Digital endocranial cast of Pampatherium humboldtii (Xenarthra, Cingulata) from the Late Pleistocene of Uruguay

Abstract

The diversity of the order Cingulata is much higher in the fossil record than that represented by the extant species. While pampatheres, one of its extinct groups, are superficially similar to armadillos, recent phylogenetic analysis grouped them with glyptodonts in the clade Glyptodonta. We describe here the first digital endocranial cast of a pampathere, Pampatherium humboldtii, from the Late Pleistocene of Uruguay and compare its morphology with that of glyptodonts and extant and fossil armadillos. Some of the characteristics observed are more similar to those of glyptodonts than to those seen in armadillos. The endocranial cast of Pampatherium has large pedunculate olfactory bulbs, a relative small cerebrum with only one cortical sulcus and a large cerebellum. Although all groups of cingulates, both extant and extinct, have a similar relative brain size, the relative brain size of pampatheres is larger than in glyptodonts and close to that of extant armadillos, The endocast morphology and the analysis of relative brain size of Pampatherium are congruent with their close affinity to glyptodonts and their inclusion in the clade Glyptodonta, although in a family of its own.

Xenarthrans of the collection of Santiago Roth from the Pampean Region of Argentina (Pleistocene), in Zurich, Switzerland

“…I therefore propose to reassign PIMUZ A/V 428 and PIMUZ A/V 430 to Pa. humboldtii . While the cranial and endocranial material is relatively well-studied for this species (e.g., Ferreira et al, 2018 ; Tambusso & Fariña, 2015a ), the postcranial remains are poorly known. PIMUZ A/V 428 offers the opportunity to analyze several complete long bones of Pa. humboldtii .…”

The virtual brain endocast of Incamys bolivianus: insight from the neurosensory system into the adaptive radiation of South American rodents

“…2023), Primates, Chilecebus carrascoensis (Ni et al . 2019), and Xenarthra (Tambusso & Fariña 2015a, 2015b). All fossils included in the quantitative analyses are known from published virtual endocasts except Do.…”

3D models related to the publication: Comparative anatomy and phylogenetic contribution of intracranial osseous canals and cavities in armadillos and glyptodonts (Xenarthra, Cingulata)

“…Although the cranial anatomy is relatively well known in xenarthrans, their internal cranial anatomy remains poorly studied. Yet, several studies have shown that their exploration provides systematic interest on their past and present diversity (Zurita et al, 2011;Fernicola et al, 2012;Billet et al, 2015;Tambusso & Fariña, 2015a;Tambusso & Fariña, 2015b;Billet et al, 2017;Boscaini et al, 2018;Boscaini et al, 2020;Tambusso et al, 2021). In a recent study (Le Verger et al, 2021), we describe and compare 8 cranial canals (involved in the vascularization and innervation of the cranium) and alveolar cavities (Figure 1) of 30 specimens belonging to the Cingulata.…”