Formation · Cretaceous
Lance Formation
Late Cretaceous unit, Wyoming
The Lance Formation of eastern Wyoming is the time equivalent of the Hell Creek Formation and yields the same latest-Cretaceous fauna: Triceratops, Edmontosaurus, tyrannosaurs and abundant microvertebrates screened from channel lags. Lance Creek is the type area and the source of much historic museum material. Shed theropod teeth labelled Nanotyrannus are contested; many workers treat them as juvenile Tyrannosaurus, so a careful listing says so.
| Country | United States |
|---|---|
| Region | Wyoming |
| Age | Maastrichtian, Late Cretaceous |
| Age range | ~69–66 Ma |
| Macrostrat rank | Fm· Macrostrat |
| Macrostrat age | 72.2–66 Ma· Macrostrat |
| Lithology | shale, sandstone, claystone, coal, siltstone· Macrostrat |
| Environment | fluvial indet., coastal indet., non-marine, barrier bar, lagoonal· Macrostrat |
| Macrostrat columns | 8 column(s) sampled from 8 unit(s)· Macrostrat |
| Group (Macrostrat) | Black Buttes coal· Macrostrat |
| PBDB collections | 188 collections, 1405 occurrences· Paleobiology Database |
Collecting and legality
Lance Creek country in Niobrara County is a patchwork of private ranch and federal land; commercial material must come from private surface with the owner's consent. Federal parcels require permits for vertebrates and prohibit sale.
Lithology and setting
Sandstones and mudstones of a low coastal plain, the Wyoming equivalent of the Hell Creek Formation.
Commonly recorded taxa (PBDB)
Genera most often recorded from this unit in the Paleobiology Database (first 200 occurrences): Mesodma (26), Cimolodon (24), Meniscoessus (24), Gypsonictops (17), Protolambda (17), Didelphodon (16), Cimolomys (14), Cimolestes (11), Leptalestes (11), Alphadon (8), Pediomys (7), Turgidodon (4), Cimexomys (3), Glasbius (3), Protalphadon (3).
Source: Paleobiology Database
Collecting rules
Elsewhere
- Macrostrat: 1090
- macrostratConcept: 9250
- PBDB: strata:Lance
- Wikidata: Q6483389
- Macrostrat stratigraphic name
- PBDB occurrences for this unit
- Wikipedia: Lance Formation
- Mindat: Lance Formation
Cite this article
Stratum Study. "Lance Formation" (Formation). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/formations/lance-formation. Accessed 2026-09-20.
@misc{stratum-lance-formation,
title = {Lance Formation},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/formations/lance-formation}},
year = {2026},
note = {Formation article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, macrostrat, 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.