Possible polychaete tube worms from the Late Emsian (Early Devonian) of the Parana Basin, Brazil

Plastically deformed and silicified worm tubes from the Late Emsian (Early Devonian) of the Parana Basin are described herein as a new species and genus of annelid worms Annulitubus mutveii gen. et sp. nov. The tubes are straight and ornamented by smooth rings. Their microstructure is homogenous, which most likely is a diagenetic alteration. The characteristic early diagenetic compression of the tubes may point out to their original elastic organic tube wall. We cannot state it with full confidence but the most likely tube producers were tube-dwelling polychaete annelids, which were otherwise uncommon in the Paleozoic times.