This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Are sponges lower animals? Why or why not? Are sponges less fit than chordates because they are less advanced or derived or complex? Are invertebrates monophyletic? If so, what synapomorphy defines them? If not, should the term invertebrate be used? Which phyla are most species-rich? Phylum # species Sponges 9,000 Cnidaria (jellyfish, corals, sea anemones) 9,000 Ctenophora (comb jellies) 100 Platyhelminthes (flatworms) Nematodes (roundworms) 12,000 Annelids (segmented worms) ,. Arthropods Crustaceans (crabs, Daphnia , isopods. Chelicerates (spiders, mites, ticks) Insects (beetles!) Molluscs (clams, snails, squid) . . Echinoderms (sea stars, sea urchins) . 7,000 Chordates ....
View Full Document