Acritarch clusters from the Cambrian (Miaolingian) of the Pribram-Jince Basin, Czech Republic

Monogeneric clusters of five acritarch genera (Adara, Cymatiosphaera, Eliasum, Synsphaeridium and Timofeevia) were discovered in palynological residues obtained from fine-grained siliciclastic samples from the middle Cambrian (Miaolingian) Jince Formation of the Pribram-Jince Basin (Czech Republic). The clusters consist of two to more than 100 individual specimens and lack a common pattern of organisation. Acritarchs within clusters fall within a similar size range, regardless of generic affinity. Proposed mechanisms for the formation of these acritarch clusters are discussed: for the Jince Formation clusters, aggregation within algal blooms or primary colonial behaviour are the most plausible explanations. In addition, a summary of reports of acritarch clusters from lower Palaeozoic strata is included: clusters of a variety of acritarch genera have been documented from rocks of early Cambrian to Late Devonian age.

Automated summary

Monogeneric clusters of five acritarch genera were found in the middle Cambrian Jince Formation, consisting of two to more than 100 individual specimens and lacking a common pattern of organization. The formation of these clusters is likely due to aggregation within algal blooms or primary colonial behavior. Clusters of various acritarch genera have also been documented in rocks from the early Paleozoic era to the Late Devonian age.