Trilobite
Isotelus
Giant asaphid trilobite
Isotelus is the large, smooth Ordovician asaphid trilobite of the Cincinnatian and Ohio's state fossil; I. maximus reached 40 cm and I. rex from Manitoba is the largest complete trilobite known. Whole Isotelus are rare and valuable; the smooth, semicircular pygidia and cephala are common fragments. Beware of Isotelus 'restored' from multiple partial individuals.
| Phylum | Arthropoda |
|---|---|
| Class | Trilobita |
| Order | Asaphida |
| Family | Asaphidae |
| Group | Trilobite |
| Size | to 70 cm (I. rex) |
| Rank (PBDB) | genus· Paleobiology Database |
| Author | (Dekay 1824)· Paleobiology Database |
| Classification (PBDB) | Arthropoda › Trilobita › Asaphida › Asaphidae· Paleobiology Database |
| Range (PBDB) | 489–433 Ma· Paleobiology Database |
| PBDB occurrences | 1141· Paleobiology Database |
Elsewhere
- GBIF: 4635813
- PBDB: 20000
- Wikidata: Q44087
- PBDB taxon page
- Wikipedia: Isotelus
- PBDB search: Isotelus
Cite this article
Stratum Study. "Isotelus" (Taxon). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/taxa/isotelus. Accessed 2026-09-20.
@misc{stratum-isotelus,
title = {Isotelus},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/taxa/isotelus}},
year = {2026},
note = {Taxon article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, pbdb, wikidata, commons. Accessed 2026-09-20.}
} 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.