Both animals and fungi are eukaryotes. The molecular phylogeny presented in Fig. 3.6 shows a shared common ancestry between animals and fungi. The phyla Porifera and Cnidaria are both within the kingdom Animalia (animals). However, cnidarians are diploblasts with 2 true germ layers. Sponges do not have specialized germ layers and are not considered diploblasts (or triploblasts). Cnidarians and annelids are both animals. Cnidarians are diploblasts (2 germ layers) and annelids are triploblasts (3 germ layers). Crustaceans are a subgrouping within the phylum Arthropoda. All crustaceans are arthropods but not all arthropods are crustaceans. Molluscs and echinoderms are both triploblastic animals. However, these two phyla differ in their embryological development (which reflects their evolutionary history). Molluscs are protostomes while echinoderms are deuterostomes.
Partner Organizations
Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.