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Loewen MA, Sertich JJW, Sampson S, O’Connor JK, Carpenter S, Sisson B, Øhlenschlæger A, Farke AA, Makovicky PJ, Longrich N, Evans DC. Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs. PeerJ 2024; 12:e17224. [PMID: 38912046 PMCID: PMC11193970 DOI: 10.7717/peerj.17224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/20/2024] [Indexed: 06/25/2024] Open
Abstract
The Late Cretaceous of western North America supported diverse dinosaur assemblages, though understanding patterns of dinosaur diversity, evolution, and extinction has been historically limited by unequal geographic and temporal sampling. In particular, the existence and extent of faunal endemism along the eastern coastal plain of Laramidia continues to generate debate, and finer scale regional patterns remain elusive. Here, we report a new centrosaurine ceratopsid, Lokiceratops rangiformis, from the lower portion of the McClelland Ferry Member of the Judith River Formation in the Kennedy Coulee region along the Canada-USA border. Dinosaurs from the same small geographic region, and from nearby, stratigraphically equivalent horizons of the lower Oldman Formation in Canada, reveal unprecedented ceratopsid richness, with four sympatric centrosaurine taxa and one chasmosaurine taxon. Phylogenetic results show that Lokiceratops, together with Albertaceratops and Medusaceratops, was part of a clade restricted to a small portion of northern Laramidia approximately 78 million years ago. This group, Albertaceratopsini, was one of multiple centrosaurine clades to undergo geographically restricted radiations, with Nasutuceratopsini restricted to the south and Centrosaurini and Pachyrostra restricted to the north. High regional endemism in centrosaurs is associated with, and may have been driven by, high speciation rates and diversity, with competition between dinosaurs limiting their geographic range. High speciation rates may in turn have been driven in part by sexual selection or latitudinally uneven climatic and floral gradients. The high endemism seen in centrosaurines and other dinosaurs implies that dinosaur diversity is underestimated and contrasts with the large geographic ranges seen in most extant mammalian megafauna.
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Affiliation(s)
- Mark A. Loewen
- Natural History Museum of Utah, Salt Lake City, UT, United States of America
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, United States of America
- Evolutionsmuseet, Knuthenborg, Maribo, Denmark
| | - Joseph J. W. Sertich
- Evolutionsmuseet, Knuthenborg, Maribo, Denmark
- Smithsonian Tropical Research Institute, Panama City, Panamá
- Department of Geosciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Scott Sampson
- California Academy of Sciences, San Francisco, California, United States of America
| | | | - Savhannah Carpenter
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, United States of America
| | - Brock Sisson
- Independent Researcher, Pleasant Grove, Utah, United States of America
| | | | - Andrew A. Farke
- Raymond M. Alf Museum of Paleontology, Claremont, California, United States of America
| | - Peter J. Makovicky
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Nick Longrich
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
- Department of Ecology and Evolution, University of Toronto, Toronto, Ontario, Canada
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2
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Ballell A, Mai B, Benton MJ. Divergent strategies in cranial biomechanics and feeding ecology of the ankylosaurian dinosaurs. Sci Rep 2023; 13:18242. [PMID: 37880323 PMCID: PMC10600113 DOI: 10.1038/s41598-023-45444-1] [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: 06/12/2023] [Accepted: 10/19/2023] [Indexed: 10/27/2023] Open
Abstract
Ankylosaurs were important megaherbivores of Jurassic and Cretaceous ecosystems. Their distinctive craniodental anatomy and mechanics differentiated them from coexisting hadrosaurs and ceratopsians, and morphological evidence suggests dietary niche partitioning between sympatric ankylosaurids and nodosaurids. Here, we investigate the skull biomechanics of ankylosaurs relative to feeding function. First, we compare feeding functional performance between nodosaurids and ankylosaurids applying finite element analysis and lever mechanics to the skulls of Panoplosaurus mirus (Nodosauridae) and Euoplocephalus tutus (Ankylosauridae). We also compare jaw performance across a wider sample of ankylosaurs through lever mechanics and phylogenetic comparative methods. Mandibular stress levels are higher in Euoplocephalus, supporting the view that Panoplosaurus consumed tougher foodstuffs. Bite force and mechanical advantage (MA) estimates indicate that Panoplosaurus had a relatively more forceful and efficient bite than Euoplocephalus. There is little support for a role of the secondary palate in resisting feeding loads in the two ankylosaur clades. Several ankylosaurs converged on similar jaw mechanics, while some nodosaurids specialised towards high MA and some ankylosaurids evolved low MA jaws. Our study supports the hypothesis that ankylosaurs partitioned dietary niches in Late Cretaceous ecosystems and reveals that the two main ankylosaur clades evolved divergent evolutionary pathways in skull biomechanics and feeding habits.
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Affiliation(s)
- Antonio Ballell
- Bristol Palaeobiology Group, School of Earth Sciences, Life Sciences Building, University of Bristol, Tyndall Avenue, Bristol, BS8 1TQ, UK.
| | - Bohao Mai
- Bristol Palaeobiology Group, School of Earth Sciences, Life Sciences Building, University of Bristol, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Michael J Benton
- Bristol Palaeobiology Group, School of Earth Sciences, Life Sciences Building, University of Bristol, Tyndall Avenue, Bristol, BS8 1TQ, UK.
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3
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Nabavizadeh A. How Triceratops got its face: An update on the functional evolution of the ceratopsian head. Anat Rec (Hoboken) 2023. [PMID: 36883781 DOI: 10.1002/ar.25196] [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: 07/12/2022] [Revised: 02/22/2023] [Accepted: 02/22/2023] [Indexed: 03/09/2023]
Abstract
Ceratopsian dinosaurs arguably show some of the most extravagant external cranial morphology across all Dinosauria. For over a century, ceratopsian dinosaurs have inspired a multitude of cranial functional studies as more discoveries continued to depict a larger picture of the enormous diversity of these animals. The iconic horns and bony frills in many ceratopsians portray a plethora of shapes, sizes, and arrangements across taxa, and their overall feeding apparatus show the development of unique specializations previously unseen in large herbivores. Here, I give a brief updated review of the many functional studies investigating different aspects of the ceratopsian head. The functional role of the horns and bony frills is explored, with an overview of studies investigating their potential for weaponization or defense in either intraspecific or anti-predatory combat, among other things. A review of studies pertaining to the ceratopsian feeding apparatus is also presented here, with analyses of studies exploring their beak and snout morphology, dentition and tooth wear, cranial musculature with associated skull anatomy, and feeding biomechanics.
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Affiliation(s)
- Ali Nabavizadeh
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
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4
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Multi-proxy dentition analyses reveal niche partitioning between sympatric herbivorous dinosaurs. Sci Rep 2022; 12:20813. [PMID: 36460688 PMCID: PMC9718793 DOI: 10.1038/s41598-022-24816-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022] Open
Abstract
Dentitions of the sympatric herbivorous dinosaurs Hungarosaurus (Ankylosauria, Nodosauridae) and Mochlodon (Ornithopoda, Rhabdodontidae) (Santonian, Hungary) were analysed to investigate their dietary ecology, using several complementary methods-orientation patch count, tooth replacement rate, macrowear, tooth wear rate, traditional microwear, and dental microwear texture analysis (DMTA). Tooth formation time is similar in Hungarosaurus and Mochlodon, and traditional and DMTA microwear features suggest low-browsing habits for both taxa, consistent with their inferred stances and body sizes. However, Mochlodon possesses a novel adaptation for increasing dental durability: the dentine on the working side of the crown is double the thickness of that on the balancing side. Moreover, crown morphology, enamel thickness, macrowear orientation, and wear rate differ greatly between the two taxa. Consequently, these sympatric herbivores probably exploited plants of different toughness, implying dietary selectivity and niche partitioning. Hungarosaurus is inferred to have eaten softer vegetation, whereas Mochlodon likely fed on tougher material. Compared to the much heavier, quadrupedal Hungarosaurus, the bipedal Mochlodon wore down more than twice as much of its crown volume during the functional life of the tooth. This heavy tooth wear might correlate with more intensive food processing and, in turn, could reflect differences in the metabolic requirements of these animals.
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Wyenberg-Henzler T. Ecomorphospace occupation of large herbivorous dinosaurs from Late Jurassic through to Late Cretaceous time in North America. PeerJ 2022; 10:e13174. [PMID: 35433123 PMCID: PMC9009330 DOI: 10.7717/peerj.13174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/06/2022] [Indexed: 01/12/2023] Open
Abstract
Following the Late Jurassic, megaherbivore communities in North America undergo a dramatic turnover in faunal composition: sauropods decline to the point of becoming relatively minor components of ecosystems, stegosaurs become extinct, and hadrosaurids, ceratopsids and ankylosaurs rise in diversity and abundance. Although a variety of causes have been proposed to account for the dramatic decrease in sauropod diversity following the Late Jurassic and could have also been applicable to the disappearance of stegosaurs, the potential for competitive replacement of sauropods by hadrosauroids as an explanation has been previously dismissed due to morphological differences without further investigation. Using twelve ecomorphological correlates of the skull, this study provides a preliminary investigation into ecomorphospace occupation of major megaherbivore clades from the Late Jurassic through to the Late Cretaceous of North America and assess if morphological differences were enough to have potentially facilitated dietary niche partitioning between sauropods and iguanodontians and stegosaurs and ankylosaurs. Overlap in reconstructed ecomorphospace was observed between sauropods (particularly non-diplodocid sauropods) and iguanodontians, as would be expected if morphological differences were not enough to facilitate niche partitioning, contrary to original claims used to dismiss the competitive replacement hypothesis. Overlap was also observed between stegosaurs and ankylosaurs, particularly between Late Cretaceous ankylosaurs. Whether this overlap is reflective competitive replacement or opportunistic occupation of recently vacated niches will require further assessment as sampling of some clades prior to the Late Cretaceous is too poor to make a reliable assessment and several underlying assumptions necessary for competition to occur (e.g., resource limitation) still need investigation. Teasing out the cause(s) of the 'sauropod decline' and extinction of stegosaurs in North America following the Late Jurassic will require future research not only into the competitive exclusion hypothesis, but other hypotheses as well with better sampling from Early Cretaceous and Late Jurassic intervals.
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6
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Condamine FL, Guinot G, Benton MJ, Currie PJ. Dinosaur biodiversity declined well before the asteroid impact, influenced by ecological and environmental pressures. Nat Commun 2021; 12:3833. [PMID: 34188028 PMCID: PMC8242047 DOI: 10.1038/s41467-021-23754-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/10/2021] [Indexed: 02/05/2023] Open
Abstract
The question why non-avian dinosaurs went extinct 66 million years ago (Ma) remains unresolved because of the coarseness of the fossil record. A sudden extinction caused by an asteroid is the most accepted hypothesis but it is debated whether dinosaurs were in decline or not before the impact. We analyse the speciation-extinction dynamics for six key dinosaur families, and find a decline across dinosaurs, where diversification shifted to a declining-diversity pattern ~76 Ma. We investigate the influence of ecological and physical factors, and find that the decline of dinosaurs was likely driven by global climate cooling and herbivorous diversity drop. The latter is likely due to hadrosaurs outcompeting other herbivores. We also estimate that extinction risk is related to species age during the decline, suggesting a lack of evolutionary novelty or adaptation to changing environments. These results support an environmentally driven decline of non-avian dinosaurs well before the asteroid impact.
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Affiliation(s)
- Fabien L Condamine
- Institut des Sciences de l'Evolution de Montpellier (Université de Montpellier | CNRS|IRD|EPHE), Montpellier, France.
| | - Guillaume Guinot
- Institut des Sciences de l'Evolution de Montpellier (Université de Montpellier | CNRS|IRD|EPHE), Montpellier, France
| | - Michael J Benton
- Department of Earth Sciences, University of Bristol, Bristol, UK
| | - Philip J Currie
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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7
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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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8
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Holland B, Bell PR, Fanti F, Hamilton SM, Larson DW, Sissons R, Sullivan C, Vavrek MJ, Wang Y, Campione NE. Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada. PeerJ 2021; 9:e11290. [PMID: 33987001 PMCID: PMC8103918 DOI: 10.7717/peerj.11290] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/26/2021] [Indexed: 01/26/2023] Open
Abstract
Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian–Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but are less frequently documented from more northern regions. The Wapiti Formation (Campanian–Maastrichtian) of northwestern Alberta is a largely untapped resource of terrestrial palaeontological information missing from southern Alberta due to the deposition of the marine Bearpaw Formation. In 2018, the Boreal Alberta Dinosaur Project rediscovered the Spring Creek Bonebed, which had been lost since 2002, along the northern bank of the Wapiti River, southwest of Grande Prairie. Earlier excavations and observations of the Spring Creek Bonebed suggested that the site yielded young hadrosaurines. Continued work in 2018 and 2019 recovered ~300 specimens that included a minimum of eight individuals, based on the number of right humeri. The morphology of several recovered cranial elements unequivocally supports lambeosaurine affinities, making the Spring Creek sample the first documented occurrence of lambeosaurines in the Wapiti Formation. The overall size range and histology of the bones found at the site indicate that these animals were uniformly late juveniles, suggesting that age segregation was a life history strategy among hadrosaurids. Given the considerable size attained by the Spring Creek lambeosaurines, they were probably segregated from the breeding population during nesting or caring for young, rather than due to different diet and locomotory requirements. Dynamic aspects of life history, such as age segregation, may well have contributed to the highly diverse and cosmopolitan nature of Late Cretaceous hadrosaurids.
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Affiliation(s)
- Brayden Holland
- Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Phil R Bell
- Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Federico Fanti
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Alma Mater Studiorum, Università di Bologna, Bologna, Italy
| | - Samantha M Hamilton
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Derek W Larson
- Philip J. Currie Dinosaur Museum, Wembley, Alberta, Canada
| | - Robin Sissons
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Corwin Sullivan
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Philip J. Currie Dinosaur Museum, Wembley, Alberta, Canada
| | - Matthew J Vavrek
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
| | - Yanyin Wang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Nicolás E Campione
- Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
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9
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Wilson JP, Ryan MJ, Evans DC. A new, transitional centrosaurine ceratopsid from the Upper Cretaceous Two Medicine Formation of Montana and the evolution of the ' Styracosaurus-line' dinosaurs. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200284. [PMID: 32431910 PMCID: PMC7211873 DOI: 10.1098/rsos.200284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Ceratopsids are among the most ubiquitous dinosaur taxa from the Late Cretaceous terrestrial formations of the Western Interior of North America, comprising two subfamilies, Chasmosaurinae and Centrosaurinae. The Two Medicine Formation of northwestern Montana has produced numerous remains of centrosaurine dinosaurs, which represent three taxa previously considered valid: Rubeosaurus ovatus, Einiosaurus procurvicornis and Achelousaurus horneri. Here, we reassess the previous referral of specimens to Rubeousaurus ovatus and demonstrate that this taxon is represented solely by its holotype specimen, which was first diagnosed as Styracosaurus ovatus. One of the specimens previously referred to 'Rubeosaurus' ovatus instead represents a new eucentrosauran centrosaurine taxon diagnosed here, Stellasaurus ancellae gen. et sp. nov. Stellasaurus expresses a unique combination of eucentrosauran centrosaurine characters, including an elongate nasal horncore, diminutive supraorbital horncores, and a parietal bearing straight, elongate P3 processes, semi-elongate P4 processes and non-elongate P5, P6 and P7 processes. Within the stratigraphic succession of Eucentrosaura, Stellasaurus occurs intermediate to Styracosaurus albertensis and Einiosaurus, and likewise reflects intermediate morphology. Assessed within the stratigraphic, geographical, taphonomic, ontogenetic and phylogenetic framework of Unified Frames of Reference, we fail to reject the hypothesis that Stellasaurus ancellae represents a transitional taxon within an anagenetic lineage of eucentrosauran centrosaurines.
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Affiliation(s)
- John P. Wilson
- Varricchio Lab, Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
| | - Michael J. Ryan
- Department of Earth Sciences, Carleton University, 2125 Herzberg Building, 1125 Colonel By Drive, Ottawa, OntarioCanadaK1S 5B6
- Department of Palaeobiology, Canadian Museum of Nature, PO Box 3443, Station ‘D’, Ottawa, Ontario, CanadaK1P 6P4
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, CanadaM5S 2C6
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, CanadaM5S 3B2
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10
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Competition structured a Late Cretaceous megaherbivorous dinosaur assemblage. Sci Rep 2019; 9:15447. [PMID: 31659190 PMCID: PMC6817909 DOI: 10.1038/s41598-019-51709-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 10/07/2019] [Indexed: 11/09/2022] Open
Abstract
Modern megaherbivore community richness is limited by bottom-up controls, such as resource limitation and resultant dietary competition. However, the extent to which these same controls impacted the richness of fossil megaherbivore communities is poorly understood. The present study investigates the matter with reference to the megaherbivorous dinosaur assemblage from the middle to upper Campanian Dinosaur Park Formation of Alberta, Canada. Using a meta-analysis of 21 ecomorphological variables measured across 14 genera, contemporaneous taxa are demonstrably well-separated in ecomorphospace at the family/subfamily level. Moreover, this pattern is persistent through the approximately 1.5 Myr timespan of the formation, despite continual species turnover, indicative of underlying structural principles imposed by long-term ecological competition. After considering the implications of ecomorphology for megaherbivorous dinosaur diet, it is concluded that competition structured comparable megaherbivorous dinosaur communities throughout the Late Cretaceous of western North America.
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11
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Ecological niche modelling does not support climatically-driven dinosaur diversity decline before the Cretaceous/Paleogene mass extinction. Nat Commun 2019; 10:1091. [PMID: 30842410 PMCID: PMC6403247 DOI: 10.1038/s41467-019-08997-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
In the lead-up to the Cretaceous/Paleogene mass extinction, dinosaur diversity is argued to have been either in long-term decline, or thriving until their sudden demise. The latest Cretaceous (Campanian-Maastrichtian [83-66 Ma]) of North America provides the best record to address this debate, but even here diversity reconstructions are biased by uneven sampling. Here we combine fossil occurrences with climatic and environmental modelling to quantify latest Cretaceous North American dinosaur habitat. Ecological niche modelling shows a Campanian-to-Maastrichtian habitability decrease in areas with present-day rock-outcrop. However, a continent-wide projection demonstrates habitat stability, or even a Campanian-to-Maastrichtian increase, that is not preserved. This reduction of the spatial sampling window resulted from formation of the proto-Rocky Mountains and sea-level regression. We suggest that Maastrichtian North American dinosaur diversity is therefore likely to be underestimated, with the apparent decline a product of sampling bias, and not due to a climatically-driven decrease in habitability as previously hypothesised.
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12
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Bukombe J, Kittle A, Senzota RB, Kija H, Mduma S, Fryxell JM, Magige F, Mligo C, Sinclair ARE. The influence of food availability, quality and body size on patch selection of coexisting grazer ungulates in western Serengeti National Park. WILDLIFE RESEARCH 2019. [DOI: 10.1071/wr18072] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Differences in body size and mouth morphologies influence dietary resource separation among savanna ungulates, and this influences their distribution across landscape.
Aim
The aim was to understand the influence of body size and mouth morphology differences on both diet and patch selection by ungulate species in western Serengeti. Two hypotheses were tested: (1) for ungulate species, the relative body sizes and muzzle widths (mean muzzle width range: 3.1- 9.85) relate directly to food biomass, and to quality of diets selected in the wet season when food is abundant; (2) in the wet season, if food is not limiting, similar-sized species should exhibit greater dietary niche overlap than ungulate species that differ greatly in body size and muzzle width; moreover, similar-sized species exhibit less dietary niche overlap than ungulate species that differ greatly in body size.
Methods
In the western Serengeti ecosystem, road transects and direct observation were used to obtain data on the distribution and diet of five ungulate species namely buffalo, zebra, wildebeest, topi and impala; which have of varying sizes (range: 70–630kg) feeding in three different vegetation types. Grassland biomass, structure, nutrient content and ungulate use were measured at sites along transects.
Key Results
Results indicated that large-bodied ungulates utilised patches of greater food abundance compared with those of smaller ungulates. Body mass was also negatively correlated with diet quality, so that smaller animals ate higher protein and lower-fibre foods, as predicted. Diet niche overlap (niche similarity) showed a strong positive relationship with body mass differences among ungulate species, in support of the second of the two predictions from this hypothesis, namely that dissimilarly sized species could eat the same food.
Conclusion
Overall, the results suggest that in this savanna system, variation in ungulate body size influences resource separation even in the food-abundant wet season, and that this helps multiple species to co-exist.
Implications
Implementing more focused conservation strategies will improve wildlife habitat quality by integrating fire as a forage management tool with grazing preferences to promote forage heterogeneity in protected areas.
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13
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Feeding in Crocodylians and Their Relatives: Functional Insights from Ontogeny and Evolution. FEEDING IN VERTEBRATES 2019. [DOI: 10.1007/978-3-030-13739-7_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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14
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Herne MC, Tait AM, Weisbecker V, Hall M, Nair JP, Cleeland M, Salisbury SW. A new small-bodied ornithopod (Dinosauria, Ornithischia) from a deep, high-energy Early Cretaceous river of the Australian-Antarctic rift system. PeerJ 2018; 5:e4113. [PMID: 29340228 PMCID: PMC5767335 DOI: 10.7717/peerj.4113] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/09/2017] [Indexed: 11/20/2022] Open
Abstract
A new small-bodied ornithopod dinosaur, Diluvicursor pickeringi, gen. et sp. nov., is named from the lower Albian of the Eumeralla Formation in southeastern Australia and helps shed new light on the anatomy and diversity of Gondwanan ornithopods. Comprising an almost complete tail and partial lower right hindlimb, the holotype (NMV P221080) was deposited as a carcass or body-part in a log-filled scour near the base of a deep, high-energy river that incised a faunally rich, substantially forested riverine floodplain within the Australian-Antarctic rift graben. The deposit is termed the 'Eric the Red West Sandstone.' The holotype, interpreted as an older juvenile ∼1.2 m in total length, appears to have endured antemortem trauma to the pes. A referred, isolated posterior caudal vertebra (NMV P229456) from the holotype locality, suggests D. pickeringi grew to at least 2.3 m in length. D. pickeringi is characterised by 10 potential autapomorphies, among which dorsoventrally low neural arches and transversely broad caudal ribs on the anterior-most caudal vertebrae are a visually defining combination of features. These features suggest D. pickeringi had robust anterior caudal musculature and strong locomotor abilities. Another isolated anterior caudal vertebra (NMV P228342) from the same deposit, suggests that the fossil assemblage hosts at least two ornithopod taxa. D. pickeringi and two stratigraphically younger, indeterminate Eumeralla Formation ornithopods from Dinosaur Cove, NMV P185992/P185993 and NMV P186047, are closely related. However, the tail of D. pickeringi is far shorter than that of NMV P185992/P185993 and its pes more robust than that of NMV P186047. Preliminary cladistic analysis, utilising three existing datasets, failed to resolve D. pickeringi beyond a large polytomy of Ornithopoda. However, qualitative assessment of shared anatomical features suggest that the Eumeralla Formation ornithopods, South American Anabisetia saldiviai and Gasparinisaura cincosaltensis, Afro-Laurasian dryosaurids and possibly Antarctic Morrosaurus antarcticus share a close phylogenetic progenitor. Future phylogenetic analysis with improved data on Australian ornithopods will help to test these suggested affinities.
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Affiliation(s)
- Matthew C. Herne
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Alan M. Tait
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, Australia
| | - Vera Weisbecker
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Hall
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, Australia
| | - Jay P. Nair
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | | | - Steven W. Salisbury
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
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15
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Ma W, Wang J, Pittman M, Tan Q, Tan L, Guo B, Xu X. Functional anatomy of a giant toothless mandible from a bird-like dinosaur: Gigantoraptor and the evolution of the oviraptorosaurian jaw. Sci Rep 2017; 7:16247. [PMID: 29176627 PMCID: PMC5701234 DOI: 10.1038/s41598-017-15709-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 10/31/2017] [Indexed: 12/26/2022] Open
Abstract
The Oviraptorosauria are a group of theropod dinosaurs that diverged from the typical carnivorous theropod diet. It includes two main lineages – Caenagnathidae and Oviraptoridae – that display a number of differences in mandibular morphology, but little is known about their functional consequences, hampering our understanding of oviraptorosaurian dietary evolution. This study presents the first in-depth description of the giant toothless mandible of Gigantoraptor, the only well-preserved stemward caenagnathid mandible. This mandible shows the greatest relative beak depth among caenagnathids, which is an adaptation seen in some modern birds for processing harder seeds. The presence of a lingual triturating shelf in caenagnathids more crownward than Gigantoraptor suggests a possible increased specialization towards shearing along this lineage. Like other oviraptorosaurs, the possession of a dorsally convex articular glenoid in Gigantoraptor indicates that propalinal jaw movement was probably an important mechanism for food processing, as in Sphenodon and dicynodonts. Oviraptorid mandibles were more suited for producing powerful bites (e.g. crushing-related) compared to caenagnathids: oviraptorids generally possess a deeper, more downturned beak, a taller coronoid process prominence and a larger medial mandibular fossa. This disparity in caenagnathid and oviraptorid mandible morphology potentially suggests specialization towards two different feeding styles – shearing and crushing-related mechanisms respectively.
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Affiliation(s)
- Waisum Ma
- Vertebrate Palaeontology Laboratory, Department of Earth Sciences, University of Hong Kong, Pokfulam, Hong Kong, China
| | - Junyou Wang
- Longhao Institute of Geology and Paleontology, Hohhot, Nei Mongol, 010011, China
| | - Michael Pittman
- Vertebrate Palaeontology Laboratory, Department of Earth Sciences, University of Hong Kong, Pokfulam, Hong Kong, China.
| | - Qingwei Tan
- Nei Mongol Museum of Nature, Hohhot, Nei Mongol, 010011, China
| | - Lin Tan
- Longhao Institute of Geology and Paleontology, Hohhot, Nei Mongol, 010011, China
| | - Bin Guo
- Nei Mongol Museum of Nature, Hohhot, Nei Mongol, 010011, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.
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16
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Chin K, Feldmann RM, Tashman JN. Consumption of crustaceans by megaherbivorous dinosaurs: dietary flexibility and dinosaur life history strategies. Sci Rep 2017; 7:11163. [PMID: 28935986 PMCID: PMC5608751 DOI: 10.1038/s41598-017-11538-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/25/2017] [Indexed: 12/03/2022] Open
Abstract
Large plant-eating dinosaurs are usually presumed to have been strictly herbivorous, because their derived teeth and jaws were capable of processing fibrous plant foods. This inferred feeding behavior offers a generalized view of dinosaur food habits, but rare direct fossil evidence of diet provides more nuanced insights into feeding behavior. Here we describe fossilized feces (coprolites) that demonstrate recurring consumption of crustaceans and rotted wood by large Late Cretaceous dinosaurs. These multi-liter coprolites from the Kaiparowits Formation are primarily composed of comminuted conifer wood tissues that were fungally degraded before ingestion. Thick fragments of laminar crustacean cuticle are scattered within the coprolite contents and suggest that the dinosaurian defecators consumed sizeable crustaceans that sheltered in rotting logs. The diet of decayed wood and crustaceans offered a substantial supply of plant polysaccharides, with added dividends of animal protein and calcium. Nevertheless, it is unlikely that the fossilized fecal residues depict year-round feeding habits. It is more reasonable to infer that these coprolites reflected seasonal dietary shifts—possibly related to the dinosaurs’ oviparous breeding activities. This surprising fossil evidence challenges conventional notions of herbivorous dinosaur diets and reveals a degree of dietary flexibility that is consistent with that of extant herbivorous birds.
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Affiliation(s)
- Karen Chin
- Department of Geological Sciences and Museum of Natural History, University of Colorado Boulder, Boulder, CO, 80309, USA.
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17
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MacLaren JA, Anderson PSL, Barrett PM, Rayfield EJ. Herbivorous dinosaur jaw disparity and its relationship to extrinsic evolutionary drivers. PALEOBIOLOGY 2017; 43:15-33. [PMID: 28216798 PMCID: PMC5270766 DOI: 10.1017/pab.2016.31] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/19/2016] [Indexed: 06/01/2023]
Abstract
Morphological responses of nonmammalian herbivores to external ecological drivers have not been quantified over extended timescales. Herbivorous nonavian dinosaurs are an ideal group to test for such responses, because they dominated terrestrial ecosystems for more than 155 Myr and included the largest herbivores that ever existed. The radiation of dinosaurs was punctuated by several ecologically important events, including extinctions at the Triassic/Jurassic (Tr/J) and Jurassic/Cretaceous (J/K) boundaries, the decline of cycadophytes, and the origin of angiosperms, all of which may have had profound consequences for herbivore communities. Here we present the first analysis of morphological and biomechanical disparity for sauropodomorph and ornithischian dinosaurs in order to investigate patterns of jaw shape and function through time. We find that morphological and biomechanical mandibular disparity are decoupled: mandibular shape disparity follows taxonomic diversity, with a steady increase through the Mesozoic. By contrast, biomechanical disparity builds to a peak in the Late Jurassic that corresponds to increased functional variation among sauropods. The reduction in biomechanical disparity following this peak coincides with the J/K extinction, the associated loss of sauropod and stegosaur diversity, and the decline of cycadophytes. We find no specific correspondence between biomechanical disparity and the proliferation of angiosperms. Continual ecological and functional replacement of pre-existing taxa accounts for disparity patterns through much of the Cretaceous, with the exception of several unique groups, such as psittacosaurids that are never replaced in their biomechanical or morphological profiles.
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Affiliation(s)
- Jamie A MacLaren
- Department of Biology , Universiteit Antwerpen , Campus Drie Eiken , Universiteitsplein , Wilrijk , Antwerp , 2610 , Belgium
| | - Philip S L Anderson
- Department of Animal Biology , University of Illinois at Urbana-Champaign , 515 Morrill Hall , 505 S. Goodwin Ave. , Urbana , Illinois 61801 , U.S.A
| | - Paul M Barrett
- Department of Earth Sciences , Natural History Museum , London , Cromwell Road , London , SW7 5BD , U.K
| | - Emily J Rayfield
- School of Earth Sciences , University of Bristol , 24 Tyndall Avenue , Bristol , BS8 1TQ , U.K
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18
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Nabavizadeh A, Weishampel DB. The Predentary Bone and Its Significance in the Evolution of Feeding Mechanisms in Ornithischian Dinosaurs. Anat Rec (Hoboken) 2016; 299:1358-88. [PMID: 27490958 DOI: 10.1002/ar.23455] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/11/2016] [Accepted: 06/16/2016] [Indexed: 11/10/2022]
Abstract
The characteristic predentary bone in ornithischian dinosaurs is a unique, unpaired element located at the midline of the mandibular symphysis. Although traditionally thought to only be a plant "nipping" bone, the true functional significance of this bone among feeding mechanisms of ornithischian dinosaurs is poorly known. Recent studies of a select few ornithischian genera have suggested rotation of the mandibular corpora around their long axes relative to their midline joint articulation with the predentary bone. This study aims to re-evaluate these hypotheses as well as provide in-depth qualitative comparative descriptions of predentary bone morphology in ornithischian genera throughout all subclades, including heterodontosaurids, thyreophorans, ornithopods, and marginocephalians. Descriptions evaluate overall shape of the predentary, its articular surfaces contacting the rostral ends of the dentaries, and the morphology of the rostral extent of the dentaries and their midline symphysis. Functionally relevant morphologies in each predentary morphotype are accentuated for further speculation of feeding mechanisms. Three predentary morphotypes are described throughout ornithischian subclades and each plays a unique role in feeding adaptations. Most notably, the predentary likely evolved as a midline axial point of the mandibular symphysis for simultaneous variable movement or rotation of the mandibular corpora in many, but not all, taxa. This simultaneous movement of the hemimandibles would have aided in feeding on both sides of the jaw at once. The function of the predentary as well as other jaw adaptations is discussed for genera throughout all subclades, focusing on both general shape and joint morphology. Anat Rec, 299:1358-1388, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ali Nabavizadeh
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey.
| | - David B Weishampel
- Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland
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19
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Dinosaurs in decline tens of millions of years before their final extinction. Proc Natl Acad Sci U S A 2016; 113:5036-40. [PMID: 27092007 DOI: 10.1073/pnas.1521478113] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Whether dinosaurs were in a long-term decline or whether they were reigning strong right up to their final disappearance at the Cretaceous-Paleogene (K-Pg) mass extinction event 66 Mya has been debated for decades with no clear resolution. The dispute has continued unresolved because of a lack of statistical rigor and appropriate evolutionary framework. Here, for the first time to our knowledge, we apply a Bayesian phylogenetic approach to model the evolutionary dynamics of speciation and extinction through time in Mesozoic dinosaurs, properly taking account of previously ignored statistical violations. We find overwhelming support for a long-term decline across all dinosaurs and within all three dinosaurian subclades (Ornithischia, Sauropodomorpha, and Theropoda), where speciation rate slowed down through time and was ultimately exceeded by extinction rate tens of millions of years before the K-Pg boundary. The only exceptions to this general pattern are the morphologically specialized herbivores, the Hadrosauriformes and Ceratopsidae, which show rapid species proliferations throughout the Late Cretaceous instead. Our results highlight that, despite some heterogeneity in speciation dynamics, dinosaurs showed a marked reduction in their ability to replace extinct species with new ones, making them vulnerable to extinction and unable to respond quickly to and recover from the final catastrophic event.
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20
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Button DJ, Rayfield EJ, Barrett PM. Cranial biomechanics underpins high sauropod diversity in resource-poor environments. Proc Biol Sci 2015; 281:rspb.2014.2114. [PMID: 25297869 PMCID: PMC4213629 DOI: 10.1098/rspb.2014.2114] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
High megaherbivore species richness is documented in both fossil and contemporary ecosystems despite their high individual energy requirements. An extreme example of this is the Late Jurassic Morrison Formation, which was dominated by sauropod dinosaurs, the largest known terrestrial vertebrates. High sauropod diversity within the resource-limited Morrison is paradoxical, but might be explicable through sophisticated resource partitioning. This hypothesis was tested through finite-element analysis of the crania of the Morrison taxa Camarasaurus and Diplodocus. Results demonstrate divergent specialization, with Camarasaurus capable of exerting and accommodating greater bite forces than Diplodocus, permitting consumption of harder food items. Analysis of craniodental biomechanical characters taken from 35 sauropod taxa demonstrates a functional dichotomy in terms of bite force, cranial robustness and occlusal relationships yielding two polyphyletic functional ‘grades’. Morrison taxa are widely distributed within and between these two morphotypes, reflecting distinctive foraging specializations that formed a biomechanical basis for niche partitioning between them. This partitioning, coupled with benefits associated with large body size, would have enabled the high sauropod diversities present in the Morrison Formation. Further, this provides insight into the mechanisms responsible for supporting the high diversities of large megaherbivores observed in other Mesozoic and Cenozoic communities, particularly those occurring in resource-limited environments.
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Affiliation(s)
- David J Button
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TP, UK Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5DB, UK
| | - Emily J Rayfield
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TP, UK
| | - Paul M Barrett
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5DB, UK
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21
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Maiorino L, Farke AA, Kotsakis T, Teresi L, Piras P. Variation in the shape and mechanical performance of the lower jaws in ceratopsid dinosaurs (Ornithischia, Ceratopsia). J Anat 2015; 227:631-46. [PMID: 26467240 DOI: 10.1111/joa.12374] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2015] [Indexed: 11/30/2022] Open
Abstract
Ceratopsidae represents a group of quadrupedal herbivorous dinosaurs that inhabited western North America and eastern Asia during the Late Cretaceous. Although horns and frills of the cranium are highly variable across species, the lower jaw historically has been considered to be relatively conservative in morphology. Here, the lower jaws from 58 specimens representing 21 ceratopsoid taxa were sampled, using geometric morphometrics and 2D finite element analysis (FEA) to explore differences in morphology and mechanical performance across Ceratopsoidea (the clade including Ceratopsidae, Turanoceratops and Zuniceratops). Principal component analyses and non-parametric permuted manovas highlight Triceratopsini as a morphologically distinct clade within the sample. A relatively robust and elongate dentary, a larger and more elongated coronoid process, and a small and dorso-ventrally compressed angular characterize this clade, as well as the absolutely larger size. By contrast, non-triceratopsin chasmosaurines, Centrosaurini and Pachyrhinosaurini have similar morphologies to each other. Zuniceratops and Avaceratops are distinct from other taxa. No differences in size between Pachyrhinosaurini and Centrosaurini are recovered using non-parametric permuted anovas. Structural performance, as evaluated using a 2D FEA, is similar across all groups as measured by overall stress, with the exception of Triceratopsini. Shape, size and stress are phylogenetically constrained. A longer dentary as well as a long coronoid process result in a lower jaw that is reconstructed as relatively much more stressed in triceratopsins.
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Affiliation(s)
- Leonardo Maiorino
- Dipartimento di Scienze, Università Roma Tre, Rome, Italy.,Center for Evolutionary Ecology, Rome, Italy
| | - Andrew A Farke
- Raymond M. Alf Museum of Paleontology, Claremont, CA, USA
| | - Tassos Kotsakis
- Dipartimento di Scienze, Università Roma Tre, Rome, Italy.,Center for Evolutionary Ecology, Rome, Italy
| | - Luciano Teresi
- Dipartimento di Matematica e Fisica, Università Roma Tre, Rome, Italy
| | - Paolo Piras
- Dipartimento di Scienze, Università Roma Tre, Rome, Italy.,Center for Evolutionary Ecology, Rome, Italy.,Dipartimento di Ingegneria Strutturale e Geotecnica, Sapienza Università di Roma, Rome, Italy.,Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Sapienza Università di Roma, Rome, Italy
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22
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Hill RV, D'Emic MD, Bever GS, Norell MA. A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12293] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Robert V. Hill
- Department of Anatomy; New York Institute of Technology College of Osteopathic Medicine; Northern Boulevard Old Westbury NY 11568-8000 USA
| | - Michael D. D'Emic
- Department of Anatomical Sciences; Stony Brook University; HSC-T8, Room 040 Stony Brook NY 11794-8081 USA
| | - G. S. Bever
- Department of Anatomy; New York Institute of Technology College of Osteopathic Medicine; Northern Boulevard Old Westbury NY 11568-8000 USA
- Division of Paleontology; American Museum of Natural History; New York NY 10024 USA
| | - Mark A. Norell
- Division of Paleontology; American Museum of Natural History; New York NY 10024 USA
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23
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Evans DC, Ryan MJ. Cranial Anatomy of Wendiceratops pinhornensis gen. et sp. nov., a Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation. PLoS One 2015; 10:e0130007. [PMID: 26154293 PMCID: PMC4496092 DOI: 10.1371/journal.pone.0130007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/14/2015] [Indexed: 11/21/2022] Open
Abstract
The fossil record of ceratopsid dinosaurs between the occurrence of their proximate sister taxa in the Turonian and the beginning of their well-documented radiation from the late Campanian of North America onwards (approximately 90 and 77 Ma) is poor, with only seven taxa described from this early period in their evolution. We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada. Over 200 bones derived from virtually all parts of the skeleton, including multiple well-preserved specimens of the diagnostic parietosquamosal frill, were collected from a medium-density monodominant bonebed, making the new taxon one of the best-represented early ceratopsids. The new taxon is apomorphic in having epiparietals at loci 2 and 3 developed as broad-based, pachyostotic processes that are strongly procurved anterodorsally to overhang the posterior and lateral parietal rami, and an ischium with a broad, rectangular distal terminus. Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia. Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.
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Affiliation(s)
- David C. Evans
- Department of Natural History, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, M5S 2C6 Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2 Canada
- * E-mail:
| | - Michael J. Ryan
- Department of Vertebrate Paleontology, Cleveland Museum of Natural History, 1 Wade Oval Drive, University Circle, Cleveland, Ohio 44106, United States of America
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Arbour VM, Currie PJ, Badamgarav D. The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia. Zool J Linn Soc 2014. [DOI: 10.1111/zoj12185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Victoria M. Arbour
- Department of Biological Sciences, University of Alberta, CW405 Biological Sciences Building, Edmonton, AB, CanadaT6G 2E9,
| | - Philip J. Currie
- Department of Biological Sciences, University of Alberta, CW405 Biological Sciences Building, Edmonton, AB, CanadaT6G 2E9,
| | - Demchig Badamgarav
- Paleontological Center, Mongolian Academy of Sciences, Box 260, Ulaanbaatar, 210351, Mongolia
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25
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Arbour VM, Currie PJ, Badamgarav D. The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia. Zool J Linn Soc 2014. [DOI: 10.1111/zoj.12185] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Victoria M. Arbour
- Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building Edmonton AB Canada T6G 2E9
| | - Philip J. Currie
- Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building Edmonton AB Canada T6G 2E9
| | - Demchig Badamgarav
- Paleontological Center; Mongolian Academy of Sciences; Box 260 Ulaanbaatar 210351 Mongolia
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26
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Resolving the long-standing enigmas of a giant ornithomimosaur Deinocheirus mirificus. Nature 2014; 515:257-60. [PMID: 25337880 DOI: 10.1038/nature13874] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 09/19/2014] [Indexed: 11/09/2022]
Abstract
The holotype of Deinocheirus mirificus was collected by the 1965 Polish-Mongolian Palaeontological Expedition at Altan Uul III in the southern Gobi of Mongolia. Because the holotype consists mostly of giant forelimbs (2.4 m in length) with scapulocoracoids, for almost 50 years Deinocheirus has remained one of the most mysterious dinosaurs. The mosaic of ornithomimosaur and non-ornithomimosaur characters in the holotype has made it difficult to resolve the phylogenetic status of Deinocheirus. Here we describe two new specimens of Deinocheirus that were discovered in the Nemegt Formation of Altan Uul IV in 2006 and Bugiin Tsav in 2009. The Bugiin Tsav specimen (MPC-D 100/127) includes a left forelimb clearly identifiable as Deinocheirus and is 6% longer than the holotype. The Altan Uul IV specimen (MPC-D 100/128) is approximately 74% the size of MPC-D 100/127. Cladistic analysis indicates that Deinocheirus is the largest member of the Ornithomimosauria; however, it has many unique skeletal features unknown in other ornithomimosaurs, indicating that Deinocheirus was a heavily built, non-cursorial animal with an elongate snout, a deep jaw, tall neural spines, a pygostyle, a U-shaped furcula, an expanded pelvis for strong muscle attachments, a relatively short hind limb and broad-tipped pedal unguals. Ecomorphological features in the skull, more than a thousand gastroliths, and stomach contents (fish remains) suggest that Deinocheirus was a megaomnivore that lived in mesic environments.
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27
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Mallon JC, Anderson JS. The functional and palaeoecological implications of tooth morphology and wear for the megaherbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada. PLoS One 2014; 9:e98605. [PMID: 24918431 PMCID: PMC4053334 DOI: 10.1371/journal.pone.0098605] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 04/30/2014] [Indexed: 11/19/2022] Open
Abstract
Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche partitioning. The inferred mechanical and dietary patterns appear constant over the 1.5 Myr timespan of the Dinosaur Park Formation megaherbivore chronofauna, despite continual species turnover.
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Affiliation(s)
- Jordan C. Mallon
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
| | - Jason S. Anderson
- Department of Comparative Biology & Experimental Medicine, University of Calgary, Calgary, Alberta, Canada
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Maidment SCR, Bates KT, Falkingham PL, VanBuren C, Arbour V, Barrett PM. Locomotion in ornithischian dinosaurs: an assessment using three-dimensional computational modelling. Biol Rev Camb Philos Soc 2013; 89:588-617. [DOI: 10.1111/brv.12071] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 10/05/2013] [Accepted: 10/14/2013] [Indexed: 11/30/2022]
Affiliation(s)
| | - Karl T. Bates
- Department of Musculoskeletal Biology II; Institute of Aging and Chronic Disease, University of Liverpool; Sherrington Buildings, Ashton Street Liverpool L69 3GE U.K
| | - Peter L. Falkingham
- Department of Comparative Biomedical Sciences; Structure and Motion Laboratory, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA; U.K
- Department of Ecology and Evolutionary Biology, Division of Biology and Medicine; Brown University, 80 Waterman Street; Providence RI 02912 U.S.A
| | - Collin VanBuren
- Department of Ecology and Evolutionary Biology; University of Toronto; 25 Willcocks Street Toronto Ontario M5S 3B2 Canada
| | - Victoria Arbour
- Department of Biological Sciences; University of Alberta; 11145 Saskatchewan Drive Edmonton Alberta T6G 2EG Canada
| | - Paul M. Barrett
- Department of Earth Sciences; The Natural History Museum; Cromwell Road London SW7 5BD U.K
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