Engraving from Seba's Thesaurus, Locupletissimi rerum naturalium thesauri accurata descriptio (Accurate description of the very rich thesaurus of the principal and rarest natural objects) published in 1734. Albertus Seba (May 12, 1665 - May 2, 1736) was a Dutch pharmacist, zoologist and collector. Engravings (1-10 ) praying mantids, (9-10) European praying mantids, (11-12) grasshoppers. Insects are a class of invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. They are among the most diverse groups of animals on the planet, including more than a million described species and representing more than half of all known living organisms.