1
|
Ősi A, Barrett PM, Nagy AL, Szenti I, Vásárhelyi L, Magyar J, Segesdi M, Csiki-Sava Z, Botfalvai G, Jó V. Trophic evolution in ornithopod dinosaurs revealed by dental wear. Nat Commun 2024; 15:7330. [PMID: 39187477 PMCID: PMC11347701 DOI: 10.1038/s41467-024-51697-9] [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: 05/10/2024] [Accepted: 08/15/2024] [Indexed: 08/28/2024] Open
Abstract
Ornithopod dinosaurs evolved numerous craniodental innovations related to herbivory. Nonetheless, the relationship between occlusion, tooth wear rate, and tooth replacement rate has been neglected. Here, we reconstruct tooth wear rates by measuring tooth replacement rates and tooth wear volumes, and document their dental microwear. We demonstrate that total tooth volume and rates of tooth wear increased steadily during ornithopod evolution, with deeply-nested taxa wearing up to 3360 mm3 of tooth volume/day. Increased wear resulted in asymmetric tooth crown formation with uneven von Ebner line increment width by the Late Jurassic, and in faster tooth replacement rates in multiple lineages by the mid-Cretaceous. Microwear displays a contrasting pattern, with decreasing complexity and pit percentages in deeply-nested and later-occurring taxa. We hypothesize that early ornithopods were browsers and/or frugivores but deeply nested iguanodontians were bulk-feeders, eating tougher, less nutritious plants; these trends correlate with increasing body mass and longer gut passage times.
Collapse
Affiliation(s)
- Attila Ősi
- ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary.
- Hungarian Natural History Museum, Baross u. 13, Budapest, 1088, Hungary.
| | - Paul M Barrett
- Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom
| | - András Lajos Nagy
- Department of Propulsion Technology, Széchenyi István University, Egyetem tér 1, 9026, Győr, Hungary
| | - Imre Szenti
- University of Szeged, Interdisciplinary Centre of Excellence, Department of Applied and Environmental Chemistry, Rerrich Béla tér 1., 6720, Szeged, Hungary
| | - Lívia Vásárhelyi
- University of Szeged, Interdisciplinary Centre of Excellence, Department of Applied and Environmental Chemistry, Rerrich Béla tér 1., 6720, Szeged, Hungary
| | - János Magyar
- ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Hungarian Natural History Museum, Baross u. 13, Budapest, 1088, Hungary
| | - Martin Segesdi
- ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Hungarian Natural History Museum, Baross u. 13, Budapest, 1088, Hungary
| | - Zoltán Csiki-Sava
- Faculty of Geology and Geophysics, University of Bucharest, 1 Nicolae Bălcescu Avenue, 010041, Bucharest, Romania
| | - Gábor Botfalvai
- ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Palaeontology, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- HUN-REN-MTM-ELTE Research Group for Paleontology, Pázmány Péter sétány 1/C, Budapest, H-1117, Hungary
| | - Viviána Jó
- ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Physical Geography, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
| |
Collapse
|
2
|
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: 4] [Impact Index Per Article: 2.0] [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.
Collapse
|
3
|
Maho T, Maho S, Scott D, Reisz RR. Permian hypercarnivore suggests dental complexity among early amniotes. Nat Commun 2022; 13:4882. [PMID: 35986022 PMCID: PMC9391490 DOI: 10.1038/s41467-022-32621-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/09/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractThe oldest known complex terrestrial vertebrate community included hypercarnivorous varanopids, a successful clade of amniotes with wide geographic and temporal distributions. Little is known about their dentition and feeding behaviour, but with the unprecedented number of specimens of the varanopid Mesenosaurus from cave deposits in Oklahoma, we show that it exhibited serrations on the tooth crowns, and exceptionally rapid rates of development and reduced longevity relative to other terrestrial amniotes. In contrast, the coeval large apex predator Dimetrodon greatly increased dental longevity by increasing thickness and massiveness, whereas herbivores greatly reduced tooth replacement rates and increased dental longevity. Insectivores and omnivores represented the primitive condition and maintained modest replacement rates and longevity. The varied patterns of dental development among these early terrestrial amniotes reveal a hidden aspect of dental complexity in the emerging diverse amniote community, very soon after their initial appearance in the fossil record.
Collapse
|
4
|
Abstract
In amniotes, daily rates of dentine formation in non-ever-growing teeth range from less than 1 to over 25 μm per day. The latter value has been suggested to represent the upper limit of odontoblast activity in non-ever-growing teeth, a hypothesis supported by the lack of scaling between dentine apposition rates and body mass in Dinosauria. To determine the correlates and potential controls of dentine apposition rate, we assembled a dataset of apposition rates, metabolic rates and body masses for ca 80 amniote taxa of diverse ecologies and diets. We used phylogenetic regression to test for scaling relationships and reconstruct ancestral states of daily dentine apposition across Amniota. We find no relationship between body mass and daily dentine apposition rate (DDAR) for non-ever-growing teeth in Amniota as a whole or within major clades. Metabolic rate, the number of tooth generations, diet and habitat also do not predict or correspond with DDARs. Similar DDARs are found in large terrestrial mammals, dinosaurs and marine reptiles, whereas primates, cetaceans and some smaller marine reptiles independently evolved exceptionally slow rates. Life-history factors may explain the evolution of dentine apposition rates, which evolved rapidly at the origin of major clades.
Collapse
Affiliation(s)
- Stephen P. Finch
- Department of Biology, Adelphi University, Garden City, NY 11530, USA
| | - Michael D. D'Emic
- Department of Biology, Adelphi University, Garden City, NY 11530, USA
| |
Collapse
|