Supporting information for phylogenetic analysis and imaging of Agriodontosaurus

The Lepidosauria is the most species-rich group of land-dwelling vertebrates. The group includes around 12,000 species of lizards and snakes (Squamata) and one species of Rhynchocephalia, the tuatara Sphenodon punctatus from New Zealand. Squamates owe their success to their generally small size, but also to their highly mobile skull that enables them to manipulate large prey. These key features of lizard and snake skulls are not seen in Sphenodon, which makes it important to understand the nature of their common ancestor. Lepidosaurs originated in the Triassic 252–201 million years ago, but confusion has arisen because of incomplete fossils, many of which are generalized lepidosauromorphs, neither squamates nor rhynchocephalians. Here we report a reasonably complete skull and skeleton of a definitive rhynchocephalian from the Middle Triassic (Anisian) Helsby Sandstone Formation of Devon, UK that is around 3–7 million years older than the oldest currently known lepidosaur. The new specie..., , # Supporting information for phylogenetic analysis and imaging of Agriodontosaurus

Dataset DOI: [10.5061/dryad.cvdncjth4](https://doi.org/10.5061/dryad.cvdncjth4)

## Description of the data and file structure

Anatomical and phylogenetic analysis of a small rhynchocephalian fossil from the Helsby Sandstone Formation of Devon, UK.

### Files and variables

#### File: OSFBeastie_mb.nex

**Description:**  MrBayes command file for phylogenetic analysis of the new specimen in context of modern and fossil Lepidosauria.

#### File: Character_List_(modified_from_talanda_et_al_2022).txt

**Description:** Modified character list for MrBayes file; including new taxa and a new character (ch383)

#### File: OSFBeastie_CT21.tnt

**Description:** tnt command file for phylogenetic analysis of the new specimen in context of modern and fossil Lepidosauria.

#### File: Complete_Specimen_(Bristol_scan).stl

**Description:** single object 3D file of the segmented Bristol scan of Agriodontosaurus

#### Fil...,