The trilobite Family Illaenidae Hawle et Corda, 1847 from the Ordovician of the Prague Basin (Czech Republic)

Abstract

ABSTRACT This present revision of Bohemian Ordovician illaenid trilobites of the Prague Basin (Czech Republic) follows the recent evaluation of their systematic position. This revision contains redescriptions and illustrations of the type species of several illaenid genera, the most up-to-date references for those genera, and an assessment of their variability and also of the palaeobiogeographic distribution of some illaenid genera. Bohemian illaenids in several cases include the type species of globally distributed taxa, whose distinction has often been uncertain and controversial. The validity of the genera Zbirovia Šnajdr, 1956 and Zdicella Šnajdr, 1956 is discussed and confirmed. The genus Alceste Hawle et Corda, 1847 stays in open nomenclature. In Ectillaenus katzeri katzeri (Barrande, 1856) allometric growth is described and Vysocania Vaněk & Vokáč, 1997 is considered to be a junior synonym of Stenopareia Holm, 1886.