Archaeocidaris is an extinct genus of echinoid that lived from the Late Devonian to the Late Permian. Its remains have been found in Africa, Europe, and North America. thumb|left|Archaeocidaris plates and spines from the Bird Spring Formation (Carboniferous) exposed in Kyle Canyon, Spring Mountains, southern Nevada.
Archaeocidaris is an extinct genus of echinoid that lived from the Late Devonian to the Late Permian. Its remains have been found in Africa, Europe, and North America. thumb|left|Archaeocidaris plates and spines from the Bird Spring Formation (Carboniferous) exposed in Kyle Canyon, Spring Mountains, southern Nevada.
==Sources== Fossils (Smithsonian Handbooks) by David Ward (Page 176)
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).