(brachiopod) |
(bryozoan) |
DEUTEROSTOMIA
(modified from Tree of Life; traits & tree after Ruppert & Barnes 1994 p. 1050-3 and Brusca & Brusca 2003 p. 875) |
(asteroid echinoderm) |
(enteropneust hemichordate) |
============================ Protostomia | <<===| ====1================== Chaetognatha (arrow worms) | | | |===2================== lophophorates (Ph. BRYOZOA, BRACHIOPODA, etc.) ==D==| | =========== ECHINODERMATA (starfish, urchins, sea cucumbers,etc.) | ==4==| ===3===| ===5======= HEMICHORDATA (acorn worms, pterobranchs) | ================ CHORDATA
Back to Zool 250 tree for animal phyla.
TRAITS SUPPORTING EACH CLADE (** plesiomorphic- a primitive state, not unique to clade):
b) coelom via enterocoely c) blastopore yields anus d) tripartite coelom ----> tripartite body plan protocoel=axocoel ----> protosome mesocoel=hydrocoel ----> mesosome metacoel=somatocoel ----> metasome e) monociliated cells** b) grasping spines around mouth c) ventral ganglion b) reduction in prosome c) U-shaped gut |
b) protocoel has external coelomopore c) tri-coelomate organization of larval stage** d) ciliated pharyngeal pores/gill slits e) post-anal tail f) stiffened, notochord-like structure g) gonads with separate gonoducts b) protocoel has external coelomopore c) larval similarities (echinoderm auricularia & bipinnaria resemble enteropneust tornaria larvae) b) muco-ciliary pre-oral locomotory organ c) paired valved collar ducts d) ventral post-anal tail (Enteropneusta only) |