Ricardo Melchor may have just knocked the presumed "first bird" off its perch. Archaeopteryx fossils have made a huge impression and inspired endless artistic renditions since they were first discovered in 1861. Although Melchor, of Argentina's National University at Pampa, has nothing as spectacular as those remarkably intact remains, he has found 100 small, seagull-like fossilized footprints that, at 210 million years old, predate Archaeopteryx by more than 50 million years. "They are startlingly birdlike, but 50 million years is an immense time lapse. Unless other evidence is found, we'll assume they belong to a new theropod dinosaur that gave rise to all bird lineages, including Archaeopteryx," he says. Melchor plans to return to the site, about 500 miles north of Buenos Aires, to look for skeletal remains and more fossils. Such relics could prove that the unseen walker was an ancestor of both the ancient Allosaurus and today's owls.
A mystery creature left inch-long footprints in Argentinian clay stone during the Triassic Period.Photograph courtesy of Ricardo Melchor.