Dinosaur Wall Mystery: How Did Dino Prints End Up On Bolivian Cliff Face?

Long before we left our mark with handprints on cavern walls, some unexpected artists left their traces on Bolivian rock faces. These mysterious imprints? None other than dinosaur tracks! A magical blend of events left us puzzling over these traces on a nearly vertical wall.

The dinosaur track wall at Bolivia’s Cretaceous Park. (Source: CC BY 2.0 ).

Mural of Mysteries

Tucked away in Bolivia's Chuquisaca, near its capital Sucre, Cal Orcko boasts the Parque Cretácico (‘Cretaceous Park’), famed for a wall teeming with the world's densest collection of dinosaur tracks. Imagine the buzz of discovering not just one, but thousands of ancient footprints! Dubbed the ‘dinosaur dancefloor', this crisscross of trails helps researchers picture various dinosaur species that once ruled, played, and competed here.

Dinosaurs crossed paths through the ages. ( CC BY-NC-SA 2.0 )

Disturbing the Dinosaurs

Cal Orcko means ‘lime hill’ in the local Quechua language, and is an indication of the rock found at the site, i.e. limestone. This site is located within the territory of FANCESA, the national cement company of Bolivia. This cement company has been quarrying limestone for many decades, and it was the workers of this company who discovered the first dinosaur footprints at Cal Orcko in 1985. It was, however, only nine years later, in 1994, that the giant dinosaur track wall was exposed by mining activities.

Although palaeontologists had begun to investigate the dinosaur tracks, exposure to the elements and mining operations resulted in the erosion and crumbling of the wall. To protect it, it shut its doors for 8 years, finally reemerging as a tourist magnet in 2006.

Dinosaur (titanosaurs) footprints. ( CC BY-SA 3.0 )

Wall of Prehistoric Fame

Undoubtedly, the park's crown jewel is the dinosaur track wall, stretching 80 m high and 1200 m long. It's a footprint treasure trove with over 5055 identified marks, branching into 462 unique trails, which showcase up to 15 different dinosaur species, all from the Cretaceous era. Hence, the park's moniker.

Footprints of some of the dinosaurs found at Cal Orcko. (Image: La gaveta )

Tracing the Footprints

It has been speculated that the Sucre area was once a large ocean inlet, and Cal Orcko a part of its shoreline. As dinosaurs walked along this shoreline during the Cretaceous period, they left their footprints in the soft clay, and were preserved when the clay solidified during the dry periods. A new layer of sediment would cover up the old one, and the process would begin again. As a result of this, multiple layers of dinosaur tracks were formed over time. This became evident in 2010, when a section of the wall collapsed. Whilst this destroyed some of the tracks, it also revealed another layer of footprints underneath it.

Dinosaur tracks and a disturbed section of the wall. ( CC BY 2.0 )

The Wall’s Rise to Fame

It has been hypothesized that the ocean inlet eventually became an isolated freshwater lake, based on the presence of freshwater creatures in the fossil evidence. Additionally, as a consequence of the shifting of the tectonic plates during the Tertiary period, the path that the dinosaurs once walked on rose upwards, and became an almost vertical wall. This is what led to today’s appearance of dinosaur tracks climbing the wall.

In the past, the cliff wall was fully accessible to the public, though in recent years, visitors could only get a glimpse of the wall from a viewing platform within the park. A new path has been unveiled, however, that allows visitors to get within a few meters of the wall, thus allowing much closer access to the dinosaur footprints.

The Wall’s Fragile Future

One of the main concerns regarding the dinosaur track wall is the fact that it is a limestone cliff. Pieces of rock, which may occasionally detach and fall from the cliff, can be considered to be a safety hazard. More alarming is the estimation that if the tracks are not adequately protected, it would be completely destroyed due to erosion in the near future. Therefore, the park is seeking to be recognized as a UNESCO World Heritage Site, which would provide it with the funds to carry out conservation work.

Top image: Fossilized dinosaur footprints at Cal Orko, Bolivia. Source: Nataliya / Adobe Stock.

By: Wu Mingren 

References

Avakian, T., 2015. A wall in Bolivia is covered in thousands of dinosaur footprints, and it's becoming a major tourist attraction. [Online]
Available at: http://www.businessinsider.com/cal-orcko-in-bolivia-is-covered-in-dinosaur-footprints-2015-6?IR=T

Cárdenas, J. A., 2014. Dinosaur tracks in Bolivia threatened with extinction. [Online]
Available at: https://phys.org/news/2014-10-dinosaur-tracks-bolivia-threatened-extinction.html

Jackson, N., 2018. Dinosaur Dance Floor. [Online]
Available at: https://www.atlasobscura.com/places/dinosaur-dance-floor

Lin, K., 2017. Bolivia Dinosaur Footprints Wall at Cal Orcko Cretaceous Park. [Online]
Available at: https://www.historicmysteries.com/bolivia-dinosaur-footprints-wall/

parquecretacicosucre.com, 2018. Parque Cretácico. [Online]
Available at: 

https://parquecretacicosucre.com/

Sucre Life, 2018. Sucre’s Dinosaur Park and Footprints (Parque Cretácico). [Online]
Available at: http://www.sucrelife.com/sucres-dinosaur-park/

Twisted Sifter, 2013. This 300 ft Wall in Bolivia has over 5000 Dinosaur Footprints. [Online]
Available at: http://twistedsifter.com/2013/10/cal-orko-wall-in-bolivia-covered-in-dinosaur-tracks/