Data from: The dentary of hadrosauroid dinosaurs: evolution through heterochrony
Data files
Sep 25, 2023 version files 371.04 KB
Abstract
The near-global success reached by hadrosaurid dinosaurs during the Cretaceous has been attributed to mastication, a behaviour commonly recognized as a mammalian adaptation. Its occurrence in a non-mammalian lineage should be accompanied by the evolution of several morphological modifications associated with food acquisition and processing. This study investigated morphological variation in the dentary, a major element of the hadrosauroid lower jaw. Eighty-four hadrosauroid dentaries were subjected to geometric morphometric and statistical analyses to investigate their taxonomic, ontogenetic, and individual variation. Results suggest increased food acquisition and processing efficiency in saurolophids through a complex pattern of evolutionary and growth-related changes. The edentulous region grew longer relative to dentary length, allowing for food acquisition specialization anteriorly and processing posteriorly, and became ventrally directed, possibly associated with foraging low-growing vegetation, especially in younger individuals. The saurolophid coronoid process became anteriorly directed and relatively more elongate, with an expanded apex, increasing moment arm length, with muscles pulling the jaw more posteriorly, increasing mechanical advantage. During growth, all hadrosauroids underwent anteroposterior dental battery elongation by the addition of teeth, and edentulous region ventralization decreased. The dental battery became deeper in saurolophids by increasing the number of teeth per tooth family. The increased coronoid process anterior inclination and relative edentulous region elongation in saurolophids are hypothesized to have evolved through hypermorphosis and/or acceleration, peramorphic heterochronic processes, and the anteroposteriorly shorter but dorsoventrally taller saurolophid dentary, likely emerged due to post-displacement in dental battery elongation and edentulous region decreased ventral orientation, a paedomorphic heterochronic process.
README: Data from: The dentary of hadrosauroid dinosaurs: evolution through heterochrony
The complementary dataset on hadrosauroid dinosaur dentaries, is stored on Zenodo, as well as with the publication "The dentary of hadrosauroid dinosaurs: evolution through heterochrony" supporting information, as a tab-delimited .txt file (Appendix S1). The dataset contains information such as specimen number, data source, page number, figure number, taxonomic, temporal, ontogenetic (growth stage), geographic and stratigraphic affinity (information on references used in the dataset is also found in the supporting information for the aforementioned publication). The dataset is utilized in analyzing hadrosauroid dentary morphology, using two-dimensional geometric morphometrics.
Description of the data and file structure
SOEDERBLOM_et_al_Data
|- SOEDERBLOM_et_al_Appendix_S1.txt (stored at the Zenodo archive)
|- SOEDERBLOM_et_al_TPS_file_Hadrosauroid_Dentary.TPS
|- SOEDERBLOM_et_al_Sliders_file_Hadrosauroid_Dentary.txt
|- SOEDERBLOM_et_al_Script_Hadrosauroid_Dentary_REVISED.R (stored at the Zenodo archive)
The dataset ("SOEDERBLOM_et_al_Appendix_S1.txt"), along with a .TPS file ("SOEDERBLOM_et_al_TPS_file_Hadrosauroid_Dentary.TPS") compiled in the program tpsUtil (Rohlf 2017a) and digitized in the program tpsDIG2 (Rohlf 2017b) containing the landmark X and Y coordinates of aforementioned digitized images of hadrosauroid dentary specimens as well as an accompanying sliders file ("SOEDERBLOM_et_al_Sliders_file_Hadrosauroid_Dentary.txt") generated from the .TPS file in tpsUtil (Rohlf 2017a), are used in the statistical computing program R (R CORE TEAM 2013).
Sharing/Access information
Links to other publicly accessible locations of the data:
- The dataset and dataset references will be accessible as supporting information (appendices) along with the accompanying published study.
Data was derived from the following sources:
- The data was derived from photographs and accompanying information obtained/provided by Dr. Albert Prieto-Márquez from multiple different natural history collections visits, as well as from published literature (see Appendix S2 for dataset references, and the column "Source" in the dataset Appendix S1. Both are uploaded as supporting information with the study at the publisher, and Appendix S1 is additionally uploaded to Zenodo).
Code/Software
In R (R CORE TEAM 2013) version 4.1.3, the script file ("SOEDERBLOM_et_al_Script_Hadrosauroid_Dentary_REVISED.R", uploaded to Zenodo) is used to run all analyses, which rely on the package geomorph (Adams & Otárola-Castillo 2013) version 3.2.1.
By following the script from up to down, including importing the aforementioned dataset, the .TPS file and sliders file (changing the file path or name of the file in the script when appropriate) when the script states so, and running the analyses in the script, data used in the study, and more, can be used to generate tables, figures and statistics. The exception is the quantile-quantile (Q-Q) plot which supports the use of parametric tests. This plot has to be generated externally, using for example the program Excel, using the data file output by the code in the R script to the work directory.
References
ADAMS, D. C. and OTÁROLA-CASTILLO, E. 2013. Geomorph: an R package for the collection and analysis of geometric morphometric shape data. Methods in Ecology and Evolution, 4, 393–399.
R CORE TEAM 2013. R: a language and environment for statistical computing. R Foundation for Statistical Computing. http://www.R-project.org
ROHLF, F. J. 2017a. TpsUtil. New York. http://life.bio.sunysb.edu/morph/
ROHLF, F. J. 2017b. TpsDIG2. New York. http://life.bio.sunysb.edu/morph/
Methods
The dataset was collected from the literature (see the publication's online Supporting Information for a dataset reference list) and digital libraries of Dr. Albert Prieto-Márquez. Information pertaining to hadrosauroid dinosaur dentary specimens was written into the dataset using Excel. Images of specimens were made into a .TPS file in tpsUtil, and then digitized with equidistant semilandmark curves in tpsDIG2. The sliders file was created in tpsUtil. The .TPS file and sliders file were then transferred into the program R, and used together with the dataset (see the file "SOEDERBLOM_et_al_Appendix_S1.txt" in Zenodo or the publication's online Supporting Information), to analyze the digitized data, using the R script.
Usage notes
A text editor (e.g. Notepad [optional]), Excel, tpsUtil, tpsDIG2, and R are required to view and/or use the data files.