Horseshoe crab are marine arthropods of the family Limulidae and order Xiphosura or Xiphosurida that live primarily in and around shallow ocean waters on soft sandy or muddy bottoms.
They occasionally come onto shore to mate. They are commonly used as bait and in fertilizer. In recent years, a decline in the number of individuals has occurred as a consequence of coastal habitat destruction in Japan and overharvesting along the east coast of North America. Tetrodotoxin may be present in the roe of species inhabiting the waters of Thailand.
Horseshoe crab are considered living fossils.
Horseshoe crabs played an important cameo role in this episode. They were shown coming ashore to lay their eggs deep in the shore sand during the night. The morning a flock of Rhamphorhynchus pterosaurs landed ashore to dig out and eat the eggs (ignoring the adult horseshoe crabs). The chain of life continued with several Eustreptospondylus that hunted the pterosaurs with various success.
One month later a new generation of horseshoe crabs was born from the surviving eggs and went back into the ocean with the tide.
Behind the scenesEdit
The species of horseshoe crab shown in the Cruel Sea could be Mesolimulus judging by the time period and location the episode takes place in.