ZOO 2700 Study Guide - Final Guide: Polyphyly, Prostomium, Springtail

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2700
• Professor: Alex Smith

Document Summary

Molluscs: most morphologically disparate living animal phylum, they have diversified into all habitats, and have a deep fossil record. Two groups: aplacophora (no shell) and testaria (shell: aplacophora: no shell. Reduced foot is known as the pedal groove instead. Mantle with cuticle and spicules: no outer shell but the epidermis secrete. Radula is an expansion of the foregut calcareous spicules or scales which are embedded in dorsal mantle. Produce trochophore larva: eumollusca= testaria= shelled (not monophyletic due to polyplacophora) Complex radula musculature: ondontophore: is a part of the feeding mechanism in molluscs, it is either cartilage which underlies and supports the radula. Polyplacophora= chitons =bearer of many plates: marine, girdle= thickened part of the mantle, aesthetes: sense organs embedded in the tegmentum of each valve. Mega and micro: 8 dorsal overlapping valves: Tegmentum: is a layer exposed at the surface and surrounded by the girdle. Articulamentum: is purely calcareous- extends well beyond neighboring girdle and the adjacent valve.