Recent groundbreaking fossil research highlights the connections between climate change, asteroids, and animal evolution, while also emphasizing the significant role of plate tectonics in these processes.
An exceptionally preserved ancient coelacanth fish from the Devonian period has been discovered in a remote area of Western Australia. This finding correlates with a time of increased tectonic activity, as outlined in a new study published in Nature Communications. (The study will be open access upon publication.)
Conducted by Flinders University along with researchers from Canada, Australia, and Europe, the study focuses on a new fossil from the Gogo Formation in WA, named Ngamugawi wirngarri. This fossil helps bridge a significant gap in the evolutionary timeline of coelacanths, showcasing the transition from their primitive ancestors to more anatomically advanced forms.
“We are excited to collaborate with the Mimbi community to honor this beautiful new fish with a name derived from the Gooniyandi language,” remarked Dr. Alice Clement, the study’s lead author and an evolutionary biologist and paleontologist at Flinders University.
“Our research indicates that tectonic plate movements greatly influenced the evolutionary rates of coelacanths. Specifically, new species were more likely to emerge during periods of intense tectonic activity that created and separated new habitats,” she explained.
This study confirms that the Late Devonian Gogo Formation is one of the most abundant and well-preserved collections of fossilized fishes and invertebrates on the planet.
Professor John Long, a Strategic Professor of Palaeontology at Flinders University, commented that this fossil, dating back to the Devonian Period (359-419 million years ago), provides valuable insights into the early development of a lineage that eventually led to humans.
“For over 35 years, we have uncovered several perfectly preserved 3D fish fossils from Gogo sites, leading to various significant findings, including mineralized soft tissues and the origins of complex sexual reproduction among vertebrates,” said Professor Long.
“Our study of this new species enabled us to explore the evolutionary history of all known coelacanths.”
Key features of human anatomy can be traced back to the Early Paleozoic era (540-350 million years ago), a time when early fishes developed traits like jaws, teeth, paired limbs, solidified brain cases, reproductive organs, chambered hearts, and paired lungs.
“Today, the Gogo Formation, located in the Gooniyandi Country in the Kimberley region of northern Western Australia, remains a dry rocky landscape, but 380 million years ago it was part of a vibrant tropical reef rich in over 50 fish species,” the researchers stated.
“Through analyzing the evolution rates over the past 410 million years, we found coelacanth evolution has dramatically slowed since the dinosaurs, with a few fascinating exceptions.”
Currently, the coelacanth is a remarkable deep-sea fish inhabiting the waters off eastern Africa and Indonesia, reaching lengths of up to 2 meters. These fish, known as “lobe-finned” due to their sturdy fin bones resembling those in human arms, are considered more closely related to lungfish and tetrapods (four-limbed vertebrates such as frogs, emus, and mice) than to most other fish species.
Over the last 410 million years, over 175 coelacanth species have been documented globally. During the Mesozoic Era, known as the age of dinosaurs, coelacanths underwent substantial diversification and some species developed unique body structures. However, they mysteriously vanished from the fossil record at the end of the Cretaceous Period around 66 million years ago.
The end-Cretaceous extinction event, triggered by a significant asteroid impact, resulted in the disappearance of about 75% of all life on Earth, including all non-avian dinosaurs. Consequently, it was assumed that coelacanths suffered the same fate.
Yet in 1938, fishermen off the coast of South Africa caught a strange-looking fish from the ocean’s depths, leading to the coelacanth being dubbed the “lazarus” fish, as it appeared to come back from extinction.
Professor Richard Cloutier, a vertebrate paleontologist at the University of Quebec in Rimouski (UQAR) and a senior co-author of the study, asserts that the latest research challenges the notion that living coelacanths are the oldest “living fossils.”
“Though they first appear in the geological record over 410 million years ago, and fragmentary fossils have been found in places like China and Australia, many early forms are not well understood, which makes Ngamugawi wirngarri the most comprehensively studied Devonian coelacanth to date.”
“As we gradually piece together this evolutionary puzzle, we begin to understand that currently living coelacanth species, commonly labeled as ‘living fossils,’ are actually still evolving and may not deserve such a mysterious title,” adds Professor Cloutier, who has previously held an honorary visiting scholarship at Flinders University.
The study’s co-authors represent various institutions, including Mahasarakham University in Thailand, the South Australian Museum, Max Planck Institute for Evolutionary Anthropology in Germany, University of Bristol, Curtin University in Western Australia, and the WA Museum.
