Witness the Largest Dinosaur Parade

Dinosaur footprints never fail to capture attention. These fossilized marks represent creatures that ruled the Earth long before humans existed, serving as direct imprints from the distant past. Recently, scientists reported in PLOS One their discovery of a new record-breaking concentration of dinosaur tracks, including continuous pathways, tail marks, and even swimming traces.

Working at this location is incredible, because the ground is virtually blanketed in dinosaur tracks, said paleontologist Ral Esperante of the Geoscience Research Institute in California.

Esperante, together with researchers from the U.S. and Bolivia, recorded over 16,000 dinosaur tracks across nine separate sites in Carreras Pampa, Bolivia. Located within Torotoro National Park, these sites span more than 80,000 square feet, roughly equivalent to 1.5 football fields. The rock layer dates to the Upper Cretaceous Period, prior to the asteroid impact that wiped out the dinosaurs around 66 million years ago.

The arrangement, size, and direction of the tracks reveal behaviors of these prehistoric animals. Most footprints are aligned northwest to southeast, suggesting herds moved along an ancient lakeshore. Tracks crossing and overlapping one another indicate repeated visits over time, and some turns and stops are evident from the impressions left behind.

Compared to other fossil locations, Carreras Pampa shows a higher proportion of dinosaurs with long strides, likely reflecting the species present. Although the team did not identify specific species, the three-toed footprints and upright posture suggest theropods, the bipedal ancestors of modern birds. By analyzing heel and toe impressions, researchers categorized the tracks into 11 distinct types.

The majority of tracks were from small to medium-sized dinosaurs, with foot lengths up to 11 inchescomparable to a mens size 14 shoe. Hip heights were estimated between 26 and 49 inches, indicating dinosaurs ranging from dog-size to human height roaming the lakeshore mud.

Besides walking, the trace fossils reveal running, swimming, and tail-dragging activity. Scientists identified 280 elongated grooves interpreted as swim tracks, formed by the kicking movements of theropods. Criteria for recognizing these included multiple sets of alternating curved scratches left by swimming motion.

This site offers a remarkable glimpse into the lives of dinosaurs here, Esperante added. It shows not only their numbers but also their behavior as they moved through this landscape.

Analysis: Uncovering Behavior Through Dinosaur Tracks in Carreras Pampa

The recent discovery of over 16,000 dinosaur footprints in Carreras Pampa, Bolivia, provides an unprecedented record of prehistoric activity. The footprints, spanning more than 80,000 square feet, reveal not just the presence of these animals, but also detailed patterns of movement along an ancient lakeshore.

Researchers identified 11 distinct track types, mostly from small to medium-sized theropods. The alignment of tracks northwest to southeast indicates herd movement, while overlapping prints and turns suggest repeated use of the area over time. Elongated grooves point to swimming behavior, demonstrating that some dinosaurs were interacting with water as part of their daily movement.

Compared to other fossil sites, Carreras Pampa shows a notable proportion of dinosaurs with long strides, hinting at the diversity of species present. This record enriches our understanding of Upper Cretaceous ecosystems, giving scientists a rare opportunity to reconstruct the behavior and environmental interactions of dinosaurs shortly before their extinction.

Sources:

• Behold the Biggest Dinosaur Parade