The Arthropods are the largest and most successful Phylum on this planet!!
All of the Insects, Spiders, Crabs, Prawns, Millipedes, Centipedes and many other groups of fascinating animals are Arthropods, all told arthropods make up more than 80% of the animal Kingdom.
An Arthropod is an animal that possesses these characteristics.
A) a mouth and anus at opposite ends of a through gut,
B) a hard jointed exoskeleton,
C) jointed limbs.
The Phylum Arthropoda is divided into 5 Subphyla (4 still in existence) each of which is in turn divided into various Classes.
- Body in two parts, no antennae.
Body in three parts, thorax in eight segments, two pairs of antennae.
- Class Cephalocarida (Small primitive shrimps only discovered in 1955)
- Class Branchiopoda (Small primitive animals with gills on their feet i.e. Daphnia)
- class Ostracoda (small animals which look like miniature bivalves)
- Class Mystacocarida (Minute thin shrimp like creatures)
- Class Copepeda (Important small crustaceans such as Cyclops)
- Class Branchiura (Small blood sucking ectoparasites)
- Class Cirripeda (Barnacles)
- Class Malacostraca (75% of all crustaceans, Crabs, Lobsters, Shrimps and Prawns as well as Woodlice and Amphipods)
Subphyllum HexapodaBody in three parts, thorax in three segments.
Subphyllum MyriapodaBody in three parts, thorax with many segments, one pair of antennae.
- Class Chilopoda (Centipedes)
- Class Diplopoda (Millipedes)
- Class Symphyla (Small centipede like creatures which live in leaf litter)
- Class Pauropoda (Small soft bodied animals of the forest floor)
Subphyllum Trilobitamorpha (Extinct) Body in three parts, thorax in many segments, one pair of antennae.
The Invertebrates, a new synthesis. by Barnes, R.S.K., Calow, P. and Olive, P.J.W. (1988) Blackwell Scientific, London ISBN=0 632 01638 8
The Invertebrata. by Borradaile,L.A., Potts, F.A. and Saunders, J.T. (2nd Ed.) (1956) Cambridge University Press, Cambridge.
Animal Diversity. by Kershaw, D.R. (1983) Unwin Hyman, London ISBN = 0 04 445177 6