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Li Z, Wang CC, Wang M, Chiang CC, Wang Y, Zheng X, Huang EW, Hsiao K, Zhou Z. Ultramicrostructural reductions in teeth: implications for dietary transition from non-avian dinosaurs to birds. BMC Evol Biol 2020; 20:46. [PMID: 32316913 PMCID: PMC7171806 DOI: 10.1186/s12862-020-01611-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 04/06/2020] [Indexed: 12/31/2022] Open
Abstract
Background Tooth morphology within theropod dinosaurs has been extensively investigated and shows high disparity throughout the Cretaceous. Changes or diversification in feeding ecology, i.e., adoption of an herbivorous diet (e.g., granivorous), is proposed as a major driver of tooth evolution in Paraves (e.g., Microraptor, troodontids and avialans). Here, we studied the microscopic features of paravian non-avian theropod and avialan teeth using high-spatial-resolution synchrotron transmission X-ray microscopy and scanning electron microscopy. Results We show that avialan teeth are characterized by the presence of simple enamel structures and a lack of porous mantle dentin between the enamel and orthodentin. Reduced internal structures of teeth took place independently in Early Cretaceous birds and a Microraptor specimen, implying that shifts in diet in avialans from that of closely related dinosaurs may correlate with a shift in feeding ecology during the transition from non-avian dinosaurs to birds. Conclusion Different lines of evidence all suggest a large reduction in biting force affecting the evolution of teeth in the dinosaur-bird transition. Changes in teeth microstructure and associated dietary shift may have contributed to the early evolutionary success of stemward birds in the shadow of other non-avian theropods.
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Affiliation(s)
- Zhiheng Li
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xizhimenwai Street, Beijing, 100044, China. .,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China.
| | - Chun-Chieh Wang
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan.
| | - Min Wang
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xizhimenwai Street, Beijing, 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China
| | | | - Yan Wang
- Institute of Geology and Paleontology, Linyi University, Linyi, 276000, Shandong, China
| | - Xiaoting Zheng
- Tianyu Natural History Museum of Shandong, Pingyi, 273300, Shandong, China
| | - E-Wen Huang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Kiko Hsiao
- Mr. Fossil Institute, New Taipei City, 23673, Taiwan
| | - Zhonghe Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xizhimenwai Street, Beijing, 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China
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Pate ML, Aguilar-Caballos MP, Beltrán-Aroca CM, Pérez-Vicente C, Lozano-Molina M, Girela-López E. Use of XRD and SEM/EDX to predict age and sex from fire-affected dental remains. Forensic Sci Med Pathol 2018; 14:432-441. [PMID: 30229429 DOI: 10.1007/s12024-018-0028-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2018] [Indexed: 11/24/2022]
Abstract
In fire scenarios, the application and accuracy of traditional odontological methods are often limited. Crystalline studies and elemental profiling have been evaluated for their applicability in determining biological profiles (age and sex) from human dentition, particularly fire- and heat-affected dental remains. Thirty-seven teeth were paired according to tooth type and donor age/sex for the analysis of crown and root surfaces pre- and post-incineration using X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDX). In unburned crowns, carbon (C) content showed a positive correlation with age, whereas phosphorus (P) and calcium (Ca) contents showed a negative correlation with age. In unburned roots, C, P and Ca contents also showed significant changes that were opposite of those observed in the crowns. In relation to sex, females exhibited a higher C ratio than males, whereas males showed significantly higher levels of oxygen (O), P and Ca in unburned roots. Incineration resulted in an increase in the crystallite size that correlated with increasing temperature. No differences in hydroxyapatite (HA) crystallite size were found between age groups; however, unburned teeth from females exhibited a larger crystallite size than did those from males. The challenges of using XRD with a 3D sample were overcome to allow analysis of whole teeth in a nondestructive manner. Further studies may be useful in helping predict the temperature of a fire.
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Affiliation(s)
- Megan L Pate
- Sección de Medicina Legal y Forense. Facultad de Medicina y Enfermería, Universidad de Córdoba, Avda Menéndez Pidal s/n., 14004, Córdoba, Spain
| | - María-Paz Aguilar-Caballos
- Departamento de Química Analítica, Instituto Universitario de Química Fina y Nanoquímica, Campus Universitario de Rabanales, Universidad de Córdoba, 14014, Córdoba, Spain
| | - Cristina M Beltrán-Aroca
- Sección de Medicina Legal y Forense. Facultad de Medicina y Enfermería, Universidad de Córdoba, Avda Menéndez Pidal s/n., 14004, Córdoba, Spain
| | - Carlos Pérez-Vicente
- Laboratorio de Química Inorgánica, Instituto Universitario de Química Fina y Nanoquímica, Campus Universitario de Rabanales, Universidad de Córdoba, 14006, Córdoba, Spain
| | | | - Eloy Girela-López
- Sección de Medicina Legal y Forense. Facultad de Medicina y Enfermería, Universidad de Córdoba, Avda Menéndez Pidal s/n., 14004, Córdoba, Spain.
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