Cambrian trilobites from Brzechów, Holy Cross Mountains (Poland) and their significance in stratigraphic correlation and biogeographic reconstructions

A revision of the trilobite fauna from Brzechow in the Holy Cross Mountains (Poland) shows that the assemblage consists of Palaeolenus medius (Bednarczyk), Issafeniella orlowinensis (Samsonowicz), Kingaspidoides sanctacrucensis (Czarnocki), Paradoxides ( Acadoparadoxides ) oelandicus Sjogren, P. ( A. ) cf. mureroensis Sdzuy and P. ( A. ) sp. It is earliest Middle Cambrian in age according to the West Gondwana standard of Geyer & Landing (2004) and can be correlated with the Cephalopyge notabilis Zone of Morocco. Moreover, the co-occurrence of the ranges of P. ( A. ) oelandicus with P. ( A .) cf. mureroensis might suggest that P. ( A. ) oelandicus appears earlier in the Brzechow sandstones than in Scandinavia, thus the strata exposed here do not find their correlative in the Scandinavian succession. As a result, the Banian/Agdzian boundary (Lower–Middle Cambrian boundary according to the West Gondwana standard) probably lies within the Kamieniec Formation, and also below the Brzechow sandstones, in the upper part of the Ocieseki Formation. Close similarity of the discussed assemblage with contemporaneous assemblages from Morocco, Jordan or New Brunswick indicates that the fauna is generally of peri-Gondwanan and Gondwanan aspect.