130-Million-Year-Old Fossils Provide Earliest Evidence of Deep-Sea Fishes
Scientists have made an extraordinary discovery in ancient rocks, unearthing the earliest known evidence of deep-sea fishes. The fossils, which predate any previous evidence by a staggering 80 million years, were found in the NW Apennines, Italy, by paleontologist Andrea Baucon from the University of Genova.
The fossil evidence consists of pits and trails, which are believed to have been produced by feeding fishes during the Early Cretaceous, approximately 130 million years ago. These bowl-shaped excavations and sinuous trails provide a glimpse into the behavior of ancient deep-sea vertebrates.
Until now, there has been no fossil evidence of deep-sea fishes older than 50 million years. This groundbreaking discovery pushes back the timeline of deep-sea colonization by an astonishing amount, providing a new understanding of the evolution of deep-sea ecosystems.
The remote age of the fossils and their significance in shedding light on the history of life on Earth has left scientists astounded. The deep-sea fishes colonized an environment thousands of meters below the surface of the Tethys Ocean, which existed between 250 and 50 million years ago. These pioneers faced extreme conditions such as total darkness, near-freezing temperatures, and high pressures.
The newly discovered fossils mark a critical point in space and time. They represent the earliest deep-sea fishes and the earliest deep-sea vertebrates. The evolution of vertebrates has been marked by habitat transitions, and the invasion of the deep sea is the least understood.
The discovery of these rare fossils challenges previous assumptions about the factors that triggered the colonization of the deep sea by vertebrates. The authors of the study propose that the abundance of organic matter during the Late Jurassic and Early Cretaceous played a significant role in attracting bottom-dwelling worms, which in turn attracted fishes.
To gain insights into the behavior associated with the earliest fossils of deep-sea vertebrates, scientists studied the behavior of modern deep-sea fishes. By exploring the depths of the Pacific Ocean and observing chimeras, also known as ghost sharks, researchers were able to draw parallels between the behavior of ancient and modern fishes.
The study of these fossils not only provides a glimpse into the origins of deep-sea vertebrate biodiversity but also offers crucial clues about the evolution of life in the deep sea. The findings have profound implications for both Earth and Life Sciences and shed light on a previously unknown chapter in the history of life on our planet.
The research involved scientists from various institutions, including the University of Lisbon, University of Genova, University of Modena and Reggio Emilia, and Newcastle University, among others. The results of their study were recently published in the journal Proceedings of the National Academy of Sciences.