Micromammals, taphonomy and paleoenvironments of the late quaternary at Tierra del Fuego: The rodents of tres arroyos 1 Micromamíferos, tafonomía y paleoambientes del cuaternario tardío en Tierra del Fuego: Los roedores de tres arroyos 1
Fernández, Fernando J.
- 1Consejo Nacional de Investigaciones Científicas y Técnicas
- 2
- 3Instituto Multidisciplinario de Historia y Ciencias Humanas
- 4Universidad de Buenos Aires
Journal
magallania
ISSN
0718-2244
0718-0209
Open Access
diamond
Volume
48
Start page
93
End page
122
We studied the micromammal remains recovered from the stratigraphic sequence of the archaeological site Tres Arroyos 1 (53 23' S, 68 47' W, Tierra del Fuego, Chile). The samples obtained from Late Pleistocene levels (ca. 12.5-10 ky) are mainly composed by Euneomys chinchilloides and Ctenomys magellanicus, with the unique occurrence of Eligmodontia cf. E. morgani, a sigmodontine today extinct in the Isla Grande de Tierra del Fuego but with populations in the southernmost mainland. These assemblages suggest very hard paleoenvironments with a general rocky and bare landscape under deep cold and windy conditions. The Late Holocene samples (ca. 1.3 ky-present), by the contrary, are composed basically by Reithrodon auritus, C. magellanicus, some sigmodontine species typically from southern Tierra del Fuego forests (e.g. Oligoryzomys longicaudatus, Abrothrix lanosa), and show a declination of E. chinchilloides. These assemblages indicate amelioration in the environmental conditions surely coupled with the regional development of shrub and herbaceous steppes and perhaps a north displacement of the forest line. Taphonomically, pleistocenic assemblages seem to be mainly produced by the trophic activity of carnivore mammals, while those holocenic suggest a mixed origin with participation of owl pellets (especially for sigmodontine remains) and human consumption (responsible for a part of the Ctenomys remains). In overall, the micromammal evidence is in agreement with the results obtained from other paleoclimatic records (e.g. pollen).