Arthropods (595)

adult agricultural ancestor animal animals annelids antennae appendage aquatic arachnid arthropod arthropoda arthropods barnes biological biology biomineralization biramous bodies brain branch brooks budd burgess cambrian carboniferous cell chelicerata chelicerates codex cole combination compound consists cord crab crustacea crustacean cuticle cuticles detect devonian diseases diversity earliest ecdysozoa ecological endocuticle entomology epicuticle epidermis evolution evolutionary excretory exocuticle exoskeleton extant external extinct features female fertilization formed fossil fossils fox ganglia geological gills grouped hardened hexapods hou humans hypothesis insect insects internal invertebrate jointed journal leg legs limb lobsters lophotrochozoa marrella mechanical mite modified molecular molting mouth muscle mx myriapoda myriapods nerve nervous ocelli onychophorans organism organs origin pair paired pairs pest phase phylogenetic phylogeny pigment produce relationship relative rely repeated reproduction respiratory retrieved rigid ruppert science scorpion segment segmentation segmented segments sensor setae shale shrimp silurian specialized species sperm spider subphylum superphylum supply tardigrades terrestrial trilobite vertebrate water zoology