Merostomata – Horseshoe crabs

Despite their name, horseshoe crabs are not true crabs but represent a unique group of arthropods with a lineage dating back hundreds of millions of years. They belong to an ancient lineage that traces its origins to the Paleozoic Era, making them living fossils. Their existence predates the dinosaurs, and they have remained relatively unchanged over vast stretches of geological time.

Horseshoe crabs boast a distinctive horseshoe-shaped carapace, which shields their cephalothorax. Their long, pointed tail for steering and righting themselves adds to their unique appearance. The carapace also plays a crucial role in protecting their vital organs. They also have compound eyes that provide excellent vision, especially in low-light conditions. These eyes aid in navigation and detecting potential mates during their annual breeding migrations.