Reconstruction of hatching sizes in the extinct animal, belemnites

• Project/Area Number: 26800264
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Yokohama National University
• Principal Investigator: WANI RYOJI 横浜国立大学, 大学院環境情報研究院, 准教授 (70508580)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 頭足類 / 孵化サイズ / 繁殖戦略 / ベレムナイト

Outline of Final Research Achievements

Based on modern and fossil specimens of cephalopods, their hatchling sizes was analyzed. In modern coleoids, there are abrupt changes of septal distances between succeeding septa, which are supposed to be related to the hatching events. In Jurassic belemnites, there is no abrupt changes of septal distances between succeeding septa, which suggests that these belemnites hatched with no chamber.

Research Products

• [Journal Article] 白亜紀アンモナイト古生物学の近年の進展：特に北太平洋地域に注目して (2017)
  • Author(s): 和仁良二
  • Journal Title: 化石 Volume: 101 Pages: 43-59
  • NAID: 130007623287
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Covariance of sutural complexity with whorl shape: evidence from intraspecific analyses of the Cretaceous ammonoid Desmoceras (2016)
  • Author(s): Aiba, D. and Wani, R.
  • Journal Title: Swiss Journal of Palaeontology Volume: 135 Issue: 1 Pages: 1-10
  • DOI: 10.1007/s13358-015-0103-0
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Inconsistent oxygen isotopic values between contemporary secreted septa and outer shell walls in modern nautilus (2015)
  • Author(s): Ohno, A., Miyaji, T., and Wani, R.
  • Journal Title: Lethaia Volume: 48 Issue: 3 Pages: 1-9
  • DOI: 10.1111/let.12109
  • Peer Reviewed
• [Journal Article] Intraspecific variation of phragmocone chamber volumes throughout ontogeny in the modern nautilid Nautilus and the Jurassic ammoniteNormannites (2015)
  • Author(s): Tajika A, Morimoto N, Wani R, Naglik C, Klug C
  • Journal Title: PeerJ Volume: 3 Pages: 1-28
  • DOI: 10.7717/peerj.1306
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Abrupt changes in distance between succeeding septa at the hatching time in modern coleoids Sepiella japonica and Spirula spirula (2015)
  • Author(s): Yamaguchi, A., Kumada, Y., Alfaro, A.C., and Wani, R.
  • Journal Title: Swiss Journal of Palaeontology Volume: 134 Issue: 2 Pages: 301-307
  • DOI: 10.1007/s13358-015-0078-x
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Abrupt changes in distance between succeeding septa at the hatching time in modern coleoids Sepiella japonica and Spirula spirula (2015)
  • Author(s): Yamaguchi, A., Kumada, Y., Alfaro, A.C. and Wani, R.
  • Journal Title: Swiss Journal of Palaeontology Volume: 134 Pages: 1-8
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] 白亜紀アンモナイト古生物学の進展 (2016)
  • Author(s): 和仁良二
  • Organizer: 日本古生物学会第165回例会
  • Place of Presentation: 京都大学
  • Year and Date: 2016-01-29
  • Invited
• [Presentation] 古生物学からみた頭足類 (2014)
  • Author(s): 和仁良二
  • Organizer: 日本水産学会シンポジウム「頭足類学の創成―水産学における応用的基礎として―」
  • Place of Presentation: 九州大学
  • Year and Date: 2014-09-19
  • Invited
• [Presentation] Abrupt changes of distance between succeeding septa at the hatching event in modern Sepia and Spirula (2014)
  • Author(s): Yamaguchi, A., Kumada, Y. and Wani, R.
  • Organizer: Cephalopods ‒ Present and Past 9 & International Coleoid Symposium
  • Place of Presentation: Zurich, Switzerland
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] 古生物学から眺める頭足類 (2014)
  • Author(s): 和仁良二
  • Organizer: シンポジウム「頭足類学を興す」
  • Place of Presentation: 沖縄県立博物館・美術館
  • Year and Date: 2014-08-20 – 2014-08-21
  • Invited
• [Book] Ammonoid Paleobiology: From macroevolution to paleogeography (2015)
  • Author(s): Wani, R. and Gupta, N.S.
  • Publisher: Springer