The earliest deep-sea vertebrates revealed by unusual fossils
The refutation of several key creationist claims continues with news that a team of Italian, Spanish, Portuguese and British scientists, led by palaeontologist Andrea Baucon of Genoa University, Italy, have discovered strong evidence of the existence of fish, 130 million years ago, pushing back the earliest known vertebrate presence in the abyssal plain by 20 million years.
Just to remind creationists, 130 million years is 130,000 times longer than they believe Earth has existed. Although all dating methods return a range of dates with a predictable variance, none of them has a lower limit anywhere approaching that magnitude.
The evidence, found in the Apennine mountains that run down the centre of Italy consists of the pits and tail-fin drag marks left in the silt in deep-ocean floor, of which the Apennines are now composed.
What information do you have on the geological formation of the Apennine Mountains in Italy?The team have published their findings in PNAS, sadly behind a paywall, but the news release from Università di Pisa gives the details:
The Apennine Mountains, also known as the Apennines (Italian: Appennini), are a long mountain range that runs down the length of the Italian Peninsula. They are an integral part of Italy's geological history and have played a significant role in shaping the country's landscape. Here is some information on the geological formation of the Apennine Mountains:In summary, the Apennine Mountains in Italy are the result of complex tectonic processes related to the collision of the African and Eurasian Plates. Their geological formation has taken millions of years and continues to shape the landscape of Italy today.
- Tectonic Origin:
- The Apennines were formed as a result of complex tectonic processes involving the collision of the African Plate and the Eurasian Plate. This tectonic interaction is known as the Alpine orogeny, which began about 50 million years ago during the Eocene epoch and continued into the Miocene epoch.
- Subduction Zone:
- The primary mechanism behind the formation of the Apennine Mountains is the subduction of the African Plate beneath the Eurasian Plate. As the African Plate slowly converged with the Eurasian Plate, it began to dive beneath the Eurasian Plate, leading to the compression and uplift of the crust in the region.
- Folded and Thrusted Structure:
- The intense tectonic forces associated with the subduction caused the sedimentary rocks that once covered the area to be folded, faulted, and thrust upward. This resulted in the creation of the characteristic folded and thrusted structure of the Apennine Mountains.
- Varied Geology:
- The Apennines are composed of a variety of rock types, including limestone, sandstone, shale, and volcanic rocks. The specific composition of the rocks varies along the length of the mountain range, leading to diverse landscapes and geological features.
- Ongoing Geological Activity:
- The Apennines are still geologically active, with occasional seismic activity and volcanism in certain areas, particularly in southern Italy. The presence of active volcanoes like Mount Vesuvius and Mount Etna is a testament to the ongoing geological processes in the region.
- Geological Divisions:
- Geologically, the Apennines are often divided into several regions, each with its own distinct geological characteristics. These include the Northern Apennines, Central Apennines, and Southern Apennines.
- Erosion and Landforms:
- Over millions of years, erosion has played a significant role in shaping the Apennines' landforms. Rivers and glaciers have carved valleys, while weathering has exposed the underlying rocks and created rugged peaks and plateaus.
- Geohistory and Paleontological Significance:
- The Apennines are of great significance to geologists and paleontologists because they contain a rich record of Earth's history, including fossils and evidence of past climates.
Extremely rare fossils reveal the earliest evidence of deep-sea fishes, pushing back the invasion of the abyssal plain by 80 million years. This revolutionary conclusion has been presented in a new study conducted by an international team of scientists led by palaeontologist Andrea Baucon and which includes Prof. Luca Pandolfi of the Department of Earth Sciences of the University of Pisa. The study has been published in the September issue of the Proceedings of the National Academy of Sciences (https://doi.org/10.1073/pnas.2306164120), one of the world's most-cited peer-reviewed multidisciplinary scientific journals.Although the main paper in PNAS is behind a paywall, the abstract and statement of significance are provided open access:
The reason for the astonishment is the remote age of the fossils, which predate any other evidence of deep-sea fish by million years. The newly discovered fossils date back to the Early Cretaceous (130 million years ago).When I first found the fossils, I can’t believe what I was seeing.
Professor Luca Pandolfi, co-author
Dipartimento di Scienze della Terra
Università di Pisa, Pisa, Italy
The newly discovered fossils are rare and unusual. They comprise bowl-shaped excavations produced by ancient feeding fishes, as well as the sinuous trail formed by the tail of a swimming fish, incising the muddy seafloor. These trace fossils do not comprise fish bones, but they record ancient behaviour. As such, the Apennine fossils mark a critical point in space and time. It is the point at which fishes moved out of the continental shelf and colonized a new harsh environment, located far away from their original habitat.The new fossils show the activity of fishes on a dinosaur-age seafloor that was thousands of meters deep.
The studied trace fossils are akin to the astronauts' footprints on the Moon.
Andrea Baucon, corresponding author.
Dipartimento di Scienze della Terra dell'Ambiente e della Vita
Università degli Studi di Genova, Genova, Italy.
Thousands of meters below the surface of the Tethys Ocean, the earliest deep-sea fishes faced extreme environmental conditions. Total darkness, near-freezing temperatures, and colossal pressures challenged the survival of these pioneers of the abyss.
Such extreme conditions required adaptations for deep-sea life that are evolutionary innovations as significant as those that allowed the colonization of the land and the air (e.g., wings and limbs).As if that weren’t enough, turbid currents swept the vast muddy plains patrolled by ancient fishes.
Professor Luca Pandolfi.
The newly discovered fossils represent not just the earliest deep-sea fishes but the earliest deep-sea vertebrates. The evolution of vertebrates – backboned animals – has been punctuated by habitat transitions from shallow marine origins to terrestrial, aerial, and deep-sea environments. Invasion of the deep sea is the least-understood habitat transition because of the low fossilization potential associated with the deep sea.
The Apennine fossils force scientists to reconsider which factors might have triggered the vertebrate colonization of the deep sea. Baucon and colleagues propose that the trigger was the unprecedented input of organic matter that occurred between the Late Jurassic and the Early Cretaceous.The new fossils shed light on an otherwise obscure chapter of the history of life on Earth.
Carlos Neto de Carvalho, co-author.
Geology Office of Idanha-a-Nova
Naturtejo UNESCO Global Geopark, Castelo Branco, Portugal.
The availability of food in the deep seas favoured bottom-dwelling worms, which, in turn, attracted fishes that used specific behaviours to expose them.
Annalisa Ferretti, co-author.
Dipartimento di Scienze Chimiche e Geologiche
Università degli Studi di Modena e Reggio Emilia, Modena, Italy.In the new study, researchers used a peculiar approach to understand fossil behaviour.Behaviour: that’s what the new fossils are all about.
Girolamo Lo Russo.
Museo di Storia Naturale di Piacenza, Piacenza, Italy
Baucon and colleagues studied the behaviour of modern fishes in their habitats.We turned to present-day seas for understanding the past.
Fernando Muñiz, co-author
Departamento de Cristalografía
Mineralogía y Química Agrícola, Universidad de Sevilla, Sevilla, Spain
supported by the words of Chiara Fioroni: “Observing modern fishes has been illuminating”. Scientists explored the depths of the Pacific Ocean to study chimaeras, also known as ghost sharks, in their living environment.The coasts of Spain and Italy have provided the key to interpreting the fossil structures.
Zain Belaústegui, co-author
Departament de Dinàmica de la Terra i de l’Oceà
Facultat de Ciències de la Terra
Universitat de Barcelona, Barcelona, Spain.
The new fossils are identical to structures produced by modern fishes that feed by either scratching the seafloor or exposing their bottom-dwelling prey by suction. This reminds of Neoteleostei, the group of vertebrates that includes modern jellynose fishes and lizardfishes.At 1500 m of depth, we observed a chimaera plunging its mouth into the sediment. It was a glimpse into the past!
Thomas Linley, co-author.
School of Natural and Environmental Sciences
Newcastle University, Newcastle Upon Tyne, UK.
A key feature of Neoteleostei is the highly developed suction feeding apparatus, therefore, the Apennine fossils may represent a very early stage of diversification of Neoteleostei into the deep sea.
Imants Priede, co-author
Oceanlab, Institute of Biological & Environmental Sciences
University of Aberdeen, Newburgh, Aberdeen, UK
Fishes such as the bathysaur and the tripod spiderfish are an important component of modern deep-sea ecosystems.
Our fossil discoveries reassess the mode and tempo of the vertebrate colonization of the deep sea. The newly discovered fossils contain fundamental clues about the very beginnings of vertebrate evolution in the deep sea, having profound implications for both Earth and Life Sciences.
Armando Piccinini, co-author
Spin Off Accademico Gen Tech, Università di Parma, Parma, Italy.The newly discovered fossils may represent the first major step in the origins of modern deep-sea vertebrate biodiversity. The roots of modern deep-sea ecosystems are in the Apennine fossils, witnessing a key habitat transition in the history of the oceans.The present is key to the past… and vice-versa!
Mário Cachão, co-author
Instituto D. Luiz
Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.
SignificanceOne can almost feel sorry for creationists having saddled themselves to a counter-factual superstition which requires them to abandon intellectual integrity and perform such mental contortions to pretend to themselves that they are right, and all the experts are wrong. An intellectually bankrupt position held for no better reason than terror of what an imaginary, mind-reading thug in the sky might do to them if they so much as consider changing their mind and accepting that real-world evidence trumps what a bunch of Bronze Age goat-herders believed.
Vertebrates are a prominent component of modern deep-sea ecosystems. However, there has been no fossil evidence of deep-seafloor vertebrates older than 50 My. Here, we report fish-feeding traces from Lower Cretaceous (130 Mya) deep-sea deposits of NW Italy. These fossils represent the earliest direct evidence of bottom-living vertebrates from the deep sea. Our findings reveal that the Early Cretaceous abyssal plains were already characterized by a modern-type deep-sea ecosystem characterized by multispecies aggregations of fishes. The studied fossils represent at least the last point of deep-sea vertebrate reorganization, if not the earliest.
Abstract
Vertebrate macroevolution has been punctuated by fundamental habitat transitions from shallow marine origins to terrestrial, freshwater, and aerial environments. Invasion of the deep sea is a less well-known ecological shift because of low fossilization potential and continual loss of abyssal fossil record by ocean floor subduction. Therefore, there has been a lack of convincing evidence of bottom-living vertebrates from pre-Paleogene deep seas. Here, we describe trace fossils from abyssal plain turbidites of the Tethys Ocean, which, combined with nannofossil dating, indicate that fishes have occupied the deep seafloor since at least the Early Cretaceous (Hauterivian–Barremian). These structures are identical to those produced by modern demersal fishes that feed by either scratching the substrate or expose their prey by water flow generated by suction or jetting. The trace fossils suggest activity of at least three fish species exploiting a productive abyssal invertebrate sediment fauna. These observations are consistent with Early Cretaceous vertebrate transition to the deep sea triggered by the availability of new food sources. Our results anticipate the appearance of deep-seafloor fishes in the fossil record by over 80 My while reassessing the mode of vertebrate colonization of the deep sea.
Baucon, A.; Ferretti, A.; Fioroni, C.; Pandolfi, L.; Serpagli, E.; et. al (2023)
The earliest evidence of deep-sea vertebrates
Proceedings of the National Academy of Sciences; 120(37) e2306164120. DOI: 10.1073/pnas.2306164120
Copyright: © 2023 The authors.
Published by [publisher] Open access.
Reprinted under a Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND 4.0).
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