Radiaspis is a genus of trilobite that lived from Late Ordovician through the Silurian to the mid-Devonian period. Fossils of "Radiaspis" have been found in present-day Europe, Australia, North Africa, and North America.
Fossil range.
"Radiaspis" is a "generally rare" species found from the Ordovician to Devonian periods. "Radiaspis" fossils have been discovered in Australia, western Europe, North America, and Morocco. Some of the earliest "Radiaspis" fossils – "Radiaspis tuberata" from Aragon – date from the early Late Ordovician, around 445 million years ago. Some of the youngest fossils date to around 386 million years ago, in the lower Givetian; it is believed that the genus "Radiaspis" and several other trilobite genera became extinct at the time of the Taghanic event.