A large phylum of invertebrate animals that includes insects, spiders, crustaceans, and their relatives. They have a segmented body, an external skeleton, and jointed limbs, and are sometimes divided among several phyla.‘Tardigrades, close relatives of Onychophora and Arthropoda, possess ornamented armored exoskeletons in high predation marine environments.’
- ‘The recently published Ecdysozoa hypothesis suggests a closer relationship of the Scalidophora, Nematode, Nematomorpha, Tardigrada, Onychophora, and Arthropoda.’
- ‘Other ecdysozoan phyla include Nematoda, Tardigrada, and Onychophora; this classification thus removes onychophorans from the Arthropoda and makes them an outgroup.’
- ‘Fifthly, the Trilobita is by far the best-represented arthropod group within Paleozoic rocks, from an important interval in the evolutionary history of the phylum Arthropoda.’
- ‘What light do fossils shed on the deep history of life's most diverse phylum, the Arthropoda?’
Modern Latin (plural), from Greek arthron ‘joint’ + pous, pod- ‘foot’.