Family Dibrachicystidae (Echinodermata: Rhombifera) from the 'Middle' Cambrian of the Barrandian area, Czech Republic

摘要

A slightly crushed but otherwise nearly complete specimen of the recently described rhombiferan echinoderm genus Vizcainoia Zamora and Smith, 2012 is documented from the "Middle" Cambrian Jince Formation of the P?íbram–Jince Basin of the Czech Republic. Isolated thecal plates, earlier determined as calyx plates of the eocrinoid Acanthocystites briareus Barrande, 1887 and/or as eocrinoid sp., occurring in diverse levels of the Jince Formation are reassigned to Dibrachicystidae gen. et sp. indet. Similarly, isolated thecal plates collected from the Buchava Formation of the Skryje–Ty?ovice Basin could be classified as Dibrachicystidae gen. et sp. indet. Specimens from the Barrandian area are the first records of the family Dibrachicystidae outside of southwestern Europe, of the family otherwise known only from the Languedocian of Montagne Noire of France and from the Caesaraugustian and Languedocian of Iberian Chains of northern Spain.