The remains were found at North Dakota’s Tanis dig site.
The dinosaur leg was reportedly preserved as debris from the impact rained down.
“We’ve got so many details with this site that tell us what happened moment by moment, it’s almost like watching it play out in the movies. You look at the rock column, you look at the fossils there, and it brings you back to that day,” Robert DePalma, the University of Manchester graduate student who leads the Tanis dig in North Dakota, told BBC News on Wednesday.
The network has spent three years filming there for a show that’s set to air in just over a week.
Along with the leg, researchers said they found fish, a fossil turtle, small mammals, skin from a triceratops, the embryo of a flying pterosaur and a fragment from the asteroid.
The network said the remains have been jumbled together, with spherules linked to the impact site off the Yucatan Peninsula.
Particles from tree resin contained inclusions that “imply an extra-terrestrial origin.”
Professor Paul Barrett, from London’s Natural History Museum, looked at the leg and deemed the dinosaur a scaly Thescelosaurus.
The limb, he noted, looks like it was “ripped off really quickly,” suggesting that the creature died “more or less instantaneously.”
The question remains: Did it actually die on the exact day?
One professor told the BBC he wants to see more peer-reviewed articles and additional independent assessments.
“Those fish with the spherules in their gills, they’re an absolute calling card for the asteroid. But for some of the other claims – I’d say they have a lot circumstantial evidence that hasn’t yet been presented to the jury,” professor Steve Brusatte, from the University of Edinburgh, said.
Julia Musto is a reporter for Fox News Digital. You can find her on Twitter at @JuliaElenaMusto.