HISTORICAL BACKGROUND FOR A REVISION OF THE PALEONTOLOGY OF THE SANTA CRUZ FORMATION (EARLY–MIDDLE MIOCENE) ALONG THE RÍO SANTA CRUZ, PATAGONIA, ARGENTINA

Abstract

In 1887, Carlos Ameghino carried out the first geological and paleontological expedition to the Río Santa Cruz (RSC), Patagonia, Argentina. Between 1887 and 1889, Florentino Ameghino studied the fossils obtained by Carlos, founding more than 120 taxa and establishing his Formación Santacruceña and Piso Santacruceño. In 1888, F. Ameghino was exonerated from the Museo de La Plata and replaced by Alcides Mercerat in 1889, starting a strong competition for the Santacrucian fossils, which since 1890 were obtained mainly on the Atlantic coast. Until 1894, Ameghino and Mercerat founded more than 500 mammal species, of which 80% correspond to Ameghino who, later, synonymized almost all Mercerat species. At the end of the 19th century, foreign explorers visited Patagonia, but they did not collect in the RSC. So the largest RSC collections were made until 1889. The Santacrucian collections of the 19th century have vague and in some cases contradictory geographical information. This is true for the Santacrucian species reassigned by F. Ameghino to the Notohippidian, an association that he located northwest of the RSC. Recent analyses show that several of these specimens were collected southwest of the RSC. These and other facts demonstrate the inconvenience of using the data from the old collections in biostratigraphic and paleoecological studies without a critical analysis of the history of their provenance. Since 2003, a research program was launched that promoted biostratigraphic and paleoecological studies of the Santa Cruz Formation (SCF). This Thematic Volume compiles contributions on geology, stratigraphy, taxonomy, and mammal association’s analyses of the SCF along the RSC.

Keywords

• Santacrucian
• Notohippidian
• Fossil mammals
• Taxonomy
• Ameghino