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prothorax

Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
No Taxon (Glossary)
No Taxon (P)
No Taxon prothorax
Explanation of Names
From Latin pro for, front, plus thorax.
Identification
prothorax noun - the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on each side. The prothorax never bears wings in extant insects, though some fossil groups possessed wing-like projections. All adult insects possess legs on the prothorax, though in a few groups (e.g., the butterfly family Nymphalidae) the forelegs are greatly reduced. In many groups of insects, the pronotum is reduced in size, but in a few it is hypertrophied, such as in all beetles (Coleoptera), in which the pronotum is expanded to form the entire dorsal surface of the thorax, and most treehoppers (family Membracidae, order Hemiptera), in which the pronotum is expanded into often fantastic shapes that enhance their camouflage or mimicry. (Initial entry based on Wikipedia entry--see Internet references.)
See Also
Divisions of thorax (front | middle | rear):
prothorax | mesothorax | metathorax

Dorsal surface of thorax (notum):

Lateral (pleural) surface of thorax:

Ventral surface of thorax:
Internet References
Wikipedia--Prothorax