21162 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Heterodiadema libycum Impressive huge vertebra of this

Impressive huge vertebra of this species of Elasmosaurus

Some of them have glued or filled fractures

Name: Northwest Africa 859

showing a perfect example of this Botryoidal crystallization typical of iron oxide

Average size of insects: 0

21162 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Heterodiadema libycum Impressive huge vertebra of thisXiphosurans are an order of arthropods related to arachnids, or, according to one recent study, actually arachnids. They are sometimes called horseshoe crabs (a name applied more specifically to the only extant family, Limulidae). They first appeared in the Tremadocian (Lower Ordovician) from Fezouata Fm in South Morocco. Currently, there are only four living species. They are members of the order Xiphosura, which contains two suborders, Xiphosurida