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

Abstract

Understanding resource utilization and economic diversification amongst Holocene hunter‐gatherers in southern Brazil requires in‐depth taphonomic analysis of faunal assemblages. Three Early to Late Holocene archaeological sites (Garivaldino, Pilger and Sangão) in Rio Grande do Sul State, southern Brazil, revealed large assemblages of small mammal (˂1 kg) remains, composed mainly of rodents. To appreciate depositional processes of fauna in relation to human consumption, taphonomic attributes and processes were evaluated. The results indicated that the remains accumulated through different antemortem taphonomic pathways, apparently linked to the size and natural history of the species represented. The small‐ and medium‐sized (<150 g) cricetid rodents (e.g. Pseudoryzomys simplex and Sooretamys angouya) were represented by a low proportion of teeth with lightly digestive corrosion suggesting that they were derived from the predatory activity of owls, possibly Tyto alba. In contrast, large‐sized cricetids (>150 g; Kunsia tomentosus, Gyldenstolpia sp. and Holochilus sp.), and several caviomorph rodents with aggregated spatial distributions (Echimyidae (†Dicolpomys fossor, Phyllomys sp., †Clyomys riograndensis and †Euryzygomatomys mordax), Caviidae (Cavia sp.) and Ctenomyidae (Ctenomys sp.)) showed evidence of thermoalteration patterns and cut marks on bones, suggesting human exploitation. A postmortem depositional environment was deduced from dendritic and branched patterns of rootlet etching, apparent mostly at Garivaldino and Pilger. Polished areas and holes on bone surfaces, and impregnation of manganese showed moderate (Sangão) or low (Garivaldino and Pilger) incidence, pointing to water transport under moderate (Pilger) and low (Garivaldino and Sangão) energy over short distances. The results obtained here provide the first clear evidence of early human exploitation of small mammals in southern Brazil, suggesting a diversification of economies. In addition, as several of the recorded rodents are today regionally or biologically extinct, a preliminary discussion about the potential impact of humans on this process is provided.

Assessment of the distribution of Pseudoryzomys simplex (Cricetidae, Sigmodontinae) in the Pampean region, central-east Argentina, in the late-Holocene

“…Amongst them, only two yield late-Holocene dates although it remains uncertain if the presence of the species in these sites could be related to this period. Since the fossil records of P. simplex from Brazil are included in a complex chronostratigraphic sequence with large sedimentary packages, several layers and few radiocarbon dates (none of them directly associated with the species), its presence cannot be accurately related within the late-Holocene period (see Fernández et al, 2019; Hadler et al, 2016; Stutz et al, 2017) and its used was avoided. Therefore, we focussed only on the eight fossil records located in the Humid Pampa subregion (Figures 1 and 2) with a chronology clearly limited to the assessed paleoclimate scenario (late-Holocene).…”

“…Pardiñas, 1995; Pardiñas et al, 2002; Pardiñas, 1999a, 1999b, 2000; Pardiñas and Tonni, 2000; Quintana, 2001; Scheifler and Messineo, 2016; Scheifler et al, 2012; Teta et al, 2013). In Brazil, P. simplex has been recorded in only three Holocene sites: Garivaldino (10.7–8.1 ka cal BP), Sangão (Unit 1: 9.8–8.2 ka cal BP and Unit 2: 5.3–4.1 ka cal BP) and Adelar Pilger (Unit II: 7.1–3.2 ka cal BP) (Fernández et al, 2019; Hadler et al, 2016). Amongst them, only two yield late-Holocene dates although it remains uncertain if the presence of the species in these sites could be related to this period.…”

“…The fossil findings of P. simplex from the Atlantic Forest of southern Brazil and from the Pampean region of central-eastern Argentina showed its broader biogeographic distribution during the Holocene (Fernández et al, 2019; Hadler et al, 2016; Pardiñas, 1995, 1999a, 1999b, 2000; Quintana, 2001; Scheifler and Messineo, 2016; Scheifler et al, 2012; Stutz et al, 2017; Teta et al, 2013). On the one hand, the occurrence of this species and other extralimital sigmodontine, Bibimys torresi (Massoia 1979), in the south-central Pampean region between 4700 and 200 ka cal BP was originally associated with the Holocene warm climatic episodes (see below; Pardiñas, 1995, 1999b, 2000; Pardiñas and Tonni, 2000).…”

Micromamíferos, tafonomía y paleoambientes del cuaternario tardío en Tierra del Fuego: Los roedores de tres arroyos 1

“…Estas marcas postdepositacionales pueden ocultar los atributos inherentes a los agentes que acumularon los restos (e.g. Andrews, 1990;Fernández et al 2019). Tabla 6.…”

Forest stability during the Holocene in Santa Catarina, southern Brazil revealed by small mammals from Gruta do Presépio

“…Taphonomic studies of micromammal remains are important for inferring the main sources of the faunal accumulation, embracing a variety of agents and processes, in order to perform supported reconstructions of the past (e.g. Andrews, 1990;Avery, 1982;Dodson and Wexlar, 1979;Fernández et al, 2019;Guillermo et al, 2021;Montalvo and Fernández, 2019;Pardiñas, 1999b;Stahl, 1996).…”