Banca de DEFESA: VIRGINIA SILVA MACIEL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VIRGINIA SILVA MACIEL
DATE: 22/11/2024
TIME: 14:00
LOCAL: Videoconferência / Canal Youtube PPGG - Youtube.com/@ppggufrn
TITLE:

BONE HISTOLOGY OF SMILODON POPULATOR AND PUMA CONCOLOR FROM THE PLEISTOCENE OF EQUATORIAL BRAZIL WITH COMMENTS ON FOSSILDIAGENESIS

KEY WORDS:

Quaternary, Felidae, Paleohistology, Paleoecology, Carnivora

PAGES: 41
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Geologia
SPECIALTY: Sedimentologia
SUMMARY:

Climate change over the last 50,000 years has significantly impacted large mammals. Large felids have been one of the groups most af ected by these fluctuations. To understand the possible causes of the extinction of some species, it is necessary to understand their paleobiology and compare it with living forms. In this study, we sampled the femoral histology of the largest saber-toothed felid in the Americas, Smilodon populator (MCC-868V), and a fossil specimen of Puma concolor (MCC 991V), both from Quaternary deposits in Rio Grande do Norte, Northeast Brazil. The presence of EFS (External Fundamental System), generations of secondary osteons, and remodeled bone tissue indicate that both individuals had reached sexual maturity. However, MCC-868V was a young adult at the time of death, and MCC-991V was a senescent adult. The estimated mass for the S. populator specimen (157 kg) is lower than expected, even though the individual analyzed was a fully grown adult. There are no histopathological indicators that this S. populator individual underwent restrictions throughout its growth, which suggests a truly smaller individual. Smaller size may be a trait selected in a local population in Northeastern Equatorial Brazil due to the specific environmental and ecological conditions of the region. The morphometric analysis found that size did not correlate with bone thickness both among several felid taxa and within a Smilodon population. As no significant histological dif erences were found between P. concolor and S. populator, it is more likely that the local extinction of Smilodon was more related to ecological pressure, such as a reduction in the availability of prey or preferred habitat. Additionally, our analysis revealed distinct diagenetic alterations in both specimens, suggesting that the fossilization processes were influenced by their respective depositional environments.

COMMITTEE MEMBERS:
Externa à Instituição - MARIELA CORDEIRO DE CASTRO - UFCAT
Presidente - 1283832 - ALINE MARCELE GHILARDI
Externo à Instituição - HERMINIO ISMAEL DE ARAUJO JUNIOR - UERJ
Externo à Instituição - TITO AURELIANO NETO - URCA