Joyce Walter G, Rollot Yann, Evers Serjoscha W, Lyson Tyler R, Rahantarisoa Lydia J, Krause David W
Departement für Geowissenschaften, Universität Freiburg, Fribourg, Switzerland.
Department of Earth Sciences, Denver Museum of Nature & Science, Denver, CO, USA.
R Soc Open Sci. 2021 May 5;8(5):210098. doi: 10.1098/rsos.210098.
The Maevarano Formation in northwestern Madagascar has yielded a series of exceptional fossils over the course of the last three decades that provide important insights into the evolution of insular ecosystems during the latest Cretaceous (Maastrichtian). We here describe a new genus and species of pelomedusoid turtle from this formation, , based on a nearly complete skeleton. A phylogenetic analysis suggests close affinities of with the coeval Madagascan . These two taxa are the only known representatives of the newly recognized clade , which is sister to the speciose clade formed by and . A close relationship with coeval Indian turtles of the clade is notably absent. A functional assessment suggests that was a specialized suction feeder that preyed upon small-bodied invertebrates and vertebrates. This is a unique feeding strategy among crown pelomedusoids that is convergent upon that documented in numerous other clades of turtles and that highlights the distinct evolutionary pathways taken by Madagascan vertebrates.
在过去三十年中，马达加斯加西北部的梅瓦拉诺组产出了一系列非凡的化石，这些化石为深入了解晚白垩世（马斯特里赫特期）岛屿生态系统的演化提供了重要线索。我们在此基于一具近乎完整的骨骼，描述了该地层中一种新的侧颈龟类属种。系统发育分析表明，它与同时期的马达加斯加侧颈龟有密切的亲缘关系。这两个分类单元是新确认的分支的仅知代表，该分支是由其他侧颈龟和非洲侧颈龟组成的物种丰富的分支的姐妹群。与同时期印度侧颈龟分支的密切关系明显不存在。功能评估表明，它是一种专门的吸食性捕食者，以小型无脊椎动物和脊椎动物为食。这是冠群侧颈龟类中一种独特的捕食策略，与在众多其他龟类分支中记录的策略趋同，突出了马达加斯加脊椎动物所采取的独特进化途径。
