Crassicornis is actually Latin for thick horn
Thorn bugs, due to their unusual appearance, have long interested naturalists. They are best known for their enlarged and ornate pronotum, which most often resembles thorns, apparently to aid camouflage. In some species, the pronotum is a horn-like extension, but can form more bizarre shapes. The specialised pronotum (or helmet) may not be simply an expansion of the prothoracic sclerite, but a fused pair of dorsal appendages of the first thoracic segment.
These may be serial homologues of insect wings, which are dorsal appendages of the second and/or third thoracic segments. Evidence for this theory includes the development of the helmet, which arises as a pair of appendages attached to each side of the dorsal prothorax by an articulation with muscles and a flexible membrane that allow it to be mobile. Also, the same genes are involved in development of the helmet and the wings.