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Wilson LN, Gardner JD, Wilson JP, Farnsworth A, Perry ZR, Druckenmiller PS, Erickson GM, Organ CL. Global latitudinal gradients and the evolution of body size in dinosaurs and mammals. Nat Commun 2024; 15:2864. [PMID: 38580657 PMCID: PMC10997647 DOI: 10.1038/s41467-024-46843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/12/2024] [Indexed: 04/07/2024] Open
Abstract
Global climate patterns fundamentally shape the distribution of species and ecosystems. For example, Bergmann's rule predicts that homeothermic animals, including birds and mammals, inhabiting cooler climates are generally larger than close relatives from warmer climates. The modern world, however, lacks the comparative data needed to evaluate such macroecological rules rigorously. Here, we test for Bergmann's rule in Mesozoic dinosaurs and mammaliaforms that radiated within relatively temperate global climate regimes. We develop a phylogenetic model that accounts for biases in the fossil record and allows for variable evolutionary dispersal rates. Our analysis also includes new fossil data from the extreme high-latitude Late Cretaceous Arctic Prince Creek Formation. We find no evidence for Bergmann's rule in Mesozoic dinosaurs or mammaliaforms, the ancestors of extant homeothermic birds and mammals. When our model is applied to thousands of extant dinosaur (bird) and mammal species, we find that body size evolution remains independent of latitude. A modest temperature effect is found in extant, but not in Mesozoic, birds, suggesting that body size evolution in modern birds was influenced by Bergmann's rule during Cenozoic climatic change. Our study provides a general approach for studying macroecological rules, highlighting the fossil record's power to address longstanding ecological principles.
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Affiliation(s)
- Lauren N Wilson
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA.
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA.
| | - Jacob D Gardner
- School of Biological Sciences, University of Reading, Reading, RG6 6EX, UK.
| | - John P Wilson
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59715, USA
| | - Alex Farnsworth
- School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1RL, UK
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zackary R Perry
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA
| | - Patrick S Druckenmiller
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Chris L Organ
- School of Biological Sciences, University of Reading, Reading, RG6 6EX, UK.
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59715, USA.
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2
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Therrien F, Zelenitsky DK, Tanaka K, Voris JT, Erickson GM, Currie PJ, DeBuhr CL, Kobayashi Y. Exceptionally preserved stomach contents of a young tyrannosaurid reveal an ontogenetic dietary shift in an iconic extinct predator. Sci Adv 2023; 9:eadi0505. [PMID: 38064561 PMCID: PMC10846869 DOI: 10.1126/sciadv.adi0505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023]
Abstract
Tyrannosaurids were large carnivorous dinosaurs that underwent major changes in skull robusticity and body proportions as they grew, suggesting that they occupied different ecological niches during their life span. Although adults commonly fed on dinosaurian megaherbivores, the diet of juvenile tyrannosaurids is largely unknown. Here, we describe a remarkable specimen of a juvenile Gorgosaurus libratus that preserves the articulated hindlimbs of two yearling caenagnathid dinosaurs inside its abdominal cavity. The prey were selectively dismembered and consumed in two separate feeding events. This predator-prey association provides direct evidence of an ontogenetic dietary shift in tyrannosaurids. Juvenile individuals may have hunted small and young dinosaurs until they reached a size when, to satisfy energy requirements, they transitioned to feeding on dinosaurian megaherbivores. Tyrannosaurids occupied both mesopredator and apex predator roles during their life span, a factor that may have been key to their evolutionary success.
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Affiliation(s)
| | - Darla K. Zelenitsky
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, Alberta, Canada
| | - Kohei Tanaka
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Jared T. Voris
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, Alberta, Canada
| | - Gregory M. Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Philip J. Currie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Christopher L. DeBuhr
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, Alberta, Canada
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3
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Whalen NS, Hunt TC, Erickson GM. Evapotranspiration-linked silica deposition in a basal tracheophyte plant (Lycopodiaceae: Lycopodiella alopecuroides): implications for the evolutionary origins of phytoliths. New Phytol 2023; 238:2224-2235. [PMID: 36869439 DOI: 10.1111/nph.18861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/24/2023] [Indexed: 05/04/2023]
Abstract
Phytoliths, microscopic deposits of hydrated silica within plants, play a myriad of functional roles in extant tracheophytes - yet their evolutionary origins and the original selective pressures leading to their deposition remain poorly understood. To gain new insights into the ancestral condition of tracheophyte phytolith production and function, phytolith content was intensively assayed in a basal, morphologically conserved tracheophyte: the foxtail clubmoss Lycopodiella alopecuroides. Wet ashing was employed to perform phytolith extractions from every major anatomical region of L. alopecuroides. Phytolith occurrence was recorded, alongside abundance, morphometric information, and morphological descriptions. Phytoliths were recovered exclusively from the microphylls, which were apicodistally silicified into multiphytolith aggregates. Phytolith aggregates were larger and more numerous in anatomical regions engaging in greater evapotranspirational activity. The tissue distribution of L. alopecuroides phytoliths is inconsistent with the expectations of proposed adaptive hypotheses of phytolith evolutionary origin. Instead, it is hypothesized that phytoliths may have arisen incidentally in the L. alopecuroides-like ancestral plant, polymerizing from intraplant silicon accumulations arising via bulk flow and 'leaky' cellular micronutrient channels. This basal, nonadaptive phytolith formation model would provide the evolutionary 'raw material' for later modification into the useful, adaptative, phytolith deposits seen in later-diverging plant clades.
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Affiliation(s)
- Niall S Whalen
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL, 32304, USA
| | - Tyler C Hunt
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL, 32304, USA
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL, 32304, USA
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4
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Hunt TC, Grejtak T, Kodangal D, Varma S, Rinaldi CE, Pathak S, Krick BA, Erickson GM. Microstructurally driven self-sharpening mechanism in beaver incisor enamel facilitates their capacity to fell trees. Acta Biomater 2023; 158:412-422. [PMID: 36603731 DOI: 10.1016/j.actbio.2022.12.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/06/2022] [Accepted: 12/22/2022] [Indexed: 01/04/2023]
Abstract
Beavers (Castor) stand out among mammals for their unique capacity to fell trees using their large, ever-growing incisors. This routine consumption of resistant fodder induces prodigious wear in the lower incisors, despite this blunting effect the incisors maintain a remarkably sharp cutting edge. Notably, the enamel edges of their incisors show a highly complex two-part microstructure of which the biomechanical import is unknown. Here, using fracture analysis, nanoindentation, and wear testing on North American beaver (C. canadensis) incisors we test the microstructure's possible contribution to maintaining incisal sharpness. Although comparable in hardness, the inner enamel preferentially fails and readily wears at 2.5 times the rate of the outer enamel. The outer microstructure redirects all fractures in parallel, decreasing fracture coalescence. Conversely, the inner microstructure facilitates crack coalescence increasing the wear rate by isolating layers of enamel prisms that readily fragment. Together these two architectures form a microstructurally driven self-sharpening mechanism contained entirely within the thin enamel shell. Our results demonstrate that enamel microstructures exposed at the occlusal surface can markedly influence both enamel crest shape and surface texture in wearing dentitions. The methods introduced here open the door to exploring the biomechanical functionality and evolution of enamel microstructures throughout Mammalia. STATEMENT OF SIGNIFICANCE: Enamel microstructure varies significantly with the diversity of diets, bite forces, and tooth shapes exhibited by mammals. However, minimal micromechanical exploration of microstructures outside of humans, leaves our understanding of biomechanical functions in a nascent stage. Using biologically informed mechanical testing, we demonstrate that the complex two-part microstructure that comprises the cutting edge of beaver incisors facilitates self-sharpening of the enamel edge. This previously unrecognized mechanism provides critical maintenance to the shape of the incisal edge ensuring continued functionality despite extreme wear incurred during feeding. More broadly, we show how the architecture of prisms and the surrounding interprismatic matrix dictate the propagation of fractures through enamel fabrics and how the pairing of enamel fabrics can result in biologically advantageous functions.
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Affiliation(s)
- Tyler C Hunt
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA; Mechanical and Physical Properties Laboratory, National High Magnetic Field Laboratory-Florida State University, Tallahassee, FL 32310, USA.
| | - Tomas Grejtak
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA 18015, USA; Department of Mechanical Engineering, Florida A&M University - Florida State University College of Engineering, Tallahassee, FL 32310, USA; Presently at Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Deeksha Kodangal
- Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA
| | - Soumya Varma
- Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA
| | - Caroline E Rinaldi
- Department of Surgery, University of Texas-Southwestern Medical Center, Dallas, TX 75390, USA
| | - Siddhartha Pathak
- Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA
| | - Brandon A Krick
- Department of Mechanical Engineering, Florida A&M University - Florida State University College of Engineering, Tallahassee, FL 32310, USA
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA; Mechanical and Physical Properties Laboratory, National High Magnetic Field Laboratory-Florida State University, Tallahassee, FL 32310, USA
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5
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Steppan SJ, Meyer AA, Barrow LN, Alhajeri BH, S Y Al-Zaidan A, Gignac PM, Erickson GM. Phylogenetics And The Evolution Of Terrestriality In Mudskippers (Gobiidae: Oxudercinae). Mol Phylogenet Evol 2022; 169:107416. [PMID: 35032645 DOI: 10.1016/j.ympev.2022.107416] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/30/2021] [Accepted: 12/08/2021] [Indexed: 01/23/2023]
Abstract
The initial vertebrate conquest of land by stegocephalians (Sarcopterygia) allowed access to new resources and exploitation of untapped niches precipitating a major phylogenetic diversification. However, a paucity of fossils has left considerable uncertainties about phylogenetic relationships and the eco-morphological stages in this key transition in Earth history. Among extant actinopterygians, three genera of mudskippers (Gobiidae: Oxudercinae), Boleophthalmus, Periophthalmus and Periophthalmodon are the most terrestrialized, with vertebral, appendicular, locomotory, respiratory, and epithelial specializations enabling overland excursions up to 14 hours. Unlike early stegocephalians, the ecologies and morphologies of the 45 species of oxudercines are well known, making them viable analogs for the initial vertebrate conquest of land. Nevertheless, they have received little phylogenetic attention. We compiled the largest molecular dataset to date, with 29 oxudercine species, and 5 nuclear and mitochondrial loci. Phylogenetic and comparative analyses revealed strong support for two independent terrestrial transitions, and a complex suit of ecomorphological forms in estuarine environments. Furthermore, neither Oxudercinae nor their presumed sister-group the eel gobies (Amblyopinae, a group of elongated gobies) were monophyletic with respect to each other, requiring a merging of these two subfamilies and revealing an expansion of phenotypic variation within the "mudskipper" clade. We did not find support for the expected linear model of ecomorphological and locomotory transition from fully aquatic, to mudswimming, to pectoral-aided mudswimming, to lobe-finned terrestrial locomotion proposed by earlier morphological studies. This high degree of convergent or parallel transitions to terrestriality, and apparent divergent directions of estuarine adaptation, promises even greater potential for this clade to illuminate the conquest of land. Future work should focus on these less-studied species with "transitional" and other mud-habitat specializations to fully resolve the dynamics of this diversification.
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Affiliation(s)
- Scott J Steppan
- Department of Biological Science, 327 Stadium Dr., Florida State University, Tallahassee Florida, 32306-4295, USA.
| | - Anna A Meyer
- Department of Biological Science, 327 Stadium Dr., Florida State University, Tallahassee Florida, 32306-4295, USA
| | - Lisa N Barrow
- Department of Biological Science, 327 Stadium Dr., Florida State University, Tallahassee Florida, 32306-4295, USA; Department of Biology, University of New Mexico, Albuquerque, NM 87131-0001, USA
| | - Bader H Alhajeri
- Department of Biological Sciences, Kuwait University, Safat, 13060, Kuwait
| | | | - Paul M Gignac
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa Oklahoma 74107-1898, USA
| | - Gregory M Erickson
- Department of Biological Science, 327 Stadium Dr., Florida State University, Tallahassee Florida, 32306-4295, USA
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6
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Wooller MJ, Bataille C, Druckenmiller P, Erickson GM, Groves P, Haubenstock N, Howe T, Irrgeher J, Mann D, Moon K, Potter BA, Prohaska T, Rasic J, Reuther J, Shapiro B, Spaleta KJ, Willis AD. Lifetime mobility of an Arctic woolly mammoth. Science 2021; 373:806-808. [PMID: 34385399 DOI: 10.1126/science.abg1134] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/12/2021] [Indexed: 11/02/2022]
Abstract
Little is known about woolly mammoth (Mammuthus primigenius) mobility and range. Here we use high temporal resolution sequential analyses of strontium isotope ratios along an entire 1.7-meter-long tusk to reconstruct the movements of an Arctic woolly mammoth that lived 17,100 years ago, during the last ice age. We use an isotope-guided random walk approach to compare the tusk's strontium and oxygen isotope profiles to isotopic maps. Our modeling reveals patterns of movement across a geographically extensive range during the animal's ~28-year life span that varied with life stages. Maintenance of this level of mobility by megafaunal species such as mammoth would have been increasingly difficult as the ice age ended and the environment changed at high latitudes.
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Affiliation(s)
- Matthew J Wooller
- Alaska Stable Isotope Facility, University of Alaska Fairbanks, Fairbanks, AK, USA. .,Department of Marine Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Clement Bataille
- Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, ON, Canada. .,Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Patrick Druckenmiller
- University of Alaska Museum of the North, Fairbanks, AK, USA.,Department of Geosciences, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Pamela Groves
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Norma Haubenstock
- Alaska Stable Isotope Facility, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Timothy Howe
- Alaska Stable Isotope Facility, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Johanna Irrgeher
- Department of General, Analytical and Physical Chemistry, Montanuniversität Leoben, Leoben, Austria
| | - Daniel Mann
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Katherine Moon
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Ben A Potter
- Arctic Studies Center, Liaocheng University, Liaocheng City, Shandong Province, China
| | - Thomas Prohaska
- Department of General, Analytical and Physical Chemistry, Montanuniversität Leoben, Leoben, Austria
| | | | - Joshua Reuther
- University of Alaska Museum of the North, Fairbanks, AK, USA
| | - Beth Shapiro
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Karen J Spaleta
- Alaska Stable Isotope Facility, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Amy D Willis
- Department of Biostatistics, University of Washington, Seattle, WA, USA
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7
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Druckenmiller PS, Erickson GM, Brinkman D, Brown CM, Eberle JJ. Nesting at extreme polar latitudes by non-avian dinosaurs. Curr Biol 2021; 31:3469-3478.e5. [PMID: 34171301 DOI: 10.1016/j.cub.2021.05.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/26/2021] [Accepted: 05/18/2021] [Indexed: 11/17/2022]
Abstract
The unexpected discovery of non-avian dinosaurs from Arctic and Antarctic settings has generated considerable debate about whether they had the capacity to reproduce at high latitudes-especially the larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian polar reproduction remains very rare, particularly for species that lived at the highest paleolatitudes (>75°). Here we report the discovery of perinatal and very young dinosaurs from the highest known paleolatitude for the clade-the Cretaceous Prince Creek Formation (PCF) of northern Alaska. These data demonstrate Arctic reproduction in a diverse assemblage of large- and small-bodied ornithischian and theropod species. In terms of overall diversity, 70% of the known dinosaurian families, as well as avialans (birds), in the PCF are represented by perinatal individuals, the highest percentage for any North American Cretaceous formation. These findings, coupled with prolonged incubation periods, small neonate sizes, and short reproductive windows suggest most, if not all, PCF dinosaurs were nonmigratory year-round Arctic residents. Notably, we reconstruct an annual chronology of reproductive events for the ornithischian dinosaurs using refined paleoenvironmental/plant phenology data and new insights into dinosaur incubation periods. Seasonal resource limitations due to extended periods of winter darkness and freezing temperatures placed severe constraints on dinosaurian reproduction, development, and maintenance, suggesting these taxa showed polar-specific life history strategies, including endothermy.
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Affiliation(s)
- Patrick S Druckenmiller
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK 99775, USA; Department of Geosciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, 319 Stadium Drive, FL 32306, USA
| | - Donald Brinkman
- Royal Tyrrell Museum of Palaeontology, Drumheller, AB T0J 0Y0, Canada
| | - Caleb M Brown
- Royal Tyrrell Museum of Palaeontology, Drumheller, AB T0J 0Y0, Canada
| | - Jaelyn J Eberle
- Univerity of Colorado Museum of Natural History, 265 UCB, Boulder, CO 80309, USA; Department of Geological Sciences, University of Colorado, Boulder, CO 80309, USA
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8
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Napoli JG, Hunt T, Erickson GM, Norell MA. Psittacosaurus amitabha, a New Species of Ceratopsian Dinosaur from the Ondai Sayr Locality, Central Mongolia. American Museum Novitates 2019. [DOI: 10.1206/3932.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- James G. Napoli
- Richard Gilder Graduate School, American Museum of Natural History
| | - Tyler Hunt
- Department of Biological Science, Florida State University
| | | | - Mark A. Norell
- Richard Gilder Graduate School, American Museum of Natural History
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9
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Persons WS, Currie PJ, Erickson GM. An Older and Exceptionally Large Adult Specimen of
Tyrannosaurus rex. Anat Rec (Hoboken) 2019; 303:656-672. [DOI: 10.1002/ar.24118] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 11/11/2018] [Accepted: 12/10/2018] [Indexed: 11/11/2022]
Affiliation(s)
- W. Scott Persons
- Department of Biological Sciences University of Alberta Edmonton Alberta Canada
| | - Philip J. Currie
- Department of Biological Sciences University of Alberta Edmonton Alberta Canada
| | - Gregory M. Erickson
- Department of Biological Sciences Florida State University Tallahassee Florida
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10
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Kay DI, Erickson GM, Kuhn‐Hendricks S, Giganc PM. Mechanical and Fracture Properties Evolution of Gnathostome Dental Enamel and Orthodentine. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.452.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David Ian Kay
- Anatomy and Cell BiologyOklahoma State University Center for Health SciencesTulsaOK
| | | | | | - Paul M Giganc
- Anatomy and Cell BiologyOklahoma State University Center for Health SciencesTulsaOK
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11
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O’Brien HD, Lynch LM, Vliet KA, Brueggen J, Erickson GM, Gignac PM. Crocodylian Head Width Allometry and Phylogenetic Prediction of Body Size in Extinct Crocodyliforms. Integr Org Biol 2019; 1:obz006. [PMID: 33791523 PMCID: PMC7671145 DOI: 10.1093/iob/obz006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Body size and body-size shifts broadly impact life-history parameters of all animals, which has made accurate body-size estimates for extinct taxa an important component of understanding their paleobiology. Among extinct crocodylians and their precursors (e.g., suchians), several methods have been developed to predict body size from suites of hard-tissue proxies. Nevertheless, many have limited applications due to the disparity of some major suchian groups and biases in the fossil record. Here, we test the utility of head width (HW) as a broadly applicable body-size estimator in living and fossil suchians. We use a dataset of sexually mature male and female individuals (n = 76) from a comprehensive sample of extant suchian species encompassing nearly all known taxa (n = 22) to develop a Bayesian phylogenetic model for predicting three conventional metrics for size: body mass, snout-vent length, and total length. We then use the model to estimate size parameters for a select series of extinct suchians with known phylogenetic affinity (Montsechosuchus, Diplocynodon, and Sarcosuchus). We then compare our results to sizes reported in the literature to exemplify the utility of our approach for a broad array of fossil suchians. Our results show that HW is highly correlated with all other metrics (all R 2≥0.85) and is commensurate with femoral dimensions for its reliably as a body-size predictor. We provide the R code in order to enable other researchers to employ the model in their own research.
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Affiliation(s)
- Haley D O’Brien
- Oklahoma State University Center for Health Sciences, 1111 West 17th Street, Tulsa, OK 74107, USA
| | - Leigha M Lynch
- Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Kent A Vliet
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - John Brueggen
- St. Augustine Alligator Farm Zoological Park, 999 Anastasia Blvd, St. Augustine, FL 32080, USA
| | - Gregory M Erickson
- Department of Biological Sciences, Florida State University, 600 West College Avenue, Tallahassee, FL 32306, USA
| | - Paul M Gignac
- Oklahoma State University Center for Health Sciences, 1111 West 17th Street, Tulsa, OK 74107, USA
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12
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Norell MA, Balanoff AM, Barta DE, Erickson GM. A Second Specimen ofCitipati OsmolskaeAssociated With a Nest of Eggs from Ukhaa Tolgod, Omnogov Aimag, Mongolia. American Museum Novitates 2018. [DOI: 10.1206/3899.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Mark A. Norell
- Division of Paleontology, American Museum of Natural History
- Richard Gilder Graduate School, American Museum of Natural History
| | - Amy M. Balanoff
- Division of Paleontology, American Museum of Natural History
- Center for Functional Anatomy and Evolution, Johns Hopkins University
| | - Daniel E. Barta
- Division of Paleontology, American Museum of Natural History
- Richard Gilder Graduate School, American Museum of Natural History
| | - Gregory M. Erickson
- Division of Paleontology, American Museum of Natural History
- Department of Biological Science, Florida State University, Tallahassee
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13
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Erickson GM, Zelenitsky DK, Kay DI, Norell MA. Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development. Proc Natl Acad Sci U S A 2017; 114:540-545. [PMID: 28049837 PMCID: PMC5255600 DOI: 10.1073/pnas.1613716114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Birds stand out from other egg-laying amniotes by producing relatively small numbers of large eggs with very short incubation periods (average 11-85 d). This aspect promotes high survivorship by limiting exposure to predation and environmental perturbation, allows for larger more fit young, and facilitates rapid attainment of adult size. Birds are living dinosaurs; their rapid development has been considered to reflect the primitive dinosaurian condition. Here, nonavian dinosaurian incubation periods in both small and large ornithischian taxa are empirically determined through growth-line counts in embryonic teeth. Our results show unexpectedly slow incubation (2.8 and 5.8 mo) like those of outgroup reptiles. Developmental and physiological constraints would have rendered tooth formation and incubation inherently slow in other dinosaur lineages and basal birds. The capacity to determine incubation periods in extinct egg-laying amniotes has implications for dinosaurian embryology, life history strategies, and survivorship across the Cretaceous-Paleogene mass extinction event.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295;
| | - Darla K Zelenitsky
- Department of Geoscience, University of Calgary, Calgary, AB, Canada T2N 1N4
| | - David Ian Kay
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295
| | - Mark A Norell
- Division of Paleontology, American Museum of Natural History, New York, NY 10024
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Prieto-Márquez A, Erickson GM, Ebersole JA. Anatomy and osteohistology of the basal hadrosaurid dinosaur Eotrachodon from the uppermost Santonian (Cretaceous) of southern Appalachia. PeerJ 2016; 4:e1872. [PMID: 27114863 PMCID: PMC4841272 DOI: 10.7717/peerj.1872] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/09/2016] [Indexed: 11/20/2022] Open
Abstract
The cranial and postcranial anatomy of the basal hadrosaurid dinosaur Eotrachodon orientalis, from the uppermost Santonian of southern Appalachia (southeastern U.S.A.), is described in detail. This animal is the only known pre-Campanian non-lambeosaurine hadrosaurid, and the most complete hadrosauroid known from Appalachia. E. orientalis possesses a mosaic of plesiomorphic and derived characters in the context of Hadrosauroidea. Characters shared with basal hadrosauroids include a short and sloping maxillary ectopterygoid shelf, caudally prominent maxillary jugal process, one functional tooth per alveolus on the maxillary occlusal plane, a jugal rostral process with a shallow caudodorsal margin and medioventrally facing articular facet, a vertical dentary coronoid process with a poorly expanded apex, and tooth crowns with accessory ridges. Derived characters shared with other hadrosaurids include a circumnarial depression compartmented into three fossae (as in brachylophosaurins and Edmontosaurus), a thin everted premaxillary oral margin (as in Gryposaurus, Prosaurolophus, and Saurolophus), and a maxilla with a deep and rostrocaudally extensive rostrodorsal region with a steeply sloping premaxillary margin (as in Gryposaurus). Eotrachodon orientalis differs primarily from the other hadrosauroid from the Mooreville Chalk of Alabama, Lophorhothon atopus, in having a slender and crestless nasal whose caudodorsal margin is not invaded by the circumnarial depression. Hadrosaurus foulkii, the only other known hadrosaurid from Appalachia, is distinct from E. orientalis in having dentary teeth lacking accessory ridges and a dorsally curved shaft of the ischium. A histological section of the tibia of the E. orientalis holotype (MSC 7949) suggests that this individual was actively growing at the time of death and, thus, had the potential to become a larger animal later in development.
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Affiliation(s)
| | - Gregory M Erickson
- Department of Biological Science, Florida State University , Tallahassee, Florida , USA
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Erickson GM, Makovicky PJ, Currie PJ, Norell MA, Yerby SA, Brochu CA. Correction: Corrigendum: Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature 2016; 531:538. [DOI: 10.1038/nature16487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Erickson GM, Makovicky PJ, Inouye BD, Zhou CF, Gao KQ. Flawed Analysis? A Response to Myhrvold. Anat Rec (Hoboken) 2015; 298:1669-72. [PMID: 26097068 DOI: 10.1002/ar.23187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 04/05/2015] [Accepted: 04/29/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, Florida
| | | | - Brian D Inouye
- Department of Biological Science, Florida State University, Tallahassee, Florida
| | - Chang-Fu Zhou
- Liaoning Paleontological Museum, Shenyang Normal University, Shenyang
| | - Ke-Qin Gao
- School of Earth and Space Sciences, Peking University, Beijing
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Erickson GM, Sidebottom MA, Kay DI, Turner KT, Ip N, Norell MA, Sawyer WG, Krick BA. Wear biomechanics in the slicing dentition of the giant horned dinosaur Triceratops. Sci Adv 2015; 1:e1500055. [PMID: 26601198 PMCID: PMC4640618 DOI: 10.1126/sciadv.1500055] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/21/2015] [Indexed: 05/18/2023]
Abstract
Herbivorous reptiles rarely evolve occluding dentitions that allow for the mastication (chewing) of plant matter. Conversely, most herbivorous mammals have occluding teeth with complex tissue architectures that self-wear to complex morphologies for orally processing plants. Dinosaurs stand out among reptiles in that several lineages acquired the capacity to masticate. In particular, the horned ceratopsian dinosaurs, among the most successful Late Cretaceous dinosaurian lineages, evolved slicing dentitions for the exploitation of tough, bulky plant matter. We show how Triceratops, a 9-m-long ceratopsian, and its relatives evolved teeth that wore during feeding to create fullers (recessed central regions on cutting blades) on the chewing surfaces. This unique morphology served to reduce friction during feeding. It was achieved through the evolution of a complex suite of osseous dental tissues rivaling the complexity of mammalian dentitions. Tribological (wear) properties of the tissues are preserved in ~66-million-year-old teeth, allowing the creation of a sophisticated three-dimensional biomechanical wear model that reveals how the complexes synergistically wore to create these implements. These findings, along with similar discoveries in hadrosaurids (duck-billed dinosaurs), suggest that tissue-mediated changes in dental morphology may have played a major role in the remarkable ecological diversification of these clades and perhaps other dinosaurian clades capable of mastication.
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Affiliation(s)
- Gregory M. Erickson
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306–4295, USA
| | - Mark A. Sidebottom
- Department of Mechanical Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
| | - David I. Kay
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306–4295, USA
| | - Kevin T. Turner
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nathan Ip
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mark A. Norell
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
| | - W. Gregory Sawyer
- Department of Mechanical and Aerospace Engineering, University of Florida, 328 Mechanical Engineering Building, Gainesville, FL 32611, USA
| | - Brandon A. Krick
- Department of Mechanical Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
- Corresponding author. E-mail:
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Brusatte SL, Vremir M, Csiki-Sava Z, Turner AH, Watanabe A, Erickson GM, Norell MA. The Osteology of Balaur bondoc, an Island-Dwelling Dromaeosaurid (Dinosauria: Theropoda) from the Late Cretaceous of Romania. Bulletin of the American Museum of Natural History 2013. [DOI: 10.1206/798.1] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zelenitsky DK, Therrien F, Erickson GM, DeBuhr CL, Kobayashi Y, Eberth DA, Hadfield F. Feathered Non-Avian Dinosaurs from North America Provide Insight into Wing Origins. Science 2012; 338:510-4. [DOI: 10.1126/science.1225376] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Darla K. Zelenitsky
- Department of Geoscience, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - François Therrien
- Royal Tyrrell Museum of Palaeontology, Drumheller, Alberta TOJ OYO, Canada
| | - Gregory M. Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306–4295, USA
| | | | - Yoshitsugu Kobayashi
- Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido 060 0810, Japan
| | - David A. Eberth
- Royal Tyrrell Museum of Palaeontology, Drumheller, Alberta TOJ OYO, Canada
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Erickson GM, Krick BA, Hamilton M, Bourne GR, Norell MA, Lilleodden E, Sawyer WG. Complex Dental Structure and Wear Biomechanics in Hadrosaurid Dinosaurs. Science 2012; 338:98-101. [DOI: 10.1126/science.1224495] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mammalian grinding dentitions are composed of four major tissues that wear differentially, creating coarse surfaces for pulverizing tough plants and liberating nutrients. Although such dentition evolved repeatedly in mammals (such as horses, bison, and elephants), a similar innovation occurred much earlier (~85 million years ago) within the duck-billed dinosaur group Hadrosauridae, fueling their 35-million-year occupation of Laurasian megaherbivorous niches. How this complexity was achieved is unknown, as reptilian teeth are generally two-tissue structures presumably lacking biomechanical attributes for grinding. Here we show that hadrosaurids broke from the primitive reptilian archetype and evolved a six-tissue dental composition that is among the most sophisticated known. Three-dimensional wear models incorporating fossilized wear properties reveal how these tissues interacted for grinding and ecological specialization.
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Erickson GM, Gignac PM, Steppan SJ, Lappin AK, Vliet KA, Brueggen JD, Inouye BD, Kledzik D, Webb GJW. Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation. PLoS One 2012; 7:e31781. [PMID: 22431965 PMCID: PMC3303775 DOI: 10.1371/journal.pone.0031781] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 01/19/2012] [Indexed: 12/14/2022] Open
Abstract
Background Crocodilians have dominated predatory niches at the water-land interface for over 85 million years. Like their ancestors, living species show substantial variation in their jaw proportions, dental form and body size. These differences are often assumed to reflect anatomical specialization related to feeding and niche occupation, but quantified data are scant. How these factors relate to biomechanical performance during feeding and their relevance to crocodilian evolutionary success are not known. Methodology/Principal Findings We measured adult bite forces and tooth pressures in all 23 extant crocodilian species and analyzed the results in ecological and phylogenetic contexts. We demonstrate that these reptiles generate the highest bite forces and tooth pressures known for any living animals. Bite forces strongly correlate with body size, and size changes are a major mechanism of feeding evolution in this group. Jaw shape demonstrates surprisingly little correlation to bite force and pressures. Bite forces can now be predicted in fossil crocodilians using the regression equations generated in this research. Conclusions/Significance Critical to crocodilian long-term success was the evolution of a high bite-force generating musculo-skeletal architecture. Once achieved, the relative force capacities of this system went essentially unmodified throughout subsequent diversification. Rampant changes in body size and concurrent changes in bite force served as a mechanism to allow access to differing prey types and sizes. Further access to the diversity of near-shore prey was gained primarily through changes in tooth pressure via the evolution of dental form and distributions of the teeth within the jaws. Rostral proportions changed substantially throughout crocodilian evolution, but not in correspondence with bite forces. The biomechanical and ecological ramifications of such changes need further examination.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America.
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Pfaller JB, Gignac PM, Erickson GM. Ontogenetic changes in jaw-muscle architecture facilitate durophagy in the turtle Sternotherus minor. J Exp Biol 2011; 214:1655-67. [DOI: 10.1242/jeb.048090] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Differential scaling of musculoskeletal traits leads to differences in performance across ontogeny and ultimately determines patterns of resource use during development. Because musculoskeletal growth of the feeding system facilitates high bite-force generation necessary to overcome the physical constraints of consuming more durable prey, durophagous taxa are well suited for investigations of the scaling relationships between musculoskeletal growth, bite-force generation and dietary ontogeny. To elucidate which biomechanical factors are responsible for allometric changes in bite force and durophagy, we developed and experimentally tested a static model of bite-force generation throughout development in the durophagous turtle Sternotherus minor. Moreover, we quantified the fracture properties of snails found in the diet to evaluate the relationship between bite force and the forces required to process durable prey. We found that (1) the static bite-force model accurately predicts the ontogenetic scaling of bite forces, (2) bite-force positive allometry is accomplished by augmenting muscle size and muscle pennation, and (3) the rupture forces of snails found in the diet show a similar scaling pattern to bite force across ontogeny. These results indicate the importance of muscle pennation for generating high bite forces while maintaining muscle size and provide empirical evidence that the allometric patterns of musculoskeletal growth in S. minor are strongly linked to the structural properties of their primary prey.
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Affiliation(s)
- Joseph B. Pfaller
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Paul M. Gignac
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Gregory M. Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
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Brusatte SL, Norell MA, Carr TD, Erickson GM, Hutchinson JR, Balanoff AM, Bever GS, Choiniere JN, Makovicky PJ, Xu X. Tyrannosaur paleobiology: new research on ancient exemplar organisms. Science 2010; 329:1481-5. [PMID: 20847260 DOI: 10.1126/science.1193304] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Tyrannosaurs, the group of dinosaurian carnivores that includes Tyrannosaurus rex and its closest relatives, are icons of prehistory. They are also the most intensively studied extinct dinosaurs, and thanks to large sample sizes and an influx of new discoveries, have become ancient exemplar organisms used to study many themes in vertebrate paleontology. A phylogeny that includes recently described species shows that tyrannosaurs originated by the Middle Jurassic but remained mostly small and ecologically marginal until the latest Cretaceous. Anatomical, biomechanical, and histological studies of T. rex and other derived tyrannosaurs show that large tyrannosaurs could not run rapidly, were capable of crushing bite forces, had accelerated growth rates and keen senses, and underwent pronounced changes during ontogeny. The biology and evolutionary history of tyrannosaurs provide a foundation for comparison with other dinosaurs and living organisms.
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Affiliation(s)
- Stephen L Brusatte
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.
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Erickson GM, Makovicky PJ, Inouye BD, Zhou CF, Gao KQ. A life table for Psittacosaurus lujiatunensis: initial insights into ornithischian dinosaur population biology. Anat Rec (Hoboken) 2009; 292:1514-21. [PMID: 19711482 DOI: 10.1002/ar.20992] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Very little is known about nonavian dinosaur population biology. Multi-individual sampling and longevity estimation using growth line counts can be used to construct life tables-the foundation for population analyses in ecology. Here we have determined the size and age distribution for a sample consisting of 80 individuals of the small ornithischian, Psittacosaurus lujiatunensis from the early Cretaceous Yixian Formation of China. Their ages ranged from less than a year to eleven years and the distribution was strongly right-skewed. This is consistent with taphonomic interpretations that these animals derive from a catastrophic death assemblage. The static life table analysis revealed the same general pattern of survivorship as tyrannosaurs including increased attrition before the attainment of full adult size. This may reflect increased physiological demands and/or predation exposure associated with reproduction. Collectively these findings suggest that most nonavian dinosaurs may have had a similar life history strategy.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA.
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Butler RJ, Galton PM, Porro LB, Chiappe LM, Henderson DM, Erickson GM. Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America. Proc Biol Sci 2009; 277:375-81. [PMID: 19846460 DOI: 10.1098/rspb.2009.1494] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65-75 cm in total body length and 0.5-0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.
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Affiliation(s)
- Richard J Butler
- Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Strasse 10, 80333 Munich, Germany.
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Erickson GM, Rauhut OWM, Zhou Z, Turner AH, Inouye BD, Hu D, Norell MA. Was dinosaurian physiology inherited by birds? Reconciling slow growth in archaeopteryx. PLoS One 2009; 4:e7390. [PMID: 19816582 PMCID: PMC2756958 DOI: 10.1371/journal.pone.0007390] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Accepted: 09/16/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Archaeopteryx is the oldest and most primitive known bird (Avialae). It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs. This hypothesis predicts that the long bones in these birds formed using rapidly growing, well-vascularized woven tissue typical of non-avialan dinosaurs. METHODOLOGY/PRINCIPAL FINDINGS We report that Archaeopteryx long bones are composed of nearly avascular parallel-fibered bone. This is among the slowest growing osseous tissues and is common in ectothermic reptiles. These findings dispute the hypothesis that non-avialan dinosaur growth and physiology were inherited in totality by the first birds. Examining these findings in a phylogenetic context required intensive sampling of outgroup dinosaurs and basalmost birds. Our results demonstrate the presence of a scale-dependent maniraptoran histological continuum that Archaeopteryx and other basalmost birds follow. Growth analysis for Archaeopteryx suggests that these animals showed exponential growth rates like non-avialan dinosaurs, three times slower than living precocial birds, but still within the lowermost range for all endothermic vertebrates. CONCLUSIONS/SIGNIFICANCE The unexpected histology of Archaeopteryx and other basalmost birds is actually consistent with retention of the phylogenetically earlier paravian dinosaur condition when size is considered. The first birds were simply feathered dinosaurs with respect to growth and energetic physiology. The evolution of the novel pattern in modern forms occurred later in the group's history.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA.
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Abstract
Ornithomimosaurs (ostrich-mimic dinosaurs) are a common element of some Cretaceous dinosaur assemblages of Asia and North America. Here, we describe a new species of ornithomimosaur, Beishanlong grandis, from an associated, partial postcranial skeleton from the Aptian-Albian Xinminpu Group of northern Gansu, China. Beishanlong is similar to another Aptian-Albian ornithomimosaur, Harpymimus, with which it shares a phylogenetic position as more derived than the Barremian Shenzhousaurus and as sister to a Late Cretaceous clade composed of Garudimimus and the Ornithomimidae. Beishanlong is one of the largest definitive ornithomimosaurs yet described, though histological analysis shows that the holotype individual was still growing at its death. Together with the co-eval and sympatric therizinosaur Suzhousaurus and the oviraptorosaur Gigantraptor, Beishanlong provides evidence for the parallel evolution of gigantism in separate lineages of beaked and possibly herbivorous coelurosaurs within a short time span in Central Asia.
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Affiliation(s)
- Peter J Makovicky
- Department of Geology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA.
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Abstract
The repeated discovery of adult dinosaurs in close association with egg clutches leads to speculation over the type and extent of care exhibited by these extinct animals for their eggs and young. To assess parental care in Cretaceous troodontid and oviraptorid dinosaurs, we examined clutch volume and the bone histology of brooding adults. In comparison to four archosaur care regressions, the relatively large clutch volumes ofTroodon, Oviraptor, andCitipatiscale most closely with a bird-paternal care model. Clutch-associated adults lack the maternal and reproductively associated histologic features common to extant archosaurs. Large clutch volumes and a suite of reproductive features shared only with birds favor paternal care, possibly within a polygamous mating system. Paternal care in both troodontids and oviraptorids indicates that this care system evolved before the emergence of birds and represents birds' ancestral condition. In extant birds and over most adult sizes, paternal and biparental care correspond to the largest and smallest relative clutch volumes, respectively.
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Abstract
Direct evidence of prey choice in carnivorous dinosaurs is rare in the fossil record. The most celebrated example pertains to purported stomach contents in the carnivorous dinosaur Coelophysis bauri, which besides revealing prey choice, also points to cannibalistic behaviour as being commonplace (Colbert 1989, 1995). Here, we test this hypothesis by conducting the first comprehensive anatomical and histological examination of the famed Coelophysis 'cannibals'. The results unequivocally show that the gut contents derive from early crocodylomorphs rather than juveniles of Coelophysis. These findings suggest that this taxon is not cannibalistic and bring into question the commonality of this behaviour among non-avian dinosaurs.
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Affiliation(s)
- Sterling J Nesbitt
- Division of Paleontology, American Museum of Natural History, New York, NY 10024-5192, USA.
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Erickson GM, Curry Rogers K, Varricchio DJ, Norell MA, Xu X. Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition. Biol Lett 2007; 3:558-61. [PMID: 17638674 PMCID: PMC2396186 DOI: 10.1098/rsbl.2007.0254] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is approached. In birds (living dinosaurs) on the other hand, reproductive activity begins well after somatic maturity. Here we used growth line counts and spacing in all of the known brooding non-avian dinosaurs to determine the stages of development when they perished. It was revealed that sexual maturation occurred well before full adult size was reached-the primitive reptilian condition. In this sense, the life history and physiology of non-avian dinosaurs was not like that of modern birds. Palaeobiological ramifications of these findings include the potential to deduce reproductive lifespan, fecundity and reproductive population sizes in non-avian dinosaurs, as well as aid in the identification of secondary sexual characteristics.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100, USA.
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Abstract
Fossil evidence for changes in dinosaurs near the lineage leading to birds and the origin of flight has been sparse. A dinosaur from Mongolia represents the basal divergence within Dromaeosauridae. The taxon's small body size and phylogenetic position imply that extreme miniaturization was ancestral for Paraves (the clade including Avialae, Troodontidae, and Dromaeosauridae), phylogenetically earlier than where flight evolution is strongly inferred. In contrast to the sustained small body sizes among avialans throughout the Cretaceous Period, the two dinosaurian lineages most closely related to birds, dromaeosaurids and troodontids, underwent four independent events of gigantism, and in some lineages size increased by nearly three orders of magnitude. Thus, change in theropod body size leading to flight's origin was not unidirectional.
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Affiliation(s)
- Alan H Turner
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA.
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Clarke JA, Tambussi CP, Noriega JI, Erickson GM, Ketcham RA. Erratum: Definitive fossil evidence for the extant avian radiation in the Cretaceous. Nature 2006. [DOI: 10.1038/nature05424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
The size and age structures for four assemblages of North American tyrannosaurs-Albertosaurus, Tyrannosaurus, Gorgosaurus, and Daspletosaurus-reveal a pronounced, bootstrap-supported pattern of age-specific mortality characterized by relatively high juvenile survivorship and increased mortality at midlife and near the maximum life span. Such patterns are common today in wild populations of long-lived birds and mammals. Factors such as predation and entrance into the breeding population may have influenced tyrannosaur survivorship. This survivorship pattern can explain the rarity of juvenile specimens in museum collections.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
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Xu X, Clark JM, Forster CA, Norell MA, Erickson GM, Eberth DA, Jia C, Zhao Q. A basal tyrannosauroid dinosaur from the Late Jurassic of China. Nature 2006; 439:715-8. [PMID: 16467836 DOI: 10.1038/nature04511] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 12/05/2005] [Indexed: 11/09/2022]
Abstract
The tyrannosauroid fossil record is mainly restricted to Cretaceous sediments of Laurasia, although some very fragmentary Jurassic specimens have been referred to this group. Here we report a new basal tyrannosauroid, Guanlong wucaii gen. et sp. nov., from the lower Upper Jurassic of the Junggar Basin, northwestern China. G. wucaii is the oldest known tyrannosauroid and shows several unexpectedly primitive pelvic features. Nevertheless, the limbs of G. wucaii share several features with derived coelurosaurs, and it possesses features shared by other coelurosaurian clades. This unusual combination of character states provides an insight into the poorly known early radiation of the Coelurosauria. Notably, the presumed predatory Guanlong has a large, fragile and highly pneumatic cranial crest that is among the most elaborate known in any non-avian dinosaur and could be comparable to some classical exaggerated ornamental traits among vertebrates.
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Affiliation(s)
- Xing Xu
- Institute of Vertebrate Paleontology and Paleoanthropology, Beijing 100044, China.
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Erickson GM. Assessing dinosaur growth patterns: a microscopic revolution. Trends Ecol Evol 2005. [PMID: 16701457 DOI: 10.1016/j.tree.2005.1008.1012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Some of the longest standing questions in dinosaur paleontology pertain to their development. Did dinosaurs grow at slow rates similar to extant reptiles or rapidly similar to living birds and mammals? How did some forms attain gigantic proportions? Conversely, how did birds (avian dinosaurs) become miniaturized? New data on dinosaur longevity garnered from bone microstructure (i.e. osteohistology) are making it possible to assess basic life-history parameters of the dinosaurs such as growth rates and timing of developmental events. Analyses of these data in an evolutionary context are enabling the identification of developmental patterns that lead to size changes within the Dinosauria. Furthermore, this rich new database is providing inroads for studying individual and population biology. All in all, paleohistological research is proving to be the most promising avenue towards gaining a comprehensive understanding of dinosaur biology.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100, USA.
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Erickson GM, Kristopher Lappin A, Larson P. Androgynous rex – The utility of chevrons for determining the sex of crocodilians and non-avian dinosaurs. ZOOLOGY 2005; 108:277-86. [PMID: 16351976 DOI: 10.1016/j.zool.2005.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Revised: 08/17/2005] [Accepted: 08/18/2005] [Indexed: 10/25/2022]
Abstract
The sex of non-avian dinosaurs has been inferred on numerous occasions using a variety of anatomical criteria, but the efficacy of none has been proven. Nearly 50 years ago Romer suggested that the cranial-most or first chevron in the tails of some reptiles, including crocodilians, is sexually dimorphic. Recent work on this subject purportedly substantiated that the female first chevron articulates in a more caudal position than in males. Furthermore, it was concluded that this element is shorter in females. These phenotypic attributes theoretically provide a broader cloacal passageway for eggs by ovipositing females and a greater attachment area for male "penile retractor muscles". Because theropod dinosaurs such as Tyrannosaurus rex presumably show similar variation in chevron anatomy, the same criteria has been advocated for sexing dinosaurs. We tested the neontological model for the chevron sexual dimorphism hypothesis using a skeletonized growth series of American alligators (Alligator mississippiensis) of known sex. No statistical support for the hypothesis was found. Furthermore, analysis of a diversity of crocodilian taxa from museum collections revealed similar findings suggesting the alligator results are not taxon specific. Study of well-preserved tyrannosaurid dinosaurs in museum collections showed nearly invariant chevron positioning like that seen in crocodilians. This suggests the usefulness of chevron anatomy for sexing dinosaurs is tenuous.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100 USA.
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Erickson GM. Assessing dinosaur growth patterns: a microscopic revolution. Trends Ecol Evol 2005; 20:677-84. [PMID: 16701457 DOI: 10.1016/j.tree.2005.08.012] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 07/27/2005] [Accepted: 08/18/2005] [Indexed: 10/25/2022]
Abstract
Some of the longest standing questions in dinosaur paleontology pertain to their development. Did dinosaurs grow at slow rates similar to extant reptiles or rapidly similar to living birds and mammals? How did some forms attain gigantic proportions? Conversely, how did birds (avian dinosaurs) become miniaturized? New data on dinosaur longevity garnered from bone microstructure (i.e. osteohistology) are making it possible to assess basic life-history parameters of the dinosaurs such as growth rates and timing of developmental events. Analyses of these data in an evolutionary context are enabling the identification of developmental patterns that lead to size changes within the Dinosauria. Furthermore, this rich new database is providing inroads for studying individual and population biology. All in all, paleohistological research is proving to be the most promising avenue towards gaining a comprehensive understanding of dinosaur biology.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100, USA.
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Clarke JA, Tambussi CP, Noriega JI, Erickson GM, Ketcham RA. Definitive fossil evidence for the extant avian radiation in the Cretaceous. Nature 2005; 433:305-8. [PMID: 15662422 DOI: 10.1038/nature03150] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Accepted: 10/19/2004] [Indexed: 11/09/2022]
Abstract
Long-standing controversy surrounds the question of whether living bird lineages emerged after non-avian dinosaur extinction at the Cretaceous/Tertiary (K/T) boundary or whether these lineages coexisted with other dinosaurs and passed through this mass extinction event. Inferences from biogeography and molecular sequence data (but see ref. 10) project major avian lineages deep into the Cretaceous period, implying their 'mass survival' at the K/T boundary. By contrast, it has been argued that the fossil record refutes this hypothesis, placing a 'big bang' of avian radiation only after the end of the Cretaceous. However, other fossil data--fragmentary bones referred to extant bird lineages--have been considered inconclusive. These data have never been subjected to phylogenetic analysis. Here we identify a rare, partial skeleton from the Maastrichtian of Antarctica as the first Cretaceous fossil definitively placed within the extant bird radiation. Several phylogenetic analyses supported by independent histological data indicate that a new species, Vegavis iaai, is a part of Anseriformes (waterfowl) and is most closely related to Anatidae, which includes true ducks. A minimum of five divergences within Aves before the K/T boundary are inferred from the placement of Vegavis; at least duck, chicken and ratite bird relatives were coextant with non-avian dinosaurs.
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Affiliation(s)
- Julia A Clarke
- Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Campus Box 8208, Raleigh, North Carolina 27695, USA.
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Erickson GM, Makovicky PJ, Currie PJ, Norell MA, Yerby SA, Brochu CA. Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature 2004; 430:772-5. [PMID: 15306807 DOI: 10.1038/nature02699] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Accepted: 05/26/2004] [Indexed: 11/08/2022]
Abstract
How evolutionary changes in body size are brought about by variance in developmental timing and/or growth rates (also known as heterochrony) is a topic of considerable interest in evolutionary biology. In particular, extreme size change leading to gigantism occurred within the dinosaurs on multiple occasions. Whether this change was brought about by accelerated growth, delayed maturity or a combination of both processes is unknown. A better understanding of relationships between non-avian dinosaur groups and the newfound capacity to reconstruct their growth curves make it possible to address these questions quantitatively. Here we study growth patterns within the Tyrannosauridae, the best known group of large carnivorous dinosaurs, and determine the developmental means by which Tyrannosaurus rex, weighing 5,000 kg and more, grew to be one of the most enormous terrestrial carnivorous animals ever. T. rex had a maximal growth rate of 2.1 kg d(-1), reached skeletal maturity in two decades and lived for up to 28 years. T. rex's great stature was primarily attained by accelerating growth rates beyond that of its closest relatives.
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Affiliation(s)
- Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-1100, USA.
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Abstract
The biomechanical performance of long bones is dictated by four key factors: element size, element shape, loading conditions, and material properties. Our understanding of the latter of these has been mostly limited to eutherian mammals and birds, which show similarity. Whether their possession of comparable material properties reflects common ancestry or independent evolution is uncertain. In the present analysis, we tested the bending strength, modulus, and failure strains of the femur and its pterygiophore homolog in actinpterygian fish. Sixty-nine specimens representing basal character states in seven major vertebrate crown clades were tested. These data were then coupled with avian and mammalian data from the literature and analyzed in an evolutionary context using phylogenetic character analysis. Mean values of 188 MPa for yield strength, 22.4 GPa for Young's modulus, and 8,437 mu epsilon for yield strain were obtained for the long bones. Analysis of variance (ANOVA) revealed comparable values between clades that span a 30,000-fold range of body mass. We conclude that material properties of the first long bones 475 million years ago were conserved throughout evolution. Major locomotory challenges to femora during vertebrate evolution were almost solely accomplished by modifications of element size and shape.
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Affiliation(s)
- Gregory M Erickson
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA, USA.
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Abstract
Did dinosaurs grow in a manner similar to extant reptiles, mammals or birds, or were they unique? Are rapid avian growth rates an innovation unique to birds, or were they inherited from dinosaurian precursors? We quantified growth rates for a group of dinosaurs spanning the phylogenetic and size diversity for the clade and used regression analysis to characterize the results. Here we show that dinosaurs exhibited sigmoidal growth curves similar to those of other vertebrates, but had unique growth rates with respect to body mass. All dinosaurs grew at accelerated rates relative to the primitive condition seen in extant reptiles. Small dinosaurs grew at moderately rapid rates, similar to those of marsupials, but large species attained rates comparable to those of eutherian mammals and precocial birds. Growth in giant sauropods was similar to that of whales of comparable size. Non-avian dinosaurs did not attain rates like those of altricial birds. Avian growth rates were attained in a stepwise fashion after birds diverged from theropod ancestors in the Jurassic period.
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Affiliation(s)
- G M Erickson
- Department of Biological Science and College of Medicine, Florida State University, Tallahassee, Florida 32306-1100, USA.
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Abstract
Sesamoid bones form within tendons in regions that wrap around bony prominences. They are common in humans but variable in number. Sesamoid development is mediated epigenetically by local mechanical forces associated with skeletal geometry, posture, and muscular activity. In this article we review the literature on sesamoids and explore the question of genetic control of sesamoid development. Examination of radiographs of 112 people demonstrated that the relatively infrequent appearances of the fabella (in the lateral gastrocnemius tendon of the knee) and os peroneum (in the peroneus longus tendon of the foot) are related within individuals (P < 0.01). This finding suggests that the tendency to form sesamoids may be linked to intrinsic genetic factors. Evolutionary character analyses suggest that the formation of these sesamoids in humans may be a consequence of phylogeny. These observations indicate that variations of intrinsic factors may interact with extrinsic mechanobiological factors to influence sesamoid development and evolution.
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Affiliation(s)
- V K Sarin
- Department of Mechanical Engineering at Stanford University, USA.
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Erickson GM. Incremental lines of von Ebner in dinosaurs and the assessment of tooth replacement rates using growth line counts. Proc Natl Acad Sci U S A 1996; 93:14623-7. [PMID: 8962103 PMCID: PMC26184 DOI: 10.1073/pnas.93.25.14623] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/1996] [Accepted: 10/08/1996] [Indexed: 02/03/2023] Open
Abstract
Dinosaur dentine exhibits growth lines that are tens of micrometers in width. These laminations are homologous to incremental lines of von Ebner found in extant mammal and crocodilian teeth (i.e., those of amniotes). The lines likely reflect daily dentine formation, and they were used to infer tooth development and replacement rates. In general, dinosaur tooth formation rates negatively correlated with tooth size. Theropod tooth replacement rates negatively correlated with tooth size, which was due to limitations in the dentine formation rates of their odontoblasts. Derived ceratopsian and hadrosaurian dinosaurs retained relatively rapid tooth replacement rates through ontogeny. The evolution of dental batteries in hadrosaurs and ceratopsians can be explained by dentine formation constraints and rapid tooth wear. In combination with counts of shed dinosaur teeth, tooth replacement rate data can be used to assess population demographics of Mesozoic ecosystems. Finally, it is of historic importance to note that Richard Owen appears to have been the first to observe incremental lines of von Ebner in dinosaurs more than 150 years ago.
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Affiliation(s)
- G M Erickson
- Department of Integrative Biology, University of California, Berkeley 94720-3140, USA
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