Tag Archives: diversification

Phylogeny and Diversification in Mollusc

The first molluscs probably arose during Precambrian times because fossils attributed to Mollusca have been found in geological strata as old as the early Cambrian period. On the basis of such shared features as spiral cleavage, mesoderm from the 4d blastomere, and trochophore larva, many zoologists argue that Mollusca are …

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