Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" - CONICET, Av. Ángel Gallardo 470, Buenos Aires, 1405DJR, Argentina.
Fundación de Historia Natural "Félix de Azara", Departamento de Ciencias Naturales y Antropología, Universidad Maimónides, Hidalgo 775, 1405BDB, Buenos Aires, Argentina.
Naturwissenschaften. 2020 Nov 19;107(6):49. doi: 10.1007/s00114-020-01705-x.
Gondwanatheria is an enigmatic mammaliaform clade distributed in the Cretaceous and Paleogene of South America, Africa, Madagascar, India and Antarctica. The Mesozoic record in South America is restricted to the Latest Cretaceous of Río Negro and Chubut provinces, Argentina and Magallanes Region of southern Chile. The aim of the present contribution is to describe a new specimen of gondwanatherian mammaliaforms from beds belonging to the Maastrichtian Chorrillo Formation, cropping out 30 km SW of El Calafate, Santa Cruz Province, Argentina. It is represented by a single molariform referable to the species Magallanodon baikashkenke with which it shares a unique combination of characters. Analysis of the unique combination of characters exhibited by Magallanodon shed doubts on the monophyly of Ferugliotheriidae and suggest that South American taxa may be closely related to each other. The wide geographical distribution and occurrence of gondwanatherians on geological units of diverse origins suggest that they were capable of facing disparate environmental conditions.
冈瓦纳兽类是一个神秘的哺乳形类群，分布于南美洲、非洲、马达加斯加、印度和南极洲的白垩纪和古近纪。南美洲的中生代记录仅限于阿根廷的内格罗河和丘布特省以及智利南部的麦哲伦地区的晚白垩世。本研究的目的是描述一种来自阿根廷圣克鲁斯省埃尔卡拉法特西南 30 公里处的马斯特里赫特期乔罗洛地层的新的冈瓦纳兽类哺乳动物标本。它由一个单一的臼齿形态，可归为 Magallanodon baikashkenke 种，与该种共享一个独特的组合特征。对 Magallanodon 表现出的独特组合特征的分析对 Ferugliotheriidae 的单系性提出了质疑，并表明南美洲的分类单元可能彼此密切相关。冈瓦纳兽类在不同起源的地质单元中的广泛地理分布和出现表明它们能够应对不同的环境条件。
