Reconstruction of life history of Desmostylus based on stable isotope analyses along enamel growth lines of molars

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540502
• 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, 研究主幹 (20250136)
• Research Collaborator: UNO Hikaru 農業環境技術研究所, 物質循環研究領域, 契約研究員 ; TARU Hajime 神奈川県立生命の星地球博物館, 学芸部, 主任学芸員
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 古生態学 / 生活史 / 安定同位体 / 微量元素 / 束柱類 / デスモスチルス / 北西太平洋 / 北東太平洋

Outline of Final Research Achievements

We analyzed stable isotope ratios of carbon, oxygen and the trace element (e.g., strontium) from the continuous samplings along the enamel growth lines of molar teeth in Desmostylus hesperus that is an extinct marine mammal known only from the Middle Miocene of the North Pacific. Based on our analyses, we confirmed that some individuals had isotope ratios of carbon and oxygen that fluctuated periodically. However, some others did not show the same result. These results suggest that some individuals of Desmostylus might have changed a place of absorbing water periodically. In contrast, the fluctuation of the trace element was not remarkable in all the individuals we analysed. It suggests that the periodic movements of individuals remained in small range. It indicates that Desmostylus had different life cycle in between, for instance, males and females.

Free Research Field

哺乳類古生物学