A Late Miocene Dolichotinae (Mammalia, Rodentia, Caviidae) from Uruguay, with comments about the relationships of some related fossil species
Titel:
A Late Miocene Dolichotinae (Mammalia, Rodentia, Caviidae) from Uruguay, with comments about the relationships of some related fossil species
Auteur:
Andrés Rinderknecht Martín Ubilla
Verschenen in:
Mastozoología neotropical
Paginering:
Jaargang 10 (2003) nr. 002 pagina's 293-302
Jaar:
2003
Inhoud:
The oldest dolichotine from Uruguay (late Miocene deposits of southwestern) is described and here assigned to the genus “ Prodolichotis” Kraglievich, 1932. It is intermediate in size between Pediolagus salinicola (Burmeister, 1876) and Dolichotis patagonum (Zimmermann, 1780) and similar to “ Prodolichotis” lacunosa (Ameghino, 1888). The material consists in an incomplete skull which has a diastema longer than P4-M3 length, the nasolacrimal foramen absent in lateral view, the anterior border of mesopterygoid fossa positioned between the anterior and posterior prisms of M2 and the internal posterior fold of M3 has diverging borders forming an angle less than 90º. This M3 morphology shared with the Dolichotinae-Caviinae clade suggests that parallel borders are a derived feature in some Dolichotinae and the condition observed in the Caviinae is a primitive state. Judging by the morphological pattern presented by “ Prodolichotis” pridiana Fields (1957)–nasolacrimal foramen in the maxilla, interorbital width less than the braincase width, and diverging M3 fold– we agree with previous opinions that this species should be included in the Caviinae instead of Dolichotinae. It is discussed a close relationship between Orthomyctera Ameghino, 1889 and Caviinae judging by their similar morphological pattern including interorbital width less than the braincase width, molar series with similar length or longer than the diastema length, nasolacrimal foramen exposed laterally in the maxilla, and similar configuration of the M3 and skull size and overall shape. The occurrence of a dolichotine in the late Miocene of southwestern Uruguay suggests open and probably arid or semiarid terrestrial environments.
Uitgever:
Sociedad Argentina para el Estudio de los Mamíferos (provided by DOAJ)
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