New endobiotic cornulitid and Cornulites sp. aff. Cornulitescelatus (Cornulitida, Tentaculita) from the Katian of Vormsi Island, Estonia

Abstract

Two species of endobiotic cornulitids are described from heliolitid corals of the Katian (Late Ordovician) of Estonia. They are thus far the earliest known showing this symbiotic relationship. Conchicolites hosholmenis n. sp. represents the only known symbiotic coral endobiont species in the genus. Cornulites sp. aff. Cornulites celatus closely resembles the North American endobiotic species C. celatus from tabulates of the Hirnantian (Late Ordovician).

Keywords:

• Cornulitida
• Heliolitida
• endobionts
• Ordovician
• Baltica
• Estonia

Acknowledgements

The authors thank Dr Dieter Weyer from the Natural History Museum of Berlin for offering specimens. O.V. is indebted to the Sepkoski Grant (Paleontological Society) and the target-financed project (from the Estonian Ministry of Education and Science) SF0180051s08 (Ordovician and Silurian climate changes, as documented from the biotic changes and depositional environments in the Baltoscandian Palaeobasin) for financial support. M.-A.M is supported by the target-financed project (from the Estonian Ministry of Education and Science) SF0140020s08. We are grateful to journal reviewers Jan Bergström (Stockholm) and Per Ahlberg (Lund) for the constructive reviews, and to M.A. Wilson (College of Wooster) who read earlier versions of the manuscript.