PROLAGOSTOMUS AMPLUS AMEGHINO, 1894 IS A JUNIOR SYNOMYM OF THE PATAGONIAN RODENT PLIOLAGOSTOMUS NOTATUS AMEGHINO, 1887 (CHINCHILLIDAE; EARLY MIOCENE, SANTA CRUZ FORMATION)
Keywords:Caviomorpha, anatomy, systematics
AbstractChinchillidae is a group of caviomorph rodents that includes the extant Chinchilla, Lagidium and Lagostomus. The latter genus, with a single living species (Lagostomus maximus), is grouped in the subfamily Lagostominae together with the extinct Eoviscaccia (Early Oligocene-Early Miocene), Prolagostomus (Early-Middle Miocene) and Pliolagostomus (Early-Middle Miocene). The Lagostominae are represented in the Santa Cruz Formation (late Early Miocene of Santa Cruz Province, Argentina) by Pliolagostomus notatus and eight species of Prolagostomus. One of these species of Prolagostomus, “Prolagostomus amplus”, was originally characterized by having all lower cheek teeth of the same size. The holotype and referred material of “Prolagostomus amplus” do not show some of the characters commonly used to distinguish Prolagostomus from other lagostomines (e.g. molars with sinuous hypoflexus/hypoflexid, anterior and lingual face of the lower molars not forming a marked angle, laminar third lobe of the M3 posteriorly or posterolingually oriented), instead, they share with Pliolagostomus notatus the presence of straight hipoflexus/hipoflexid in all cheek teeth, anterior and lingual face of the lower molars forming a marked angle, third lobe of the M3 subtriangular and lingually oriented, mental foramen dorsolaterally located. Therefore, we consider that “Prolagostomus amplus” is a synonym of Pliolagostomus notatus.
How to Cite
Authors publishing in Ameghiniana have the option of making their article freely available online. Authors opting for the Open Access must pay a fee of $300 (US dollars) to cover article-processing costs and to ensure the article is made open access. Please contact the Production Team after the acceptance of your manuscript if you are interested in making your article Open Access. This option implies by default a license Creative Commons Attribution Non-Commercial-NoDerivs License (CC BY NC ND). If your funding institution requires a different licensing option please communicate this to the Production Team after the acceptance of your manusctipt.