Reptile
Trionyx
Soft-shelled turtle
Trionyx is the historic name for soft-shelled turtle shell fragments in Cretaceous and Paleogene river deposits; the pitted, vermiculate sculpture of trionychid shell is unmistakable and very common in Hell Creek and Judith River microsites. Modern workers assign most Cretaceous material to other trionychid genera, so 'Trionychidae indet.' is the safer label. Shell fragments are among the cheapest dinosaur-bed fossils.
| Phylum | Chordata |
|---|---|
| Class | Reptilia |
| Order | Testudines |
| Family | Trionychidae |
| Group | Reptile |
| Rank (PBDB) | genus· Paleobiology Database |
| Author | Geoffroy Saint-Hilaire 1809· Paleobiology Database |
| Classification (PBDB) | Chordata › Reptilia › Testudines › Trionychidae· Paleobiology Database |
| Range (PBDB) | 126–0 Ma· Paleobiology Database |
| PBDB occurrences | 421· Paleobiology Database |
Photographs
Elsewhere
- WoRMS AphiaID: 397353
- GBIF: 2442547
- PBDB: 37682
- Wikidata: Q5079121
- PBDB taxon page
- Wikipedia: Trionyx
- PBDB search: Trionyx
Cite this article
Stratum Strata. "Trionyx" (Taxon). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/taxa/trionyx. Accessed 2026-09-21.
@misc{stratum-trionyx,
title = {Trionyx},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/taxa/trionyx}},
year = {2026},
note = {Taxon article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, pbdb, wikidata, commons, nhm. 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.