Earliest Alligator Ancestor Found in Colorado Fossils — SkimNews
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Mandrasuchus milleri has been identified as the oldest known alligatorine, with the oldest skulls dating to just 350,000 years after the asteroid strike that ended the Cretaceous 66 million years ago
- Denver Museum of Nature & Science researchers recovered bones from about 15 individuals plus hundreds of teeth, bones, and bony skin plates at Corral Bluffs in central Colorado, beginning around a decade ago
- The 2-metre predator had pointed front teeth for seizing prey and bulbous back "button" teeth for crushing shellfish — an opportunistic diet researchers say helped crocodilians survive the extinction
- The team compared 330 anatomical features against nearly 150 living and extinct crocodilians, and used radiometrically dated volcanic ash to pin the fossils' age
- One skeleton was found inside what researcher Sadie Sherman says may have been a burrow, suggesting the animals sheltered underground from harsh post-impact conditions
- Independent experts Adam Cossette (New York Institute of Technology) and Pedro Godoy (University of São Paulo) called the fossils "compelling" and "beautifully preserved"
- The species name honors Ian Miller, a former Denver Museum worker who found many of the specimens; the genus name references Corral Bluffs and the Egyptian crocodile-headed god Sobek
Why it matters: Mandrasuchus milleri pins down when alligatorids split from other crocodilians — a timeline researchers had described as "muddy." Its abundance just 350,000 years after the asteroid reframes the post-impact recovery: semiaquatic, burrowing generalists rebounded far faster than the devastated dinosaurs, meaning freshwater ecosystems bounced back earlier than the wider fossil record had shown.
Ask SkimNews
