Silurian paulinitid polychaetes from Gotland

Silurian paulinitids constitute a large and diverse group of jawed polychaetes which flourished in the tropical epicontinental sea in the Gotland area. They are represented by five genera: Gotlandites, Hindenites, Lanceolatites, Kettnerites [with the subgenus K (Aeolus)], and Langeites. Twenty species and nine subspecies and varieties from latest Llandovery to Late Ludlow are identified, based on apparatuses reconstructed by utilizing isolated elements (seolecodonts). A biologicaI species concept is employed, incorporating taxa based on jaw elements as weU as on apparatuses. The local temporal and geographic occurrences of the paulinitids on Gotland are established. Some lineages evolve very slowly throughout the sequence, and one group forms a complex of shott lineages. A third category of taxa is found only in specific environments. It is eoncluded that at least some species are intracontinentaIly distributed. The study is based on several tens of thousands of jaws from more than 700 samples from 342 localities.