Do Fossil Prints Show Dinosaur Flight Evolved More Than Once?

Researchers studying tracks fossilized in Cretaceous-era lakeshore mud in what is now South Korea argue this week in Proceedings of the National Academy of Sciences that the dinosaur footprints are “indirect evidence of pre-avian aerial behavior” in a tiny microraptor.

The tracks, which belong to a sparrow-sized theropod related to Tyrannosaurus rex, are spaced far enough apart to indicate that the tiny dino was moving across the mud very quickly. That speed, the researchers argue, is faster than the animal should have been able to go just by running with its hindlimbs. However, if flapping wings were added into the equation to give a power boost, the spacing might make sense.

If the microraptor did, in fact, have flight-capable wings, that would mean that the ability to fly may have evolved in multiple lineages of dinosaurs, not just the descendants of Archaeopteryx we see as modern birds. Other researchers are not convinced of the analysis, arguing that the tracks may not all have come from the same individual at the same time.

Jason Dinh, climate editor for Atmos, joins guest host Sophie Bushswick to talk about the debate, and other stories from the week in science, including an archeological find of medieval-era Silk Road cities in the Uzbek mountains, breathing differences in people born with the inability to smell, and the surprising ability of hornets to hold their liquor.