Diagenetic changes on bone histology of Quaternary mammals from a tropical cave deposit in southeastern Brazil

Author(s)

Mayer, Elver Luiz ^{[1, 2]} ; Hubbe, Alex ^{[3, 4]} ; Botha-Brink, Jennifer ^{[5, 6]} ; Ribeiro, Ana Maria ^{[1, 7]} ; Haddad-Martim, Paulo Miguel ^[8] ; Neves, Walter ^[9]

Affiliation

^[1] Univ Fed Rio Grande do Sul, Programa Pasgrad Geociencias, Av Bento Goncalves 9500, BR-91501970 Porto Alegre, RS - Brazil

^[2] Inst Estudos Xingu, Rua Constantino Ferreira Viana, Quadra 8, BR-68380000 Sao Felix Do Xingu, PA - Brazil

^[3] Univ Fed Bahia, Inst Geociencias, Dept Oceanog, BR-40170020 Salvador, BA - Brazil

^[4] Inst Carste, Rua Barcelona 240-302, BR-30360260 Belo Horizonte, MG - Brazil

^[5] Univ Free State, Dept Zool & Entomol, ZA-9300 Bloemfontein - South Africa

^[6] Natl Museum, Karoo Palaeontol, Box 266, ZA-9300 Bloemfontein - South Africa

^[7] Secretaria Meio Ambience Rio Grande Sul, Museu Ciencias Nat, Setor Paleontol, Av Salvador Franca 1427, BR-90690000 Porto Alegre, RS - Brazil

^[8] Univ Estadual Campinas, Inst Geociencias, BR-13083855 Campinas, SP - Brazil

^[9] Univ Sao Paulo, Inst Escudos Avancados, Rua Praca Relogio 109, BR-05508050 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY; v. 537, JAN 1 2020.
• Web of Science Citations: 1

Abstract

Karst caves are suitable environments for the accumulation and preservation of fossils. Cave deposits are often complex and the environmental conditions within cave sites result from intricate interactions between various biological, physical and chemical factors. However, it is not fully understood how the complexity of the environmental conditions of caves influences bone diagenesis. The study of the initial stages of bone diagenesis depends to a large extent on understanding the changes in the bone histology. To contribute to this issue, we examine a set of postmortem changes affecting the bone histology of Quaternary mammals that accumulated naturally in Locus 2, a pitfall site in Cuvieri Cave, located in the tropical region of Brazil. Our analyses show that bones deposited in caves may be subject to a peculiar set of environmental conditions that in tropical regions may prevent the preservation of bone histological structure. The effect of diagenetic processes on the bones differs depending on the taphonomic stage of the bone and the diagenetic alterations appear to have influenced each other. The deposition of bioclasts following the entrapment of individuals in Locus 2 favours the proliferation of bacteria on bones and appears to be important in directing the diagenetic alteration. The hydrological regime of the cave, that is recharge with potential phases of higher humidity, also is important in directing the diagenetic alteration and further decreased the preservation potential of the bone microstructure. The formation of macroscopic and microscopic cracks related to bone weathering in caves shows that the taphonomic processes peculiar to these environments are poorly understood, highlighting the need for more research to be conducted on cave taphonomy. (AU)

• FAPESP's process: 09/03753-4 - Formation processes of a fossiliferous pitfall deposit in Gruta Cuvieri (MG): taxonomy, taphonomy and spacial distribution of mammal fossils from the Pleistocene
• Grantee: Elver Luiz Mayer
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 04/01321-6 - Origins and microevolution of man in the Americas: a paleoanthropological approach (III)
• Grantee: Walter Alves Neves
• Support type: Research Projects - Thematic Grants