Image: scientificamerican.com
The Story
Birds crossed the K–Pg boundary; no comparable fossil trail shows non-avian dinosaurs continuing afterward.
The strongest evidence concerns fossils near the boundary, not living descendants after it. New Mexico material once reported as hundreds of thousands of years younger became a test case for dating, reworking, and contamination; the conventional reading remains that the asteroid ended non-avian dinosaur survival, while birds crossed the catastrophe.
- Evidence standardA post-boundary fossil must be securely dated in place and shown not to have been reworked from older rocks.
- Current readingThe available mainstream account supports avian survival, not persistent non-avian populations.
- Scientific American presents the asteroid extinction as eliminating all nonbird dinosaurs while birds survived.
- The Smithsonian reports no evidence of living non-avian dinosaurs today and identifies birds as the surviving dinosaur group.
- The New Mexico survival claim faced controversy because fossils can be misdated or moved into younger strata by erosion or burrowing.
Deeper Insight
Reworked or misdated New Mexico fossils muddy the clean ending. Extinction may have been a retreat, not a single stroke.
Dating and reworking disputes surround 30 New Mexico fossils placed roughly 500,000 years after the asteroid. The evidence is contested, but a bone near the boundary keeps one possibility alive: extinction may have been a long squeeze, not one clean stroke.
- What it could changeA confirmed post-impact dinosaur population would rewrite how scientists read the fossil record and mass extinctions.
- How it touches todayThe debate shows how one disputed bone can carry more weight than a mountain of tidy assumptions.
- Our futureWe could mistake a species' disappearance from view for its final breath, and miss the last refuge entirely.
- The originating discussion proposes that small or mid-sized non-avian dinosaurs might have survived in refuges such as Antarctica, while acknowledging that sustained modern populations are implausible.
- A Discover report describes 30 New Mexico fossils interpreted by James Fassett as evidence that dinosaurs survived the asteroid by roughly half a million years.
- A 2025 Science study revisits late-Cretaceous New Mexican dinosaur diversity and the possibility that earlier fossil sampling gave an incomplete picture of end-Cretaceous survival.
Sources · 9
Featured · Primary source · science.org
Late-surviving New Mexican dinosaurs illuminate high end-Cretaceous diversity and provinciality | Science
Late-surviving New Mexican dinosaurs illuminate high end-Cretaceous diversity and provinciality | Science # Late-surviving New Mexican dinosaurs illuminate high end-Cretaceous diversity and provinciality Andrew G. Flynn https://orcid.org/0000-0002-1371-1878, Stephen L. Brusatte https://orcid.org/000
Read sourceAnalysis · reddit.com
What are your arguments that supposedly prove that certain dinosaurs were not extinct in the event "K—PG" or "meteor fall"?
I personally think it's impossible that any animal with more than 50kg has managed to survive with a sustainable population to be able to reach today's we have. Top comments: - Joke answer: Birds exist Real answer: I think there *is* a significant possibility that there were at least *some* Non-avian dinosaurs that survived the K-Pg extinction. Dinosaurs at the end of the Cretaceous were incredibl
Read sourceAnalysis · discovermagazine.com
Some Dinos May've Survived the Cataclysm | Discover Magazine
Some Dinos May've Survived the Cataclysm | Discover Magazine # Some Dinos May've Survived the Cataclysm If mammals, birds, and lizards pulled through, why not some dinosaurs? Written by Barry E DiGregorio 2007-08-29T05:00:00 | 1 min read According to the going theory, a six-mile-wide asteroid slamme
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