The dinosaur footprints of the cliff of Cal Orck'o are five kilometers from downtown Sucre. It currently covers an area of approximately 1,200 meters in length and a variable height of 110 meters, with an inclination of 72°. It is one of the biggest deposits (study of trace fossils) of footprints in the world, from a period that has few records.
The site belongs to the Mesozoic Era, Cretaceous Period (Upper Maastrichtian).
In Bolivia this formation contains a variety of fossils deposited in rocks containing the boundary between the Cretaceous and Tertiary (Paleocene).
Towards the end of the Cretaceous period, 68 million years ago, there was a large marine entrance extending from the South Atlantic coast, crossing what is now Argentina, until the Valley of Potosi in Bolivia.
The Late Cretaceous was a time of warm climate and it was characterized by periodic floods, in a landscape dominated by plant forms such as ginkgo, conifers, pine, cycads and magnolias. During this time, the huge titanosaurs, the last giant long-necked dinosaurs, were roaming the plains leaving their footprints in the clay soil of what is now the most important cliff of dinosaur footprints in the world, Cal-Orck'o.
Through a natural bridge that had formed between North and South America, who were isolated, there was an interesting exchange of fauna that would bring the first dinosaur species from the northern hemisphere to the southern hemisphere that established in what is now South America as they advanced.
Among the immigrant species were herbivorous dinosaurs such as hadrosaurs with gregarious habits, which traveled in large herds that included many adults and juvenile specimens; Ankylosaurs and ceratopsians were in these migratory groups who were searching for food and escaping from predators that followed his traces.
During the rainy season these lands were flooded with mud, a layer of sediment was formed encapsulating and preserving the footprints leaving the stage set for the registration of new steps. And the dinosaur's footprints from cal Orck'o were formed.
Several million years later, a huge meteor would be the most likely factor in the mass extinction at the end of the Cretaceous period.
Later, during the Tertiary the Andes began to form due to the continuous movement of continental masses, radically changing the topography, forming hills and mountains, raising the central valley of Bolivia and the Potosi Basin, taking that land so high that they were separated from the sea, these movements formed the Highland and nearby regions, this way what was once a beach became the cliff where are the dinosaur footprints of Cal Orck'o and exposing one of the most important, extensive 'trace fossils' of the world.
Other fossils found in this region include the bones and shells of turtles, crocodile teeth, crocodile vertebrae as well as fragments of pterosaurs. The most common remains in the cliff of dinosaur footprints are fossils of fishes. The two most common are Pucapritis and Gastroclupea brannisai, the latter similar to current sardines. In this region have also been found Picnodontiformes teeth and scales and skull fragments of Siluriformes as well as stromatolites and Pucalithus stenmanni algae, invertebrates as pelicípodos, gastropods and coprolites (fossilized esses), among other debris.
The dinosaurs footprints of Cal Orck'o has more than five thousand tetrapod footprints of about 15 different species, among which are the titanosaur sauropods, theropods, ornithopods and Ankylosaurios.
Finally, the discovery of Cal Orck'o has such a big historic relevance because the site is the most important location of dinosaur footprints in the world in terms of size, diversity and geological value, the cliff revealed secrets forcing to reconstruct the history of the planet and correct scientific errors of these animals that disappeared millions of years ago.