INVESTIGADORES
VERA barbara Soledad
artículos
Título:
New data on Propyrotherium (Mammalia, Pyrotheria) from the middle Eocene age (Chubut, Argentina): anatomy, age constraints, and phylogeny
Autor/es:
VERA, BÁRBARA; FOLINO, MICAELA; WALTER SOECHTING; NICOLE BÖTTCHER
Revista:
The Science of Nature
Editorial:
Springer
Referencias:
Año: 2022
Resumen:
Pyrotheria is one of the most peculiar orders of South American native ungulates, whose members evolved from the early? Eocene to the late Oligocene period when they became extinct. Here, we described the most complete specimen of Propyrotherium saxeum ever found, one of the lesser-known representatives of pyrotheres that characterized the middle-late Eocene period of Patagonia (Argentina). It includes a nearly complete mandible and a tusk-like tooth of the same individual, as well as other isolated upper and lower teeth. Propyrotherium saxeum has a dental formula that includes at least P2M3 and i2?p3m3 (lack of p2). It is characterized by some peculiar features of the mandible (e.g., ascending ramus longer than high, hiding the m3 and straight incisura mandibular) and dentition (e.g., cristid obliqua in p3m3, cristid between posterior lophid and distal cingulid in m1m3, P3M3 and p3m3 bilophodont, P2 and p3m3 bi-rooted, P3M3 three-rooted, paraconid in p3). The phylogenetic analysis reveals that Propyrotherium is more closely related to Pyrotherium and Baguatherium, differing from the previous hypothesis, and supports the monophyly of Pyrotheriidae including (Carolozittelia (Griphodon (Pyrotherium, Baguatherium, Propyrotherium))). The absolute age obtained through UPb zircon dating of the Sarmiento Formation at Cañadón Pelado, the fossils original locality, indicates that the fossil-bearing tuff would have been deposited between 39.65 and 40.41 Ma, with a weighted mean age of 40.03 ± 0.38 Ma (Bartonian). This implies a biochron much longer than previously thought for Propyrotherium and provides a chronological framework for the fauna of Cañadón Pelado.