Hemicrinus tithonicus Pisera & Dzik, 1979 from the Tithonian of Rogoźnik; cups ZPAL CaI/1356 (holotype) and 1355 (from Pisera & Dzik 1979)

Diagnoza

Cup and the stem axes make an angle of 100-110°. Arm facets are equal in size and occur at alsmost the same level.

Porównanie

This species differs from Hemicrinus thersites in its more bent cup axis. From other congeners it differs in its pentagonal shap and larger cup. Hemicrinus tithonicus exhibits a slight variability in degree of separation of radial plates, outline regularity, and stem thickness.

Autekologia

Występowanie geograficzne

Zasięg czasowy

Materiały muzealne

ZPAL

Literatura

Pisera, A. & Dzik, J. 1979. Tithonian crinoids from Rogoźnik (Pieniny Klippen Belt, Poland) and their evolutionary relationships. Eclogae geologicae Helvetiae 72, 805-849.

Speden, I.G. 1959. Phyllocrinus furcillatus sp. nov, a cyrtocrinid from the Upper Jurassic of Kawhia, New Zealand. Palaeontology 2, 150-155.

Głuchowski, E. 1987. Jurassic and Early Cretaceous Articulate Crinoidea from the Pieniny Klippen Belt and the Tatra Mts, Poland. Studia Geologica Polonica 94, 1-102.

Manni, R., Nicosia, U. & Szabó J. 1992. Late Jurassic crinoids from the Eperkés-hegy (Bakony Mts., Hungary). Fragmenta Mineralogica et Palaeontologica 15, 115-137