Middle ear morphology in dormice (Rodentia: Gliridae)

Abstract

Dormouse middle ears have been examined from the points of view of comparative anatomy (Doran 1878; Bondy 1907; Hinchcliffe and Pye 1969), function in relation to ecology (Simkin 1965), and phylogenetic systematics (e.g. Ognev 1947; Lavocat and Parent 1971; Parent 1980, 1983; Wahlert et al. 1993; Potapova 2001), in most cases being considered only as small parts of much wider studies. Perhaps surprisingly, the anatomical descriptions of the ear region of dormice have not been entirely congruent. One group has stated that the stapedius muscle is missing in Glis glis (Hinchcliffe and Pye 1969; Pye and Hinchcliffe 1976), whereas another group described this muscle in dormice (Lavocat and Parent 1971; Parent 1976, 1980). While Hinchcliffe and Pye (1969) referred to ‘‘slight trabeculation’’ in the tympanic cavity of Glis, Simkin (1965) and Potapova (2001) described a chambered middle ear cavity. The conducting apparatus of dormice has been largely ignored, although there are brief descriptions of the ossicles in Doran (1878) and Ognev (1947). Rodent phylogeny is in a state of flux (Huchon et al. 2002), the clades and the names given to them often differing by study. The term ‘‘myomorph’’ is used here informally to denote the clade to which the Muridae belongs, which probably also contains the Spalacidae (considered to be a separate family by Norris et al. 2004), Dipodidae, Geomyidae and Heteromyidae. The