Taxonomy and palaeoecology of a decapod crustacean assemblage from the Oxfordian of Stranska skala (Southern Moravia, Czech Republic)
Abstract
Primitive brachyurans and other decapods have been extensively reported from deposits of Oxfordian age, often termed microbial-sponge and coral megafacies distributed across the entirety of Europe. During the Oxfordian, coral reefs were far less common than microbial-sponge build-ups.
The occurrences of decapods associated with such coral facies include those in France, Romania and the Czech Republic. Regarding the Czech Republic, the assemblage from the Stranska skala Hill has been evaluated; it is composed of at least six species including Gastrosacus wetzleri, Eomunidopsis cf.
E. neojurensis, Longodromites angustus, Goniodromites narinosus, Goniodromites serratus and Eodromites grandis. Besides the dorsal carapace material, isolated chelae are described as well.
As they are not preserved in direct association with taxonomically significant carapaces, they are treated in open nomenclature. Differential diversity of decapods at Stranska skala is relatively low compared to slightly younger Tithonian coral-associated assemblages from Romania.
Out of 36 studied specimens, three bear a swelling on the branchial region interpreted to be a result of an isopod infestation. The relatively high percentage of infestation (8.33%) can be explained by collection bias since carapaces with bopyriform swellings can be considered more attractive to collectors.