Data from: Organic-walled microfossils from the Kistedalen Formation, Norway: acritarch chronostratigraphy of the Baltic Miaolingian and evolutionary trends of placoid acritarchs

New acritarch data from the Kistedalen Formation based on two sections
with continuous exposure allow to establish the most detailed Miaolingian
acritarch biozonation in Baltica to date. Six interval zones previously
established in Gondwana, the Eliasum llaniscum, Cristallinium cambriense,
Adara alea, Timofeevia lancarae, Cristallinium dubium and Vulcanisphaera
turbata zones, are identified, and their correlations within the
Acado-Baltic Province examined. The diagnoses of Retisphaeridium,
Cristallinium, Retisphaeridium dichamerum, Retisphaeridium lechistanium,
Cristallinium dubium and Cristallinium cambriense are emended and the new
species Retisphaeridium rugulatum sp. nov. and Retisphaeridium minimum sp.
nov. are described. The diagnosis of Retisphaeridium ovillense (Cramer
& Díez) Vanguestaine is emended and the species assigned to
Dictyotidium ovillense comb. nov. The main evolutionary changes of the
placoid acritarchs during the Miaolingian are analysed. Comparison with
previous acritarch data from the Kistedalen Formation suggest that
different extraction methodologies may result in significant bias in the
recovered fossil record.