Palaeopytogeography of Devonian miospore assemblages

BREUER, P., STEEMANS, P., DI PASQUO, M.

Faro, Portugal

Congreso; The CIMP Faro’09, II Joint Meeting of Spores/Pollen and Acritarch CIMP Subcommissions; 2009

CIMA (University of the Algarve

The review of the Emsian‐Givetian miospore assemblages from the literature allows evaluation of the provincialism of assemblages on a worldwide scale during this interval. Coefficient of similarity is calculated between palynofloras from northern Euramerica, southern Euramerica, northwestern Gondwana, southwestern Gondwana and eastern Gondwana. The resulting low values correspond to low to moderate similarity of miospore assemblages during the interval investigated. The provincialism may be explained by a latitudinal climatic gradient as no palaeogeographic barrier is known during this time interval. However, it seems that a progressive homogenization of the vegetation took place in the Middle Devonian. This transition from provincialism to cosmopolitanism during the Devonian is not only shown by palynofloras but also by the palaeogeographic distribution of many other fossil groups. It is probably due to a decrease of the latitudinal climatic gradient.