海箭(Solutes)是一類已滅絕的棘皮動物化石發現於中寒武紀到早泥盆紀[2],分佈於歐洲北美澳大利亞等地。[3]海箭的身體呈不對稱的箭鏃形,近兩側對稱,主體為由大量不規則骨板構成的萼,附帶一根向前延伸的細腕和一條長長的、稱作homoiostele的莖尾。肛門位於萼基部的一側,口孔則位於腕基與肛門之間。大多數海箭營自由生活,少數早期種類則以莖尾固著在基質上。[4][5]

海箭綱
化石時期:鼓山期早泥盆世
Fossil specimen of Coleicarpus sprinklei
Coleicarpus sprinklei的化石
Castericystis之外廓剪影
科學分類 編輯
界: 動物界 Animalia
門: 棘皮動物門 Echinodermata
亞門: 海扁果亞門 Homalozoa
綱: 海箭綱 Soluta
Jaekel英語Otto Jaekel, 1901
異名
  • Homoiostelea Gill & Caster, 1960[1]

海箭的分類地位尚有爭議,有假說認為它們是幹群棘皮動物,為棘皮動物演化出輻射對稱性前的早期演化支[6];另一假說認為它們是由輻射對稱棘皮動物演化而來,身體特化而失去了輻射對稱性,可能屬於海蕾亞門[7]

參考文獻

  1. ^ Homoiostelea (disused) - PBDB Taxon. [2024-04-28]. (原始內容存檔於2024-04-28) (英語). 
  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]. (原始內容存檔於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.