Cimolopteryx fossil map
Where fossils of Cimolopteryx have been found, shown on the Earth as it looked about 66 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 66 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Prehistoric birds |
|---|---|
| Lived | 83.6–66 million years ago (Campanian to Maastrichtian) |
| Periods | Cretaceous |
| Family | Cimolopterygidae |
| Named by | Marsh 1889 |
| Fossil records | 6 occurrences at 5 locations (PBDB) |
| Found in | United States, Canada |
| Rock formations | Lance, Hell Creek, Frenchman, Dinosaur Park |
About Cimolopteryx
Cimolopteryx (meaning "Cretaceous wing") is a prehistoric bird genus from the Late Cretaceous Period. It is currently thought to contain only a single species, Cimolopteryx rara. The only specimen confidently attributed to C. rara was found in the Lance Formation of Wyoming, dating to the end of the Maastrichtian age, which ended about 66 million years ago. The dubious species "Cimolopteryx" maxima has been described from both the Lance Formation and the Hell Creek Formation of Montana. The humeral end of a left coracoid from the Frenchman Formation of southern Saskatchewan has also been attributed to the genus.
Text in “About” is quoted from the Wikipedia article Cimolopteryx (revision 1341506002), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 23 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q5120156.
