what type of symmetry does a gastropod fossil have
There are about about 13,000 named genera for both Recent and fossil gastropods. They have a long and rich fossil record from the Early Cambrian that shows periodic extinctions of subclades, followed by diversification of new groups.he shell is partly or entirely lost in the juveniles or adults of some groups, with total loss occurring in several groups of land slugs and sea slugs (nudibranchs). Externally, gastropods appear to be bilaterally symmetrical. However, they are one of the most successful clades of asymmetric organisms known.