Two types of fossil specimens of horseshoe crab have been found in Canada which date back to at least 100 million years. According to a report in Live Science, this finding has revealed a new genus of the Horseshoe Crab called Lunataspis Aurora, which roamed along the shorelines of the planet half a billion years ago. The ancient Horseshoe Crab is estimated to have been just 1.5 inches (4 centimeters) from head to tail-tip which is much smaller than its modern-day relatives that can span nearly 20 inches (50 centimeters), the report claims.

According to David Rudkin, Researcher at the Royal Ontario Museum, the fossils were small because the crab was either too young or it didn't grow any bigger. Rudkin and his colleagues made the discovery of the fossils of this species in 445-million-year-old rocks from the Ordovician period in central and northern Manitoba. The specimens included patches of the animals' outer-covering and even evidence of their compound eyes. Analysis of the recent finds also indicates the ocean creatures haven't changed much over the eons.

It is said that Horseshoe Crabs are not actually crabs but are instead more closely related to spiders and scorpions. Like their eight-legged relatives, Horseshoe Crabs sport a flexible exoskeleton made of chitin rather than the hard-shell armoring worn by crabs.