(rotifer) |
(nematode worm) |
ASCHELMINTHES
(=pseudocoelomate phyla) (A grouping of convenience;
|
(nematomorph worm) |
(priapulid worm) |
==C== (branch uncertain) ======== Cycliophora ("small-wheel bearer"; newest phylum) | | ===3=============== Rotifera (rotifers= "wheel bearers") |====2========| <<==1===| ===4=============== Acanthocephala (spiny headed worms) | | =============6=============== Gastrotricha (gastrotrichs, hairy-belly worms) | | =5==| ===9=============== Nematoda (round worms) | ===8==| | | ==10=============== Nematomorpha (horsehair worms) | | =7==| ==12=============== Priapula (penis worms) | | ==11==| ===14======== Kinorhyncha (spiny-snout propelled worms) ==13==| ===15======== Loricifera (corset-bearer worms)
Back to Zool 250 tree for animal phyla or Protostomia
b) pseudocoelom c) extracellular cuticle d) bilaterally asymmetrical, determinate cleavage e) mesoderm from blastopore rim f) direct development g) protonephridia** b) sessile, filter-feeding rotifer-like adult c) wheel-like ring of multiciliated cells surrounds the mouth d) U-shaped gut e) complex life cycle with sexual and asexual stages f) unique Pandora larva (extracellular cuticle absent) b) sperm structure with anterior flagella b) one ventral nerve cord b) apical proboscis with intracellular hooks c) two lateral nerve cords b) radial pharynx c) tripartite epipharyngeal brain b) pseudocoelom lost c) two lateral nerve cords |
b) cuticle molted c) introvert with cuticular spines, teeth or scalids b) protonephridia lost c) circular trunk muscles lost d) non-ciliated sperm b) four nerve cords (dorsal, ventral, 2 lateral) b) no amphids c) one ventral nerve cord b) rings of scalids on introvert c) chitinous cuticle d) one ventral nerve cord b) unique caudal appendage c) unique loricate larva b) circular trunk muscles lost b) tri-radiate, myo-epithelial sucking pharynx |