Postcranial anatomy of the early notoungulate Allalmeia atalaensis from the Eocene of Argentina

We redescribe and interpret the postcranial elements of Allalmeia atalaensis Rusconi, found in the Divisadero Largo Formation, Mendoza, Argentina. Allalmeia is one of the few basal notoungulates with preserved postcranial remains. Rusconi initially documented a skull, several vertebrae and part of the appendicular skeleton but these specimens were subsequently lost. Recently though, distal components of the holotype humeri, the proximal portion of the right femur, several broken diaphyses and most of the left and right pes (MCNAM-PV 507), were relocated. Preparation of this material has revealed new details, especially from the plantar side of the feet. The calcaneum has a distal peroneal process with marked rugosity in the lateral end, a well-developed calcaneal plantar tubercle and a large sustentaculum tali. The naviculars exhibit a well-developed medial tuberosity and slightly contact the calcaneum on the dorsal side, a condition called a ‘reverse alternating tarsus’. The disposition and morphology of the cuneiforms are similar to those of more recent typotheres and the archaic ungulate Tetraclaenodon puercensis. The phalangeal rows are oblique to each other, as in some extant digitigrade mammals. The ungual phalanges are claw-like suggesting that they might have borne claws. Long bones are gracile in comparison with other notoungulates, but with well-developed muscle origins and insertions. The use of body-mass allometric equations and a comparison with extant analogues suggests that Allalmeia was a small, generalized, digitigrade animal. An estimated body mass of approximately 3 kg is consistent with oldfieldthomasiids and archaic ungulates.     

Assessing Prehispanic Herding Strategies through Stable Isotope Analysis: A Case Study from the Dry Puna of Argentina

ABSTRACT

The main goal of this work is to study the camelid herding and management strategies employed by the human groups that occupied the Dry Puna of Argentina during the late Holocene. Carbon and nitrogen stable isotope compositions were measured on bone collagen from domesticated South American camelids (llamas: Lama glama) recovered at two archaeological sites (Huirunpure and Chayal Cave). These results were interpreted using an already published data set of δ ¹³C and δ ¹⁵N values measured on bone collagen from modern herds of llamas managed in a traditional way. Our results showed that even though the archaeological sites of Huirunpure and Chayal Cave are located within different settings – at 4020 and 3700?masl respectively – and present different chronologies – 0–650 and 1300–1500 CE respectively – the llamas from both sites exhibit similar δ ¹³C and δ ¹⁵N values. This pattern was explained considering the characteristics of the vegetation communities that grow in the vicinity of both sites as well as the paleoenvironmental records of the Andean highlands. In sum, this work presents and discusses some preliminary results on the study of prehispanic herding practices in the Dry Puna of Argentina during the first 1500 years of the Common Era through stable isotope analysis.