Roedores sigmodontinos (Mammalia: Rodentia: Cricetidae) y otros micromamíferos como indicadores de ambientes hacia el Ensenadense cuspidal en el sudeste de la provincia de Buenos Aires (Argentina)

PARDIÑAS, U.F.J.

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2004 p. 437 - 450

0002-7014

Abstract. SIGMODONTINE RODENTS (MAMMALIA: RODENTIA: CRICETIDAE) AND OTHER MICROMAMMALS AS PALEOENVIRONMENTAL INDICATORS DURING UPPERMOST ENSENADAN IN SOUTHEASTERN BUENOS AIRES PROVINCE (ARGENTINA). A rich micromammal assemblage from Middle -Upper Pleistocene deposits in a coastal cliff locality here named Complejo Ferroviario (37º 48’ 57” S, 57º 28’ 32” W, Mar Chiquita county, Buenos Aires Province) is described. Magnetostratigraphical data from a profile near the fossiliferous locality indicate that the studied assemblage is younger than the Brunhes-Matuyama boundary (0.78 Ma). The sample is largely dominated by sigmodontine rodents (Sigmodontinae: Cricetidae), including Akodon sp., CalomysSIGMODONTINE RODENTS (MAMMALIA: RODENTIA: CRICETIDAE) AND OTHER MICROMAMMALS AS PALEOENVIRONMENTAL INDICATORS DURING UPPERMOST ENSENADAN IN SOUTHEASTERN BUENOS AIRES PROVINCE (ARGENTINA). A rich micromammal assemblage from Middle -Upper Pleistocene deposits in a coastal cliff locality here named Complejo Ferroviario (37º 48’ 57” S, 57º 28’ 32” W, Mar Chiquita county, Buenos Aires Province) is described. Magnetostratigraphical data from a profile near the fossiliferous locality indicate that the studied assemblage is younger than the Brunhes-Matuyama boundary (0.78 Ma). The sample is largely dominated by sigmodontine rodents (Sigmodontinae: Cricetidae), including Akodon sp., CalomysENSENADAN IN SOUTHEASTERN BUENOS AIRES PROVINCE (ARGENTINA). A rich micromammal assemblage from Middle -Upper Pleistocene deposits in a coastal cliff locality here named Complejo Ferroviario (37º 48’ 57” S, 57º 28’ 32” W, Mar Chiquita county, Buenos Aires Province) is described. Magnetostratigraphical data from a profile near the fossiliferous locality indicate that the studied assemblage is younger than the Brunhes-Matuyama boundary (0.78 Ma). The sample is largely dominated by sigmodontine rodents (Sigmodontinae: Cricetidae), including Akodon sp., CalomysAkodon sp., Calomys cf. C. laucha-C. musculinus, Holochilus cf. H. brasiliensis (Desmarest), and Reithrodon auritus (Fischer). Few remains of caviomorph rodents (Ctenomys sp., Clyomys sp., Dolichotis sp., Galea sp., and Microcavia sp.) and marmosine marsupials (Lestodelphys sp.) are also present. The remains are mainly found in discrete subelliptical structures attributable to fossil owl pellets. Several evidences suggest that the recorded taxa were preyed in a single event and inhabited at the same location during the assemblage formation. All taxa, except two (Clyomys sp. and Lestodelphys sp.), are currently sympatric in an area of about five degrees west of the fossiliferous locality. The estimated annual mean precipitation for deposition times is 200 mm lower than present one. The “disharmonic” presence of Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.C. laucha-C. musculinus, Holochilus cf. H. brasiliensis (Desmarest), and Reithrodon auritus (Fischer). Few remains of caviomorph rodents (Ctenomys sp., Clyomys sp., Dolichotis sp., Galea sp., and Microcavia sp.) and marmosine marsupials (Lestodelphys sp.) are also present. The remains are mainly found in discrete subelliptical structures attributable to fossil owl pellets. Several evidences suggest that the recorded taxa were preyed in a single event and inhabited at the same location during the assemblage formation. All taxa, except two (Clyomys sp. and Lestodelphys sp.), are currently sympatric in an area of about five degrees west of the fossiliferous locality. The estimated annual mean precipitation for deposition times is 200 mm lower than present one. The “disharmonic” presence of Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.Ctenomys sp., Clyomys sp., Dolichotis sp., Galea sp., and Microcavia sp.) and marmosine marsupials (Lestodelphys sp.) are also present. The remains are mainly found in discrete subelliptical structures attributable to fossil owl pellets. Several evidences suggest that the recorded taxa were preyed in a single event and inhabited at the same location during the assemblage formation. All taxa, except two (Clyomys sp. and Lestodelphys sp.), are currently sympatric in an area of about five degrees west of the fossiliferous locality. The estimated annual mean precipitation for deposition times is 200 mm lower than present one. The “disharmonic” presence of Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.Lestodelphys sp.) are also present. The remains are mainly found in discrete subelliptical structures attributable to fossil owl pellets. Several evidences suggest that the recorded taxa were preyed in a single event and inhabited at the same location during the assemblage formation. All taxa, except two (Clyomys sp. and Lestodelphys sp.), are currently sympatric in an area of about five degrees west of the fossiliferous locality. The estimated annual mean precipitation for deposition times is 200 mm lower than present one. The “disharmonic” presence of Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.Clyomys sp. and Lestodelphys sp.), are currently sympatric in an area of about five degrees west of the fossiliferous locality. The estimated annual mean precipitation for deposition times is 200 mm lower than present one. The “disharmonic” presence of Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.Clyomys, a fossorial echymyid from subtropical lowlands, is explained as a relict in a matrix of arid-semiarid taxa.