Assertion: eurypterid's relative | /r/HasProperty | restricted to the lower cambrian
Facets:
Source sentences:
text: Other dominant Cambrian invertebrates with hard parts were trilobites (like the one on the upper left, Nevadella from the Lower Cambrian of southwest Nevada); archaeocyathids (relatives of sponges that were restricted to the Lower Cambrian), and problematic conical fossils known as hyolithids (like the one on the upper right, also from the Lower Cambrian of Nevada).