Experimental neoichnology of post-autotomy arm movements of sea lilies and possible evidence of thrashing behaviour in Triassic holocrinids

Echinoderms exhibit remarkable powers of autotomy. For instance, crinoids can shed arm and stalk portions when attacked by predators. In some species, it has been reported that the autotomized arms display vigorous movements, which are thought to divert the attention of predators. This phenomenon, h...

Full description

Saved in:
Bibliographic Details
Published in:Scientific reports 2020-09, Vol.10 (1), p.15147-15147, Article 15147
Main Authors: Gorzelak, Przemysław, Salamon, Mariusz A., Brom, Krzysztof, Oji, Tatsuo, Oguri, Kazumasa, Kołbuk, Dorota, Dec, Marek, Brachaniec, Tomasz, Saucède, Thomas
Format: Article
Language:English
Subjects:
631/181/414
704/158/2462
Animals
Behavior, Animal
Biological Evolution
Biomechanical Phenomena
Earth Sciences
Echinodermata - physiology
Extremities - physiology
Fossils
Humanities and Social Sciences
Movement
multidisciplinary
Paleontology
Predatory Behavior
Science
Science (multidisciplinary)
Sciences of the Universe
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Echinoderms exhibit remarkable powers of autotomy. For instance, crinoids can shed arm and stalk portions when attacked by predators. In some species, it has been reported that the autotomized arms display vigorous movements, which are thought to divert the attention of predators. This phenomenon, however, has not been well explored. Here we present results of experiments using the shallowest water species of living stalked crinoid ( Metacrinus rotundus ) collected at 140 m depth. A wide range of movements of detached arms, from sluggish writhing to violent flicks, was observed. Interestingly, autotomized arms produce distinct traces on the sediment surface. They are composed of straight or arched grooves usually arranged in radiating groups and shallow furrows. Similar traces were found associated with detached arms of the oldest (Early Triassic) stem-group isocrinid ( Holocrinus ). This finding may suggest that the origins of autotomy-related thrashing behaviour in crinoids could be traced back to at least the Early Triassic, underscoring the magnitude of anti-predatory traits that occurred during the Mesozoic Marine Revolution. A new ethological category, autotomichnia, is proposed for the traces produced by thrashing movements of shed appendages.
ISSN:2045-2322
2045-2322
DOI:10.1038/s41598-020-72116-1