A Hope for an Integrated Taxonomy of Fossil and Extant Clam Shrimps

Abstract

Clam shrimps are large bivalved branchiopod crustacean. They first occurred in the Devonian, and flourished during the Mesozoic in Asia. Fossil clam shrimps play an important role in the subdivision and correlation of non-marine fossil-bearing strata. The phosphatized carapaces or carapace external/internal moulds are the main objects for taxonomical studies. The delicate ornament and the ontogenetically developing morphological patterns on the growth bands of carapaces are the main fossil taxonomic criteria. While modern clam shrimp taxonomy is based on soft body morphological features and molecular data, which could not be found in the fossil records. This makes it difficult to discuss the fossil and modern clam shrimp phylogenetic relationship. Nowadays scanning electron microscopes are widely available, and can play an important role in investigating clam shrimp carapace morphology which could be common language to integrate fossil and modern taxonomy.