| 翻訳と辞書 |
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 790–520 BCE to 900–1200 CE. No live specimens are known, but there are several historical records of rodents from Saint Kitts and Nevis that could conceivably refer to ''Pennatomys''. The animal apparently belongs to a group within the tribe Oryzomyini that includes many other island-dwelling species.
''Pennatomys nivalis'' was a medium-sized species without many distinctive adaptations. The nasal bones were short and blunt-ended. The zygomatic plate, a bony plate at the side of the skull, was broad. The bony palate was long and flat. The root of the lower incisor was housed in a bony protuberance, the capsular process. The molars were low-crowned and possess accessory crests such as mesolophs. The upper molars all had three roots.
==Taxonomy==
Oryzomyini, also known as rice rats, is a diverse grouping of North, Central, and South American rodents within the family Cricetidae. Remains of extinct rice rats are known throughout the Lesser Antilles, but the systematic relationships among those animals are poorly understood, and many species remain unnamed.〔Turvey et al., 2010, pp. 748–500〕 Rice rat fossils were first recorded from Saint Kitts in 1907 by archeologist C.W. Branch〔Branch, 1907, p. 332〕 and were later found in abundance in Amerindian archeological sites on nearby Nevis and Sint Eustatius.〔Turvey et al., 2010, p. 750〕 The rice rat of these islands was formally described and named as ''Pennatomys nivalis'' in a 2010 article by zoologist Samuel Turvey and coworkers. The generic name, ''Pennatomys'', combines the Latin ''pennatus'' "winged" with ''-mys'' "mouse", a standard element in the names of rodent genera, and honors archeologist Elizabeth Wing.〔Turvey et al., 2010, p. 758〕 The specific name, ''nivalis'', is Latin for "snowy" and refers to Nevis. This island's name derives from the Spanish ''Nuestra Señora de las Nieves'' "Our Lady of the Snows", a reference to the clouds (mistaken for snow) that surround the island's central peak.〔Turvey et al., 2010, p. 761〕
Cladistic analysis of morphological characters suggest that ''Pennatomys'' is most closely related to a clade, the ''Nectomys'' subclade, that includes members of ''Aegialomys'', ''Amphinectomys'', ''Nectomys'', ''Sigmodontomys'', ''Melanomys'', ''Megalomys'' (another Antillean rice rat), and possibly ''Nesoryzomys''. However, the exact position of ''Pennatomys'' was poorly resolved because of missing data.〔Turvey et al., 2010, p. 765〕 Turvey and colleagues placed ''P. nivalis'' as the only member of its own genus because of its distinctive characters and the absence of evidence for close relationships with any other oryzomyine genus.〔Turvey et al., 2010, p. 763〕 ''Pennatomys'' probably belongs to a subgroup of Oryzomyini known as "clade D". This clade contains a number of species only occurring on islands—including members of ''Aegialomys'', ''Megalomys'', ''Nesoryzomys'', ''Noronhomys'', ''Oryzomys'', and ''Pennatomys''. Turvey and colleagues suggested that this is related to the high proportion of semiaquatic species in clade D—most other oryzomyines are forest dwellers.〔Turvey et al., 2010, p. 766〕 As a whole, Oryzomyini includes over a hundred species in about thirty genera.〔Weksler, 2006, pp. 1, 10; Weksler et al., 2006, p. 1, table 1〕 It 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.〔Musser and Carleton, 2005, ''passim''〕 However DNA analysis demonstrated a sister-taxa relationship with ''Megalomys'' as an endemic Lesser Antillean radiation within clade D, and also showed that the different island populations showed a high degree of genetic differentiation from each other.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Pennatomys」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|