Arachnida

class of arthropods Arachnids (Arachnida) is a class of organisms united by key anatomical and physiological traits. It contains 9 orders with 274 known species. Key order groups include Araneae, Ixodida, Mesostigmata, Opiliones, Pseudoscorpiones, and Sarcoptiformes. Among its members, 29 species are currently classified as threatened (Critically Endangered, Endangered, or Vulnerable). It belongs to Arthropods (Arthropoda).