The recently uncovered theropod and sauropod footprints from the Late Jurassic Mahara Formation are the oldest dinosaur tracks documented in Chile and along the western edge of the ancient supercontinent Gondwana.

“The Late Jurassic fossil record highlights significant disparities in the density and distribution of dinosaur footprints between Laurasia and Gondwana,” stated Dr. Marco Yurac from the School of Paleontology and his colleagues.

“In Europe alone, numerous footprint sites have been identified, including regions in Italy, Croatia, Poland, Spain, Switzerland, France, Germany, and Portugal.”

“Moreover, North America boasts extensive track sites rich in ichthyological evidence.”

“Conversely, dinosaur footprints in Gondwana are relatively scarce and fragmentary, with notable exceptions like footprint-bearing outcrops in the High Atlas Mountains of Morocco.”

“Beyond these, ichthyological evidence is limited, with only a few records from Australia.”

“In South America, the majority of dinosaur footprints are found along the eastern coast, particularly in Brazil, Guyana, and Uruguay, with additional reports from northern locales like Colombia.”

“In contrast, on the western coast of South America, corresponding to Gondwana’s western boundary, Late Jurassic dinosaur footprints have only been discovered in Chile.”

A track consisting of four consecutive imprints from a large three-fingered dinosaur in the Mahalla Formation of Chile. Image credit: Yurac et al., doi: 10.1186/s13358-025-00419-9.

Paleontologists have discovered five distinct formations containing footprints within the Majara Formation in the Quebrada Huatacondo area of Chile.

These footprints were created by theropod and sauropod dinosaurs approximately 160 million years ago.

“Around 160 million years ago, northern Chile experienced cycles of flooding and drought,” explained the researchers.

“While the climate was primarily arid, temporary wetlands formed from seasonal water accumulation, attracting a variety of animals, from small theropods to massive carnivorous dinosaurs.”

“As dinosaurs traversed wet mud near these water sources, their footprints were imprinted into the soft sediment.”

“Subsequent flooding gently covered these tracks, preserving them for millions of years.”

The Majara footprints reveal the existence of giant (51-52.8 cm), large (43.5-46.5 cm), and medium-sized (25-27 cm) theropod dinosaurs.

One surface showcases over 25 footprints (ranging from 8 to 13 cm), attributed to microscopic theropods.

“These footprints represent the smallest theropod prints ever recorded in Chile, and likely extend across the entire western margin of Gondwana,” said the scientists.

Another surface is the only stratigraphic level exhibiting solely sauropod footprints (potentially undertracks).

“Due to their poor state of preservation, exact quantitative measurements were not feasible,” commented the authors.

“Nonetheless, analyses of the digital model suggest at least nine footprints with configurations indicative of potential movements.”

Paleontologists assert that this discovery represents the earliest known dinosaur footprints from Chile and the western margin of Gondwana.

“These footprints offer crucial insights for reconstructing the paleoenvironment and behavioral patterns of dinosaurs in northern Chile during the Late Jurassic, reflecting the temporary inhabitation of semi-arid floodplain and ephemeral wetland ecosystems,” the researchers concluded.

This significant finding is detailed in a research paper published in the Swiss Journal of Paleontology.

_____

M. Yurac et al. 2025. Upper Jurassic dinosaur footprints from the Mahara Formation of the Huatacondo region (Tarapaca Basin, Chile): Reassessment of known localities and discovery of new footprints. Swiss Journal of Paleontology 144, 72; doi: 10.1186/s13358-025-00419-9