A very fine complete typical adult retaining most of the test on both sides. The smooth inner whorls, ribbing with ventrolateral tubercles and the high keel, all show well. For a convincing demonstration of dimorphism it should be compared with the inner whorls of the macroconch CAR 23.1. The major difference is that this shows uncoiling of the umbilical seam and is clearly an adult, whereas CAR 23.1 shows no uncoiling and is clearly a nucleus. From glacial drift derived from the Ampthill Clay of eastern England.
Size: 50 mm
Size: 50 mm