1
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Marsicano CA, Pardo JD, Smith RMH, Mancuso AC, Gaetano LC, Mocke H. Giant stem tetrapod was apex predator in Gondwanan late Palaeozoic ice age. Nature 2024; 631:577-582. [PMID: 38961286 DOI: 10.1038/s41586-024-07572-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/15/2024] [Indexed: 07/05/2024]
Abstract
Current hypotheses of early tetrapod evolution posit close ecological and biogeographic ties to the extensive coal-producing wetlands of the Carboniferous palaeoequator with rapid replacement of archaic tetrapod groups by relatives of modern amniotes and lissamphibians in the late Carboniferous (about 307 million years ago). These hypotheses draw on a tetrapod fossil record that is almost entirely restricted to palaeoequatorial Pangea (Laurussia)1,2. Here we describe a new giant stem tetrapod, Gaiasia jennyae, from high-palaeolatitude (about 55° S) early Permian-aged (about 280 million years ago) deposits in Namibia that challenges this scenario. Gaiasia is represented by several large, semi-articulated skeletons characterized by a weakly ossified skull with a loosely articulated palate dominated by a broad diamond-shaped parasphenoid, a posteriorly projecting occiput, and enlarged, interlocking dentary and coronoid fangs. Phylogenetic analysis resolves Gaiasia within the tetrapod stem group as the sister taxon of the Carboniferous Colosteidae from Euramerica. Gaiasia is larger than all previously described digited stem tetrapods and provides evidence that continental tetrapods were well established in the cold-temperate latitudes of Gondwana during the final phases of the Carboniferous-Permian deglaciation. This points to a more global distribution of continental tetrapods during the Carboniferous-Permian transition and indicates that previous hypotheses of global tetrapod faunal turnover and dispersal at this time2,3 must be reconsidered.
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Affiliation(s)
- Claudia A Marsicano
- Universidad de Buenos Aires, FCEN, Departamento de Cs. Geológicas, Buenos Aires, Argentina.
- CONICET-UBA, Instituto de Estudios Andinos (IDEAN), Buenos Aires, Argentina.
| | - Jason D Pardo
- Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA.
| | - Roger M H Smith
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
- Department Karoo Palaeontology, Iziko South African Museum, Cape Town, South Africa
| | - Adriana C Mancuso
- Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA), CCT-Mendoza (CONICET), Mendoza, Argentina
| | - Leandro C Gaetano
- Universidad de Buenos Aires, FCEN, Departamento de Cs. Geológicas, Buenos Aires, Argentina
- CONICET-UBA, Instituto de Estudios Andinos (IDEAN), Buenos Aires, Argentina
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Helke Mocke
- Geological Survey of Namibia, National Earth Science Museum, Windhoek, Namibia
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2
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Singh SA, Elsler A, Stubbs TL, Rayfield EJ, Benton MJ. Predatory synapsid ecomorphology signals growing dynamism of late Palaeozoic terrestrial ecosystems. Commun Biol 2024; 7:201. [PMID: 38368492 PMCID: PMC10874460 DOI: 10.1038/s42003-024-05879-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/01/2024] [Indexed: 02/19/2024] Open
Abstract
Terrestrial ecosystems evolved substantially through the Palaeozoic, especially the Permian, gaining much new complexity, especially among predators. Key among these predators were non-mammalian synapsids. Predator ecomorphology reflect interactions with prey and competitors, which are key controls on carnivore diversity and ecology. Therefore, carnivorous synapsids may offer insight on wider ecological evolution as the first complex, tetrapod-dominated, terrestrial ecosystems formed through the late Palaeozoic. Using morphometric and phylogenetic comparative methods, we chart carnivorous synapsid trophic morphology from the latest Carboniferous to the earliest Triassic (307-251.2 Ma). We find a major morphofunctional shift in synapsid carnivory between the early and middle Permian, via the addition of new feeding modes increasingly specialised for greater biting power or speed that captures the growing antagonism and dynamism of terrestrial tetrapod predator-prey interactions. The further evolution of new hypo- and hypercarnivorous synapsids highlight the nascent intrinsic pressures and complexification of terrestrial ecosystems across the mid-late Permian.
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Affiliation(s)
- Suresh A Singh
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK.
| | - Armin Elsler
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Thomas L Stubbs
- School of Life, Health and Chemical Sciences, Open University, Milton Keynes, MK7 6AE, UK
| | - Emily J Rayfield
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Michael J Benton
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
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3
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Ecological neutral theory reveals the effect of biases in the fossil record. Nat Ecol Evol 2023; 7:1360-1361. [PMID: 37500907 DOI: 10.1038/s41559-023-02138-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
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4
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Dunne EM, Thompson SED, Butler RJ, Rosindell J, Close RA. Mechanistic neutral models show that sampling biases drive the apparent explosion of early tetrapod diversity. Nat Ecol Evol 2023; 7:1480-1489. [PMID: 37500908 PMCID: PMC10482683 DOI: 10.1038/s41559-023-02128-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/20/2023] [Indexed: 07/29/2023]
Abstract
Estimates of deep-time biodiversity typically rely on statistical methods to mitigate the impacts of sampling biases in the fossil record. However, these methods are limited by the spatial and temporal scale of the underlying data. Here we use a spatially explicit mechanistic model, based on neutral theory, to test hypotheses of early tetrapod diversity change during the late Carboniferous and early Permian, critical intervals for the diversification of vertebrate life on land. Our simulations suggest that apparent increases in early tetrapod diversity were not driven by local endemism following the 'Carboniferous rainforest collapse'. Instead, changes in face-value diversity can be explained by variation in sampling intensity through time. Our results further demonstrate the importance of accounting for sampling biases in analyses of the fossil record and highlight the vast potential of mechanistic models, including neutral models, for testing hypotheses in palaeobiology.
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Affiliation(s)
- Emma M Dunne
- GeoZentrum Nordbayern, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK.
| | - Samuel E D Thompson
- Department of Life Sciences, Imperial College London, Ascot, UK
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Richard J Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - James Rosindell
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - Roger A Close
- Department of Earth Sciences, University of Oxford, Oxford, UK
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5
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Henderson S, Dunne EM, Fasey SA, Giles S. The early diversification of ray-finned fishes (Actinopterygii): hypotheses, challenges and future prospects. Biol Rev Camb Philos Soc 2023; 98:284-315. [PMID: 36192821 PMCID: PMC10091770 DOI: 10.1111/brv.12907] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 01/12/2023]
Abstract
Actinopterygii makes up half of living vertebrate diversity, and study of fossil members during their Palaeozoic rise to dominance has a long history of descriptive work. Although research interest into Palaeozoic actinopterygians has increased in recent years, broader patterns of diversity and diversity dynamics remain critically understudied. Past studies have investigated macroevolutionary trends in Palaeozoic actinopterygians in a piecemeal fashion, variably using existing compendia of vertebrates or literature-based searches. Here, we present a comprehensive occurrence-based dataset of actinopterygians spanning the whole of the Palaeozoic. We use this to produce the first through-Palaeozoic trends in genus and species counts for Actinopterygii. Diversity through time generally tracks metrics for sampling, while major taxonomic problems pervading the Palaeozoic actinopterygian record obscure diversity trends. Many described species are concentrated in several particularly problematic 'waste-basket' genera, hiding considerable morphological and taxonomic diversity. This taxonomic confusion also feeds into a limited understanding of phylogenetic relationships. A heavy sampling bias towards Europe and North America exists in both occurrence databases and available phylogenetic matrices, with other regions underrepresented despite yielding important data. Scrutiny of the extent to which spatial biases influence the actinopterygian record is lacking, as is research on other forms of bias. Low richness in some time periods may be linked to geological biases, while the effects of taphonomic biases on Palaeozoic actinopterygians have not yet been investigated. Efforts are already underway both to redescribe poorly defined taxa and to describe taxa from underrepresented regions, helping to address taxonomic issues and accuracy of occurrence data. New methods of sampling standardisation utilising up-to-date occurrence databases will be critical in teasing apart biological changes in diversity and those resulting from bias. Lastly, continued phylogenetic work will enable the use of phylogenetic comparative methods to elucidate the origins of actinopterygian biogeography and subsequent patterns of radiation throughout their rise to dominate aquatic faunas.
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Affiliation(s)
- Struan Henderson
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Emma M Dunne
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,GeoZentrum Nordbayern, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Loewenichstraße 28, Erlangen, 91054, Germany
| | - Sophie A Fasey
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sam Giles
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Department of Earth Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
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6
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Brodie JF, Mannion PD. The hierarchy of factors predicting the latitudinal diversity gradient. Trends Ecol Evol 2023; 38:15-23. [PMID: 36089412 DOI: 10.1016/j.tree.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 12/24/2022]
Abstract
The numerous explanations for why Earth's biodiversity is concentrated at low latitudes fail to explain variation in the strength and even direction of the gradient through deep time. Consequently, we do not know if today's gradient is representative of what might be expected on other planets or is merely an idiosyncrasy of Earth's history. We propose a hierarchy of factors driving the latitudinal distribution of diversity: (i) over geologically long time spans, diversity is largely predicted by climate; (ii) when climatic gradients are shallow, diversity tracks habitat area; and (iii) historical contingencies linked to niche conservatism have geologically short-term, transient influence at most. Thus, latitudinal diversity gradients, although variable in strength and direction, are largely predictable on our planet and possibly others.
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Affiliation(s)
- Jedediah F Brodie
- Division of Biological Sciences & Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA; Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, 94 300 Kota Samarahan, Malaysia.
| | - Philip D Mannion
- Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, UK
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7
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Henderson S, Dunne EM, Giles S. Sampling biases obscure the early diversification of the largest living vertebrate group. Proc Biol Sci 2022; 289:20220916. [PMID: 36259213 PMCID: PMC9579763 DOI: 10.1098/rspb.2022.0916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Extant ray-finned fishes (Actinopterygii) dominate marine and freshwater environments, yet spatio-temporal diversity dynamics following their origin in the Palaeozoic are poorly understood. Previous studies investigate face-value patterns of richness, with only qualitative assessment of biases acting on the Palaeozoic actinopterygian fossil record. Here, we investigate palaeogeographic trends, reconstruct local richness and apply richness estimation techniques to a recently assembled occurrence database for Palaeozoic ray-finned fishes. We identify substantial fossil record biases, such as geographical bias in sampling centred around Europe and North America. Similarly, estimates of diversity are skewed by extreme unevenness in the occurrence distributions, reflecting historical biases in sampling and taxonomic practices, to the extent that evenness has an overriding effect on diversity estimates. Other than a genuine rise in diversity in the Tournaisian following the end-Devonian mass extinction, diversity estimates for Palaeozoic actinopterygians appear to lack biological signal, are heavily biased and are highly dependent on sampling. Increased sampling of poorly represented regions and expanding sampling beyond the literature to include museum collection data will be critical in obtaining accurate estimates of Palaeozoic actinopterygian diversity. In conjunction, applying diversity estimation techniques to well-sampled regional subsets of the 'global' dataset may identify accurate local diversity trends.
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Affiliation(s)
- Struan Henderson
- School of Geography Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Emma M Dunne
- School of Geography Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.,GeoZentrum Nordbayern, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Sam Giles
- School of Geography Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.,Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
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8
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Buatois LA, Davies NS, Gibling MR, Krapovickas V, Labandeira CC, MacNaughton RB, Mángano MG, Minter NJ, Shillito AP. The Invasion of the Land in Deep Time: Integrating Paleozoic Records of Paleobiology, Ichnology, Sedimentology, and Geomorphology. Integr Comp Biol 2022; 62:297-331. [PMID: 35640908 DOI: 10.1093/icb/icac059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/19/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
The invasion of the land was a complex, protracted process, punctuated by mass extinctions, that involved multiple routes from marine environments. We integrate paleobiology, ichnology, sedimentology, and geomorphology to reconstruct Paleozoic terrestrialization. Cambrian landscapes were dominated by laterally mobile rivers with unstable banks in the absence of significant vegetation. Temporary incursions by arthropods and worm-like organisms into coastal environments apparently did not result in establishment of continental communities. Contemporaneous lacustrine faunas may have been inhibited by limited nutrient delivery and high sediment loads. The Ordovician appearance of early land plants triggered a shift in the primary locus of the global clay mineral factory, increasing the amount of mudrock on the continents. The Silurian-Devonian rise of vascular land plants, including the first forests and extensive root systems, was instrumental in further retaining fine sediment on alluvial plains. These innovations led to increased architectural complexity of braided and meandering rivers. Landscape changes were synchronous with establishment of freshwater and terrestrial arthropod faunas in overbank areas, abandoned fluvial channels, lake margins, ephemeral lakes, and inland deserts. Silurian-Devonian lakes experienced improved nutrient availability, due to increased phosphate weathering and terrestrial humic matter. All these changes favoured frequent invasions to permament establishment of jawless and jawed fishes in freshwater habitats and the subsequent tetrapod colonization of the land. The Carboniferous saw rapid diversification of tetrapods, mostly linked to aquatic reproduction, and land plants, including gymnosperms. Deeper root systems promoted further riverbank stabilization, contributing to the rise of anabranching rivers and braided systems with vegetated islands. New lineages of aquatic insects developed and expanded novel feeding modes, including herbivory. Late Paleozoic soils commonly contain pervasive root and millipede traces. Lacustrine animal communities diversified, accompanied by increased food-web complexity and improved food delivery which may have favored permanent colonization of offshore and deep-water lake environments. These trends continued in the Permian, but progressive aridification favored formation of hypersaline lakes, which were stressful for colonization. The Capitanian and end-Permian extinctions affected lacustrine and fluvial biotas, particularly the invertebrate infauna, although burrowing may have allowed some tetrapods to survive associated global warming and increased aridification.
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Affiliation(s)
- Luis A Buatois
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Neil S Davies
- Department of Earth Sciences, University of Cambridge, Cambridge, Cambridgeshire CB2 3EQ, UK
| | - Martin R Gibling
- Department of Earth and Environmental Sciences, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Verónica Krapovickas
- Departamento de Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina
| | - Conrad C Labandeira
- Department of Paleobiology, Smithsonian Institution, Washington DC 20013-7012, USA.,Department of Entomology and BEES Program, University of Maryland, College Park, Maryland 21740, USA.,College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Robert B MacNaughton
- Geological Survey of Canada (Calgary), Natural Resources Canada, Calgary, Alberta T2L 2A7, Canada
| | - M Gabriela Mángano
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Nicholas J Minter
- School of the Environment, Geography, and Geosciences, University of Portsmouth, Portsmouth, Hampshire PO1 3QL, UK
| | - Anthony P Shillito
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, UK
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9
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Gee BM. Returning to the roots: resolution, reproducibility, and robusticity in the phylogenetic inference of Dissorophidae (Amphibia: Temnospondyli). PeerJ 2021; 9:e12423. [PMID: 34820181 PMCID: PMC8582317 DOI: 10.7717/peerj.12423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 10/11/2021] [Indexed: 11/22/2022] Open
Abstract
The phylogenetic relationships of most Paleozoic tetrapod clades remain poorly resolved, which is variably attributed to a lack of study, the limitations of inference from phenotypic data, and constant revision of best practices. While refinement of phylogenetic methods continues to be important, any phylogenetic analysis is inherently constrained by the underlying dataset that it analyzes. Therefore, it becomes equally important to assess the accuracy of these datasets, especially when a select few are repeatedly propagated. While repeat analyses of these datasets may appear to constitute a working consensus, they are not in fact independent, and it becomes especially important to evaluate the accuracy of these datasets in order to assess whether a seeming consensus is robust. Here I address the phylogeny of the Dissorophidae, a speciose clade of Paleozoic temnospondyls. This group is an ideal case study among temnospondyls for exploring phylogenetic methods and datasets because it has been extensively studied (eight phylogenetic studies to date) but with most (six studies) using a single matrix that has been propagated with very little modification. In spite of the conserved nature of the matrix, dissorophid studies have produced anything but a conserved topology. Therefore, I analyzed an independently designed matrix, which recovered less resolution and some disparate nodes compared to previous studies. In order to reconcile these differences, I carefully examined previous matrices and analyses. While some differences are a matter of personal preference (e.g., analytical software), others relate to discrepancies with respect to what are currently considered as best practices. The most concerning discovery was the identification of pervasive dubious scorings that extend back to the origins of the widely propagated matrix. These include scores for skeletal features that are entirely unknown in a given taxon (e.g., postcrania in Cacops woehri) and characters for which there appear to be unstated working assumptions to scoring that are incompatible with the character definitions (e.g., scoring of taxa with incomplete skulls for characters based on skull length). Correction of these scores and other pervasive errors recovered a distinctly less resolved topology than previous studies, more in agreement with my own matrix. This suggests that previous analyses may have been compromised, and that the only real consensus of dissorophid phylogeny is the lack of one.
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Affiliation(s)
- Bryan M. Gee
- Burke Museum and Department of Biology, University of Washington, Seattle, WA, United States of America
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10
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Brocklehurst N. The First Age of Reptiles? Comparing Reptile and Synapsid Diversity, and the Influence of Lagerstätten, During the Carboniferous and Early Permian. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.669765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Terrestrial ecosystems during the Pennsylvanian (late Carboniferous) and Cisuralian (early Permian) are usually described in the literature as being dominated by synapsids, the mammal-line amniotes. The pelycosaurs (a paraphyletic grouping of synapsid families) have been considered more speciose, abundant, and ecologically diverse than contemporary reptile-line amniotes. However, this dominance has never been subjected to quantitative testing accounting for sampling bias. Moreover, in recent years the amniote phylogeny has undergone numerous revisions, with suggestions that varanopids and recumbirostran microsaurs fall within reptiles, and that diadectomorphs may be pelycosaurian-grade synapsids. An examination of local species richness (alpha diversity) of synapsids and reptiles during the Pennsylvanian and Cisuralian at different spatial scales shows that these taxonomic revisions have substantial impacts on relative diversity patterns of synapsids and reptiles. Synapsids are only found to be consistently more diverse through the early Permian when using the “traditional” taxonomy. The recent taxonomic updates produce diversity estimates where reptile diversity is consistent with, or in some cases higher than that of synapsids. Moreover, biases in preservation may affect patterns. Where preservation favors smaller vertebrates, e.g., Richards Spur, South Grandfield, reptiles overwhelmingly dominate. If smaller vertebrates are expected to make up the bulk of amniote diversity, as they do in the present day, such lagerstätten may be more representative of true diversity patterns. Therefore, the dominance of pelycosaurs during this interval should be reconsidered, and this interval may be considered the First Age of Reptiles.
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11
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Mann A, Calthorpe AS, Maddin HC. Joermungandr bolti, an exceptionally preserved 'microsaur' from the Mazon Creek Lagerstätte reveals patterns of integumentary evolution in Recumbirostra. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210319. [PMID: 34295525 PMCID: PMC8292758 DOI: 10.1098/rsos.210319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/24/2021] [Indexed: 05/14/2023]
Abstract
The Carboniferous Pennsylvanian-aged (309-307 Ma) Mazon Creek Lagerstätte produces some of the earliest fossils of major Palaeozoic tetrapod lineages. Recently, several new tetrapod specimens collected from Mazon Creek have come to light, including the earliest fossorially adapted recumbirostrans. Here, we describe a new long-bodied recumbirostran, Joermungandr bolti gen. et sp. nov., known from a single part and counterpart concretion bearing a virtually complete skeleton. Uniquely, Joermungandr preserves a full suite of dorsal, flank and ventral dermal scales, together with a series of thinned and reduced gastralia. Investigation of these scales using scanning electron microscopy reveals ultrastructural ridge and pit morphologies, revealing complexities comparable to the scale ultrastructure of extant snakes and fossorial reptiles, which have scales modified for body-based propulsion and shedding substrate. Our new taxon also represents an important early record of an elongate recumbirostran bauplan, wherein several features linked to fossoriality, including a characteristic recumbent snout, are present. We used parsimony phylogenetic methods to conduct phylogenetic analysis using the most recent recumbirostran-focused matrix. The analysis recovers Joermungandr within Recumbirostra with likely affinities to the sister clades Molgophidae and Brachystelechidae. Finally, we review integumentary patterns in Recumbirostra, noting reductions and losses of gastralia and osteoderms associated with body elongation and, thus, probably also associated with increased fossoriality.
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Affiliation(s)
- Arjan Mann
- Department of Earth Sciences, Carleton University, 2115 Herzberg Laboratories,1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Ami S. Calthorpe
- Department of Earth Sciences, Carleton University, 2115 Herzberg Laboratories,1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Hillary C. Maddin
- Department of Earth Sciences, Carleton University, 2115 Herzberg Laboratories,1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
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12
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Maidment SCR, Dean CD, Mansergh RI, Butler RJ. Deep-time biodiversity patterns and the dinosaurian fossil record of the Late Cretaceous Western Interior, North America. Proc Biol Sci 2021; 288:20210692. [PMID: 34157868 PMCID: PMC8220268 DOI: 10.1098/rspb.2021.0692] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In order for palaeontological data to be informative to ecologists seeking to understand the causes of today's diversity patterns, palaeontologists must demonstrate that actual biodiversity patterns are preserved in our reconstructions of past ecosystems. During the Late Cretaceous, North America was divided into two landmasses, Laramidia and Appalachia. Previous work has suggested strong faunal provinciality on Laramidia at this time, but these arguments are almost entirely qualitative. We quantitatively investigated faunal provinciality in ceratopsid and hadrosaurid dinosaurs using a biogeographic network approach and investigated sampling biases by examining correlations between dinosaur occurrences and collections. We carried out a model-fitting approach using generalized least-squares regression to investigate the sources of sampling bias we identified. We find that while the raw data strongly support faunal provinciality, this result is driven by sampling bias. The data quality of ceratopsids and hadrosaurids is currently too poor to enable fair tests of provincialism, even in this intensively sampled region, which probably represents the best-known Late Cretaceous terrestrial ecosystem on Earth. To accurately reconstruct biodiversity patterns in deep time, future work should focus on smaller scale, higher resolution case studies in which the effects of sampling bias can be better controlled.
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Affiliation(s)
- Susannah C R Maidment
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.,School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Christopher D Dean
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Robert I Mansergh
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.,Department of Earth Sciences, 5 Gower Place, London WC1E 6BS, UK
| | - Richard J Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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13
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Stockdale MT, Benton MJ. Environmental drivers of body size evolution in crocodile-line archosaurs. Commun Biol 2021; 4:38. [PMID: 33414557 PMCID: PMC7790829 DOI: 10.1038/s42003-020-01561-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 12/02/2020] [Indexed: 01/29/2023] Open
Abstract
Ever since Darwin, biologists have debated the relative roles of external and internal drivers of large-scale evolution. The distributions and ecology of living crocodilians are controlled by environmental factors such as temperature. Crocodilians have a rich history, including amphibious, marine and terrestrial forms spanning the past 247 Myr. It is uncertain whether their evolution has been driven by extrinsic factors, such as climate change and mass extinctions, or intrinsic factors like sexual selection and competition. Using a new phylogeny of crocodilians and their relatives, we model evolutionary rates using phylogenetic comparative methods. We find that body size evolution follows a punctuated, variable rate model of evolution, consistent with environmental drivers of evolution, with periods of stability interrupted by periods of change. Regression analyses show warmer environmental temperatures are associated with high evolutionary rates and large body sizes. We confirm that environmental factors played a significant role in the evolution of crocodiles.
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Affiliation(s)
- Maximilian T. Stockdale
- grid.5337.20000 0004 1936 7603School of Geographical Sciences, University Road, Bristol, BS8 1RL United Kingdom
| | - Michael J. Benton
- School of Earth Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ United Kingdom
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14
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Allen BJ, Wignall PB, Hill DJ, Saupe EE, Dunhill AM. The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval. Proc Biol Sci 2020; 287:20201125. [PMID: 32546099 DOI: 10.1098/rspb.2020.1125] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian-Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian-Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20-40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.
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Affiliation(s)
- Bethany J Allen
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Paul B Wignall
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Daniel J Hill
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Erin E Saupe
- Department of Earth Sciences, University of Oxford, Oxford, UK
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15
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Schachat SR, Labandeira CC, Clapham ME, Payne JL. A Cretaceous peak in family-level insect diversity estimated with mark-recapture methodology. Proc Biol Sci 2019; 286:20192054. [PMID: 31847775 PMCID: PMC6939917 DOI: 10.1098/rspb.2019.2054] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/22/2019] [Indexed: 12/20/2022] Open
Abstract
The history of insects' taxonomic diversity is poorly understood. The two most common methods for estimating taxonomic diversity in deep time yield conflicting results: the 'range through' method suggests a steady, nearly monotonic increase in family-level diversity, whereas 'shareholder quorum subsampling' suggests a highly volatile taxonomic history with family-level mass extinctions occurring repeatedly, even at the midpoints of geological periods. The only feature shared by these two diversity curves is a steep increase in standing diversity during the Early Cretaceous. This apparent diversification event occurs primarily during the Aptian, the pre-Cenozoic interval with the most described insect occurrences, raising the possibility that this feature of the diversity curves reflects preservation and sampling biases rather than insect evolution and extinction. Here, the capture-mark-recapture (CMR) approach is used to estimate insects' family-level diversity. This method accounts for the incompleteness of the insect fossil record as well as uneven sampling among time intervals. The CMR diversity curve shows extinctions at the Permian/Triassic and Cretaceous/Palaeogene boundaries but does not contain any mass extinctions within geological periods. This curve also includes a steep increase in diversity during the Aptian, which appears not to be an artefact of sampling or preservation bias because this increase still appears when time bins are standardized by the number of occurrences they contain rather than by the amount of time that they span. The Early Cretaceous increase in family-level diversity predates the rise of angiosperms by many millions of years and can be better attributed to the diversification of parasitic and especially parasitoid insect lineages.
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Affiliation(s)
- Sandra R. Schachat
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Conrad C. Labandeira
- Department of Paleobiology, Smithsonian Institution, Washington, DC 20013, USA
- Department of Entomology, University of Maryland, College Park, MD 20742, USA
- College of Life Sciences, Capital Normal University, Beijing 100048, People’s Republic of China
| | - Matthew E. Clapham
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA
| | - Jonathan L. Payne
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
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16
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Pardo JD, Small BJ, Milner AR, Huttenlocker AK. Carboniferous–Permian climate change constrained early land vertebrate radiations. Nat Ecol Evol 2019; 3:200-206. [DOI: 10.1038/s41559-018-0776-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 12/03/2018] [Indexed: 12/13/2022]
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17
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Brocklehurst N, Dunne EM, Cashmore DD, Frӧbisch J. Physical and environmental drivers of Paleozoic tetrapod dispersal across Pangaea. Nat Commun 2018; 9:5216. [PMID: 30523258 PMCID: PMC6284015 DOI: 10.1038/s41467-018-07623-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 11/08/2018] [Indexed: 11/18/2022] Open
Abstract
The Carboniferous and Permian were crucial intervals in the establishment of terrestrial ecosystems, which occurred alongside substantial environmental and climate changes throughout the globe, as well as the final assembly of the supercontinent of Pangaea. The influence of these changes on tetrapod biogeography is highly contentious, with some authors suggesting a cosmopolitan fauna resulting from a lack of barriers, and some identifying provincialism. Here we carry out a detailed historical biogeographic analysis of late Paleozoic tetrapods to study the patterns of dispersal and vicariance. A likelihood-based approach to infer ancestral areas is combined with stochastic mapping to assess rates of vicariance and dispersal. Both the late Carboniferous and the end-Guadalupian are characterised by a decrease in dispersal and a vicariance peak in amniotes and amphibians. The first of these shifts is attributed to orogenic activity, the second to increasing climate heterogeneity. The late Paleozoic was a time of major transition for tetrapods. Here, Brocklehurst and colleagues analyse the biogeography of Paleozoic tetrapods and find shifts in dispersal and vicariance associated with Carboniferous mountain formation and end-Guadalupian climate variability.
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Affiliation(s)
- Neil Brocklehurst
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK. .,Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.
| | - Emma M Dunne
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Daniel D Cashmore
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Jӧrg Frӧbisch
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.,Institut für Biologie, Humboldt-Universität zu Berlin, Invalidenstraße 42, Berlin, 10115, Germany
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