The species of genus Chasicotatus Scillato-Yané (Eutatini, Dasypodidae)

Abstract

Chasicotatus was originally described as a monotypic genus based on Chasicotatus ameghinoi\nScillato-Yané, 1979, from the upper member of Arroyo Chasicó Formation (Las Barrancas Member, late\nChasicoan). An additional species, Chasicotatus peiranoi, was erected by Esteban and Nasif (1996). This\nwork presents the description of two new species previously recognized but never published by Scillato-\nYané (1982), with a study and description of the osteoderm�s internal structure from three of four species\nof the genus. On this basis, the genus is revised and expanded diagnoses are provided for the previously\nknown taxa, so that the species are clearly differentiated by internal and external osteodermal features. The\ngeographical distribution of the species of genus Chasicotatus supports advanced palaeoenvironmental\nhypotheses previously proposed by different authors.