Acquisition of and quality assessment in a dataset for dental microwear texture analysis (DMTA) of sauropod teeth
This article has been Reviewed by the following groups
Discuss this preprint
Start a discussion What are Sciety discussions?Listed in
- Evaluated articles (Peer Community in Paleontology)
Abstract
Dental microwear texture analysis (DMTA) has been widely used in the study of dietary habits and trends of animals, based on the abrasion patterns preserved in dental enamel. Therefore, it is seen as an important tool when it comes to understanding the ecology, niche partitioning, and competition between co-occurring taxa, both extant and extinct. During the Late Jurassic, sauropod dinosaur faunas were quite diverse, with distinct groups inhabiting the same ecosystems. Being the largest mega-herbivores of their ecosystems, competition for resources could have been a determining factor that led to such diversity, making sauropods a good study-group for DMTA. Here we describe the complete process of creating a large DMTA dataset of 119 teeth attributed to most major sauropod groups from the Late Jurassic. We describe in detail the production of dental molds, casts, and the steps taken throughout the measuring process of the three-dimensional surface textures.We also describe the way in which we tested the quality of our data, as well as the taphonomical implications for future studies using the resulting dataset. Not only did our tests confirm the lack of a taphonomic impact on the acquired data but also the comparability of measurements obtained from both molds and original teeth. The end result is the first large DMTA sauropod teeth dataset, consisting of 971 measurements.
Article activity feed
-
Dental microwear is a powerful tool for inferring diet, jaw function, behavior, and environment, among other things, in extinct organisms (e.g., Mallon and Anderson, 2014; Calandra and Merceron, 2016). During the past decades, researchers have developed a variety of analytical techniques, while also highlighting potential pitfalls relative to data collection and interpretation (e.g., Schmidt and Ungar, 2023). Additionally, standards of data reporting and archival have evolved substantially, facilitated by the rise of new methods and online data repositories.
Although the study of dental microwear was largely developed in extant mammals and their close extinct relatives, dental microwear plays an increasingly large role in reconstructing the paleoecology and functional morphology of non-avian dinosaurs. Late Jurassic-aged terrestrial …
Dental microwear is a powerful tool for inferring diet, jaw function, behavior, and environment, among other things, in extinct organisms (e.g., Mallon and Anderson, 2014; Calandra and Merceron, 2016). During the past decades, researchers have developed a variety of analytical techniques, while also highlighting potential pitfalls relative to data collection and interpretation (e.g., Schmidt and Ungar, 2023). Additionally, standards of data reporting and archival have evolved substantially, facilitated by the rise of new methods and online data repositories.
Although the study of dental microwear was largely developed in extant mammals and their close extinct relatives, dental microwear plays an increasingly large role in reconstructing the paleoecology and functional morphology of non-avian dinosaurs. Late Jurassic-aged terrestrial ecosystems, dominated by the gigantic long-necked sauropod dinosaurs, are a particularly interesting target for studies of dental microwear (e.g., Calvo, 1994; Fiorillo, 1998; Whitlock, 2011; Winkler et al., 2025). What did these multi-ton herbivores eat, and how did multiple species co-exist? Dental microwear can help investigate these questions for the Late Jurassic and across the Mesozoic.
Analysis of dental microwear is a multi-part process, including cleaning the surface of the tooth, generating a mold, and creating an epoxy cast, before collecting data on the types of wear, their locations, and abundance. Multiple methodological steps create multiple opportunities for variation and error in data collection, on top of biological and taphonomic variation (e.g., King et al., 1999; Böhm et al., 2019). Thus, it is important to document methods and data in detail. The current study by Saleiro et al. (2025) does precisely this for a sample of Jurassic sauropods.
Notably, the authors developed a relatively large sample (119 teeth) encompassing roughly contemporaneous sauropods in the Upper Jurassic deposits of North America, Africa, and Europe, with particularly detailed documentation for the sampling protocols. Across the literature, the written detail for methods is variable for microwear sampling methods, and so this comprehensive treatment is an important contribution and landmark for future work. Furthermore, the detailed documentation and context are important supporting information for a separate study using a subset of the data (Winkler et al., 2025) and any future contributions drawing upon the data.
Saleiro and colleagues compared measurements from original teeth, molds, and casts, and found that for their sample, measurements of complexity values from original teeth and impressions of those teeth (molds) were comparable, but casts were not. Additionally, no major differences were found for teeth preserved in mudstone versus sandstone, used as a proxy for taphonomic effects. Perhaps most significantly, this study serves as a detailed record of methods and data that has been used in other broader analyses and has the potential to be reused elsewhere, which may in turn reduce the need to re-sample delicate fossil specimens.
Beyond documentation of a dataset, the reviewers of this contribution noted significant potential for additional hypothesis testing. Some of this is undertaken in a publication by Winkler et al. (2025), including most of the authors on this recommended work; additional potential for research remains both with the data here and through additional sampling. For instance, a more nuanced analysis of taphonomic effects could be possible in the future, perhaps comparing isolated teeth versus those still in the jaws (contrasting with variation by only sediment type, as studied here). Given the observed differences between molds, original teeth, and casts, and given the ubiquity of analysis of casts in microwear studies, some additional methological investigations are also potentially warranted. The poor quality of data from casts was surprising to me, and so I (alongside one of the reviewers) wondered if methodological adjustments to cast production could result in a better outcome. The sample of the same teeth with multiple surface types available for analysis was also limited (n=4) and should be expanded upon in the future. So, that particular comparison presents important food for thought but I caution drawing general conclusions from this single study.
In sum, this work by Saleiro and colleagues is an important counterpart to the other published analysis of this dataset (Winkler et al., 2025), provides documentation and openly available data for others who wish to analyze the data, and presents a case study in how different samples and sampling protocols need to be carefully considered in analysis and interpretation of microwear from fossils.
References
Böhm, K., Winkler, D. E., Kaiser, T. M., and Tütken, T. (2019). Post-mortem alteration of diet-related enamel surface textures through artificial biostratinomy: A tumbling experiment using mammal teeth. Palaeogeography, Palaeoclimatology, Palaeoecology, 518, 215–231. https://doi.org/10.1016/j.palaeo.2019.01.008
Calandra, I., and Merceron, G. (2016). Dental microwear texture analysis in mammalian ecology. Mammal Review, 46(3), 215–228. https://doi.org/10.1111/mam.12063
Calvo, J. O. (1994). Jaw mechanics in sauropod dinosaurs. Gaia: Revista de Geociencias, Museu Nacional de História Natural, University of Lisbon, 10, 183–193.
Fiorillo, A. R. (1998). Dental micro wear patterns of the sauropod dinosaurs Camarasaurus and Diplodocus: Evidence for resource partitioning in the Late Jurassic of North America. Historical Biology, 13(1), 1–16. https://doi.org/10.1080/08912969809386568
King, T., Andrews, P., and Boz, B. (1999). Effect of taphonomic processes on dental microwear. American Journal of Physical Anthropology, 108(3), 359–373. https://doi.org/10.1002/(SICI)1096-8644(199903)108:3%253C359::AID-AJPA10%253E3.0.CO;2-9
Mallon, J. C., and Anderson, J. S. (2014). The functional and palaeoecological implications of tooth morphology and wear for the megaherbivorous dinosaurs from the Dinosaur Park Formation (Upper Campanian) of Alberta, Canada. PLoS ONE, 9(6), e98605. https://doi.org/10.1371/journal.pone.0098605
Saleiro, A., Tschopp, E., Daash, A., Kaiser, T. M., Wiesinger, R., and Winkler, D. E. (2025). Acquisition of and quality assessment in a dataset for dental microwear texture analysis (DMTA) of sauropod teeth. PaleorXiv, 8uhsp, ver. 4 peer-reviewed by PCI Paleo. https://doi.org/10.31233/osf.io/8uhsp_v4
Schmidt, C. W., and Ungar, P. S. (2023). Dental microwear analysis: Wear we are going, Wear we have been. In C. S. Larsen (Ed.), A Companion to Biological Anthropology (pp. 572–586). Wiley & Sons, Ltd. https://doi.org/10.1002/9781119828075.ch34
Whitlock, J. A. (2011). Inferences of diplodocoid (Sauropoda: Dinosauria) feeding behavior from snout shape and microwear analyses. PLoS ONE, 6, e18304. https://doi.org/10.1371/journal.pone.0018304
Winkler, D. E., Tschopp, E., Saleiro, A., Wiesinger, R., and Kaiser, T. M. (2025). Dental microwear texture analysis reveals behavioural, ecological and habitat signals in Late Jurassic sauropod dinosaur faunas. Nature Ecology & Evolution, 9(9), 1719–1730. https://doi.org/10.1038/s41559-025-02794-5
-
-
-
-