21140 - Soft Bodied Aglaspid (Tremaglaspis) + Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Dyrosaurus phosphaticus Impressive specimen of the genus

Impressive specimen of the genus Leonaspis

Native copper is an uncombined form of copper that occurs as a natural mineral

Crystals of brochantite can range from emerald green to black-green to blue-green

Germany (14)

21140 - Soft Bodied Aglaspid (Tremaglaspis) + Xiphosurid (Horseshoe Crab Ancestor) Lower Ordovician Dyrosaurus phosphaticus Impressive specimen of the genusXiphosurans 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