Beneath the hills of Colombia’s Eastern Cordillera lies an ancient record, preserved in the layers of rock known as the La Luna Formation. Dating back to the Upper Cretaceous, about 90 million years ago, this formation provides a glimpse into a world dominated by marine ecosystems, when vast, warm seas covered much of what is now South America. Yet, despite its potential, the fossil record from this period in Colombia has remained surprisingly sparse — until now.
In a groundbreaking discovery, a team of researchers has unearthed fossilized remains of the extinct fish family Enchodontidae from the La Luna Formation in the municipality of Matanza, Santander Department. These fossils, which include jaw and skull fragments, represent the first comprehensive report of Enchodus, a genus within the Enchodontidae family, from this region. Enchodus was a predatory fish, easily recognized by its distinctive sharp teeth, which made it one of the dominant marine predators of its time.
The fossils collected from the field were embedded in calcareous mudstone and concretions. The team utilized morphological analyses, along with computed tomography (CT) scans, to study the specimens in detail. These scans revealed not only the external features of the fossils but also internal structures hidden within the rock matrix — features crucial for taxonomic classification.
One of the most exciting aspects of this discovery is its contribution to understanding the diversity and distribution of Enchodus. The genus was already known to have a wide geographic range, with fossils found across North America, Europe, and Africa, but records from South America, particularly Colombia, have been rare. These newly uncovered specimens, some of which show distinctive morphological features, may even point to the presence of new, yet undescribed species of Enchodus.
The fossils were found in the Galembo Member of the La Luna Formation, a sedimentary sequence rich in organic material and known for its preservation of marine life. The environment in which these fish lived was likely a shallow, oxygen-starved sea, contributing to the preservation of skeletal remains. Despite the disarticulated nature of the fossils — a sign of active sea-bottom conditions and scavenger activity — the bones and teeth of these ancient predators offer a fascinating look at marine ecosystems during the Late Cretaceous.
This discovery not only fills a gap in Colombia’s fossil record but also raises intriguing questions about the factors that influenced the preservation and fossilization of marine life in the region. Why, in a period known for rich marine biodiversity, are fossils from the Colombian Upper Cretaceous so hard to come by? The answers to these questions may lie in the geological and environmental conditions of the time, but further research is needed to unravel these mysteries.
The findings also highlight the potential for future discoveries in the La Luna Formation. As more specimens are uncovered and analyzed, we may uncover further evidence of marine vertebrate diversity in this region. Each fossil tells a story, and these new specimens of Enchodus are beginning to piece together a chapter of the evolutionary history of marine life in South America.
These findings are detailed in the recently published article:
I extend warm thanks to Jose M. Torres-Parada for the opportunity to collaborate on this project. May many more come our way!
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