Pampatherium humboldtii (Lund, 1839) (Xenarthra, Cingulata) of the Southern Brazilian Quaternary: cranial anatomy and taxonomic remarks

Abstract

This work presents a new specimen of Pampatheriidae, which consists of a skull without the rostrum. The fossil comes from an outcrop along the Chuí Creek, Santa Vitória do Palmar Municipality, Rio Grande do Sul State (RS), Brazil. It was found in a sedimentary layer of the Lagoon System III, of 40 cm thickness and consisting predominantly of fine sand and up to 20-25% silt and clay, together with other vertebrate and invertebrate fossils, some of which are related to the mammalian taxa of the Late Pleistocene of the Pampean Region of Buenos Aires Province, Argentina, of Lujanian age. The comparison of the material with the Quaternary Brazilian pampatheres from the Lagoa Santa region, Minas Gerais; Jacobina, Bahia; and Rio Madeira, Rondônia; as well as with those from Uruguay and Argentina, permits the assignment of the specimen to Pampatherium humboldtii (Lund). The specimen represents the first cranial material of this species described from RS, as up until now P. humboldtii was represented mainly by isolated osteoderms. In addition, a preliminary revision of the Pampatheriidae material from the P.W. Lund Collection is presented.

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

“…Since Ameghino ( 1891 ) synonymed Chlamydotherium with Pampatherium , several authors persisted in using Chlamydotherium without discussing the taxonomic validity of the genus (e.g., Winge, 1915 ). Nowadays, however, the validity of Pampatherium is no longer debated (Ferreira et al, 2018 ). From the Pampean region, according to Ferreira et al ( 2018 ), four pampatheriine species have been described: Holmesina paulacoutoi Cartelle & Bohórquez, 1984 , Pa. humboldtii , Pa. typum and Tonnicinctus mirus Góis et al, 2015 .…”

“…Nowadays, however, the validity of Pampatherium is no longer debated (Ferreira et al, 2018 ). From the Pampean region, according to Ferreira et al ( 2018 ), four pampatheriine species have been described: Holmesina paulacoutoi Cartelle & Bohórquez, 1984 , Pa. humboldtii , Pa. typum and Tonnicinctus mirus Góis et al, 2015 . Identification of PIMUZ A/V 428 and PIMUZ A/V 430 represented by at least one fixed scapular or pelvic buckler osteoderm is based on Góis et al ( 2015 ).…”

“…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 .…”