Publication at Faculty of Science |
2010
Abstract
Two specimens of rare trilobites from the Middle Ordovician Šárka Formation (= Darriwilian, Oretanian), both coming from Osek near Rokycany locality, are shortly described. An excellently preserved entire proetide specimen substantially differs from all other Middle Ordovician representatives of this order known from the Prague Basin.
We place it tentatively in the genus Mezzaluna as a new species Mezzaluna? xeelee sp. n. Malformed exoskeleton of the rare cheirurid Areiaspis barrandei shows atypically developed left 9th pleural tip.
Possible mechanisms of this malformation are shortly discussed and unpublished observations on the morphology of the species are added.