''Triaenops goodmani'' is an extinct bat from

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

in the genus ''

Triaenops ''Triaenops'' is a genus of bat in the family Rhinonycteridae. It is classified in the tribe Triaenopini, along with the closely related genus ''Paratriaenops'' and perhaps the poorly known ''Cloeotis''. The species of ''Paratriaenops'', which oc ...

''. It is known from three lower jaws collected in a cave at Anjohibe in 1996, and described as a new species in 2007. The material is at most 10,000 years old. A bat

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

(upper arm bone) from the same site could not be identified as either ''T. goodmani'' or the living '' T. menamena''. ''T. goodmani'' is identifiable as a member of ''Triaenops'' or the related genus '' Paratriaenops'' by a number of features of the teeth, such as the single-cusped, canine-like fourth

premolar The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

and the presence of a gap between the entoconid and hypoconulid cusps on the first two

molars The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, '' ...

. ''T. goodmani'' is larger than the living species of ''Triaenops'' and ''Paratriaenops'' on Madagascar, and on the first molar the

protoconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn i ...

cusp is only slightly higher than the hypoconid, not much higher as in the other species.

Taxonomy and distribution

In 1996, a team led by David Burney collected

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

s containing remains of bats and other animals from the cave of Anjohibe in northwestern Madagascar. The bats in the sample were described by Karen Samonds (previously Irwin) in her 2006 Ph.D. dissertation and a 2007 paper. She found several living species in addition to two extinct ones that she described as new, ''Triaenops goodmani'' and ''

Hipposideros besaoka ''Macronycteris besaoka'' is an extinct bat from Madagascar in the genus '' Macronycteris''. It is known from numerous jaws and teeth, which were collected in a cave at Anjohibe in 1996 and described as a new species in 2007. The site where ''H. ...

''. At the time, the genus ''

'' was thought to include three species on Madagascar–''Triaenops auritus'', ''Triaenops furculus'', and ''Triaenops rufus''.Samonds, 2007, p. 46 Since then, Steven Goodman and Julie Ranivo have discovered that the name ''rufus'' is not in fact applicable to the Madagascar species and proposed the name ''

Triaenops menamena ''Triaenops menamena'' is a bat in the genus ''Triaenops'' found on Madagascar, mainly in the drier regions. It was known as ''Triaenops rufus'' until 2009, when it was discovered that that name had been incorrectly applied to the species. ''Triae ...

'' for the Madagascan bats previously known as ''Triaenops rufus''. In addition, Petr Benda and Peter Vallo have removed the other two Madagascan species to a separate genus '' Paratriaenops'', so that they are now known as '' Paratriaenops auritus'' and '' Paratriaenops furcula''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

of the

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''goodmani'', honors Steven Goodman for his research on Madagascan bats. The material of ''T. goodmani'' is from locality OLD SE within the cave and is about 10,000 years old or younger. A

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analysis using morphological data could not resolve the relationships of ''Triaenops goodmani'', but did not place it with the other species of ''Triaenops'' and ''Paratriaenops'' studied. In a 2008 paper, Amy Russell and colleagues commented that cranial (skull) characteristics of ''T. goodmani'' suggest it is a member of the "''T. furcula/T. auritus'' group", now placed in ''Paratriaenops''.

Description

''Triaenops goodmani'' is known from three

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

s (lower jaws): one with the fourth premolar (p4) and first and second molars (m1–2) and two with the second and third molars (m2–3). The jaw is relatively robust. The p4 resembles a canine, having a single cusp that is about as high as the highest cusp on m1 and lacking accessory shelves or cusps. The molars are narrow-crowned and longer than in ''T. menamena'', ''P. auritus'', and ''P. furcula''. Length of m2 ranges from 1.55 to 1.57 mm and width from 0.98 to 1.02 mm. On m1, the

trigonid The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth ...

(front group of cusps) is narrower and slightly higher than the

talonid The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth ...

at the back. The

, one of the main cusps in the trigonid, is the highest cusp,Samonds, 2007, p. 47 but is only slightly higher than the hypoconid (a cusp in the talonid); in living Madagascan ''Triaenops'' and ''Paratriaenops'', the protoconid is substantially higher than the hypoconid. The

paraconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn i ...

metaconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn i ...

(both cusps in the trigonid), and entoconid (a cusp in the talonid) are lower than in ''Paratriaenops auritus''. The hypoconulid (part of the talonid) is small but distinct and is the lowest cusp. It is separated from the entoconid by a gap. ''T. goodmani'' lacks a ridge, the preentocristid, connecting the entoconid to the metaconid. There is a crest ( cingulum) at the front and back of the tooth. The last two molars are similar to m1, but in m2 the talonid is only slightly wider than the trigonid and in m3 the two are of equal width. In addition, a shelf is present between the protoconid and hypoconid on m2 and m3 is smaller, lacks the gap between the entoconid and hypoconulid, and has a weak ridge between the entoconid and metaconid. These characteristics are typical of ''Triaenops'' and ''Paratriaenops''.Samonds, 2007, p. 48 From the same site where ''T. goodmani'' was found, Samonds also recorded the distal (far) end of a ''Triaenops''

(upper arm bone), with a width of 3.58 mm. This bone was similar to humeri of ''T. menamena'', but she did not identify it as either species because of the small size difference between ''T. menamena'' and ''T. goodmani''.Samonds, 2007, p. 49 In site NCC-1 (estimated 69,600 to 86,800 years old),Samonds, 2007, p. 43 two ''Triaenops'' mandibles were recorded, one with p4 and m1 and another with m1–2 and part of m3.Samonds, 2007, p. 55 Relative to living ''Triaenops'' and ''Paratriaenops'', m1 in those jaws is longer and narrower. Although sample sizes are small, the measurements do not resemble those of ''T. goodmani''. In addition, the ridge between the entoconid and metaconid is stronger than in ''T. goodmani''. Samonds identified these jaws only as ''Triaenops''.Samonds, 2007, p. 57

References

Literature cited

*Benda, P. and Vallo, P. 2009. Taxonomic revision of the genus ''Triaenops'' (Chiroptera: Hipposideridae) with description of a new species from southern Arabia and definitions of a new genus and tribe. Folia Zoologica 58(Monograph 1):1–45. *Goodman, S.M. and Ranivo, J. 2009
The geographical origin of the type specimens of ''Triaenops rufus'' and ''T. humbloti'' (Chiroptera: Hipposideridae) reputed to be from Madagascar and the description of a replacement species name
(subscription required). Mammalia 73:47–55. *Russell, A.L., Goodman, S.M. and Cox, M.P. 2008
Coalescent analyses support multiple mainland-to-island dispersals in the evolution of Malagasy ''Triaenops'' bats (Chiroptera: Hipposideridae)
Journal of Biogeography 35:995–1003. *Samonds (Irwin), K.E. 2006. The origin and evolution of Malagasy bats: Implications of new Late Pleistocene fossils and cladistic analyses for reconstructing biogeographic history. Ph.D. Dissertation, Department of Anatomical Sciences, Stony Brook University, xx + 403 pp. *Samonds, K.E. 2007
Late Pleistocene bat fossils from Anjohibe Cave, northwestern Madagascar
Acta Chiropterologica 9(1):39–65. {{Good article Extinct mammals Triaenops Holocene extinctions