The cancellothyridid brachiopod Terebratulina chrysalis from the Selandian Kerteminde Marl at Gundstrup, Denmark

The articulate brachiopod Terebratulina chrysalis is very common in the Upper Cretaceous chalk of northern Europe and in the Danian chalk, bryozoan limestone and coralline-bryozoan limestone mounds of Denmark. It was one of the few brachiopod species that survived the mass extinction at the Cretaceous–Palaeogene boundary and it belongs to a long-lived group of closely related Cretaceous–Recent species. It represents a non-specialised generalist which with a rootlike pedicle was able to attach itself to a great variety of both hard and soft substrates. The great adaptability is probably the main reason for its evolutionary success. This is the first systematic study concerning brachiopods from the Kerteminde Marl Formation in Denmark. Hitherto Terebratulina chrysalis is the only known brachiopod from the Gundstrup blocks, referred to the Kerteminde Marl.