Armoured test of Early Devonian Mesoconularia (Conulariida) from the Prague Basin (Czech Republic): probable adaptation to increased predation pressure
Abstract
An unusually complex type of skeletal ornamentation in the new conulariid species, Mesoconularia (1) lukesi sp. nov. from upper Emsian strata of the Prague Basin (Czech Republic) is described. The complex structure of elevated and heavily mineralized tubercles arrayed in transverse rows on the outer surface of the test of this conulariid is interpreted as a protective structure which probably evolved in response to increasing durophagy in the early Devonian.
Favourable preservation of M. (?) lukesi sp. nov. revealed several hitherto unknown morphological features which could be important for reconstruction of the organisation and growth of the conulariid test. Polygonal imprints observed on the inner surface of the test laminae may represent epidermal cell moulds.
The mineral component of the test of M. (?) lukesi consists of of carbonate-fluorapatite (francolite) and exhibits a homogeneous microstructure in both the outer and the inner layers of the test.