Article: A Lower Cretaceous gastropod with fossilized intestines

Margarites (Atira) mirabilis sp. nov. is a small trochid gastropod of Lower Cretaceous (Albian) age and is found in the Lower Greensand (Folkestone Beds) of Kent and Surrey. A unique feature in the description of this fossil gastropod is an account of the digestive tract, based on discovery of a specimen in which the contents of the gut have been phosphatized, thus reproducing as a mould the form and internal structures of the organ. The presence of the intestinal groove with bordering typhlosoles, minor longitudinal folds of the intestine, and an anal sphincter are all clearly demonstrable. Similarities with the gut of Recent Trochidae suggest that ecology and feeding habits of the family have remained unchanged. From the arcuate course of the rectum it is inferred that the left hypobranchial gland, missing in living species of Margarites, if ever present, was probably lost already in Lower Cretaceous times.