In a new study published in Nature Communications, researchers have uncovered the most well-preserved coelacanth fossil from hundreds of millions of years ago. This fossil was found in the Gogo Formation, located in northern Western Australia on Gooniyandi Country. Coelacanths are ancient sea creatures that first evolved during this period, and the fossil sheds light on their early development.
Coelacanth Evolution Over Time
The research also examined the evolution of hundreds of coelacanth species throughout history. Contrary to expectations, their evolution was not primarily influenced by ocean environments. During the age of dinosaurs, around 250 million years ago, coelacanth species diversified significantly. Fossil evidence of over 175 species has been found globally. However, 66 million years ago, near the end of the Cretaceous period, coelacanth fossils vanished, leading scientists to believe they were wiped out by the asteroid impact that caused the extinction of the dinosaurs.
Rediscovery of the “Lazarus Fish”
That theory was overturned in 1938 when a South African fishing crew caught a mysterious fish. Marjorie Courtenay-Latimer, a museum worker with a passion for natural sciences, recognized its uniqueness and consulted J. L. B. Smith, an expert in fish studies. Smith identified the fish as Latimeria, the first living coelacanth discovered, a species previously thought to be extinct. The discovery was compared to finding a living Triceratops in modern times, and Latimeria was nicknamed the “Lazarus fish.”
A New Coelacanth Species: Ngamugawi Wirngarri
Researchers from Flinders University, alongside international colleagues, recently discovered a new fossil species of coelacanth in the same region. Named Ngamugawi wirngarri in honor of a local elder, this new species is the first to receive a name from the Gooniyandi language. Found in a tropical reef setting, this 380-million-year-old fossil is the best-preserved coelacanth from the Devonian Period. The specimen offers valuable insights into the early anatomy of coelacanths.
Role of Plate Tectonics in Coelacanth Evolution
The study also analyzed the evolutionary history of all known coelacanth species. Researchers discovered that, while coelacanths have evolved slowly, tectonic plate activity played a key role in their development. During periods of increased tectonic shifts, new coelacanth species were more likely to emerge due to changing habitats.
Modern Coelacanths and Their Evolution
The research team also examined the two existing coelacanth species, Latimeria chalumnae and Latimeria menadoensis. Though they appear almost identical to their ancient ancestors, subtle differences in their DNA and body proportions show that these fish have continued to evolve, albeit slowly. This suggests that, while often called “living fossils,” coelacanths are still undergoing evolutionary changes.
