Arachnids belongs to Class Arachnida (Arthropoda Chelicerata) that comprises over 100.000 described Species, including spiders, scorpions, harvestmen, ticks, mites, and solifuges.
Adult arachnids have eight legs while insects have six legs. However, arachnids also have two further pairs of appendages adapted for feeding, defense, and sensory perception. The first pair, the chelicerae, serve in feeding and defense. The other pair of appendages, the pedipalps, have been adapted for feeding, locomotion, and reproductive functions.
Unlike insects, arachnids do not have antennae or wings. Their body is organized into two parts called the cephalothorax and the abdomen. The cephalothorax is derived from the fusion of the cephalon (head) and the thorax, and is usually covered by a single, unsegmented carapace It is typically divided into a preabdomen and a postabdomen, although this is only clearly visible in scorpions, while in the order acarina the abdominal sections are completely fused.
Scorpion, ticks and solifuges are very rare in Dominican and Mexican amber.