Juvenile eucladid crinoid from the Middle Devonian of Turkey


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Ausich W., GÖNCÜOĞLU M. C.

GEODIVERSITAS, vol.42, no.14, pp.215-221, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 14
  • Publication Date: 2020
  • Doi Number: 10.5252/geodiversitas2020v42a14
  • Title of Journal : GEODIVERSITAS
  • Page Numbers: pp.215-221
  • Keywords: Crinoid, Devonian, Famennian, Hakkari, southeastern Turkey, SE TURKEY, HAKKARI, ONTOGENY, PLATE, REVISION, HOMOLOGY, FOSSIL, AREA

Abstract

A microcrinoid-sized eucladid crinoid (Eucladida Wright, 2017) is described from the Yiginli Formation (Devonian, Famennian) in the Buyuk Zap Anticline in the Hakkari region of SE Turkey. Compared to other eucladids of similar size, the Yiginli Formation specimen is at a quite advanced morphological stage with arms present through at least the secundibrachials. Early post-larval development is a key for understanding homologies among crinoid clades; however Paleozoic crinoids in the microcrinoid range (<= 2.0 mm) are very rare. This specimen is either at a very advanced developmental stage for its size, or typical microcrinoids are neotenic.