Xiphosurida Horseshoe Crab Ancestor

Phylum Arthropoda, Class Merostomata, Order Xiphosurida
Geologic Age: Ordovician
Fossil is 44 mm long
Fezouata Formation, Zagora, Morocco
Remarks: Horseshoe crabs are often called “living fossils” because they have changed little over geologic time. over time. Trilobites are related to ancient horseshoe, but the relationship is distant. Still, they look a lot like trilobites (Harpetids particularly), especially the ealier horseshoe crabs, or thier ancestors like this Ordovician Xiphosurida.

Also see: Trilobite Relatives







Xiphosurida Horseshoe Crab Ancestor Trilobite Relative

Xiphosurida Arthropod Trilobite Ancestor


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