Ufj. Pardinas, Arid conditions during the Early Holocene in southwestern Buenos Aires Province (Argentina): Vertebrates and taphonomy., AMEGHINIANA, 38(3), 2001, pp. 227-236
Fishes, amphibians, birds, marsupials, armadillos, and rodents are describe
d from a Holocene site located at Camping Americano, near Monte Hermoso (38
degrees 57' 47" S 61 degrees 22' 48" W, Buenos Aires province, Argentina).
The fossil bearing sediments are referred to the Lower Holocene on the bas
is of a radiocarbon AMS date of 8.9 yr BP. The assemblage is largely domina
ted by the caviomorph rodent Ctenomys, with low frequencies of sigmodontine
s (Eligmodontia, Reithrodon), marmosines, (Lestodelphys), edentates and oth
er vertebrates. Several lines of evidence suggest a multiple taphonomical o
rigin, including owl pellets, water transport and in situ burial. This inte
rpretation plus the presence of some faunistic elements of xeric environmen
ts [as the marmosine Lestodelphys halli (Thomas)] and a low specific richne
ss of sigmodotine rodents indicate that the assemblage were deposited under
dryer climatic conditions than the present ones. Additionally, the global
faunistic evidence, such as the high frequency of the octodontid Ctenomys o
r the bone concentrations of the fish Corydoras, suggests an interdune pale
oenvironment with small fresh-water bodies, similar to the general landscap
e dominating nowadays the sandy "Southern barrier" of southwest Buenos Aire
s Province. According to the present intertidal location of the studied dep
osits, the absolute chronology and the inferred paleoenvironment, the forme
r position of the coast line is discussed.