The history of Ctenomys in the fossil record: a young radiation of an ancient family

VERZI, D.H.; DE SANTI, N.A.; OLIVARES, A.I.; MORGAN, C.C.; ALVAREZ, A.

Tuco-tucos. An evolutionary approach to the diversity of a Neotropical rodent

SPRINGER NATURE

Año: 2021; p. 3 - 15

Like the other families of South American hystricomorph rodents (Upham andPatterson 2015; Álvarez et al. 2017), Ctenomyidae has a deep evolutionary history,which is evidenced in the fossil record of this family since the late Oligocene. Theseearliest fossils, closer to the origin of the clade, and the first (middle Pleistocene)members of the crown clade are the ones that contribute relevant temporal information for the calibrations of molecular phylogenies. The temporally extended stemgroup evidences strong extinction, and includes even middle Pleistocene species ofthe only surviving genus, Ctenomys. The history of the strikingly diverse crownclade which includes at least 69 extant species (Freitas 2016) as well as a few extinctspecies is, on the contrary, surprisingly short. Although this could be influenced bybiases inherent to the fossil record, it is nevertheless significant that most Pleistocenespecies included in the analyses are recovered as members of the stem group. Thisentails a new perspective regarding the timing of taxonomic, ecological, and morphofunctional diversification of extant Ctenomys, which should be taken intoaccount in future evolutionary analyses of the genus.