Print version ISSN 0327-9383
ELISSAMBURU, Andrea; DONDAS, Alejandro and DE SANTIS, Luciano. Morphometry of paleocaves at the Chapadmalal "Formation" assigned to fossorial rodent Actenomys sp. (Rodentia, Caviomorpha), Paedotherium (Notoungulata), and to other fossil mammals. Mastozool. neotrop. [online]. 2011, vol.18, n.2, pp. 227-238. ISSN 0327-9383.
Paleocaves assigned to fossorial rodent Actenomys sp. (Rodentia, Caviomorpha) are present at the Chapadmalal "Formation", cropping out from Mar del Plata to Miramar. The assignation is based on the high frequency of fossil material of Actenomys sp. within the paleocaves and in the digging capacity recognized for the genera. Although it is evident that Actenomys sp. built caves and most of these correspond to the genera, it is not the only coetaneal mammal with the capacity of construction of these structures. Paleocaves of Chapadmalalan and Marplatan age were analyzed morphometrically and the generic assignation of their producers was evaluated. Paleocaves in transverse section were selected, its dorsoventral and lateromedial diameter was measured and used for calculating a structural index. The fossil material exposed in paleocaves was determined to a specific level in all possible cases. The statistical analyses performed include frequency distributions, correlations, residual analyses, and mean differences on individual measurements and on the index. Paleocaves constructed by Actenomys sp., in juvenile and adult stages, and by Paedotherium sp. are recognized. Metric difference between paleocaves of Chapadmalalan and Marplatan ages are recognized, in possible association with a different abundance of Paedotherium sp. and Actenomys sp. The presence of paleocaves of Lagostomopsis sp. is reinforced and is suggested the possible construction, or opportunistic use, of paleocaves by Eumysops sp., Dolicavia sp. and other Caviidae.
Keywords : Actenomys; Chapadmalal "Fm."; Paedotherium; Paleocaves; Paleoecology.