Close. Arthropoda is the phylum under Animalia. From there you have the four subphyla Crustacea (crustaceans), Hexapoda (insects), Myriapoda (centipedes and millipedes), and Chelicerata (chelicerates). So they are closely related relatively speaking, but they’re separate subphyla.
If anything, funnily enough, the clade Pancrustacea is comprised of just crustaceans and hexapods to the exclusion of myriapods and chelicerates. Even more messy – I learned just now that – is that Arthropoda can be divided into two clades Chelicerata and Mandibulata (where Mandibulata contains myriapods and Pancrustacea), so in reality, not only are horseshoe crabs more closely related to a black widow spider than to crabs, but crabs are substantially more closely related to a mosquito than to horseshoe crabs.
Close. Arthropoda is the phylum under Animalia. From there you have the four subphyla Crustacea (crustaceans), Hexapoda (insects), Myriapoda (centipedes and millipedes), and Chelicerata (chelicerates). So they are closely related relatively speaking, but they’re separate subphyla.
If anything, funnily enough, the clade Pancrustacea is comprised of just crustaceans and hexapods to the exclusion of myriapods and chelicerates. Even more messy – I learned just now that – is that Arthropoda can be divided into two clades Chelicerata and Mandibulata (where Mandibulata contains myriapods and Pancrustacea), so in reality, not only are horseshoe crabs more closely related to a black widow spider than to crabs, but crabs are substantially more closely related to a mosquito than to horseshoe crabs.
Thanks for the info, I love learning this kinda stuff.