Análisis faunístico de vertebrados de las “toscas del Río de La Plata” (Buenos Aires, Argentina): un yacimiento paleontológico en desaparición

SOIBELZON, E.; GASPARINI, G. M.; ZURITA, A. E.; SOIBELZON L. H.

Revista del Museo Argentino de Ciencias Naturales

Año: 2008 vol. 10 p. 291 - 308

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> At the coast of the río de la Plata in the Buenos Aires city lies a classic paleontological site, known as “toscas del Río de La Plata” or simple as “las toscas”. It has been studied for over 120 years and, although it has been widely spread, today is only possible to observe it during low tide. For this reason, most of the available materials are those collected during the first half of the twentieth century, and that so far have only been incorporated into scarce taxonomic reviews. Among the fossils collected in “las toscas” highlights Glyptodon munizi Ameghino, Neosclerocalyptus pseudornatus Ameghino, Mesotherium cristatum Serrés, Arctotherium angustidens Gervais y Ameghino and Theriodictis platensis (Mercerat); all are exclusive species from the Ensenadan Stage (early to -middle Pleistocene). The sediments of “las toscas” were deposited during times of normal polarity, more precisely during the event “Jaramillo” (Chron C1r1n, ca. de 1 Ma). Faunistic evidences (e.g. Tolypeutes, Catagonus) allow to interpret “las toscas” as an open environment with dry conditions and probably colder than the present.