Horseshoe crabs are an ancient lineage with an evolutionary history stretching back 450 million years (Ordovician period) and are generally considered...
Chaetae are stiff bristles made of chitin that characterize many species of annelid worms.
Reconstruction of Shaihuludia shurikeni from the Spence Shale...
Horseshoe crabs, or xiphosurans, are an order of marine and brackish water arthropods. Despite their common name, they are not really crabs, and are more...
