阿根廷科尔多瓦国立大学Gustavo G. Voldman课题组取得一项新突破。他们首次报道了阿根廷晚古生代牙形石的牙形石记录——对西南冈瓦纳晚古生代冰期的生物地层和古气候的限制。这一研究成果发表在2024年4月26日出版的国际学术期刊《地质学》上。

本研究首次发现报道了在阿根廷的晚古生代牙形石，标志着这一化石群在冈瓦纳大陆高纬度地区的最南端出现。

研究人员在La Rioja省Precordillera北部Rincón Blanco剖面中，从Río del Penon(RDP)组的硅质碎屑中找到了牙形石，化石组合包括Neognathodus  colombiensis和Neognathodus “pre-colombiensis”，与Moscovian早期(北美Atokan晚期)的N. colombiensis带相对应。

此外，牙形石动物群为腕足动物Tivertonia jachalensis-Streptorhynchus inaequiornatus(TS)带建立了一个重要的时间限制。TS带是南美洲南部广泛使用的生物地层单位。Neognathodus的温水亲和性与阿根廷中西部盆地TS区典型的古赤道动物成分的记录相一致，这一证据支持了早期冈瓦纳南部纬度气候改善的观点。

附：英文原文

Title: First documentation of Late Paleozoic conodonts from Argentina: Biostratigraphic and paleoclimatic constraints for the Late Paleozoic Ice Age in SW Gondwana

Author: Gustavo G. Voldman, Gabriela A. Cisterna, Andrea F. Sterren, Miguel Ezpeleta, James E. Barrick

Issue&Volume: 2024-04-26

Abstract: We present the first discovery of Late Paleozoic conodonts in Argentina, marking the southernmost occurrence of this fossil group in the dominantly cold, high latitudes of Gondwana. Recovered from the siliciclastic Río del Peón (RDP) Formation at the Rincón Blanco section in the northern Precordillera, La Rioja Province, the fossil assemblage includes Neognathodus colombiensis and Neognathodus “pre-colombiensis,” precisely indicating the early Moscovian (late Atokan in North America) N. colombiensis Zone. Furthermore, the conodont fauna establishes a crucial temporal constraint for the brachiopod Tivertonia jachalensis-Streptorhynchus inaequiornatus (TS) Zone, which is a widely employed biostratigraphic unit in southern South America. The warm-water affinity of Neognathodus is in accordance with the record of typical paleoequatorial faunal elements in the TS Zone in several central western Argentinian basins, thus reinforcing the idea of a climatic amelioration in the southern latitudes of Gondwana during the early Moscovian.

DOI: 10.1130/G52133.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G52133.1/638899/First-documentation-of-Late-Paleozoic-conodontsredirectedFrom=fulltext