Coelacanths are a remarkable group of fish that have long intrigued scientists due to their ancient lineage and distinctive anatomy. For decades, only two species of living coelacanths were known, residing along the East African coast and in the waters of Indonesia. However, recent research has added a new chapter to the story of these enigmatic creatures. A collaborative effort led by scientists from the Natural History Museum of Geneva and the University of Geneva has resulted in the identification of an additional species of coelacanth. This discovery was facilitated by cutting-edge technology, including the use of the European Synchrotron Radiation Facility in Grenoble, a sophisticated particle accelerator designed to analyze matter in extraordinary detail.
Fossilization, the process that allows the preservation of biological remains for millions of years, typically involves the entombment of organisms within sedimentary rocks. Over vast periods, these fossils can undergo significant transformations due to geological activity, making it challenging for paleontologists to reconstruct the original appearance and biology of ancient species. Nonetheless, advancements in imaging technology have provided new opportunities to delve into the past with unprecedented clarity.
The team of paleontologists involved in this discovery included researchers from the Natural History Museum in Frankfurt, the Senckenberg Research Institute, and the European Synchrotron Radiation Facility. They recently published their findings in the scientific journal PLOS ONE. By examining 240-million-year-old coelacanth fossils from the Middle Triassic period, the team revealed anatomical details never before seen in this ancient lineage. These fossils were discovered in clay nodules located near Saverne, in the Lorraine region of France. Remarkably well-preserved in three dimensions, the specimens, each measuring around fifteen centimeters in length, allowed for an in-depth exploration of coelacanth anatomy.
To analyze the fossils, some specimens were transported to the European Synchrotron Radiation Facility (ESRF) in Grenoble. The ESRF is home to a unique type of particle accelerator that generates high-energy X-rays known as synchrotron light. These X-rays are exceptionally effective in penetrating dense rock and revealing the hidden structures within, including the delicate details of fossils. Over hundreds of hours, researchers meticulously isolated each bone of the fossilized skeleton using specialized software, producing virtual 3D models. These digital reconstructions enable scientists to examine fossil structures with a clarity that traditional methods cannot match.
The project was spearheaded by Luigi Manuelli, who was a doctoral researcher at the University of Geneva’s Department of Genetics & Evolution and part of the Natural History Museum’s team. Under the supervision of paleontologist Lionel Cavin, and with funding from the Swiss National Science Foundation, the research achieved groundbreaking results. The newly identified coelacanth species has been named Graulia branchiodonta. This name pays homage to the “Graoully,” a legendary dragon from Lorraine’s folklore, and highlights the fish’s distinctive feature—large, gill-associated teeth.
The fossils studied represent juvenile members of the species, revealing unique traits that differentiate them from modern coelacanths. One of the most notable features is the well-developed system of sensory canals, suggesting that Graulia branchiodonta was a more active predator compared to the contemporary coelacanth species, Latimeria. Modern coelacanths are known for their slow, languid movements, but the newly discovered species appears to have been more dynamic and agile in its environment. Additionally, Graulia branchiodonta possessed a large gas bladder, a structure that could have had multiple roles, ranging from aiding buoyancy to facilitating respiration or even enhancing auditory capabilities. Ongoing studies by the Geneva team are expected to shed further light on this intriguing feature and its potential functions.
The research into Graulia branchiodonta is part of a broader investigation into coelacanths from the Triassic period, a few million years after Earth’s most severe mass extinction event 500 million years ago. This catastrophic event wiped out a significant percentage of marine and terrestrial species, leading to a reshuffling of life forms that opened ecological niches for survivors like the coelacanths. Researchers from the Natural History Museum of Geneva are actively pursuing new fossil finds across various locations worldwide, aiming to piece together the evolutionary story of these resilient fish.
Beyond morphological studies, the scientists are also delving into the genetic heritage of coelacanths. By comparing the genomes of modern vertebrates with data gathered from fossilized specimens, they hope to unlock clues about how these “living fossils” have managed to persist relatively unchanged for hundreds of millions of years. These studies could provide insights not only into coelacanth evolution but also into the broader evolutionary patterns that have shaped the diversity of life on Earth.
The discovery of Graulia branchiodonta underscores the power of modern paleontological techniques. Through interdisciplinary collaboration and the use of state-of-the-art technology like the synchrotron, scientists are able to push the boundaries of what is known about ancient life. As the research continues, it promises to reveal more about the extraordinary history of coelacanths, a lineage that has survived multiple mass extinctions and continues to captivate with its blend of ancient features and surprising novelties.
Source: University of Geneva