Morphometric data for Mesodma species discrimination

Multituberculates remain one of the more poorly understood mammalian clades. The North American multituberculate record is comprised mostly of isolated teeth and incomplete jaws leading to interpretations of relationships based on limited anatomy. Despite the fragmentary record, the p4 of cimolodontan multituberculates is both common and a source of diagnostic characters in systematic studies. The results of a recent morphometric study on the neoplagiaulacid Mesodma suggest that p4 size may be more useful than shape in diagnosing the various species referred to this genus. We tested this hypothesis by applying two different morphometric methods (2D geometric morphometrics and linear measurements) to two samples – (1) one including the p4s of four known species (M. ambigua, M. thompsoni, M. formosa, and M. pygmaea), and (2) a sample of unidentified p4s of Mesodma from the Bug Creek Anthills locality of Northeastern Montana. Our results indicate that while form explains most of the morpho..., 2D GMM: To capture the relevant morphology of the p4, digital landmarks were placed at the anterior-most and posterior-most projections of the serrate crest (TL1 and TL2 respectively). TL1 was positioned at the point of maximum curvature at the anterior margin of the crown. TL2 was placed at the posteriormost part of the crown-root junction at the posterior root. After TL1 and TL2 were located, a curve was traced in TPSDig (version 2.31; Rohlf 2013a) along the apical portion of the crown to join the two landmarks. Eighteen semilandmarks were then resampled from the curve with 19 helper points (HP) placed between semilandmarks to assist in later standardization. We resampled all landmarks to be equally spaced using TPSUtil (version 1.78; Rohlf 2013b). Landmark configurations were then prepared for 2D GMM analyses.
Linear Measurements: Standard linear measurements taken in millimeters were collected for specimens in both the known species data set (KDS) and the Bug Creek Anthill data set..., , # Morphometric data for *Mesodma* species discrimination

We use the following data sets, code, and supplemental information to run all of our morphometric analyses in our study including the following:

* Procrustes analysis
* Principal component analysis
* Linear discriminant analysis
* Canonical Variate analysis
* MANOVA + Pairwise comparisons
* Figure generation using GGplot2
* Both Appendix 1 and 2

## Methods for the files used

2D GMM: To capture the relevant morphology of the p4, digital landmarks were placed at the anterior-most and posterior-most projections of the serrate crest (TL1 and TL2 respectively). TL1 was positioned at the point of maximum curvature at the anterior margin of the crown. TL2 was placed at the posteriormost part of the crown-root junction at the posterior root. After TL1 and TL2 were located, a curve was traced in TPSDig (version 2.31; Rohlf 2013a) along the apical portion of the crown to join the two landmarks. Eighteen semilandmarks wer...