Braincase and digital endocast of a loricatan pseudosuchian (Reptilia: Archosauria) from the Upper Triassic of Nova Scotia (Canada)

We present a detailed description of an incomplete but excellently preserved braincase and a digitally generated endocast of a pseudosuchian archosaur from the Upper Triassic (Carnian) Evangeline Member of the Wolfville Formation of Nova Scotia (Canada). The general morphology of the braincase particularly resembles that of the rauisuchid Postosuchus kirkpatricki from the Upper Triassic (Norian) of Texas. Indeed, the quantitative phylogenetic analyses found the Wolfville specimen within Rauisuchidae (Postosuchus spp., Polonosuchus silesiacus, and Rauisuchus tiradentes) among loricatan pseudosuchians based on the presence of a deep and dorsoventrally elongate basisphenoid recess. Although the specimen described here shows differences with Postosuchus kirkpatricki and Postosuchus alisonae, its fragmentary condition and the absence of overlapping elements with other rauisuchids (Polonosuchus silesiacus and Rauisuchus tiradentes) led us to be cautious and identify it as aff. Postosuchus sp...., Specimen scan and digitalization
The surfaces of the braincase YPM VPPU 020750 were 3D-scanned with an Artec Spider 3D Scanner, and the scanning data were collected and processed in Geomagic Studio (3D systems, Rock Hill, South Carolina). Images of 3D surface meshes were produced using MeshLab.
Subsequently, the specimen was mCT-scanned using a GE Phoenix v|tome| xm 240/180 Dual mCT system at the National Museum of Natural History (Smithsonian Institution) with a voxel size of 125 mm, a source voltage of 175 kV, and a source current of 150 mA. It generated 1432 images, each with a height of 2024 pixels and a width of 2014 pixels. The scan data were exported in DICOM format and subsequently imported into the digital visualization software Avizo (v.9.1). The endocast was reconstructed using the Segmentation Editor with key anatomical structures isolated and highlighted in different colors. Finally, images of the digital endocast visualized inside the transparent braincase were exported.
P..., # Braincase and digital endocast of a loricatan pseudosuchian (Reptilia: Archosauria) from the Upper Triassic of Nova Scotia (Canada)

Dataset DOI: [10.5061/dryad.ghx3ffc27](10.5061/dryad.ghx3ffc27)

## Description of the data and file structure

No experiments involved.

### Files and variables

#### File: Nesbitt_matrix_YPM.nex

**Description:** Character-taxon matrix in NEXUS format for phylogenetic analysis.

#### File: Nesbitt_matrix_YPM.tnt

**Description:** Character-taxon matrix in .tnt format for phylogenetic analysis using TNT v. 1.6.

#### File: YPM_VPPU_020750_Endocast.stl

**Description:** Digitally generated endocast based microCT-scanning data of the braincase.

#### File: YPM_VPPU_020750_Labyrinth.stl

**Description:** Digitally generated cast of inner ear labyrinth based microCT-scanning data of the braincase.

#### File: YPM_VPPU_020750_Braincase.stl

**Description:** .stl file of 3D rendering of the braincase of YPM VPPU 020750. 

## Code/software

3D scanning: Geomag...,