Chiroteuthid familiesRichard E. Young and Michael Vecchione
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Chiroteuthid families are a group of six families that share some similar features but whose inclusion as a monophyletic clade has not been firmly established. The most distinctive feature of the group is the loss of the true tentacle club and its replacement by a variety of unusual clubs that generally have more than four series of suckers.
An oegopsid ...
- without primary tentacular club (possible exception in Planctoteuthis).
- with secondary tentacular club.
- Suckers generally in two series (exceptions in Joubiniteuthidae and some Promachoteuthidae and Magnapinnidae).
- Buccal connectives attach to ventral borders of arms IV.
- Primary club apparently lost except in Planctoteuthis; secondary club present and characterized by:
- Protective membranes of club symmetrical (ie, dorsal and ventral membranes identical) when present.
- Keel absent.
- Terminal pad absent.
- Club not expanded.
- Club straight.
- Fins usually terminal (muscular mantle terminates in anterior half of fins).
- A tail, often very long, and supported by the secondary conus of the gladius, generally present.
The relationships among the families of this apparent clade are obscure with one exception. The Chiroteuthididae and Mastigoteuthididae have sometimes been placed within the same family due to similarities in the shape of the funnel locking-apparatus and the presence of elongate arms IV (e.g., Chun, 1910).
Chun, C. 1910. Die Cephalopoden. Oegopsida. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition, "Valdivia" 1898-1899, 18: 1-522 + Atlas.
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- Content changed 21 April 2008
Citing this page:
Young, Richard E. and Michael Vecchione. 2008. Chiroteuthid families. Version 21 April 2008 (under construction). http://tolweb.org/Chiroteuthid_families/19410/2008.04.21 in The Tree of Life Web Project, http://tolweb.org/