An extraordinary fossil discovery is shedding new light on prehistoric life in what is now Zion National Park.
Paleontologists have uncovered skull elements of a 200 million-year-old coelacanth fish, marking the most significant vertebrate fossil found in the park to date.
The fossil bones are believed to be from a lower Jurassic coelacanth, an ancient lobe-finned fish distantly related to lungfish and tetrapods, the lineage that gave rise to reptiles, amphibians, birds and mammals. This primitive fish lived in a freshwater environment around 200 million years ago, unlike its few living relatives today which inhabit saltwater.
The fossil specimens were recently recovered in Zion by a collaborative team from the National Park Service and the St. George Dinosaur Discovery Site. Analyses so far indicate the fossils represent a new coelacanth species that has not been formally described yet. Paleontologists Andrew Milner and Jim Kirkland are in the process of formally characterizing this primitive fish as part of their research.
This rare coelacanth find provides valuable clues about the diversity of related species living during the Early Jurassic period. Comparing these fossils to other coelacanths from the same geologic time period will help scientists reconstruct the evolutionary relationships, biology and environments these fish inhabited.
According to researchers, the discovery is especially significant because vertebrate body fossils are rare in the rock layers exposed at Zion. The fossilized skull bones indicate there were appropriate conditions for preserving specimens in the Whitmore Point Member geological layer of the Moenave Formation where they were found. This gives hope that more vertebrate fossils are waiting to be unearthed from these rocks.
In addition to shedding light on biological diversity, these 200 million-year-old remains also reveal insights into the ancient environment of Zion. Researchers say the freshwater-adapted coelacanth points to the past presence of an ancient lake ecosystem within the region.
While the fossil discovery promises to enhance understanding of Zion’s natural history, conducting paleontological work in national parks also poses challenges. Strict regulations prohibit large-scale excavations and surface disturbances. As an alternative, the latest photogrammetry technology is allowing scientists to create detailed 3D models of significant fossil sites throughout the park. These non-invasive digital reconstructions help quantify and monitor erosion over time while preserving a record of fragile fossils.
This remarkable glimpse into the distant past was made possible thanks to collaboration between different research institutions. As work continues, this rare coelacanth fossil is sure to provide a wealth of information about the ecosystems and organisms that existed in the Zion area millions of years before humans set foot there.
Cover photo courtesy of: James St. John
