More than 16,600 theropod footprints were identified at Carreras Pampa in Torotoro National Park, Bolivia, making it the world’s largest known concentration of carnivorous dinosaur tracks. The single fossil surface contains 1,321 trackways, 1,378 swimming traces and numerous isolated prints across about 80,730 sq ft. Footprint sizes range from chicken-height to dinosaurs estimated at 33 ft, suggesting multiple species used the site as a frequently traveled lakeshore corridor. The study, published in PLOS One after six years of fieldwork, also documents primitive bird prints and other biological traces.
Bolivia’s Carreras Pampa Reveals World’s Largest Theropod Footprint Site — 16,600+ Tracks
Argentinean paleontologist Pablo Gallina is shown in 2008 next to several dinosaur footprints discovered by two countrymen in the Icla municipality, Chuquisaca, Bolivia . Photo by Omar Medina Ramirez/EPA
Researchers have identified more than 16,600 footprints left by carnivorous, two-legged dinosaurs at the Carreras Pampa locality in Torotoro National Park, central Bolivia. The discoveries—dating to roughly 66 million years ago—establish the site as the largest known concentration of theropod tracks in the world. The results are based on six years of fieldwork by an international team and were published in the peer-reviewed journal PLOS One.
Record-Breaking Track Surface
Field teams mapped 1,321 distinct theropod trackways plus hundreds of isolated prints, tail-drag impressions and 1,378 traces interpreted as swimming attempts. All traces occur on a single continuous bedding plane composed of nine connected sectors that together cover about 80,730 square feet—an area comparable to a soccer field.
Range Of Sizes And Behaviors
The footprints show a wide size range, indicating multiple types of theropods used the area. Some prints correspond to large individuals estimated at up to 33 feet (about 10 m) long, while others were left by very small animals roughly 12 inches tall—about the height of a modern chicken. In several sectors, footprints were impressed while animals moved through shallow water, scraping the muddy bottom before rising water levels buried and preserved the marks.
"The study of this gigantic dinosaur track site is highly significant for several reasons. It is the largest known site to date and far exceeds other similar sites in the number of preserved footprints," said Spanish paleontologist Raúl Esperante, the study's lead author, in an interview with Infobae.
Unlike skeletal remains, which are rare in the region, trackways preserve behavioral detail. From stride length and track spacing, researchers estimated walking speeds, pauses, changes in direction and even swimming attempts. The orientation of many trackways shows a consistent bidirectional pattern, interpreted as repeated movement along the shoreline of an ancient freshwater lake.
A Prehistoric Corridor
Investigators conclude Carreras Pampa functioned not as a permanent habitat but as a frequently used corridor—a kind of prehistoric highway—likely linking areas that are now in southern Peru and northwestern Argentina. The surface also contains primitive bird footprints and other signs of biological activity, reinforcing the view that the site recorded a diverse and active ecosystem shortly before the end of the Cretaceous.
"The preservation of many of the footprints is excellent and the number recorded is unprecedented," said Richard Butler, a paleontologist at the University of Birmingham and co-author of the study. He added that the site offers an exceptional opportunity to understand dinosaur movement and behavior shortly before their extinction.
Bolivia was already known internationally for the Cal Orck'o locality near Sucre—which preserves roughly 12,000 footprints on a near-vertical rock face—and Carreras Pampa strengthens the country's importance for the study of fossilized tracks. Researchers say fieldwork will continue and that additional footprints may be exposed in surrounding areas, potentially expanding our picture of South America’s prehistoric landscape.
