1. Phylum Arthropoda, Subphylum Chelicerata Chelicerae are pointed appendages which are used to grasp food Subphylum Chelicerata includes sea spiders (class Pycnogonida) and arachnids (class Arachnida)!

2. Horseshoe Crabs Horseshoe crabs belong to class Merostomata (“thigh mouth”) Appendages used for feeding at one end, and for swimming/locomotion at the other Critically important in coastal marine food webs – Why? © Steffen Foerster Photography/ShutterStock, Inc.

3. Horseshoe crabs Oldest record of horseshoe crab fossils date back 450 million years ago Horseshoe crab blood contains hemocyanin to carry oxygen; blue Blood contains amebocytes which release a clotting factor when exposed to bacteria – Used to detect contamination in medications http://www-tc.pbs.org/wnet/wp-content/blogs.dir/3/files/2008/06/590_crash_blood.jpg