Environmental adaptive strategies for feeding under water in the Tethytheria (Mammalia: Afrotheria) based on isotopic and texture analyses of teeth.

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05333
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: National Museum of Nature and Science, Tokyo
• Principal Investigator: Kohno Naoki 独立行政法人国立科学博物館, 地学研究部, グループ長 (20250136)
• Research Collaborator: UNO Hikaru 早稲田大学, 理工学術院・総合研究所, 研究員 ; TARU Hajime 神奈川県立生命の星地球博物館, 学芸部, 主任学芸員 ; YAMADA Eisuke 山梨県立博物館, 学芸課, 学芸員
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: テチス獣類 / テクスチャー / 索餌戦略 / 安定同位体 / 水生適応

Outline of Final Research Achievements

Carbon and oxygen isotopic analyzes were conducted to the basal taxa of the Proboscidea (i.e., the elephants) from the Paleocene marine phosphatic formation (ca. 60 Ma) distributed in the Ground Daoui, the Ouled Abdoun Basin, Morocco, located on the northern Africa, to estimate their habitat and feeding preferences. As a result, basal taxa of the Paleocene elephants were suggested to be aquatic. In addition, they were considered to have been inhabited around the marine coast of the Tethys Sea (=ancient Mediterranean　Sea). From these results, the elephants were aquatic in the initial stage of their evolution, and surprisingly, they were inhabited along the coast of the Tethys Sea during their initial evolution and adaptation in the Paleocene. Accordingly, the tethytheres as a whole evolved initially as marine mammals, and they were thought to be returned to lake or river secondarily and to land thirdly along the coast of and/or in North Africa.

Free Research Field

哺乳類古生物学