Legend as soon as had it that the massive, three-toed footprints scattered throughout the central highlands of Bolivia got here from supernaturally robust monsters – able to sinking their claws even into strong stone.
Then scientists got here right here within the Sixties and dispelled kids’s fears, figuring out that the unusual footprints in actual fact belonged to gigantic, two-legged dinosaurs that stomped and splashed over 60 million years in the past, within the historic waterways of what’s now Toro Toro, a village and standard nationwide park within the Bolivian Andes.
Now, a group of paleontologists, largely from California’s Loma Linda College, have found and meticulously documented 16,600 such footprints left by theropods, the dinosaur group that features the Tyrannosaurus rex. Their examine, based mostly on six years of normal discipline visits and revealed final Wednesday within the peer-reviewed journal PLOS One, experiences that this discovering represents the best variety of theropod footprints recorded wherever on the earth.
“There’s no place in the world where you have such a big abundance of (theropod) footprints,” mentioned Roberto Biaggi, a co-author of the examine led by Spanish paleontologist Raúl Esperante. “We have all these world records at this particular site.”
Prints file dinosaur habits — together with makes an attempt to swim
The dinosaurs that dominated the earth and roamed this area additionally made awkward makes an attempt to swim right here, based on the examine, scratching at what was squishy lake-bottom sediment to depart one other 1,378 traces.
The longest swim trackway studied by the researchers measured over 130 meters in size. “To date, it remains the longest exposed swim trackway in the world,” the authors write within the examine.
They pressed their claws into the mud simply earlier than water ranges rose and sealed their tracks, defending them from centuries of abrasion, scientists mentioned.
Park ranger José Vallejos stands subsequent to petrified dinosaurs footprints in Carreras Pampa in Toro Toro Nationwide Park, north of Potosi, Bolivia, Saturday, Dec. 6, 2025.
Juan Karita / AP
“The preservation of many of the tracks is excellent,” mentioned Richard Butler, a paleontologist on the College of Birmingham who was not concerned within the analysis. He mentioned that, to his data, the variety of footprints and trackways present in Toro Toro had no precedent.
“This is a remarkable window into the lives and behaviors of dinosaurs at the end of the Cretaceous,” Butler added, referring to the interval round 66 million years in the past on the finish of which an asteroid influence abruptly extinguished all dinosaurs and 75% of residing species together with them, based on scientists.
Footprints face preservation threats
Though they’ve survived for thousands and thousands of years, human life has threatened these traces. For many years, farmers threshed corn and wheat on the footprint-covered plateaus. Close by quarry staff didn’t assume a lot of the formations as they blasted rock layers for limestone. And simply two years in the past, researchers mentioned, freeway crews tunneling by way of hillsides practically worn out a significant web site of dinosaur tracks earlier than the nationwide park intervened.
Such disturbances could have one thing to do with the realm’s hanging absence of dinosaur bones, enamel and eggs, consultants say. For the entire footprints and swim traces discovered throughout Bolivia’s Toro Toro, there are just about no skeletal stays of the type that litter the peaks and valleys of Argentine Patagonia and Campanha in Brazil.
However the lack of bones might have pure causes, too. The group mentioned the amount and sample of tracks – and the actual fact they had been all present in the identical sediment layer – recommend that dinosaurs didn’t settle in what’s now Bolivia as a lot as trudge alongside an historic coastal superhighway stretching from southern Peru into northwest Argentina.
The vary in footprint sizes indicated that enormous creatures roughly 10 meters (33 ft) tall moved in a herd with tiny theropods the scale of a rooster, 32 centimeters (1 foot) tall on the hip.
A petrified footprint by a dinosaur is seen in Carreras Pampa in Toro Toro Nationwide Park, north of Potosi, Bolivia, Saturday, Dec. 6, 2025.
Juan Karita / AP
In presenting a snapshot of on a regular basis habits footprints “reveal what skeletons cannot,” mentioned Anthony Romilio, a paleontologist on the College of Queensland in Australia who additionally didn’t take part within the examine. Simply from footprints, researchers can inform when dinosaurs strolled or sped up, stopped or circled.
It’s not clear why so many dinosaurs roamed the positioning
However the motive they flocked in droves to this wind-swept plateau stays a thriller.
“It may have been that they were all regular visitors to a large, ancient, freshwater lake, frequenting its expansive muddy shoreline,” provided Romilio.
Biaggi urged that they had been “running away from something or searching for somewhere to settle.”
What’s sure is that analysis into this treasure trove of a dinosaur tracksite will proceed.
“I suspect that this will keep going over the years and many more footprints will be found right there at the edges of what’s already uncovered,” Biaggi mentioned.
Latest dinosaur footprint discoveries
Researchers have unearthed different dinosaur footprints lately.
In March, scientists in England uncover a 650 foot path of dinosaur footprints made 160 million years in the past by huge sauropod dinosaurs.
That discovery was introduced only a few months after a group of paleontologists discovered matching dinosaur footprints on what at the moment are two completely different continents, separated by 1000’s of miles of ocean.
In October 2023, engineers within the U.Ok. made a “dramatic discovery” of dinosaur footprints that consultants consider may very well be from a mantellisaurus, a kind of dinosaur that had simply three toes on every foot and traveled on its hind legs.
