Diversidade de pequenos mamíferos (Didelphimorphia e Rodentia) do Holoceno do Nordeste do Estado do Rio Grande do Sul, Brasil: implicações taxonômicas e paleoambientais

Abstract

SMALL MAMMALS DIVERSITY (DIDELPHIMORPHIA AND RODENTIA) FROM THE HOLOCENE OF NORTHEASTERN RIO GRANDE DO SUL STATE, SOUTHERN BRAZIL: TAXONOMIC AND PALEOENVIRONMENTAL IMPLICATIONS. Despite the increase in knowledge about small mammals from the Holocene of Rio Grande do Sul State and their importance as paleoenvironmental indicators, most assemblages from archaeological sites remains without a detailed analysis. This paper studies the rich small mammals content recovered from the archaeological site RS-C-61: Adelar Pilger, Harmonia, which shows evidence of continuous human occupation throughout the Holocene, from about 8,000 years BP to 3,000 years BP. The assemblage of this site is composed of 25 taxa, including fi ve didelphid marsupials, 15 cricetid and fi ve caviomorph rodents. Most marsupials are also registered in two other sites, Afonso Garivaldino Rodrigues and Sangão. Among Cricetidae, Gyldenstolpia, Kunsia and Oxymycterus are fi rst recorded for Quaternary of Rio Grande do Sul State. On the other hand, the caviomorph assemblage of Pilger site is less diverse than those of the Afonso Garivaldino Rodrigues and Sangão sites. Pilger site includes both small mammals of open (e.g. Thylamys, Calomys, Cavia) and forest (Delomys, Sooretamys and Phyllomys) environments, also supported by palynological data. Three caviomorph (Euryzygomatomys mordax, Dicolpomys fossor and Clyomys riograndensis) are extinct and, compared to the recent fauna of seasonal forest of Rio Grande do Sul, three other taxa (Gyldenstolpia sp., Kunsia tomentosus and Pseudoryzomys simplex) suff ered regional extinctions.

Holocene small mammals hunted by owls and humans in southern Brazil: taphonomic evidence and biological significance

“…; and the references cited therein), the evidence of small mammals at Garivaldino, Pilger and Sangão reflects changes in the species composition during the Holocene, which can be linked to a progressive transformation of the general landscape from mostly open grasslands in the Early Holocene to forests in the Late Holocene (Hadler et al . , , , ; Rodrigues ; Stutz et al . , ).…”

“…As often happens in rockshelters, these archaeological sites contain plenty of small mammal remains (marsupials, caviomorphs and sigmodontine rodents), which have been studied from a taxonomic and palaeoecological perspective (Hadler et al . , , , ; Rodrigues ; Stutz et al . , ).…”

Roedores sigmodontíneos (Mammalia, Rodentia, Cricetidae) holocênicos do Rio Grande do Sul, Brasil – o Sítio RS-TQ-58: Afonso Garivaldino Rodrigues

“…Além destes, a amostra também contém os gêneros incertae sedis Delomys e Juliomys (MNI= 39) e 16 indivíduos identificados apenas a nível de subfamília devido ao grau de fragmentação. Um número pouco menor de táxons (15) foi registrado para o sítio Pilger, também situado na parte nordeste do Rio Grande do Sul, cerca de 23 km a leste do Garivaldino (Hadler et al, 2016 Castro & Langer, 2011).…”

“…Rodrigues, 2008;Hadler et al, 2008Hadler et al, , 2009Hadler et al, , 2016. Os roedores sigmodontíneos permanecem ainda pouco estudados, com apenas a assembleia do sítio RS-C-61: Adelar Pilger descrita detalhadamente quanto à taxonomia e considerações paleoambientais (Hadler et al, 2016).…”

“…Várias destas, incluindo o maior sigmodontíneo vivente (Kunsia tomentosus) e equimiídeos como Dicolpomys fossor e Clyomys riograndensis, desaparecem em direção ao Holoceno superior, enquanto se verifica um aumento de espécies de ambiente florestal. Estes processos são de grande relevância, já que implicam tanto em extinções de caráter regional como total, que poderiam estar relacionadas com mudanças ambientais que afetaram as principais formações vegetais (Hadler et al, 2013(Hadler et al, , 2016.…”