image ID practing tool

• check out http://www.dec.state.ny.us/website/dow/stream/orderpageone.htm

phylum Onychophora - velvet worms

• perhaps between Arthropoda and Annelida
• terrestrial (wet places); subtropical
• thin chitinous cuticle
• legs not jointed
• molts every few days
• simple eyes
• mandibles derived from claws (end of legs) - unlike arthropods

phylum Arthropoda

• metameric (segmented) - often fused into tagmata (e.g. head, thorax)
• ecdysis (molting, along ecdysal lines)
• chitinous exoskeleton - therefore small (although aquatic can be larger)
• epicuticle (outer - thin, cement/lipids/wax), exocuticle (strong, missing at joints), endocuticle (missing at respiratory surfaces)
• no circular muscles (except a group of millipeeds)
• no cilia (well, some, but heavily modified), flagella only in sperm of some
• haemocyl in body cavity (open circulatory system)
• book lungs - spiracle connects to atrium (attached to muscle), with things long things with little things (looks comb-ish) (xiphosura, scorpions, amblypygi, uropygi, araneae)
• trachea - branch-like (all the rest, some araneae)
• body parts nomenclature
  • top: tergum (notum if on thorax of insect)
  • bottom: sternum
  • sides: pleuron

3 subphyla

Trilobita - all extinct

Chelicerata

Mandibulata

BIOL 412 stuff of note