Researchers uncover a well-preserved fossil coelacanth that challenges our understanding of how Earth’s geology drives the evolution of ancient marine life. The study reveals that tectonic activity, rather than ocean temperature or oxygen levels, was the primary driver behind the diversification of these living fossils.
A Fossil Treasure Trove
A truly exceptional coelacanth fossil found in Western Australia—the first of its kind from the entire continent—defuses another piece of the puzzle regarding these mysterious fish and how they evolved.
Coelacanths (which many consider to be “living fossils”) were presumed dead at the end of Cretaceous, but that idea was quashed in 1938 when one was caught by fishermen off South Africa. These deep-sea denizens, which can measure up to two meters in length, are distinctively shaped and link the ganoid fish group to tetrapods — land-living vertebrates that include frogs, birds and mammals.
The new fossil, named Ngamugawi wirngarri, is the most complete coelacanth from the Devonian period, when these ancestral fish first evolved. This discovery is highly significant for researchers as it provides new information about the early morphology and evolution of coelacanths, offering a window into a fascinating group that has long been cloaked in obscurity.
Their Latest Trick: Tectonic Shifts in Coelacanth Evolution
Long thought to be one of the best examples of a ‘living fossil,’ the new study suggests otherwise. After studying the evolutionary relationships among all known species of coelacanth, the researchers found something surprising: Tectonic activity (climate change) was not causing diversity in ocean temperatures or oxygen levels but driving diversity in coelacanths.
When these areas were heaved above the waves, new species of coelacanth appeared at an increased rate — meaning their development was aided by tectonic catastrophes that overturned their watery world. The result suggests that while environmental factors are often addressed, the dynamic of the constitutional geology at Earth, had a significant impact on their way to evolutions of these early fish.
The goby isn’t really “stuck” in its current form — it keeps evolving just like all other organisms do — but it’s an excellent example of how geological processes can shape the evolution of life, even for species that appear not to have changed at all over millions of years. The discovery of this unexpected link between tectonic activity and coelacanth diversity has revealed new ways to study the complex relationships that exist between the Earth’s ever-changing systems and the evolutionary paths taken by its inhabitants.
Conclusion
The finding of the extraordinary Ngamugawi wirngarri fossil recently has completely flipped our idea of how the rock record buries critical aspects of Earth’s biology, and what it tells us about ancient marine life diversification. They note that the study demonstrates how paleontological research continues to play a vital role in uncovering the mysteries of the past and testing our assumptions about genealogy. The fossil record is full of surprises, and as we sift through our planet’s ancient history, more unexpected links between how the Earth works as a physical system and the ways life evolves to deal with it are sure to come.
