The epitensoric chorda tympani of Laonastes aenigmamus (Rodentia, Diatomyidae) and its phylogenetic implications

Abstract

a b s t r a c tEarlier studies have shown that the epitensoric position of the chorda tympani is a systematically useful apomorphic character in some mammalian orders (primates, carnivores, rodents). Newly made histological serial sections of a fetal stage now reveal that Laonastes aenigmamus (Diatomyidae), a rodent species first described in 2005, is epitensoric as well. Because Ctenodactylus gundi is the only other taxon within the Ctenohystrica having this derived character state, we conclude that this is an additional synapomorphy substantiating a sister group relationship between Diatomyidae and Ctenodactylidae.

Vergleichende Entwicklungsgeschichte — A Festschrift on the occasion of the 80th birthday of Prof. Dr. Wolfgang Maier, Tübingen

“…It is, together with the fissura petrotympanica (Glaser'sche Spalte), an apomorphy of Anthropoidea (Maier 2008). The epitensoric chorda tympani is also a synapomorphy of Herpestidae (Ruf and Maier 2010), some monophyletic subgroups of Rodentia (Ruf et al 2009, Tröscher et al 2015, and is also present in Equidae (Maier and Ruf 2011). Related to these discoveries, Maier found an entotympanicum in Equus (Maier et al 2013) and in Artiodactyla (Maier 2013b).…”