海箭(Solutes)是一类已灭绝的棘皮动物化石发现于中寒武纪到早泥盆纪[2],分布于欧洲北美澳大利亚等地。[3]海箭的身体呈不对称的箭镞形,近两侧对称,主体为由大量不规则骨板构成的萼,附带一根向前延伸的细腕和一条长长的、称作homoiostele的茎尾。肛门位于萼基部的一侧,口孔则位于腕基与肛门之间。大多数海箭营自由生活,少数早期种类则以茎尾固着在基质上。[4][5]

海箭纲
化石时期:鼓山期早泥盆世
Fossil specimen of Coleicarpus sprinklei
Coleicarpus sprinklei的化石
Castericystis之外廓剪影
科学分类 编辑
界: 动物界 Animalia
门: 棘皮动物门 Echinodermata
亚门: 海扁果亚门 Homalozoa
纲: 海箭纲 Soluta
Jaekel英语Otto Jaekel, 1901
异名
  • Homoiostelea Gill & Caster, 1960[1]

海箭的分类地位尚有争议,有假说认为它们是干群棘皮动物,为棘皮动物演化出辐射对称性前的早期演化支[6];另一假说认为它们是由辐射对称棘皮动物演化而来,身体特化而失去了辐射对称性,可能属于海蕾亚门[7]

参考文献

编辑
  1. ^ Homoiostelea (disused) - PBDB Taxon. [2024-04-28]. (原始内容存档于2024-04-28) (英语). 
  2. ^ Lefebvre, Bertrand; Derstler, Kraig; Sumrall, Colin D. A reinterpretation of the solutan Plasiacystis mobilis (Echinodermata) from the Middle Ordovician of Bohemia. Zoosymposia. 2012, 7: 287–306. doi:10.11646/zoosymposia.7.1.27. 
  3. ^ Soluta. Mindat.org. [2024-04-28]. (原始内容存档于2024-04-28). 
  4. ^ Daley, Paul E. J. The first solute which is attached as an adult: a Mid-Cambrian fossil from Utah with echinoderm and chordate affinities. Zoological Journal of the Linnean Society. 1996, 117 (4): 405–440. ISSN 0024-4082. doi:10.1111/j.1096-3642.1996.tb01659.x . 
  5. ^ Lefebvre, Bertrand; Lerosey-Aubril, Rudy. Laurentian origin of solutan echinoderms: new evidence from the Guzhangian (Cambrian Series 3) Weeks Formation of Utah, USA. Geological Magazine. 2017, 155 (5): 1190–1204. S2CID 132681380. doi:10.1017/S0016756817000152. 
  6. ^ Smith, Andrew B. The pre-radial history of echinoderms. Geological Journal. 2005, 40 (3): 255–280. S2CID 86388965. doi:10.1002/gj.1018. 
  7. ^ David, Bruno; Lefebvre, Bertrand; Mooi, Rich; Parsley, Ronald. Are homalozoans echinoderms? An answer from the extraxial-axial theory. Paleobiology. 2000, 26 (4): 529–555. S2CID 86167693. doi:10.1666/0094-8373(2000)026<0529:AHEAAF>2.0.CO;2.