Editing Crinoid (section)

==Locomotion==
[[File:Crinoid and comatule.jpg|thumb|upright=1.2|A stalked crinoid (white) and a comatulid (red) in deep sea, showing the differences between these two sister groups]]

Most modern crinoids, i.e., the feather stars, are free-moving and lack a stem as adults. Examples of fossil crinoids that have been interpreted as free-swimming include ''Marsupites'', ''Saccocoma'' and ''Uintacrinus''.<ref>{{cite web |url=https://www.fossilera.com/pages/about-crinoids |title=About Crinoids |publisher=FossilEra |access-date=15 March 2019}}</ref> In general, crinoids move to new locations by crawling, using the cirri as legs. Such a movement may be induced in relation to a change in current direction, the need to climb to an elevated perch to feed, or because of an agonistic behaviour by an encountered individual.<ref name=Shaw>{{cite journal |author1=Shaw, G.D. |author2=Fontaine, A.R.  |year=2011 |title=The locomotion of the comatulid ''Florometra serratissima'' (Echinodermata: Crinoidea) and its adaptive significance |journal=Canadian Journal of Zoology |volume=68 |issue=5 |pages=942–950 |doi=10.1139/z90-135 }}</ref> Crinoids can also swim. They do this by co-ordinated, repeated sequential movements of the arms in three groups. At first the direction of travel is upwards but soon becomes horizontal, travelling at about {{convert|7|cm|in|1|abbr=on}} per second with the oral surface in front. Swimming usually takes place as short bursts of activity lasting up to half a minute, and in the comatulid ''[[Florometra serratissima]]'' at least, only takes place after mechanical stimulation or as an escape response evoked by a predator.<ref name=Shaw/>

In 2005, a stalked crinoid was recorded pulling itself along the sea floor off the [[Grand Bahama|Grand Bahama Island]]. While it has been known that stalked crinoids could move, before this recording the fastest motion known for a stalked crinoid was {{convert|0.6|m|ft|0|abbr=off}} per hour. The 2005 recording showed one of these moving across the seabed at the much faster rate of {{convert|4|to|5|cm|in|1|abbr=on}} per second, or {{convert|144|to|180|m|ft|0|abbr=on}} per hour.<ref>{{cite conference |last1=Baumiller |first1=Tomasz K. |last2=Messing |first2=Charles G. |title=Crawling In Stalked Crinoids: In Situ Observations, Functional Morphology, and Implications for Paleozoic Taxa |book-title=Geological Society of America Abstracts with Programs |volume=37 |issue=7 |date=6 October 2005 |page=62 |url=https://gsa.confex.com/gsa/2005AM/finalprogram/abstract_96883.htm |access-date=6 April 2014 |archive-url=https://web.archive.org/web/20140407090700/https://gsa.confex.com/gsa/2005AM/finalprogram/abstract_96883.htm |archive-date=7 April 2014 |url-status=dead }}</ref>