Explore this animal in Size of Extinct Animals ↗
234 / Mesozoic
Hesperornis
Hesperornis regalis
Its wings shrank to small bones while rear-set legs turned it into a superb Mesozoic pursuit diver.
View original image · 1536 × 1024- Time range
- About 83–78 million years ago
- Final stage
- Late Cretaceous
- Geographic range
- Warm inland seas and coasts · North America
01 / DEFINITION & ECOLOGY
What was Hesperornis?
Hesperornis (Hesperornis regalis) was an extinct organism known from About 83–78 million years ago, with a range in Warm inland seas and coasts · North America.
Life and ecology
Flightless Hesperornis chased fish underwater with powerful legs. Teeth lined its long jaws, and it probably moved awkwardly on shore.
02 / DISAPPEARANCE
Why did Hesperornis disappear?
Its record ends about 78 million years ago. Hesperornithines as a group persisted later and disappeared at the end of the Cretaceous, but that event does not explain the loss of this genus.
03 / EVIDENCE
How do scientists know about Hesperornis?
Many skeletons preserve teeth, vestigial wings and rear-set hips and legs whose function can be compared with living divers.
04 / SOURCES & FURTHER READING
Check the source record
Use the scientific name to compare taxonomy, occurrence records and the fossil record. Database coverage and classifications may differ.
05 / REVISION HISTORY
How has this record changed?
- Removed an extinction cause that credited a mass extinction occurring after this species' last dated record.
- Verified authoritative entity sources and added three responsive reconstruction sizes.
- Initial bilingual species record published.
06 / CORRECTIONS & ADDITIONS