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Valenzuela-Toro AM, Mehta R, Pyenson ND, Costa DP, Koch PL. Feeding morphology and body size shape resource partitioning in an eared seal community. Biol Lett 2023; 19:20220534. [PMID: 36883314 PMCID: PMC9993223 DOI: 10.1098/rsbl.2022.0534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Body size and feeding morphology influence how animals partition themselves within communities. We tested the relationships among sex, body size, skull morphology and foraging in sympatric otariids (eared seals) from the eastern North Pacific Ocean, the most diverse otariid community in the world. We recorded skull measurements and stable carbon (δ13C) and nitrogen (δ15N) isotope values (proxies for foraging) from museum specimens in four sympatric species: California sea lions (Zalophus californianus), Steller sea lions (Eumetopias jubatus), northern fur seals (Callorhinus ursinus) and Guadalupe fur seals (Arctocephalus townsendi). Species and sexes had statistical differences in size, skull morphology and foraging significantly affecting the δ13C values. Sea lions had higher δ13C values than fur seals, and males of all species had higher values than females. The δ15N values were correlated with species and feeding morphology; individuals with stronger bite forces had higher δ15N values. We also found a significant community-wide correlation between skull length (indicator of body length), and foraging, with larger individuals having nearshore habitat preferences, and consuming higher trophic level prey than smaller individuals. Still, there was no consistent association between these traits at the intraspecific level, indicating that other factors might account for foraging variability.
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Affiliation(s)
- Ana M Valenzuela-Toro
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Rita Mehta
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Nicholas D Pyenson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Department of Paleontology and Geology, Burke Museum of Natural History and Culture, Seattle, WA 98105, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Paul L Koch
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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Martín-Orti R, Tostado-Marcos C, Loureiro JP, Molpeceres-Diego I, Tendillo-Domínguez E, Santos-Álvarez I, Pérez-Lloret P, González-Soriano J. The Digestive System of the Arctocephalus australis in Comparison to the Dog as a Land-Carnivore Model. Animals (Basel) 2022; 12:ani12131634. [PMID: 35804533 PMCID: PMC9264872 DOI: 10.3390/ani12131634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Marine mammals are warm-blooded vertebrates that behave in the same way as land mammals do but they spend most or all of their lives in the ocean. There is much previous research on whales, dolphins, or even different types of seals, including their behavior, health, anatomy or perception. Between all these fields, it is commonly accepted that anatomy is considered critical to understanding many physiological adaptations. For example, their ability to dive by holding their breath underwater for long periods of time. During this process they can postpone digestion for several hours. However, and contrary to what might be expected, our results show that being a carnivore seems to be the critical characteristic defining their digestive apparatus, the adaptations to the aquatic environment being less significant. Abstract Marine mammals play a critical ecological role as both predator and prey. They are divided into three groups that share similar adaptations to their aquatic life, but that have very different origins and life patterns: sirenians, pinnipeds, cetaceans. The species object of our interest is the South American fur seal or Arctocephalus australis, a carnivore classified within the group of pinnipeds. The objective of the present study was to evaluate whether the anatomical characteristics of the Arctocephalus australis’ digestive system are similar to that of other land-carnivores or if, on the contrary, this species shows anatomical adaptations related to their life in the ocean. The study was carried out on 11 cadavers of the species Arctocephalus australis, made up of two adults and nine juveniles, by means of the anatomical dissection of their entire isolated digestive system. We demonstrate that, with several exceptions, the anatomical characteristics of the digestive system of the Arctocephalus australis are similar to those in other carnivores. Therefore, our data constitute an important contribution for clinical diagnostic and conservation purposes, for both veterinarians and biologists.
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Affiliation(s)
- Rosario Martín-Orti
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Carlos Tostado-Marcos
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Juan-Pablo Loureiro
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Ignacio Molpeceres-Diego
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Enrique Tendillo-Domínguez
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Inmaculada Santos-Álvarez
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Pilar Pérez-Lloret
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Juncal González-Soriano
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
- Correspondence:
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3
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Engelman RK. Occipital condyle width (OCW) is a highly accurate predictor of body mass in therian mammals. BMC Biol 2022; 20:37. [PMID: 35130893 PMCID: PMC8883515 DOI: 10.1186/s12915-021-01224-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/26/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Body mass estimation is of paramount importance for paleobiological studies, as body size influences numerous other biological parameters. In mammals, body mass has been traditionally estimated using regression equations based on measurements of the dentition or limb bones, but for many species teeth are unreliable estimators of body mass and postcranial elements are unknown. This issue is exemplified in several groups of extinct mammals that have disproportionately large heads relative to their body size and for which postcranial remains are rare. In these taxa, previous authors have noted that the occiput is unusually small relative to the skull, suggesting that occiput dimensions may be a more accurate predictor of body mass. RESULTS The relationship between occipital condyle width (OCW) and body mass was tested using a large dataset (2127 specimens and 404 species) of mammals with associated in vivo body mass. OCW was found to be a strong predictor of body mass across therian mammals, with regression models of Mammalia as a whole producing error values (~ 31.1% error) comparable to within-order regression equations of other skeletal variables in previous studies. Some clades (e.g., monotremes, lagomorphs) exhibited specialized occiput morphology but followed the same allometric relationship as the majority of mammals. Compared to two traditional metrics of body mass estimation, skull length, and head-body length, OCW outperformed both in terms of model accuracy. CONCLUSIONS OCW-based regression models provide an alternative method of estimating body mass to traditional craniodental and postcranial metrics and are highly accurate despite the broad taxonomic scope of the dataset. Because OCW accurately predicts body mass in most therian mammals, it can be used to estimate body mass in taxa with no close living analogues without concerns of insufficient phylogenetic bracketing or extrapolating beyond the bounds of the data. This, in turn, provides a robust method for estimating body mass in groups for which body mass estimation has previously been problematic (e.g., "creodonts" and other extinct Paleogene mammals).
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Affiliation(s)
- Russell K Engelman
- Department of Biology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
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4
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Rule JP, Adams JW, Rovinsky DS, Hocking DP, Evans AR, Fitzgerald EMG. A new large-bodied Pliocene seal with unusual cutting teeth. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201591. [PMID: 33391813 PMCID: PMC7735334 DOI: 10.1098/rsos.201591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 10/14/2020] [Indexed: 05/24/2023]
Abstract
Today, monachine seals display the largest body sizes in pinnipeds. However, the evolution of larger body sizes has been difficult to assess due to the murky taxonomic status of fossil seals, including fossils referred to Callophoca obscura, a species thought to be present on both sides of the North Atlantic during the Neogene. Several studies have recently called into question the taxonomic validity of these fossils, especially those from the USA, as the fragmentary lectotype specimen from Belgium is of dubious diagnostic value. We find that the lectotype isolated humerus of C. obscura is too uninformative; thus, we designate C. obscura as a nomen dubium. More complete cranial and postcranial specimens from the Pliocene Yorktown Formation are described as a new taxon, Sarcodectes magnus. The cranial specimens display adaptations towards an enhanced ability to cut or chew prey that are unique within Phocidae, and estimates indicate S. magnus to be around 2.83 m in length. A parsimony phylogenetic analysis found S. magnus is a crown monachine. An ancestral state estimation of body length indicates that monachines did not have a remarkable size increase until the evolution of the lobodontins and miroungins.
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Affiliation(s)
- James P. Rule
- Department of Anatomy and Developmental Biology, Melbourne, Victoria 3800, Australia
- Palaeontology, Museums Victoria, Melbourne, Victoria 3001, Australia
| | - Justin W. Adams
- Department of Anatomy and Developmental Biology, Melbourne, Victoria 3800, Australia
| | - Douglass S. Rovinsky
- Department of Anatomy and Developmental Biology, Melbourne, Victoria 3800, Australia
| | - David P. Hocking
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
- Palaeontology, Museums Victoria, Melbourne, Victoria 3001, Australia
| | - Alistair R. Evans
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
- Palaeontology, Museums Victoria, Melbourne, Victoria 3001, Australia
| | - Erich M. G. Fitzgerald
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
- Palaeontology, Museums Victoria, Melbourne, Victoria 3001, Australia
- National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
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5
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Rule JP, Adams JW, Fitzgerald EMG. Colonization of the ancient southern oceans by small-sized Phocidae: new evidence from Australia. Zool J Linn Soc 2020. [DOI: 10.1093/zoolinnean/zlaa075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Abstract
Most of the diversity of extant southern true seals (Phocidae: Monachinae) is present in the Southern Ocean, but a poor fossil record means that the origin of this fauna remains unknown. Australia represents a large gap in the record bordering the Southern Ocean that could possibly inform on the origins of the extant Antarctic monachines, with most known fossils remaining undescribed. Here we describe the oldest Australian fossil pinniped assemblage, from the Late Miocene to the Early Pliocene of Beaumaris. Two fossils are referrable to Pinnipedia, five (possibly six) to Phocidae and a humerus is referrable to Monachinae. The humerus is not referrable to any extant tribe, potentially representing an archaic monachine. The description of this assemblage is consistent with the Neogene pinniped fauna of Australia being exclusively monachine before the arrival of otariids (fur seals and sea lions). The Beaumaris humerus, along with other Neogene phocids from the Southern Ocean margins, were smaller than their extant Antarctic relatives, possibly driven by longer food chains with less energy efficiency between trophic levels. This suggests that small archaic phocids potentially used the Southern Ocean as a means of dispersal before the arrival of extant Antarctic monachines.
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Affiliation(s)
- James P Rule
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Vertebrate Palaeontology, Museums Victoria, Melbourne, Victoria, Australia
| | - Justin W Adams
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Erich M G Fitzgerald
- Vertebrate Palaeontology, Museums Victoria, Melbourne, Victoria, Australia
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
- National Museum of Natural History, Smithsonian Institution, Washington DC, USA
- Department of Life Sciences, Natural History Museum, London, UK
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Bonola M, Girondot M, Robin JP, Martin J, Siegwalt F, Jeantet L, Lelong P, Grand C, Chambault P, Etienne D, Gresser J, Hielard G, Arqué A, Régis S, Lecerf N, Frouin C, Lefebvre F, Sutter E, Vedie F, Barnerias C, Thieulle L, Bordes R, Guimera C, Aubert N, Bouaziz M, Pinson A, Flora F, Duru M, Benhalilou A, Murgale C, Maillet T, Andreani L, Campistron G, Sikora M, Rateau F, George F, Eggenspieler J, Woignier T, Allenou JP, Louis-Jean L, Chanteur B, Béranger C, Crillon J, Brador A, Habold C, Le Maho Y, Chevallier D. Fine scale geographic residence and annual primary production drive body condition of wild immature green turtles ( Chelonia mydas) in Martinique Island (Lesser Antilles). Biol Open 2019; 8:bio.048058. [PMID: 31757806 PMCID: PMC6918739 DOI: 10.1242/bio.048058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The change of animal biometrics (body mass and body size) can reveal important information about their living environment as well as determine the survival potential and reproductive success of individuals and thus the persistence of populations. However, weighing individuals like marine turtles in the field presents important logistical difficulties. In this context, estimating body mass (BM) based on body size is a crucial issue. Furthermore, the determinants of the variability of the parameters for this relationship can provide information about the quality of the environment and the manner in which individuals exploit the available resources. This is of particular importance in young individuals where growth quality might be a determinant of adult fitness. Our study aimed to validate the use of different body measurements to estimate BM, which can be difficult to obtain in the field, and explore the determinants of the relationship between BM and size in juvenile green turtles. Juvenile green turtles were caught, measured, and weighed over 6 years (2011–2012; 2015–2018) at six bays to the west of Martinique Island (Lesser Antilles). Using different datasets from this global database, we were able to show that the BM of individuals can be predicted from body measurements with an error of less than 2%. We built several datasets including different morphological and time-location information to test the accuracy of the mass prediction. We show a yearly and north–south pattern for the relationship between BM and body measurements. The year effect for the relationship of BM and size is strongly correlated with net primary production but not with sea surface temperature or cyclonic events. We also found that if the bay locations and year effects were removed from the analysis, the mass prediction degraded slightly but was still less than 3% on average. Further investigations of the feeding habitats in Martinique turtles are still needed to better understand these effects and to link them with geographic and oceanographic conditions. Summary: This study validates the use of different body measurements to estimate body mass. We show a yearly and north-south pattern between them, strongly correlated with net primary production.
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Affiliation(s)
- Marc Bonola
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Marc Girondot
- Laboratoire Écologie, Systématique, Évolution, Université Paris-Sud, AgroParisTech, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Jean-Patrice Robin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Jordan Martin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Flora Siegwalt
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Lorène Jeantet
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Pierre Lelong
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Clément Grand
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Philippine Chambault
- UMR MARBEC, IFREMER, CNRS, IRD, University of Montpellier, Avenue Jean Monnet, 34200 Sète, France
| | - Denis Etienne
- DEAL Martinique, Pointe de Jaham, BP 7212, 97274 Schoelcher Cedex, France
| | - Julie Gresser
- DEAL Martinique, Pointe de Jaham, BP 7212, 97274 Schoelcher Cedex, France
| | - Gaëlle Hielard
- Office de l'Eau Martinique, 7 Avenue Condorcet, BP 32, 97201 Fort-de-France, Martinique, France
| | - Alexandre Arqué
- Office de l'Eau Martinique, 7 Avenue Condorcet, BP 32, 97201 Fort-de-France, Martinique, France
| | - Sidney Régis
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Nicolas Lecerf
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Cédric Frouin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Fabien Lefebvre
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Emmanuel Sutter
- DEAL Martinique, Pointe de Jaham, BP 7212, 97274 Schoelcher Cedex, France
| | - Fabien Vedie
- DEAL Martinique, Pointe de Jaham, BP 7212, 97274 Schoelcher Cedex, France
| | - Cyrille Barnerias
- DEAL Martinique, Pointe de Jaham, BP 7212, 97274 Schoelcher Cedex, France
| | - Laurent Thieulle
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Robinson Bordes
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Christelle Guimera
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Nathalie Aubert
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Myriam Bouaziz
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Adrien Pinson
- Surfrider Foundation Europe, 97000 Fort-de-France, Martinique, France
| | - Frédéric Flora
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Matthieu Duru
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Abdelwahab Benhalilou
- Association POEMM, 73 lot papayers, Anse a l'âne, 97229 Les Trois Ilets, Martinique, France
| | - Céline Murgale
- Association POEMM, 73 lot papayers, Anse a l'âne, 97229 Les Trois Ilets, Martinique, France
| | - Thomas Maillet
- Association POEMM, 73 lot papayers, Anse a l'âne, 97229 Les Trois Ilets, Martinique, France
| | - Lucas Andreani
- Association POEMM, 73 lot papayers, Anse a l'âne, 97229 Les Trois Ilets, Martinique, France
| | - Guilhem Campistron
- Association POEMM, 73 lot papayers, Anse a l'âne, 97229 Les Trois Ilets, Martinique, France
| | - Maxym Sikora
- ONF International, 78 route de Moutte, 97207 Fort-de-France, France
| | - Fabian Rateau
- ONF International, 78 route de Moutte, 97207 Fort-de-France, France
| | - Francis George
- ONF International, 78 route de Moutte, 97207 Fort-de-France, France
| | | | - Thierry Woignier
- Aix Marseille University, University Avignon, CNRS, IRD, IMBE, Marseille, 13397, France
| | - Jean-Pierre Allenou
- IFREMER Délégation de Martinique, 79 Route de Pointe-Fort 97231 Le Robert, France
| | | | | | | | - Jessica Crillon
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France.,Laboratoire Écologie, Systématique, Évolution, Université Paris-Sud, AgroParisTech, CNRS, Université Paris Saclay, 91405 Orsay, France
| | - Aude Brador
- Parc Marin de Martinique, Agence Française pour la Biodiversité, Avenue des Caneficiers, 97200 Fort-de-France, France
| | - Caroline Habold
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Yvon Le Maho
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Damien Chevallier
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
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Bisconti M, Lambert O, Bosselaers M. Revision of " Balaena" belgica reveals a new right whale species, the possible ancestry of the northern right whale, Eubalaena glacialis, and the ages of divergence for the living right whale species. PeerJ 2017; 5:e3464. [PMID: 28663936 PMCID: PMC5490463 DOI: 10.7717/peerj.3464] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/24/2017] [Indexed: 12/03/2022] Open
Abstract
In 1941, Abel established Balaena belgica based on a series of fused cervical vertebrae and citing other cranial fragments from the late Neogene of the Antwerp harbor (northern Belgium). Later, Plisnier-Ladame & Quinet (1969) added a neurocranium and other skeletal remains from the same area to this species. Recently, the neurocranium was re-assigned to the genus Eubalaena thanks to newer phylogenetic analyses. Here, a new description is provided of materials previously assigned to “Balaena” belgica together with taxonomic revisions. Our work suggests that the cervical complex originally designated as the type of “Balaena” belgica is too poorly preserved to be used as such and is assigned to Balaenidae gen. et sp. indet., thus making “Balaena” belgica a nomen dubium. In addition to the neurocranium, the other remains consist in a fragment of maxilla assigned to Balaenidae gen. et sp. indet. and in a humerus assigned to Eubalaena sp. Discovered in the Kruisschans Sands Member of the Lillo Formation (3.2–2.8 Ma, Piacenzian, Late Pliocene), the neurocranium is designated as the holotype of the new species Eubalaena ianitrix. Our phylogenetic analysis supports a sister-group relationship of Eubalaena ianitrix and Eubalaena glacialis, and helps constraining the ages of origin for balaenid clades. Ecological and phylogenetic data suggest that Eubalaena ianitrix may represent the direct ancestor of Eubalaena glacialis, the latter having evolved through phyletic transformation including body size increase during the temperature decline of the Late Pliocene.
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Affiliation(s)
| | - Olivier Lambert
- Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Mark Bosselaers
- Royal Belgian Institute of Natural Sciences, Brussels, Belgium.,Zeeland Royal Society of Sciences, Middelburg, the Netherlands
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8
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Dewaele L, Amson E, Lambert O, Louwye S. Reappraisal of the extinct seal " Phoca" vitulinoides from the Neogene of the North Sea Basin, with bearing on its geological age, phylogenetic affinities, and locomotion. PeerJ 2017; 5:e3316. [PMID: 28533965 PMCID: PMC5436577 DOI: 10.7717/peerj.3316] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 04/14/2017] [Indexed: 11/30/2022] Open
Abstract
Background Discovered on the southern margin of the North Sea Basin, “Phoca” vitulinoides represents one of the best-known extinct species of Phocidae. However, little attention has been given to the species ever since its original 19th century description. Newly discovered material, including the most complete specimen of fossil Phocidae from the North Sea Basin, prompted the redescription of the species. Also, the type material of “Phoca” vitulinoides is lost. Methods “Phoca” vitulinoides is redescribed. Its phylogenetic position among Phocinae is assessed through phylogenetic analysis. Dinoflagellate cyst biostratigraphy is used to determine and reassess the geological age of the species. Myological descriptions of extant taxa are used to infer muscle attachments, and basic comparative anatomy of the gross morphology and biomechanics are applied to reconstruct locomotion. Results Detailed redescription of “Phoca” vitulinoides indicates relatively little affinities with the genus Phoca, but rather asks for the establishment of a new genus: Nanophoca gen. nov. Hence, “Phoca” vitulinoides is recombined into Nanophoca vitulinoides. This reassignment is confirmed by the phylogenetic analysis, grouping the genus Nanophoca and other extinct phocine taxa as stem phocines. Biostratigraphy and lithostratigraphy expand the known stratigraphic range of N. vitulinoides from the late Langhian to the late Serravallian. The osteological anatomy of N. vitulinoides indicates a relatively strong development of muscles used for fore flipper propulsion and increased flexibility for the hind flipper. Discussion The extended stratigraphic range of N. vitulinoides into the middle Miocene confirms relatively early diversification of Phocinae in the North Atlantic. Morphological features on the fore- and hindlimb of the species point toward an increased use of the fore flipper and greater flexibility of the hind flipper as compared to extant Phocinae, clearly indicating less derived locomotor strategies in this Miocene phocine species. Estimations of the overall body size indicate that N. vitulinoides is much smaller than Pusa, the smallest extant genus of Phocinae (and Phocidae), and than most extinct phocines.
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Affiliation(s)
- Leonard Dewaele
- Department of Geology, Ghent University, Ghent, Belgium.,O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Eli Amson
- Arbeitsgruppe Morphologie und Formengeschichte, Humboldt Universität Berlin, Berlin, Germany.,Paläontologisches Institut und Museum, University of Zürich, Zürich, Switzerland
| | - Olivier Lambert
- O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
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Velez-Juarbe J. Eotaria citrica, sp. nov., a new stem otariid from the "Topanga" formation of Southern California. PeerJ 2017; 5:e3022. [PMID: 28243536 PMCID: PMC5326546 DOI: 10.7717/peerj.3022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/24/2017] [Indexed: 11/20/2022] Open
Abstract
A new taxon of stem otariid, Eotaria citrica sp. nov., is described from the upper Burdigalian to lower Langhian “Topanga” formation of Orange County, California. The new species is described from mandibular and dental remains that show a unique combination of plesiomorphic and derived characters. Specifically, it is characterized by having trenchant and prominent paraconid cusps in p3–m1, lingual cingula of p2–4 with faint crenulations, premolars and molars with vestigial metaconid, bilobed root of m2 and a genial tuberosity located under p3. Furthermore, additional material of the contemporaneous Eotaria crypta is described, providing new information on the morphology of this taxon. Both species of Eotaria represent the earliest stem otariids, reinforcing the hypothesis that the group originated in the north Eastern Pacific Region. At present, the “Topanga” Fm. pinniped fauna includes Eotaria citrica, Eotaria crypta, the desmatophocid Allodesmus sp., the odobenids Neotherium sp., Pelagiarctos sp. and includes the oldest records of crown pinnipeds in California. Overall this pinniped fauna is similar to the nearly contemporaneous Sharktooth Hill bonebed. However, unambiguous records of Eotaria are still missing from Sharktooth Hill. This absence may be due to taphonomic or paleoenvironmental factors. The new “Topanga” record presented here was integrated into an overview of the late Oligocene through early Pleistocene pinniped faunas of Southern California. The results show an overall increase in body size over time until the Pleistocene. Furthermore, desmatophocids were the largest pinnipeds during the middle Miocene, but were extinct by the beginning of the late Miocene. Odobenids diversified and became the dominant pinnipeds in late Miocene through Pleistocene assemblages, usually approaching or exceeding 3 m in body length, while otariids remained as the smallest taxa. This pattern contrasts with modern assemblages, in which the phocid Mirounga angustirostris is the largest pinniped taxon in the region, odobenids are extinct and medium and small size ranges are occupied by otariids or other phocids.
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Affiliation(s)
- Jorge Velez-Juarbe
- Department of Mammalogy, Natural History Museum of Los Angeles County, Los Angeles, CA, USA; Department of Paleobiology, National Museum of Natural History, Washington, DC, USA
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10
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Churchill M, Clementz MT. The evolution of aquatic feeding in seals: insights from
Enaliarctos
(Carnivora: Pinnipedimorpha), the oldest known seal. J Evol Biol 2015; 29:319-34. [DOI: 10.1111/jeb.12783] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 10/06/2015] [Accepted: 10/09/2015] [Indexed: 11/28/2022]
Affiliation(s)
- M. Churchill
- Department of Anatomy New York Institute of Technology Old Westbury NY USA
- Department of Geology and Geophysics University of Wyoming Laramie WY USA
- Program in Ecology University of Wyoming Laramie WY USA
| | - M. T. Clementz
- Department of Geology and Geophysics University of Wyoming Laramie WY USA
- Program in Ecology University of Wyoming Laramie WY USA
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11
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Tanaka Y, Kohno N. A New Late Miocene Odobenid (Mammalia: Carnivora) from Hokkaido, Japan Suggests Rapid Diversification of Basal Miocene Odobenids. PLoS One 2015; 10:e0131856. [PMID: 26244784 PMCID: PMC4526471 DOI: 10.1371/journal.pone.0131856] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/08/2015] [Indexed: 12/02/2022] Open
Abstract
The modern walrus, Odobenus rosmarus, is specialized and only extant member of the family Odobenidae. They were much more diversified in the past, and at least 16 genera and 20 species of fossil walruses have been known. Although their diversity increased in the late Miocene and Pliocene (around 8–2 Million years ago), older records are poorly known. A new genus and species of archaic odobenid, Archaeodobenus akamatsui, gen. et sp. nov. from the late Miocene (ca. 10.0–9.5 Ma) top of the Ichibangawa Formation, Hokkaido, northern Japan, suggests rapid diversification of basal Miocene walruses. Archaeodobenus akamatsui is the contemporaneous Pseudotaria muramotoi from the same formation, but they are distinguishable from each other in size and shape of the occipital condyle, foramen magnum and mastoid process of the cranium, and other postcranial features. Based on our phylogenetic analysis, A. akamatsui might have split from P. muramotoi at the late Miocene in the western North Pacific. This rapid diversification of the archaic odobenids occurred with a combination of marine regression and transgression, which provided geological isolation among the common ancestors of extinct odobenids.
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Affiliation(s)
- Yoshihiro Tanaka
- Hokkaido University Museum, Kita 8 Nishi 5, Kita-ku, Sapporo, Hokkaido, 060–0808, Japan
- Department of Geology, University of Otago, 360 Leith walk, PO Box 56, Dunedin, 9054, New Zealand
- Numata Fossil Museum, 2-7-49, 1 Minami, Numata Town, Hokkaido, 078–2202, Japan
- * E-mail:
| | - Naoki Kohno
- Department of Geology and Paleontology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, 305–0005, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305–8752, Japan
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12
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Yapuncich GS, Gladman JT, Boyer DM. Predicting euarchontan body mass: A comparison of tarsal and dental variables. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157:472-506. [DOI: 10.1002/ajpa.22735] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 01/14/2015] [Accepted: 02/21/2015] [Indexed: 11/07/2022]
Affiliation(s)
| | - Justin T. Gladman
- The Graduate Center; City University of New York; New York NY 10016
- New York Consortium in Evolutionary Primatology (NYCEP); New York NY 10028
| | - Doug M. Boyer
- Department of Evolutionary Anthropology; Duke University; Durham NC 27708
- New York Consortium in Evolutionary Primatology (NYCEP); New York NY 10028
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13
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Churchill M, Clementz MT, Kohno N. Cope's rule and the evolution of body size in Pinnipedimorpha (Mammalia: Carnivora). Evolution 2014; 69:201-15. [PMID: 25355195 DOI: 10.1111/evo.12560] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 10/20/2014] [Indexed: 11/28/2022]
Abstract
Cope's rule describes the evolutionary trend for animal lineages to increase in body size over time. In this study, we tested the validity of Cope's rule for a marine mammal clade, the Pinnipedimorpha, which includes the extinct Desmatophocidae, and extant Phocidae (earless seals), Otariidae (fur seals and sea lions), and Odobenidae (walruses). We tested for the presence of Cope's rule by compiling a large dataset of body size data for extant and fossil pinnipeds and then examined how body size evolved through time. We found that there was a positive relationship between geologic age and body size. However, this trend is the result of differences between early assemblages of small-bodied pinnipeds (Oligocene to early Miocene) and later assemblages (middle Miocene to Pliocene) for which species exhibited greater size diversity. No significant differences were found between the number of increases or decreases in body size within Pinnipedimorpha or within specific pinniped clades. This suggests that the pinniped body size increase was driven by passive diversification into vacant niche space, with the common ancestor of Pinnipedimorpha occurring near the minimum adult body size possible for a marine mammal. Based upon the above results, the evolutionary history of pinnipeds does not follow Cope's rule.
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Affiliation(s)
- Morgan Churchill
- Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming, 8207; Program in Ecology, University of Wyoming, Laramie, Wyoming, 82071.
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