鉸齒
雙殼綱
雙殼綱物種的鉸齒位於殼體背部沿線的鉸線。雙殼綱的殼並沒有腹足綱物種的虹管溝去讓虹管伸出來,其殼上也沒有部分腕足動物那種讓其肉莖伸出來的開口。所以在實際生活中,殼體需要能夠稍微打開,以讓其斧足和虹管從中間的殼間隙縫伸出,當再次關閉之時,又不會使兩瓣殼無法對齊。鉸齒的出現讓兩殼可以更好的閉合。
對於雙殼綱大多數的科來說,牠們的兩瓣殼在鉸線兩邊幾乎是完全對稱,就只在鉸齒在每一邊都有些微差異,否則兩瓣殼就無法完全緊閉。
腕足動物門
腕足動物是另一組有鉸齒的有殼動物的門,但牠們的是上、下開合,而不是左、右開合。在腕足動物的傳統分類裡,會分為有鉸綱(Articulata)和無鉸綱(Inarticulata)兩部分:當中只有有鉸綱的物種有鉸齒,而無鉸綱物種只靠肌肉來拉緊兩瓣殼[6][7][8]。現時有鉸綱的物種在新的分類中,主要被分到小嘴貝綱。
參考文獻
- Carter, Burt. (英语).
- Sturm, C. F., T. A. Pearce, and A. Valdes. 2006. The Mollusks: A guide to their Study, Collection, and Preservation. American Malacological Society, Pittsburgh, PA, U.S.A. xii+455 Pp.
- Huber, Markus (2010). Compendium of Bivalves. A Full-color Guide to 3'300 of the World's Marine Bivalves. A Status on Bivalvia after 250 Years of Research. Hackenheim: ConchBooks. pp. 901 pp. + CD. ISBN 978-3-939767-28-2, at p. 59
- Bivalves by J.H. Leal, Bailey-Matthews Shell Museum, Florida, USA (PDF). [2012-11-13]. (原始内容 (PDF)存档于2013-05-11).
- Invertebrate Paleobiology on-line syllabus on Bivalves, by Dr. Burt Carter, Georgia Southwestern State University, at: http://itc.gsw.edu/faculty/bcarter/paleo/labs/moll/biv2.htm
- Ax, P. . Springer. 2003: 87–93. ISBN 3-540-00146-8 (英语).
- Ruppert, E.E; Fox, R.S.; Barnes, R.D. . 7th ed. Brooks/Cole. 2004: 821–829. ISBN 0-03-025982-7.
- Moore, R.C. . Moore, Lalicher, and Fischer (编). . New York: McGraw-Hill. 1952 (英语).
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