Horseshoe crabs are not crabs: they are more closely related to spiders. The shape of their bodies has not changed much since the era of dinosaurs. Therefore, by looking at them one may feel like time traveling to the distant back. Today there are four living species of horseshoe crabs: three of them live in Asia and the other one lives in North America.
Its body is covered by hard armors. A pair of big compound eyes locate at the back of the front semicircle-shaped shell. The rear triangular-shaped shell has several spikes at the border and can be folded downwards. It has a long and thin tail, which could be used to adjust the position of its body then it is accidentally flipped upside down. Its mouth is located at the center of its legs under the armor. The leg can be used to transfer foods into the mouth. Behind the legs it also has unique book gills, which can help them swimming.
An interesting fact about horseshoe crabs is that their blood is blue. It is precious and can be used to detect bacterial. To show this I hided a piece of blue 1*4 plate under the front armor as an Easter egg.
This model contains about 150 pieces and measures 17 cm long.