Horseshoe crabs: 450 million years almost unchanged

Older than dinosaurs and not true crabs

Horseshoe crabs appeared 450 million years ago, 220 million years before dinosaurs, with domed shells, 10 legs and a 30-centimeter tail spine for flipping. in total today for sure

Despite the name they are spider relatives, not crabs, with 4 surviving species in America and Asia after 5 mass extinctions over 450 million years.

Blue blood, full moons and 1 million eggs

Their blue copper blood clots around bacteria, powering the LAL test that screens every vaccine and implant, using blood from 500000 crabs ежегодно with 85 percent released alive.

Each spring females lay up to 100000 eggs on full-moon high tides, feeding 1 million migrating shorebirds, though only about 10 chicks from 100000 eggs survive.

• Appeared 450 million years ago
• Only 4 species today
• Blue blood tests vaccines and implants
• Lay 100000 eggs on full moons
• Tail spine reaches 30 centimeters