Scientists have discovered a missing piece of the evolutionary puzzle in a 130-million-year-old rock. This discovery is the result of international cooperation. Faculty of Science, University of Lisbon (Portugal) is involved.
in spite of vertebrate Despite being a major component of modern deep-sea ecosystems, there is no fossil evidence of deep-sea fish dating back more than 50 million years. Now, recent excavations of extremely rare fossils provide the oldest known evidence of deep-sea fish. This causes the timeline of deep-sea colonization to be postponed to his staggering 80 million years.
The results of this study were recently published in the journal Proceedings of the National Academy of Sciences.
“When I first found the fossil, I couldn’t believe what I was seeing,” says study leader Andrea Baucon, a paleontologist at the University of Genoa in Italy. It was he who discovered fish fossils in the northwestern Apennines near Piacenza, Modena and Livorno (Italy).
The reason for this surprise is the distant age of the fossil, which is millions of years older than evidence of other deep-sea fish.Newly discovered fossils date back to early times Cretaceous period (130 million years ago). “The new fossils show fish activity on the ocean floor during the dinosaur era, at depths of several thousand meters,” added Andrea Baucon.
Scientists used photogrammetry to provide photo-textured height maps of the fossil pits and traces. These represent the earliest evidence of deep-sea vertebrates.Credit: Girolamo Lo Russo
Newly discovered fossils are rare and rare. These consist of bowl-shaped excavations formed by ancient fish feedings and winding tracks cut through the muddy ocean floor by the tails of swimming fish. These trace fossils do not contain body fossils such as fish bones, but they record ancient behavior. The Apennine fossils thus mark an important point in space and time. It is the point where fish migrated from the continental shelf and established themselves in new, harsh environments far from their original habitat.
Thousands of meters from the surface of the Tethyan Sea (an ancient sea that existed between 250 and 50 million years ago and is the precursor to the modern Mediterranean Sea), early deep-sea fishes were found to be relatively small compared to their shallow-sea origins. They faced extreme environmental conditions. : Total darkness, near-zero temperatures, and immense pressure challenged the survival of the Abyssal Settlers.
The video shows the chimera swimming on top of sediment in the Kermadec Trench (1,544 meters deep) and then feeding by sticking its mouth into the sediment. In a new study, scientists studied the behavior of modern fish to understand the behaviors associated with the oldest fossils of deep-sea vertebrates.Credit: Thomas Linley, Alan Jamison
Such extreme conditions require deep-sea organisms to adapt, evolutionary innovations as important as wings and limbs that allowed them to colonize land and air.
The newly discovered fossils represent not only the oldest deep-sea fish, but also the oldest deep-sea vertebrates. The evolution of vertebrates (vertebrates) has been interrupted by habitat transitions from shallow marine origins to terrestrial, aerial, and deep-sea environments. Deep-sea invasions are the least understood habitat successions because of the low fossilization potential associated with the deep sea.
“The new fossils shed light on an obscure chapter in the history of life on Earth,” comments Carlos Neto de Carvalho, a researcher at the Don Luis Institute, Faculty of Science, University of Lisbon, Portugal.
Apennine fossils are forcing scientists to reconsider what factors led to the colonization of vertebrates in the deep sea. The authors propose that the trigger was an unprecedented input of organic matter that occurred during the late to late period. Jurassic and the Early Cretaceous. The availability of food in the deep sea gave an advantage to bottom-dwelling insects, which attracted fish that behaved in certain ways to expose the insects.
In this study, researchers looked to the modern ocean to understand the behavior of fossils and studied the behavior of modern fish in their habitat. Scientists have explored the deep waters of the Pacific Ocean to study the habitat of chimeras, also known as ghost sharks.
The new fossils are identical to structures produced by modern fish that feed by scratching the ocean floor or exposing bottom-dwelling prey through suction. This is reminiscent of the neoteleostei, a group of vertebrates that includes modern crannosefish and lizardfish.
“Contrary to popular belief, deep-sea sediments are filled with fossilized remains of ancient organisms, but usually from smaller organisms that live far up in the water column as plants and zooplankton.” Mario Kacian, co-author of the book, explains: He studies and conducts research at the Instituto Dom Luiz in Ciencias Urisboa.
“However, to discover and interpret direct evidence of vertebrate organic activity imprinted and geologically preserved in such deposits after their geological transformation and exposure as the Northern Apennines. That was mainly located in the Miocene and Pliocene geological epochs, the last 20 million years ago, and this is a really, very, unusual discovery,” adds Mario Cachoun.
Newly discovered fossils could be a major step in the origin of modern deep-sea vertebrate biodiversity. The roots of modern deep-sea ecosystems lie in Apennine fossils, which bear witness to important habitat changes in ocean history. “Our fossil discoveries re-evaluate the mode and the tempo of deep-sea vertebrate colonization.Newly discovered fossils contain fundamental clues about the very first thing “The study of vertebrate evolution in the deep sea has profound implications for both Earth and life sciences,” summarizes Andrea Baucon.
Reference: “The earliest evidence of deep-sea vertebrates” Andrea Baucon, Annalisa Ferretti, Chiara Fioroni, Luca Pandolfi, Enrico Serpagli, Armando Piccinini, Carlos Neto de Carvalho, Mario Cachan, Written by Thomas Linley, Fernando Muniz, Zane Belaustegui, Alan Jamison, Girolamo Lo Russo, Filippo Guerini, Sara Ferland, Imants Pliede, September 5, 2023. Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2306164120
The results of this study were published in Italy (University of Genoa, University of Modena, University of Reggio Emilia, University of Padova, Pisa, University of Parma, Museum of Natural History of Piacenza, Museum of Natural History of South Tyrol), Portugal (Naturtejo UNESCO Global Geopark, Naturtejo UNESCO Global This was done in collaboration with researchers affiliated with the scientific institutions of the Geopark. University of Lisbon), England (University of Newcastle), Spain (University of Seville and Barcelona), Australia (University of Western Australia), Scotland (University of Aberdeen).