Zoology 10th Edition by Stephen Miller,John Harley

Exercise 12

Arthropoda is a monophyletic taxon. Arthropoda, along with the Onychophora and Tardigrada, comprise the clade Panarthropoda. Onychophorans are terrestrial animals, found in tropical and subtropical regions. They prey on small invertebrates using streams of adhesive slime. Tardigrades live in marine and freshwater substrates and in the water film on terrestrial lichens and mosses. They feed on plant fluids and may undergo cryptobiosis. Within the Arthropoda the Trilobitomorpha was the first lineage to diverge from ancestral arthropods. The Chelicerata forms a second monophyletic lineage. The Myriapoda, Crustacea, and Hexapoda are all mandibulates. The Crustacea and Hexapoda comprise a pancrustacean lineage. "Crustacea" is probably paraphyletic with the Hexapoda a monophyletic lineage within the Pancrustacea.
Defend the statement that hexapods are crustaceans that have adapted to terrestrial habitats.