DOI: 10.5061/dryad.q83bk3jqm
title: Data from: Cranial anatomy and phylogenetic affinities of Bolosaurus major, with new information on the unique bolosaurid feeding apparatus and evolution of the impedance-matching ear

description: Resolving the phylogenetic relationships of early amniotes, in particular
 stem reptiles, remains a difficult problem. Three-dimensional
 morphological analysis of well-preserved stem-reptile specimens can reveal
 important anatomical data and clarify regions of phylogeny. Here, we
 present the first thorough description of the unusual early Permian stem
 reptile Bolosaurus major, including the first comprehensive description of
 a bolosaurid braincase. We describe previously obscured details of the
 palate, allowing for insight into bolosaurid feeding mechanics. Aspects of
 the rostrum, palate, mandible, and neurocranium suggest that B. major had
 a particularly strong bite. We furthermore found B. major has a
 surprisingly slender stapes, similar to that of the middle Permian stem
 reptile Macroleter poezicus, which may suggest enhanced hearing abilities
 compared to other Paleozoic amniotes (e.g., captorhinids). We incorporated
 our new anatomical information into a large phylogenetic matrix (150 OTUs,
 590 characters) to explore the relationship of Bolosauridae among stem
 reptiles. Our analyses generally recovered a polyphyletic ‘Parareptilia,’
 and found Bolosauridae to diverge from the reptile stem after
 Captorhinidae + Araeoscelidia. We also included Bolosaurus major within a
 smaller matrix (10 OTUs, 27 characters) designed to explore the
 interrelationships of Bolosauridae and found all species of Bolosaurus to
 be monophyletic. While reptile relationships still require further
 investigation, our phylogeny suggests repeated evolution of
 impedance-matching ears in Paleozoic stem reptiles.
description: Two datasets were analyzed using phylogenetic methods (i.e.,
 parsimony and Bayesian). See publication for more specific methods,
 citation below: K.M. Jenkins, W. Foster, J.G. Napoli,
 D.L. Meyer, G.S. Bever, B-A.S. Bhullar. <em>In Review</em>.
 Cranial anatomy and phylogenetic affinities of <em>Bolosaurus
 major</em>, with new information on the unique bolosaurid feeding
 apparatus and evolution of the impedance-matching ear. <em>The
 Anatomical Record</em>. DOI: https://doi.org/10.1002/ar.25546 1) The first dataset analyzed is an original taxon-character matrix (select "Download full dataset" to view). Supplemental to this are two additional files (1) an illustrated character list ("StemReptile_Megamatrix_IllustratedCharacterList_2024"), and (2) the list of taxa scored ("Taxa_Examined_2024"). The trees produced from this dataset include parsimony ("All_Parsimony_tre_files") and Bayesian ("Bayes_150_FBD") results. The input file for the Bayesian trees is "Full_Matrix_Bayes_150.nex". 2) The second dataset is a smaller, previously published and edited dataset focused on bolosaurid taxa. The taxon character matrix for this dataset is "BoloMatrix_Falconnect_edited" and trees produced are shown within the text (Figure 16).
description: # Cranial anatomy and phylogenetic affinities of Bolosaurus major, with
 new information on the unique bolosaurid feeding apparatus and evolution
 of the impedance-matching ear
 [https://doi.org/10.5061/dryad.q83bk3jqm](https://doi.org/10.5061/dryad.q83bk3jqm) Included are supplemental files used for this work. It includes: 1. Word Document with table of all taxa included in the phylogenetic analyses and their sources. 2. Word Document with all characters used in phylogenetic analyses. Their states are fully illustrated, and sources from which characters are compiled are listed at the top of the document. 3. Mesquite File - This is an original mesquite file constructed for this work to produce a taxon-character matrix which corresponds to the Character List and Taxa List provided in 1 & 2 (i.e., "StemReptile_MegaMatrix_Mesquite_2024_April"). This matrix was analyzed in both parismony and Bayesian frameworks. See publication for more detailed phylogenetic methods. 4. A folder of all tree Files (.tre) for all parsimony analyses produced from the larger taxon-character matrix provided in 3. This includes Equal Weights and Implied Weights (k=3,6,12,24) trees. Of note, these files include all trees produced from those analyses (not just the consensus tree). The last tree in each .tre file is the consensus tree. 5. A nexus file (input file) for the Bayesian analysis. This was made using the matrix in 3. 6. A folder of all output files for the Bayesian analysis, including the maximum compatibility tree. 7. Mesquite File edited from Falconnet (2012). All trees produced from this matrix are shown in text (Figure 16). Please click on the additional links to access all these files. ## Sharing/Access information Additional CT scan information is available on Morphosource.org.