Trilobite
Elrathia kingii
Utah trilobite
Elrathia kingii from the Wheeler Shale is the most abundant and most widely sold trilobite in the world, a small ptychopariid with a wide thorax and small pygidium, dark grey-black on light grey shale. Millions have been quarried near Delta, Utah, and made into jewellery; a natural specimen costs a few dollars. It is nonetheless enhanced: scribed outlines, blackened shells and cast-resin replicas glued to real shale all circulate.
| Phylum | Arthropoda |
|---|---|
| Class | Trilobita |
| Order | Ptychopariida |
| Family | Alokistocaridae |
| Group | Trilobite |
| Size | 1–4 cm |
| Rank (PBDB) | species· Paleobiology Database |
| Author | (Meek 1870)· Paleobiology Database |
| Accepted name (PBDB) | Elrathia kingi· Paleobiology Database |
| Classification (PBDB) | Arthropoda › Trilobita › Ptychopariida › Alokistocaridae· Paleobiology Database |
| Range (PBDB) | 506–497 Ma· Paleobiology Database |
| PBDB occurrences | 9· Paleobiology Database |
Restoration and fakes
Genuine Elrathia have slightly convex shells with fine surface texture; painted or resin examples are flat, glossy and uniform. A blade under the edge of a resin 'trilobite' lifts it.
Elsewhere
- GBIF: 4633927
- PBDB: 311126
- Wikidata: Q1333301
- PBDB taxon page
- Wikipedia: Elrathia
- PBDB search: Elrathia
Cite this article
Stratum Strata. "Elrathia kingii" (Taxon). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/taxa/elrathia-kingii. Accessed 2026-09-21.
@misc{stratum-elrathia-kingii,
title = {Elrathia kingii},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/taxa/elrathia-kingii}},
year = {2026},
note = {Taxon article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, pbdb, wikidata, commons. Accessed 2026-09-21.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.