The job of the pivot table is to summarize your source data table based on the criteria you specify in the filter fields (Report Filter, Column Labels, and Row Labels). You can think of it as a very advanced way to arrange and filter your data.
The Limulidae are the only recent family of the order Xiphosura, and contain all four living species of horseshoe crabs: 1  Carcinoscorpius rotundicauda, the mangrove horseshoe crab, found in Southeast Asia. 2  Limulus polyphemus, the Atlantic horseshoe crab, found along the American Atlantic coast and in the Gulf of Mexico.
Species Description: The horseshoe crab, Limulus polyphemus, is more closely related to chelicerates such as spiders, scorpions, ticks and mites than it is to true crabs and other crustaceans. Horseshoe crabs are considered to be living fossils that have evolved little in the past 250 million years.pecies Description: The horseshoe crab, Limulus polyphemus, is more closely related to chelicerates such as spiders, scorpions, ticks and mites than it is to true crabs and other crustaceans. Horseshoe crabs are considered to be living fossils that have evolved little in the past 250 million years.