Caudal tubes taphonomy of the Neogene genus Eleutherocercus (Cingulata, Glyptodontidae) and its taxonomic implications

NUÑÉZ-BLASCO, ALIZIA; TOMASSINI, RODRIGO; MARIN-MONFORT, MARÍA DOLORES; MIÑO-BOILINI, ANGEL; BONINI, RICARDO; ZURITA, ALFREDO

Madrid

Congreso; Eleutherocercus is a glyptodont Doedicurinae genus with records in the Late Miocene-Late Pliocene of southern South America. It includes six species, most of them recognized on the basis of morphological characteristics of the dorsal carapace and caudal t; 2023

Palaeontological Virtual Congress

Eleutherocercus is a glyptodont Doedicurinae genus with records in the Late Miocene-Late Pliocene of southern South America. It includes six species, most of them recognized on the basis of morphological characteristics of the dorsal carapace and caudal tube. One interesting aspect to highlight in this taxon is the notable difference between the ornamentation pattern of the carapace and the caudal tube. Very wellpreserved specimens evidence that the osteoderms of the carapace have a smooth surface with numerous large foramina, representing the original pattern. On the contrary, for caudal tubes two ornamentation patters were described: Type A represented by a “rosette” pattern, which includes a central figure surrounded by several small figures, and Type B represented by a smooth surface pattern with large foramina arranged in a circular disposition. Recent studies on living and fossil cingulates suggested that the original ornamentation pattern can be modified by taphonomic processes. Here, the study of several well-preserved caudal tubes reflects that the “rosette” pattern represents the original ornamentation in Eleutherocercus. Likewise, we infer that the Type B ornamentation is the result of taphonomic alterations, which generated the degradation of the figures that compose the original “rosette” pattern and the enlargement of the foramina. Considering that some species of Eleutherocercus (e.g., E. tucumanus (MACN2893) and E. paranensis (MACN6253)) have been defined based on Type B ornamentation pattern, their taxonomic assignment should be reviewed. We finally remark on the importance of taphonomy as a complementary discipline to avoid systematic and phylogenetic misinterpretations.