ARTHROPODA (VI): Trilobitomorpha and Uniramia (Other arthropod study images ;
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b) 3 tagmata:
b) SuperCl. MYRIAPODA: (>13,000 terrestrial spp; 1 mm - 30 cm)
- Cl. CHILOPODA (centipedes, 2800 spp.) 15 - 177 pairs of legs; 1st pair bears poison claws; mostly predatory
- Cl. DIPLOPODA (millipedes, >10,000 spp.): 100 - 700 pairs of legs; adjacent trunk segments fuse yielding 2 pairs of legs per body unit (diplosegment); mostly herbivores
c) SuperCl. HEXAPODA (the insects):
- APTERYGOTA: 4 classes; lack wings; ametabolous (gradual) development; internalized mouthparts (entognathus)
- Cl. PTERYGOTA: the winged insects; external mouthparts (ectognathus)
d) Ommatidium form (4-part crystalline style in Crustacea + Hexapoda but not Myriapoda) raises doubts about uniramian monophyly
Copyright (c) 2012 by A. Richard Palmer. All rights reserved.
(revised Dec. 31, 2011)