A monograph of the Polish Oxfordian echinoids: Part 2, Subclass Euechinoidea Bronn, 1860

Urszula Radwańska


The non-cidaroid echinoids (subclass Euechinoidea Bronn, 1860) from the Oxfordian epicontinental sequence of Poland (Polish Jura, Holy Cross Mountains, Mid-Polish Anticlinorium) are assigned to the genera Hemipedina Wright, 1855, Hemicidaris L. Agassiz, 1838, Hemitiaris Pomel, 1883, Pseudocidaris Étallon, 1859, Stomechinus Desor, 1856, Eucosmus L. Agassiz in Agassiz and Desor, 1846, Glypticus L. Agassiz, 1840, Pleurodiadema de Loriol, 1870, Diplopodia McCoy, 1848, Trochotiara Lambert, 1901, Desorella Cotteau, 1855, and Heterocidaris Cotteau, 1860, plus one acropeltid taxon, and one taxon left in open nomenclature.

Within the genus Hemicidaris L. Agassiz, 1838, the relationship between Hemicidaris intermedia (Fleming, 1828), Hemicidaris crenularis L. Agassiz, 1839 [non Lamarck, nec Goldfuss] and Hemicidaris quenstedti Mérian, 1855, all with confused taxonomy, is discussed.

Based on test structure, the genera Polydiadema Lambert, 1883, and Trochotiara Lambert, 1901, of the family Emiratiidae Ali, 1990, are proved to be separate; the common species mamillana of F.A. Roemer (1836) is a typical Trochotiara.

An attention is paid to the morphology of the tiny, juvenile specimens, common in Eucosmus decoratus L. Agassiz in L. Agassiz and Desor, 1846, and in Pleurodiadema stutzi (Moesch, 1867).


Euechinoidea; Taxonomy; Hemicidaris; Trochotiara; Juvenile echinoids; Upper Jurassic; Poland

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