| A | B |
|---|
| Chelicerata | Subphylum consisting of arthropods with chelicera |
| Arthropoda | Chelicerata is a subphylum of this phylum |
| spinneret | used to spin webs |
| silk glands | located in abdomen, used to make silk |
| chelicera | specially designed mouth parts |
| pedipalps | second set of specially designed mouthparts |
| horseshoe crabs | type of marine chelicerate |
| book lung | used for respiration by spiders |
| two | chelicerates have this many segments |
| to catch prey | spiders spin webs with this purpose |
| cephalothorax | instead of a head and thorax, chelicerates have this |
| abdomen | segment that contains most organs |
| horseshoe crabs | appeared in the Ordovician period |
| Arachnids | all have 4 pairs of walking legs |
| mites | parasites often smaller than 1mm |
| ticks | parasites that spread Lyme disease |
| scorpians | carnivorous, has a stinging barb at the end of the abdomen |
| trilobite larva | common name for young horseshoe crabs |
| silk | strong, flexible protein |
| uses of silk | spinning webs, cocoons, wrappings for prey |
