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Bianucci G, Lambert O, Urbina M, Merella M, Collareta A, Bennion R, Salas-Gismondi R, Benites-Palomino A, Post K, de Muizon C, Bosio G, Di Celma C, Malinverno E, Pierantoni PP, Villa IM, Amson E. A heavyweight early whale pushes the boundaries of vertebrate morphology. Nature 2023; 620:824-829. [PMID: 37532931 DOI: 10.1038/s41586-023-06381-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 06/28/2023] [Indexed: 08/04/2023]
Abstract
The fossil record of cetaceans documents how terrestrial animals acquired extreme adaptations and transitioned to a fully aquatic lifestyle1,2. In whales, this is associated with a substantial increase in maximum body size. Although an elongate body was acquired early in cetacean evolution3, the maximum body mass of baleen whales reflects a recent diversification that culminated in the blue whale4. More generally, hitherto known gigantism among aquatic tetrapods evolved within pelagic, active swimmers. Here we describe Perucetus colossus-a basilosaurid whale from the middle Eocene epoch of Peru. It displays, to our knowledge, the highest degree of bone mass increase known to date, an adaptation associated with shallow diving5. The estimated skeletal mass of P. colossus exceeds that of any known mammal or aquatic vertebrate. We show that the bone structure specializations of aquatic mammals are reflected in the scaling of skeletal fraction (skeletal mass versus whole-body mass) across the entire disparity of amniotes. We use the skeletal fraction to estimate the body mass of P. colossus, which proves to be a contender for the title of heaviest animal on record. Cetacean peak body mass had already been reached around 30 million years before previously assumed, in a coastal context in which primary productivity was particularly high.
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Affiliation(s)
- Giovanni Bianucci
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
| | - Olivier Lambert
- D.O. Terre et Histoire de la Vie, Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium
| | - Mario Urbina
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Marco Merella
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
| | - Alberto Collareta
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
| | - Rebecca Bennion
- D.O. Terre et Histoire de la Vie, Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium
- Evolution & Diversity Dynamics Lab, UR Geology, Université de Liège, Liège, Belgium
| | - Rodolfo Salas-Gismondi
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Lima, Perú
- Facultad de Ciencias y Filosofía/Centro de Investigación para el Desarrollo Integral y Sostenible, Laboratorios de Investigación y Desarrollo, Universitad Peruana Cayetano Heredia Lima, Lima, Perú
| | - Aldo Benites-Palomino
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Lima, Perú
- Department of Paleontology, University of Zurich, Zurich, Switzerland
| | - Klaas Post
- Natuurhistorisch Museum Rotterdam, Rotterdam, The Netherlands
| | - Christian de Muizon
- Département Origines et Évolution, CR2P (CNRS, MNHN, Sorbonne Université), Muséum National d'Histoire Naturelle, Paris, France
| | - Giulia Bosio
- Dipartimento di Scienze dell'Ambiente e della Terra, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Claudio Di Celma
- School of Science and Technology, University of Camerino, Camerino, Italy
| | - Elisa Malinverno
- Dipartimento di Scienze dell'Ambiente e della Terra, Università degli Studi di Milano-Bicocca, Milano, Italy
| | | | | | - Eli Amson
- Staatliches Museum für Naturkunde Stuttgart, Stuttgart, Germany.
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Evolution: Back to heavy bones in salty seas. Curr Biol 2022; 32:R42-R44. [PMID: 35015995 DOI: 10.1016/j.cub.2021.11.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In amniote vertebrates that transitioned from land to sea, bone mass typically increases and later decreases as active swimming evolves. A new study now has found that heavy bones re-evolved in some fossil marine mammals, suggesting that this trajectory can be reversed.
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