21177 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Malachite This is a piece worth

This is a piece worth of study and publication

probably by the alteration of olivine grains

The protocetids had large fore-limbs and hindlimbs that could support the body on land

Borealaspis

Protacanthina

21177 - Premium Grade Soft Bodied Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Malachite This is a piece worthXiphosurans 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