Cranial anatomy, intraspecific variation, and positional variation within Calyptosuchus wellesi (Pseudosuchia: Aetosauria) based on new specimens from the Upper Triassic Chinle Formation (Adamanian, early middle-Norian) of Petrified Forest National Park, Arizona, USA

Calyptosuchus wellesi is an aetosaur known from the upper Blue Mesa Member and lowermost Sonsela Member of the Chinle Formation in Arizona, and the Tecovas Formation of the Dockum Group, Texas. The taxon is considered biostratigraphically informative and aids in correlating Upper Triassic strata across the southwestern United States. Our anatomical understanding of Calyptosuchus was primarily based on the holotype specimen from Texas and referred specimens, including several disarticulated elements from the Placerias Quarry in northern Arizona. We provide a re-interpretation of the holotype specimen and describe two new specimens referrable to Calyptosuchus from northern Arizona. Together these specimens provide new information on the cranial anatomy, including dentition, and the positional and intraspecific variation within the carapace and vertebral column, respectively, of the taxon. This new evidence suggests that the skull anatomy of Calyptosuchus is more similar to that of Neoaeto..., Supplemental 1: Character descriptions, updated character scorings, notes on phylogenetic analyses, and supplemental figures.
Supplemental 2: TXT file of master character matrix.
Supplemental 3: TXT script for Bayesian phylogenetic analyses.
Supplemental 4: TNT file for parsimony analyses. Same as master character matrix. Omit OTU's respectively for RUN 1 and RUN 2. 
Supplemental 5: NEX file for Bayesian analysis RUN 1. All specimens of Calyptosuchus are coded as seperate OTU's. 
Supplemental 6: NEX file for Bayesian analysis RUN 2. All specimens of Calyptosuchus are coded into a combined OTU., , # Cranial anatomy, intraspecific variation, and positional variation within Calyptosuchus wellesi (Pseudosuchia: Aetosauria) based on new specimens from the Upper Triassic Chinle Formation (Adamanian, early middle-Norian) of Petrified Forest National Park, Arizona, USA.

[Access this dataset on Dryad](https://doi.org/10.5061/dryad.w0vt4b91s)

The supplementary data includes .tnt, .txt, and .nex files required to replicate the phylogenetic analyses presented in this study. Also included is a .docx word file with the modified character list, modified scorings, and unpublished supplementary figures. All data files can be viewed in a standard text editor except for the .docx which requires Microsoft Word. 

## Description of the data and file structure

1. The Character list.docx contains the modified character list, modified scorings, and unpublished supplemental figures and tables.
2. The Master_matrix.txt contains the master character matrix from which the parsimony and Bayesian matrices...