A new genus of oryzomyine rodent (Cricetidae: Sigmodontinae) from the Pleistocene of Argentina

PARDIÑAS, U.F.J.

JOURNAL OF MAMMALOGY

Año: 2008 vol. 89 p. 1270 - 1278

0022-2372

Based on a right maxillary with 1st molar recovered in Pleistocene (Ensenadan) deposits 20 from south-central Buenos Aires province, Argentina, a new genus and species of 21 Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of 22 the largest known extinct or extant sigmodontines, morphologically related to the marsh 23 rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 20 from south-central Buenos Aires province, Argentina, a new genus and species of 21 Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of 22 the largest known extinct or extant sigmodontines, morphologically related to the marsh 23 rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 20 from south-central Buenos Aires province, Argentina, a new genus and species of 21 Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of 22 the largest known extinct or extant sigmodontines, morphologically related to the marsh 23 rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 20 from south-central Buenos Aires province, Argentina, a new genus and species of 21 Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of 22 the largest known extinct or extant sigmodontines, morphologically related to the marsh 23 rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). st molar recovered in Pleistocene (Ensenadan) deposits 20 from south-central Buenos Aires province, Argentina, a new genus and species of 21 Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of 22 the largest known extinct or extant sigmodontines, morphologically related to the marsh 23 rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these 24 taxa by the combination of several traits in the 1st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus). st upper molar, in particular a well25 developed mesoloph and the free connection of both para- and protoflexus. The 26 occurrence of this sigmodontine suggests warmer and probably moister conditions 27 during deposition times, a hypothesis reinforced by other vertebrates exhumed together 28 (e.g., turtles, coypus, the giant armadillo †Propraopus).Propraopus).