Publication Date:
2024-01-12
Description:
A new species of Theridomys, T. truci, is described. It occurs in a stratigraphic succession at Saint Martin de Castillon (Vaucluse, France) approximately at the boundary between Lower and Upper Oligocene. Its characteristics are: small size; moderate hypsodonty; thin and regular enamel borders; flat occlusal surfaces; wide and short synclines and synclinids; first syncline of the upper molars of the same size as the second; the first synclinid begins its development in the lower molars and the fourth syncline in the upper molars; the external tubercles of the upper molars are fused, forming a labial wall. The phyletic relationships of T. truci are discussed and a new hypothesis on the evolution of the T. lembronicus lineage is proposed. Une nouvelle esp\xc3\xa8ce de Theridomys, T. truci, trouv\xc3\xa9e dans plusieurs niveaux de la s\xc3\xa9rie stratigraphique de Saint-Martin-de-Castillon (Vaucluse, France), \xc3\xa0 la limite entre l\'Oligoc\xc3\xa8ne inf\xc3\xa9rieur et l\'Oligoc\xc3\xa8ne sup\xc3\xa9rieur, est d\xc3\xa9crite. Ses caract\xc3\xa8res sont: une faible taille, une hypsodontie mod\xc3\xa9r\xc3\xa9e, un \xc3\xa9mail relativement mince et r\xc3\xa9gulier sur tout le pourtour de la dent, une surface occlusale plane, des synclinaux et synclinides larges et courts. Aux molaires sup\xc3\xa9rieures, le premier synclinal est de m\xc3\xaame longueur que le second et le 4e synclinal appara\xc3\xaet; les tubercles externes fusionnent en une muraille labiale continue. Aux molaires inf\xc3\xa9rieures, le premier synclinide commence son d\xc3\xa9veloppement. Les relations phyl\xc3\xa9tiques de T. truci sont discut\xc3\xa9es et une nouvelle hypoth\xc3\xa8se concernant l\'\xc3\xa9volution de la lign\xc3\xa9e de T. lembronicus est propos\xc3\xa9e.
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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