|
In anatomy, posterolateral palatal pits are gaps at the sides of the back of the bony palate, near the last molars.〔Weksler, 2006, p. 34〕 Posterolateral palatal pits are present, in various degrees of development, in several members of the rodent family Cricetidae. Many members of the family lack them or have only simple pits, but Arvicolinae (voles, lemmings, and relatives) and Oryzomyini (rice rats and relatives) have more highly developed posterolateral palatal pits.〔Carleton, 1980, table 7〕 Posterolateral palatal pits are also present in some other rodents, including ''Glis'', ''Jaculus'', ''Hystrix'', ''Abrocoma'', ''Ctenomys'', ''Chinchilla'', and ''Lagidium''.〔Jenkins et al., 2005, appendix 3〕 == Sigmodontinae == Many members of the mainly South American cricetid subfamily Sigmodontinae have posterolateral palatal pits. In Oryzomyini (rice rats), the largest tribe of the Sigmodontinae, all but some species—''Mindomys hammondi'' and ''Sigmodontomys aphrastus'' usually have only one small pit on each side of the palate—have prominent posterolateral palatal pits, often more than one on each side of the palate. In many oryzomyines, the pits are located in a deep depression or fossa.〔Weksler, 2006, p. 34; Weksler et al., 2006, p. 17〕 This depression has been termed the "palatal fossa" in the genus ''Cerradomys''; its varying depth serves as a diagnostic character separating some of the species.〔Percequillo et al., 2008, table 1〕 The presence of complex posterolateral palatal pits is a synapomorphy either of Oryzomyini〔Voss and Carleton, 1993, p. 31〕 or of Oryzomyini minus ''Mindomys''.〔Weksler, 2006, p. 124〕 Members of the genus ''Nephelomys'' usually have complex posterolateral palatal pits, recessed into deep fossae, but ''N. caracolus'' and ''N. nimbosus'' have simpler pits.〔Weksler et al., 2006, p. 19〕 One of the putative subdivisions within Oryzomyini, Clade D, has posterolateral palatal pits recessed into a fossa as one of its synapomorphies,〔Weksler, 2006, pp. 130, 138〕 although the feature is reversed in several subgroups.〔Weksler, 2006, pp. 131, 134〕 The extinct island endemic ''Noronhomys vespuccii'' also had smaller pits, perhaps because of its short palate.〔Carleton and Olson, 1999, p. 37〕 Among members of the tribe Thomasomyini, posterolateral palatal pits are small or absent.〔Voss et al., 2001, p. 129〕 ''Aepeomys'' lacks them,〔Voss et al., 2002, p. 12〕 but ''Rhagomys longilingua'' does have posterolateral palatal pits.〔Luna and Patterson, 2003, p. 9〕 The possible thomasomyine ''Abrawayaomys chebezi'' has small posterolateral palatal pits.〔Pardiñas et al., 2009, p. 45〕 Members of the Phyllotini tribe always have posterolateral palatal pits.〔Hershkovitz, 1962, p. 23; Steppan, 1995, p. 38〕 In some species, they are displaced to the back from their usual position just before the mesopterygoid fossa into the fossa.〔Steppan, 1995, pp. 38–39〕 The condition of the pits has been used to separate species of ''Phyllotis''.〔Hershkovitz, 1962, p. 348〕 The tribe Ichthyomyini is characterized by inconspicuous posterolateral palatal pits.〔Voss, 1988, pp. 291, 320〕 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「Posterolateral palatal pits」の詳細全文を読む スポンサード リンク
|