Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Relay Strategy and Adaptation to a Muddy Environment in Isselicrinus (Isselicrinidae: Crinoidea)

Shin-Ichi Fujiwara, Tatsuo Oji, Yasutaka Tanaka and Yasuo Kondo
PALAIOS
Vol. 20, No. 3 (Jun., 2005), pp. 241-248
Stable URL: http://www.jstor.org/stable/27670336
Page Count: 8
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Relay Strategy and Adaptation to a Muddy Environment in Isselicrinus (Isselicrinidae: Crinoidea)
Preview not available

Abstract

Abundant columns of Isselicrinus ariakensis occur in a limited interval of the Upper Eocene Sakasegawa Formation in western Japan. Most of these are several centimeters in length, but curiously they usually stand upright, perpendicular to the bedding plane of the mudstone, and occur as bundles of 2 to 10 columns, with their original distal parts oriented downward. Based on detailed observation of the modes of occurrence as well as on CT scanning of the specimens, a reconstruction of the presumed mode of life is presented. The individuals of Isselicrinus adopted a relay strategy in the muddy substrate, using pre-existing upright columns as anchorage. Similar upright columns of Isselicrinus are also found, or have been reported, from other Eocene and Miocene strata in Japan, Argentina, and Denmark, suggesting that these Isselicrinus adopted this specialized mode of life as an adaptation to muddy bottoms.

Page Thumbnails

  • Thumbnail: Page 
241
    241
  • Thumbnail: Page 
242
    242
  • Thumbnail: Page 
243
    243
  • Thumbnail: Page 
244
    244
  • Thumbnail: Page 
245
    245
  • Thumbnail: Page 
246
    246
  • Thumbnail: Page 
247
    247
  • Thumbnail: Page 
248
    248