Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia)
Abstract Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in t...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-02-01
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| Series: | Swiss Journal of Palaeontology |
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| Online Access: | https://doi.org/10.1186/s13358-024-00304-x |
| _version_ | 1797273412492591104 |
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| author | Kinga Gere András Lajos Nagy Torsten M. Scheyer Ingmar Werneburg Attila Ősi |
| author_facet | Kinga Gere András Lajos Nagy Torsten M. Scheyer Ingmar Werneburg Attila Ősi |
| author_sort | Kinga Gere |
| collection | DOAJ |
| description | Abstract Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards. |
| first_indexed | 2024-03-07T14:43:02Z |
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| institution | Directory Open Access Journal |
| issn | 1664-2376 1664-2384 |
| language | English |
| last_indexed | 2024-03-07T14:43:02Z |
| publishDate | 2024-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Swiss Journal of Palaeontology |
| spelling | doaj.art-bf161751d48d4588a69548330567cdff2024-03-05T20:09:19ZengSpringerOpenSwiss Journal of Palaeontology1664-23761664-23842024-02-01143111810.1186/s13358-024-00304-xComplex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia)Kinga Gere0András Lajos Nagy1Torsten M. Scheyer2Ingmar Werneburg3Attila Ősi4Institute of Geography and Earth Sciences, Department of Paleontology, ELTE Eötvös Loránd UniversityDepartment of Propulsion Technology, Széchenyi István UniversityUniversität Zürich, Paläontologisches InstitutSenckenberg Centre for Human Evolution and Palaeoenvironment, Universität TübingenInstitute of Geography and Earth Sciences, Department of Paleontology, ELTE Eötvös Loránd UniversityAbstract Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards.https://doi.org/10.1186/s13358-024-00304-xPlacodontiaTooth wear analysisDurophagyMarine reptile |
| spellingShingle | Kinga Gere András Lajos Nagy Torsten M. Scheyer Ingmar Werneburg Attila Ősi Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) Swiss Journal of Palaeontology Placodontia Tooth wear analysis Durophagy Marine reptile |
| title | Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) |
| title_full | Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) |
| title_fullStr | Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) |
| title_full_unstemmed | Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) |
| title_short | Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia) |
| title_sort | complex dental wear analysis reveals dietary shift in triassic placodonts sauropsida sauropterygia |
| topic | Placodontia Tooth wear analysis Durophagy Marine reptile |
| url | https://doi.org/10.1186/s13358-024-00304-x |
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