EVALUATION OF EARLY DIAGENETIC INFLUENCE ON NITROGEN ISOTOPES WITHIN FOSSIL AMINO ACIDS: TOWARDS ESTIMATION OF ANCIENT FOOD WEBS AND CHEMOSYMBIOSYS

• Project/Area Number: 15K13584
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Kanazawa University
• Principal Investigator: JENKINS Robert 金沢大学, 自然システム学系, 助教 (10451824)
• Research Collaborator: HAGEHASHI Daijirou ; CHIKARAISHI Yoshito ; HASEGAWA Takashi ; GOTO Akiko
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 生態系復元 / 窒素同位体比 / 殻体内有機物 / 化石 / アミノ酸 / 食物網解析 / 層位古生物学 / 生態系 / 食物連鎖 / 海洋生物学 / 分子化石

Outline of Final Research Achievements

Compound-Specific Isotope Analysis (CSIA) of nitrogen within amino acids in the fossil shells provides a solution to reconstruct paleoecosystems. However fundamental studies on this relatively new techniques hasn’t been performed yet. Thus, we use modern and fossil (800 and 6000 years ago) Turbo sazae (Gastropoda), which is presumed to be a primary consumer, i.e. its trophic level should be 2.0. Some of the modern materials were heated at 200 and 400 °C in an oven. We use the middle layer, consisting of a nacreous structure, of Turbo for this study.
The sample heated at 400 °C were partially dissolved and no amino acid was found. The other samples, with excellent shell microstructures are present, show around 1.9-2.3 for the trophic level estimated on the basis of the CSIA of amino acids. The result indicates that early diagenesis will not affect the nitrogen isotopes of amino acids in shells for at least 6000 years.

Research Products

• [Int'l Joint Research] Institute of Paleobiology PAS(ポーランド)
• [Int'l Joint Research] ポーランド科学アカデミー古生物学研究所(ポーランド)
• [Presentation] EVALUATION OF EARLY DIAGENETIC INFLUENCE ON NITROGEN ISOTOPES WITHIN FOSSIL AMINO ACIDS: TOWARDS AN ESTIMATION OF ANCIENT FOOD WEBS (2016)
  • Author(s): Daijiro HAGEHASHI, Robert G. JENKINS, Akiko S. GOTO, Yoshito CHIKARAISHI, and Takashi HASEGAWA
  • Organizer: 1st International Workshop on Ancient Hydrocarbon Seep and Cognate Communities
  • Place of Presentation: ワルシャワ（ポーランド）
  • Year and Date: 2016-06-13
  • Int'l Joint Research
• [Presentation] EVALUATION OF EARLY DIAGENETIC INFLUENCE ON NITROGEN ISOTOPES WITHIN FOSSIL AMINO ACIDS: TOWARDS ESTIMATION OF ANCIENT FOOD WEBS (2016)
  • Author(s): Hagehashi, D., Jenkins, R.G., Goto, A.S., Chikaraishi, Y., Hasegawa, T.
  • Organizer: 1st International Workshop on Ancient Hydrocarbon Seep and Cognate Communities
  • Place of Presentation: Warsaw, Poland
  • Year and Date: 2016-06-13
  • Int'l Joint Research
• [Presentation] 個別アミノ酸窒素同位体比を用いた栄養段階推定法は化石に応用できるのか？～初期続成が及ぼす殻体内アミノ酸の変質に着目して～ (2016)
  • Author(s): 兀橋 大二郎，ジェンキンズ ロバート，後藤（桜井） 晶子，力石 嘉人，長谷川 卓
  • Organizer: 日本地球惑星科学連合2016年大会
  • Place of Presentation: 幕張（千葉）
  • Year and Date: 2016-05-25
• [Presentation] 個別アミノ酸窒素同位体比を用いた栄養段階推定法は化石に応用できるのか？～初期続成が及ぼす殻体内アミノ酸の変質に着目して～ (2016)
  • Author(s): 兀橋 大二郎、ジェンキンズ ロバート、後藤（桜井） 晶子、力石 嘉人、長谷川 卓
  • Organizer: 日本地球惑星科学連合２０１６年大会
  • Place of Presentation: 幕張，千葉
  • Year and Date: 2016-05-25
• [Remarks] ジェンキンズ研究室のページ
  • URL: http://www.geobiology.jp/
• [Remarks] 金沢大学研究者情報
  • URL: http://ridb.kanazawa-u.ac.jp/public/detail.php?id=4181