Stages in the development of the larva of Terebratulina septentrionalis.... The youngest larva has two segments, a third then appears, the larva then fixes itself, and the second segment folds over the first and develops bristles round its edge.
Description: English: A Terebratulina sp. lampshell, view of the hinge, 11mm, from Hill Down, Wiltshire, UK, middle Upper Cretaceous (Coniacian). Date: 30 September 2011. Source: Own work. Author: Dwergenpaartje.
Description: English: A Terebratulina sp. lampshell, view of the opening, 11mm, from Hill Down, Wiltshire, UK, middle Upper Cretaceous (Coniacian). Date: 30 September 2011. Source: Own work. Author: Dwergenpaartje.