A more parsimonious vision about the recently new species of armadillo dasypodids Eutatus crispianii Brambilla and Ibarra, 2017 from the Late Pleistocene of Northern Pampa

BRUNETTO, ERNESTO; LUNA, CARLOS ALBERTO; VEZZOSI, RAÚL

Corrientes

Congreso; XXVII Jornadas Argentinas de Paleontología de Vertebrados; 2018

Centro de Ecología Aplicada del Litoral (CONICET-UNNE)

In a recent publication the potentially new species of armadillo Eutatini have been reported from the Lujanian Stage/Age of Northern Pampean Region, only on the basis of the description of fixed osteoderms supposedly attributed to the pelvic buckler. However, several observations prevent us from accepting the validity of these assumptions. Here we discuss the chronology, stratigraphical provenance and the assignment of the fossil record MG-G-Pv 020 (ex MGPV-E1) to a new Eutatini species. The fossiliferous bearing contains a mixture of Quaternary faunal elements that recently have been assigned by OSL dating to Middle Pleistocene (MIS7?MIS6) from Santa Fe. Clearly these deposits not correspond with the local chronostratigraphic/geochronology Lujanian Stage/Age and neither with the Saladillo Formation. The lack of a geochronological context in the study and the absence of a local knowledge about the stratigraphic succession inhibit its correlation with other palaeontological comparable sites and a robust inference about its chrononolgy to Late Pleistocene. The MG-G-Pv 020, a specimen that preserved only osteoderms from the buckler shows several morphological and microstructural characters (e.g. external surface foramina, development of piliferous foramina, glandular cavities and ducts, among others) that are included within the range of variability of Eutatus seguiniBrambilla and Ibarra, 2017. Meanwhile, others characters previously cited as diagnoses among the species for the genus are reviewed. The discussed caveats regarding of the chronology and taxonomy on a supposed new Eutatini species indicate that detailed stratigrapical and anatomical studies are needed before the statistical and morphometric hypotheses advanced can be accepted.