Suggested to be the ancestral arthropods
Four extant classes
Posses
Head and elongated trunk with many leg bearing segments
No waxy epicuticle (cf insects)
susceptible to desiccation
usually nocturnal
inhabit moist areas
1 pr antennae
1 pr mandibles (prognathous)
1 or 2 pr maxillae
Often
Indirect sperm transfer
Anamorphic development
(add segments and legs with successive moults)
Ocelli
Class Pauropoda
No eyes
Triflagellate antennae
Pseudoculi (vibration sensitive)
0.2-5.0 mm & Colourless
Anamorphic
3prs legs at birth, 9prs at maturity
No heart or tracheal system (due to small size?)
Soil and humus dwellers
Fungi/detritivore feeders
Often aggregated (>500 m2)
Class Symphyla
2-10mm
eyeless & colourless
Anamorphic
6-7prs legs at birth, 12 prs at maturity
Tracheal system anterior body only
1 pr spiracles (on head)
Live deep in soil
Often aggregated (>5000 m2)
Highly flexible
Spermatophore deposited on ground
Female collects and stores in mouth
Egg taken from gonopore to mouth
Coated in sperm
Silk glands on cerci
Class Diplopoda (Millipedes)
2-280mm
Double trunk segments
2prs legs/spiracles
Anamorphic
3prs legs at birth, 751 prs (record)
Dorsoventrally flattened, hemicylindrical, cylindrical
Tergites are sclerotised and calcified
Slow but powerful gait
Coil up for protection
Ozadenes-stink glands
Ozopores-gland openings
Hydrogen cyanide, alkaloids, quinones
Longevity >10 yrs
Predominantly detritivores (gut flora)
Few carnivorous
Direct and indirect sperm transfer
Class Chilopoda
1 pr mandibles, 2 pr maxilla
Maxillapeds modified into poison claws
Indirect sperm transfer
Soft elastic cuticle
Rigidity dependent on Hydrostatic / exoskeleton
Thigmotactic
Carnivorous (often vertebrates)
Anamorphic and epimorphic orders
Posses trachea and spiracles (with trichomes)
Elaborate courtship behaviour
male deposits spermatophore
Often tend eggs and young
Fecundity <50 for brooders
several hundred in non parental care
Longevity 1-6yrs
4 orders
Geophilida
31-181 prs legs
Epimorphic
Usually white
soil dwelling
small, elongate
Scolopendrida
Large tropical/subtropical
> 30cm
21-23prs legs
Epimorphic
Robust, aggressive (frogs/mice)
Lithobida
Anamorphic
mostly temperate
15 pr legs at maturity
Shorter bodied
Scutigerida
Tropical/subtropical
short rigid bodies
Anamorphic
15prs extremely long legs
Craterostigmida
Tasmanian/New Zealand
2-5cm long
15 prs legs