Chancelloriidae

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"Chancelloriidae" is a name applied to a type of fossil that is are common from the Early Cambrian to the early Late Cambrian. Many of these fossils consists only of spines and other fragments, and it is not certain that they belong to the same type of organism. Other specimens appear to be more complete and to represent sessile, bag-shaped organisms with a soft skin that has composite calcareous sclerites from which radiate sharp spines.

Contents

[edit] First description

Chancelloriidae were first described by Charles Doolittle Walcott in 1920.[1]

[edit] Function of spines

Since the sclerites were external and non-interlocking, they could not have functioned as supporting "struts". Since the body was sessile and attached to the sea-bed, the sclerites would not aided locomotion by increasing traction. So the only conceivable function for the sclerites appears to be defense against predators, rather similar to the spines on modern cacti.[2]

[edit] References

  1. ^ Walcott, C. D. (1920) "Cambrian geology and paleontology IV:6—Middle Cambrian Spongiae", Smithsonian Miscellaneous Collections volume 67 pages 261–364
  2. ^ Bengtson, S. (2002), “Origins and early evolution of predation”, in Kowalewski, M., and Kelley, P.H., The fossil record of predation. The Paleontological Society Papers 8, The Paleontological Society, pp. 289– 317, <http://www.nrm.se/forskningochsamlingar/fossil/paleozoologi/personal/stefanbengtson/stefanbengtsonpublikationer.4.4e32c81078a8d924980007638.html> 

[edit] See also