Challenge to reveal ecosystem evolution: Compound specific isotope analysis on fossilized amino acids

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18650
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: Kanazawa University
• Principal Investigator: Jenkins Robert 金沢大学, 地球社会基盤学系, 准教授 (10451824)
• Co-Investigator(Kenkyū-buntansha): 長谷川 卓 金沢大学, 地球社会基盤学系, 教授 (50272943)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 生態系 / 栄養段階 / 化石 / アミノ酸 / 同位体分析

Outline of Final Research Achievements

The current research investigated how to apply relatively new method of the compound-specific isotope analysis of amino acids in fossilized shells to estimate ancient ecosystem pyramids. We collected well- and excellently preserved molluscan shells from the world. After checking of preservation state of the fossil shells, we analyzed isotope of each amino acid in fossil gastropod from Miocene of Poland. As a result, the isotopic composition indicates the gastropod was secondary consumer. The result is reasonable, because the gastropod has been strongly suggested by classical paleontological investigations that the gastropod was a predator of sea urchin.

Free Research Field

古生物学

Academic Significance and Societal Importance of the Research Achievements

持続可能な人間社会の構築には，地球環境や生態系への理解が欠かせない．そのために生物多様性変動や各生物の生態系における役割とその時代変化を過去にも遡って捉える必要がある．過去の生態系変動を捉えるための具体的な手がかりは，生物（化石）の形態的特徴や胃内容物の解析に重きが置かれていた．本研究は化石中のアミノ酸の地球化学分析に着目し，1000万年スケールで古生物の遺骸（化石）から直接的に過去の生態系における生態的位置関係を推定する具体的な手法と適用方法を示した．これにより，生態系全体の環境への応答性を長い時間軸で具体的に検証可能となり，地球全体の持続可能性のための基礎的情報を提供への道筋を示した．