The genesis of an exceptional palaeontological site with fossil whales, dolphins and seals, revealed

What is it about?

In one of the driest areas on the planet, the Ica Desert of southern Peru, one of the most important marine vertebrate fossil assemblage worldwide takes its place. This area is so exceptional that it hosts thousands of fossilized skeletons of whales, dolphins, seals, sharks, bony fishes, birds and reptiles, dating back to a time interval between 14 and 6 million years ago (an epoch that geologists call the Miocene). Where today is a desert that extends for hundreds of kilometers along the coast of Peru, in the past there was a large marine bay, the Pisco Basin, characterized by a great abundance of nutrients and a rich biodiversity. The inhabitants of this ancient bay have been preserved in sedimentary strata for millions of years and are now exposed around the town of Ica thanks to tectonic uplift and erosion in the present-day desert environment. In a study published in the international scientific journal PLOS ONE (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0254395), researchers have unveiled the causes at the origin of this outstanding fossil assemblage thanks to a multidisciplinary research approach. The exceptional preservation and high concentration of fossils are not due to a single cause, but rather to the concomitance of different environmental conditions favorable to fossilization. The low availability of oxygen at the bottom, the rapid burial of carcasses, and the precipitation of minerals such as apatite and dolomite in the bone cavities immediately after burial, together with an original abundance of life, allowed for the formation of this important deposit, leading to the fossilization of thousands of specimens.

Featured Image

Photo by Todd Cravens on Unsplash

Photo by Todd Cravens on Unsplash

Why is it important?

One of the most important Fossil-Lagerstätten (sedimentary deposits that exhibit extraordinary fossils with exceptional preservation) worldwide was analyzed by reconstructing the causes beneath its origin. Thanks to this research, a quantitative and qualitative evaluation of this outstanding paleontological site was carried out, laying the foundation for future investigations in similar contests as well as for the valorization and conservation of this exceptional localities. In fact, these results may be useful for the elaboration of programs that include paleontological sites in tourism, increasing the public’s awareness and appreciation of these valuable paleontological resources, thus enhancing the attention on the Peruvian geoheritage. Ultimately, the Ica Desert may be recognized as a geosite to be protected and enhanced. In addition, the study of past marine ecosystems such as that witnessed by the Pisco vertebrate assemblage allow for a better understanding of the roots of the modern Humboldt Current Ecosystem, which nowadays characterizes the Pacific South American coast.

Perspectives