryzomys
, and Pennatomys
. Zijlstra and colleagues suggested that this is related to the high proportion of semiaquatic and non-forest species in clade D—most other oryzomyines are forest dwellers. As a whole, Oryzomyini includes over a hundred species in about thirty genera. Oryzomyini is one of several tribes within the subfamily Sigmodontinae of the family Cricetidae
, which encompasses hundreds of other species of mainly small rodents, distributed chiefly in Eurasia and the Americas.
teeth. As usual in muroid rodents, there are three molars on both sides of the upper jaw (referred to as M1, M2, and M3 from front to back) and lower jaw (referred to as m1, m2, and m3). Agathaeromys is generally similar to other oryzomyines, but differs from other genera in a variety of details of the molar crowns. Agathaeromys donovani (M1 length 2.03–2.84 mm) is substantially larger than A. praeuniversitatis (M1 length 1.77–1.94 mm).
at the front of M1, the anterocone, is separated into two smaller cusps by an indentation. In A. donovani, a ridge generally connects the two cusps at the front margin of the tooth, so that the indentation separating them is closed at the front (an anteromedian fossette), but in A. praeuniversitatis, it is open toward the front (an anteromedian flexus). An additional crest, the anteroloph, is present behind the anterocone. Further to the back, there is a pair of cusps—the protocone
at the lingual, or inner, side and the paracone
at the labial, or outer, side. A crest issues from the paracone and is attached to the front or middle part of the protocone. Behind the paracone, the mesoloph crest is present; an additional crest usually connects the two. At the back of the tooth, there are two additional large cusps—the hypocone
(lingual) and metacone
(labial)—and a prominent crest, the posteroloph, issues from the hypocone and is located behind the metacone. In A. donovani, the metacone is generally connected to the posteroloph, but in A. praeuniversitatis, it is directly connected to the hypocone. The valleys that separate the cusps extend from the lingual and labial margins to about the midline of the molar. In addition to a large root at the front and two large roots at the back (one labial, one lingual) there is a small additional labial root.
There is no anterocone on M2, but a large anteroloph is present in front of the paracone. There is a protoflexus—an indentation in the crown in front of the protocone. As in M1, the paracone is connected to the front or middle of the protocone, the mesoloph is well-developed, and the valleys meet at the midline of the tooth. There are three roots: two at the labial and one at the lingual side.
M3 is a small, triangular tooth. There is large basin in the middle, and a mesoloph is present. At the back of the tooth, there is a distinct posteroloph. In A. donovani, there are two roots at the front (labial and lingual) and one at the back. There are no M3 of A. praeuniversitatis with preserved roots.
There is no anteroconid in m2 and the tooth lacks an additional crest (the anterolophid) in front of the metaconid, but there is an anterolabial cingulum in front of the protoconid. There is a mesolophid. In addition to a large root at the back, there are two roots at the front in A. donovani, which are sometimes partially fused, but only one in A. praeuniversitatis.
The anterolabial cingulum and anteroconid are both absent on m3. The mesolophid is usually absent. As in m2, there are two roots at the front in A. donovani and only one in A. praeuniversitatis, but the front roots are usually fused in A. donovani.
(upper jaw) is known only for A. donovani. In these fossils, the back margin of the incisive foramen
(an opening in the palate
) is about at the same level as the front of M1, and the back margin of the zygomatic plate
(a bony plate at the side of the skull, connected to the zygomatic arch
) is also close to the front of M1. Mandible
s (lower jaws) of both species are known. The mental foramen
(an opening in the front of the jaw bone) opens towards the labial side of the bone, except in one mandible of A. praeuniversitatis, in which its opening is located higher. There is a well-developed capsular process
—a raising in the bone that houses the root of the lower incisor
. The masseteric ridges (two ridges on the labial side of the bone that anchor some of the chewing muscles) are joined into a single crest towards the front and reach to a point below the front of m1.
A single mandible from Porto Spanjo (one of the sites where fossils of A. donovani have been found), without preserved molars, differs from all Agathaeromys dentaries and is thought to represent an unknown different sigmodontine rodent. This jaw is more slender than A. donovani dentaries, has a shorter diastema
(gap) between the incisors and molars, has the incisor less shifted lingually relative to the molars, and has more roots under the molars, as shown by the preserved alveoli
.
and sea level fluctuations that the material of A. praeuniversitatis is likely 540,000 to 230,000 years old and that of A. donovani is likely 900,000 to 540,000 years old. Agathaeromys probably descends from an unknown oryzomyine that migrated to the island from mainland Venezuela sometime during the Pleistocene
.
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...
rodents from 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 ....
of Bonaire, West Indies. Two species are known, which differ in size and some details of tooth morphology. The larger A. donovani, the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
, is known from hundreds of teeth, found in four localities that are probably 900,000 to 540,000 years old. A. praeuniversitatis, the smaller species, is known from 35 teeth found in a single fossil site, which is probably 540,000 to 230,000 years old.
Although material of Agathaeromys was first described in 1959, the genus was not formally named and diagnosed until 2010. It probably belongs to "clade D" within the oryzomyine group, together with many other island-dwelling species. The molars
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"....
of both species possess several accessory crests in addition to the main cusps
Cusp (dentistry)
A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...
. In addition to some differences in features of the chewing surface of the molars, A. donovani has more roots on its lower molars than does A. praeuniversitatis.
Taxonomy
Material of Agathaeromys was first described by Dirk Hooijer in 1959 in the same paper that first named the extinct giant rat of CuraçaoCuraçao
Curaçao is an island in the southern Caribbean Sea, off the Venezuelan coast. The Country of Curaçao , which includes the main island plus the small, uninhabited island of Klein Curaçao , is a constituent country of the Kingdom of the Netherlands...
, Megalomys curazensis
Megalomys curazensis
Megalomys curazensis is a species of rodent from the Pleistocene of the island of Curaçao, off northwestern Venezuela. It is a member of the genus Megalomys, which also includes species from other islands of the Lesser Antilles. It is known from abundant but fragmentary material found throughout...
. Hooijer described a few fossil teeth and jaws from Fontein, Bonaire, as an indeterminate species of Thomasomys
Thomasomys
Thomasomys is a genus of rodent in the family Cricetidae, named after British zoologist Oldfield Thomas. It contains the following species:* Anderson's Oldfield Mouse * Apeco Oldfield Mouse...
("Thomasomys sp.") and considered them to be similar to species now placed in Delomys
Delomys
Delomys is a genus of South American rodents in the tribe Thomasomyini of family Cricetidae. Three species are known, all found in Argentina and Brazil. They are as follows:* Montane Atlantic Forest Rat...
. In his 1974 monograph on the geology of the ABC islands (Aruba
Aruba
Aruba is a 33 km-long island of the Lesser Antilles in the southern Caribbean Sea, located 27 km north of the coast of Venezuela and 130 km east of Guajira Peninsula...
, Bonaire, and Curaçao—three Dutch
Kingdom of the Netherlands
The Kingdom of the Netherlands is a sovereign state and constitutional monarchy with territory in Western Europe and in the Caribbean. The four parts of the Kingdom—Aruba, Curaçao, the Netherlands, and Sint Maarten—are referred to as "countries", and participate on a basis of equality...
islands off northwestern Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
), Paul Henri de Buisonjé listed Thomasomys sp. from additional fossil sites on Bonaire and additionally mentioned Oryzomys sp. from a different Bonaire site, Seroe Grandi. Although the Bonaire material represented one of the few fossil records of Thomasomys, it was only rarely mentioned in the literature.
In 2010, Jelle Zijlstra, Anneke Madern, and Lars van den Hoek Ostende reviewed the material. They considered it unlikely that the Bonaire "Thomasomys" would belong to the southern Brazilian genus Delomys or to Thomasomys, which occurs only in the mountains of the Andes. Using a cladistic
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
analysis of the Sigmodontinae
Sigmodontinae
The subfamily Sigmodontinae is one of the most diverse groups of mammals. It includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count...
, they provided evidence that the Bonaire material belonged to the tribe Oryzomyini
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...
, rather than Thomasomyini (which includes Thomasomys). They carried out another cladistic analysis focused on Oryzomyini, which suggested that the Bonaire "Thomasomys" and the material from Seroe Grandi (De Buisonjé's "Oryzomys sp.") were closely related, but distinct from any recognized oryzomyine genus. Therefore, they named a new oryzomyine genus, Agathaeromys, with two species: Agathaeromys donovani (type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
) for the material previously identified as Thomasomys; and Agathaeromys praeuniversitatis for the material from Seroe Grandi. The name Agathaeromys combines the Greek words "good", "air", and "mouse", referring to the name of the island of Bonaire and to the "fresh air" that contributions by Marcelo Weksler and colleagues brought to the classification of Oryzomyini. The name donovani honors Stephen Donovan for his contributions to the scientific knowledge of the Caribbean and praeuniversitatis refers to Leiden University
Leiden University
Leiden University , located in the city of Leiden, is the oldest university in the Netherlands. The university was founded in 1575 by William, Prince of Orange, leader of the Dutch Revolt in the Eighty Years' War. The royal Dutch House of Orange-Nassau and Leiden University still have a close...
's Pre-University College, which provided an opportunity for Zijlstra to participate in the project that led to the identification of Agathaeromys.
Although Zijlstra and colleagues could not precisely determine the position of Agathaeromys within Oryzomyini, their results suggest that it occupies a position near the base of "clade D", one of the major subgroups of Oryzomyini. This clade contains a number of species only occurring on islands—including members of Aegialomys
Aegialomys
Aegialomys is a genus of oryzomyine rodents from the lowlands and mountains of western Peru and Ecuador, including the Galápagos Islands. The species in this genus have historically been placed in Oryzomys, but according to cladistic research, the genus is more closely related to a group...
, Agathaeromys, 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...
, Nesoryzomys
Nesoryzomys
Nesoryzomys is a genus of rodent in the tribe Oryzomyini of family Cricetidae, endemic to the Galápagos Islands. Other rodents restricted to the Galápagos include Megaoryzomys curioi and Aegialomys galapagoensis.-References:...
, Noronhomys, 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...
, and Pennatomys
Pennatomys
Pennatomys nivalis is an extinct oryzomyine rodent from the islands of Sint Eustatius, Saint Kitts, and Nevis in the Lesser Antilles. The only species in the genus Pennatomys, it is known from skeletal remains found in Amerindian archeological sites on all three islands, with dates ranging from...
. Zijlstra and colleagues suggested that this is related to the high proportion of semiaquatic and non-forest species in clade D—most other oryzomyines are forest dwellers. As a whole, Oryzomyini includes over a hundred species in about thirty genera. Oryzomyini is one of several tribes within the subfamily Sigmodontinae of the family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
, which encompasses hundreds of other species of mainly small rodents, distributed chiefly in Eurasia and the Americas.
Description
Agathaeromys is characterized mainly on the basis of features of the molarMolar (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"....
teeth. As usual in muroid rodents, there are three molars on both sides of the upper jaw (referred to as M1, M2, and M3 from front to back) and lower jaw (referred to as m1, m2, and m3). Agathaeromys is generally similar to other oryzomyines, but differs from other genera in a variety of details of the molar crowns. Agathaeromys donovani (M1 length 2.03–2.84 mm) is substantially larger than A. praeuniversitatis (M1 length 1.77–1.94 mm).
Upper dentition
The cuspCusp (dentistry)
A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...
at the front of M1, the anterocone, is separated into two smaller cusps by an indentation. In A. donovani, a ridge generally connects the two cusps at the front margin of the tooth, so that the indentation separating them is closed at the front (an anteromedian fossette), but in A. praeuniversitatis, it is open toward the front (an anteromedian flexus). An additional crest, the anteroloph, is present behind the anterocone. Further to the back, there is a pair of cusps—the protocone
Protocone
thumb|500px|right|Right upper molar showing the four main upper molars cusps.The protocone is a cusp of the molars of the upper dentition in Placental and Marsupial vertebrates .It is found at the mesiolingual area of the tooth...
at the lingual, or inner, side and the paracone
Paracone
An atmospheric reentry or spaceflight mission abort concept using an inflatable cone.A notable feature of the paracone concept is that it facilitates an abort throughout the entire flight profile....
at the labial, or outer, side. A crest issues from the paracone and is attached to the front or middle part of the protocone. Behind the paracone, the mesoloph crest is present; an additional crest usually connects the two. At the back of the tooth, there are two additional large cusps—the hypocone
Hypocone
The hypocone is the name for a main cusp found on the molars of the upper dentition of hominids. It is found on the distal lingual side of the tooth. It fits into the grooves of the lower dentition and is an adaptation for the overall grinding and tearing of foods using the occlusal of the tooth...
(lingual) and metacone
Metacone
thumb|500px|left|Right upper molar showing the four main upper molars cusps.The metacone is a cusp on the molars of the upper dentition in hominids. It is found at the buccal distal area of the tooth...
(labial)—and a prominent crest, the posteroloph, issues from the hypocone and is located behind the metacone. In A. donovani, the metacone is generally connected to the posteroloph, but in A. praeuniversitatis, it is directly connected to the hypocone. The valleys that separate the cusps extend from the lingual and labial margins to about the midline of the molar. In addition to a large root at the front and two large roots at the back (one labial, one lingual) there is a small additional labial root.
There is no anterocone on M2, but a large anteroloph is present in front of the paracone. There is a protoflexus—an indentation in the crown in front of the protocone. As in M1, the paracone is connected to the front or middle of the protocone, the mesoloph is well-developed, and the valleys meet at the midline of the tooth. There are three roots: two at the labial and one at the lingual side.
M3 is a small, triangular tooth. There is large basin in the middle, and a mesoloph is present. At the back of the tooth, there is a distinct posteroloph. In A. donovani, there are two roots at the front (labial and lingual) and one at the back. There are no M3 of A. praeuniversitatis with preserved roots.
Lower dentition
The anteroconid—the cusp at the front of m1—is usually divided in two by a central indentation (the anteromedian fossettid) in A. donovani, but this fossettid is absent in A. praeuniversitatis. Behind the anteroconid is the protoconid—metaconid pair of cusps. There is an anterolabial cingulum—a crest at the front labial margin, in front of the protoconid. There is a long crest behind the metaconid, a mesolophid. There is usually no corresponding crest (an ectolophid) behind the protoconid. Another pair of cusps—the hypoconid and the entoconid—is located at the back of the tooth. The entoconid, the lingual cusp of the two, is oriented forwards. There is always a large root at the front of the tooth and another at the back. A. donovani usually has a small labial root between the two large roots and often also another small root at the lingual side, but only one of four A. praeuniversitatis m1s even has the labial rootlet.There is no anteroconid in m2 and the tooth lacks an additional crest (the anterolophid) in front of the metaconid, but there is an anterolabial cingulum in front of the protoconid. There is a mesolophid. In addition to a large root at the back, there are two roots at the front in A. donovani, which are sometimes partially fused, but only one in A. praeuniversitatis.
The anterolabial cingulum and anteroconid are both absent on m3. The mesolophid is usually absent. As in m2, there are two roots at the front in A. donovani and only one in A. praeuniversitatis, but the front roots are usually fused in A. donovani.
Jaws
The maxillaMaxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
(upper jaw) is known only for A. donovani. In these fossils, the back margin of the incisive foramen
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:...
(an opening 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...
) is about at the same level as the front of M1, and the back margin of the zygomatic plate
Zygomatic plate
In rodent anatomy, the zygomatic plate is a bony plate derived from the flattened front part of the zygomatic arch . At the back, it connects to the front root of the zygomatic arch, and at the top it is connected to the rest of the skull via the antorbital bridge. It is part of the maxillary...
(a bony plate at the side of the skull, connected to 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...
) is also close to the front of M1. Mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
s (lower jaws) of both species are known. The mental foramen
Mental foramen
The mental foramen is one of two holes located on the anterior surface of the mandible. It permits passage of the mental nerve and vessels. The mental foramen descends slightly in edentulous individuals.- Variations :...
(an opening in the front of the jaw bone) opens towards the labial side of the bone, except in one mandible of A. praeuniversitatis, in which its opening is located higher. There is a well-developed capsular process
Capsular process
In rodents, the capsular process or projection is a bony capsule that contains the root of the lower incisor. It is visible on the labial side of the mandible as a raising in the bone...
—a raising in the bone that houses the root of the lower incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
. The masseteric ridges (two ridges on the labial side of the bone that anchor some of the chewing muscles) are joined into a single crest towards the front and reach to a point below the front of m1.
A single mandible from Porto Spanjo (one of the sites where fossils of A. donovani have been found), without preserved molars, differs from all Agathaeromys dentaries and is thought to represent an unknown different sigmodontine rodent. This jaw is more slender than A. donovani dentaries, has a shorter 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:...
(gap) between the incisors and molars, has the incisor less shifted lingually relative to the molars, and has more roots under the molars, as shown by the preserved alveoli
Dental alveolus
Dental alveolus are sockets in the jaws in which the roots of teeth are held in the alveolar process of maxilla with the periodontal ligament. The lay term for dental alveoli is tooth sockets...
.
Age and range
Agathaeromys donovani is known from four fossil sites—Fontein, Porto Spanjo, Barcadera-Karpata, and "80 m above sea level"—that have yielded 259, 148, 54, and 5 molars, respectively. Agathaeromys praeuniversitatis is known from 35 molars from a single site (Seroe Grandi). Although the deposits have not been precisely dated, Zijlstra and colleagues suggested on the basis of correlations with similar deposits on nearby CuraçaoCuraçao
Curaçao is an island in the southern Caribbean Sea, off the Venezuelan coast. The Country of Curaçao , which includes the main island plus the small, uninhabited island of Klein Curaçao , is a constituent country of the Kingdom of the Netherlands...
and sea level fluctuations that the material of A. praeuniversitatis is likely 540,000 to 230,000 years old and that of A. donovani is likely 900,000 to 540,000 years old. Agathaeromys probably descends from an unknown oryzomyine that migrated to the island from mainland Venezuela sometime 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 ....
.
Literature cited
- De Buisonjé, P.H. 1974. Neogene and Quaternary geology of Aruba, Curaçao and Bonaire. Uitgaven Natuurwetenschappelijke Studiekring voor Suriname en de Nederlandse Antillen 78:1–291.
- Hooijer, D.A. 1959. Fossil rodents from Curaçao and Bonaire. Studies on the Fauna of Curaçao and Other Caribbean Islands 9(35):1–27.
- Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. Pp. 894–1531 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
- Turvey, S.T., Weksler, M., Morris, E.L., and Nokkert, M. 2010. Taxonomy, phylogeny, and diversity of the extinct Lesser Antillean rice rats (Sigmodontinae: Oryzomyini), with description of a new genus and species (subscription required). Zoological Journal of the Linnean Society 160:748–772.
- Weksler, M. 2006. Phylogenetic relationships of oryzomyine rodents (Muroidea: Sigmodontinae): separate and combined analyses of morphological and molecular data. Bulletin of the American Museum of Natural History 296:1–149.
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