ヒオリスは古生代ロフォラートである
Joseph Moysiuk1, Martin R Smith2,3, Jean-Bernard Caron1,4
1Departments of Ecology and Evolutionary Biology and Earth Sciences, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada.
Nature
|January 13, 2017
まとめ
この研究では カンブリア紀のハポロフレンティスを再構築し ロフォフォアと消化管を明らかにしました これらの特徴は,ヒオリスがロフォラートと関連していることを示し,その進化的意義を明らかにしている.
科学分野:
- 古生物学
- 進化生物学
- カンブリア期 化石
背景:
- ハイオリティは,地球規模で分布する カンブリア時代の化石で,未解決の生態学的および進化的重要性がある.
- 軟体解剖学と独特のスクレリトムは,しばしば incertae sedis または軟体動物に関連する様々な分類に繋がっています.
研究 の 目的:
- カンブリア紀中期のヒオリットハプロフレンティスの 軟体解剖学と生態学的役割を再構築する.
- 動物界におけるヒオリスの遺伝的位置を明らかにする.
主な方法:
- バージス・シェールとスペンス・シェール Lagerstätten の ハプロフレンティス の 1,500 種 以上 の 標本 の 検査.
- 栄養と消化器官を含む柔らかい組織を再構成する.
主要な成果:
- ハプロフレンティスは半セシルでエピベンティックなサスペンションフィードとして再構築されます.
- 特別に保存された柔らかい組織は,ロフォフォアと,背側門を持つU形の消化道を示しています.
- これらの特徴は,ロフォフォラト類 (腕足類,フォロニド類,トモチド類) との親和性を示している.
結論:
- この発見は,ヒオリフとロフォラートとの明確な関係を確立しています.
- これは,ヒオリトの既知の形態学的差異を大幅に増加させる.
- この研究により この著名な化石群をめぐる 長い間存在してきた 分類学的な不確実性が解消されました
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