The trunk replaces the longer mandible as the main feeding organ in elephant evolution--Supplementary codes

The long-trunked elephantids underwent a significant evolutionary stage characterized by an exceptionally elongated mandible. The initial elongation and subsequent regression of the long mandible, along with its co-evolution with the trunk, present an intriguing issue that remains incompletely understood. Through comparative functional and eco-morphological investigations, as well as feeding preference analysis, we reconstructed the feeding behavior of major groups of longirostrine elephantiforms. In the Platybelodon clade, the rapid evolutionary changes observed in the narial region, strongly correlated with mandible and tusk characteristics, suggest a crucial evolutionary transition where feeding function shifted from the mandible to the trunk, allowing proboscideans to expand their niches to more open regions. This functional shift further resulted in elephantids relying solely on their trunks for feeding., Cladistic analysis
Cladistic analyses were performed to evaluate the phylogenetic hypothesis of trilophodont longirostrine proboscideans. The data matrix contained 37 taxa, including most of the known trilophodont longirostrine taxa at the species level, and Phiomia serridens, an Oligocene basal elephantiform, was selected as outgroup. Additionally, a basal elephantoid, Tetralophodon longirostris was also included to assess which clade the true elephantids originated from. The morphological characters included 5 characters from upper tusks, 9 from mandibular tusks, 37 from cheek teeth, 19 from the cranium, and 10 from the mandible, mainly following Tassy, 1996; Shoshani, 1996; and Wang et al., 2017. For a description of the characters and states, please see Appendix; for the data matrix, please see Figure 1–Source Data 1. Two methods, Bayesian tip-dating (BTD) and maximum parsimony (MP) analyses were performed.
In BTD analysis, the fossil ages were incorporated as tip calibrations (Gavr..., , # Title of Dataset:

The trunk replaces the longer mandible as the main feeding organ in elephant evolutionSupplementary data

Brief summary of dataset contents, contextualized in experimental procedures and results.

## Description of the Data and file structure

**Codes information: (All codes are written in English)**

Code S1  Script file for Bayesian total-evidence dating analysis (.nex file). (Open it in MrBayes Software)

Code S2  Script auxiliary file for most parsimonious analysis, applying for some ordered and irreversible characters (characters 19–24 in the TNT program, please note that these character numbers were automatically assigned by TNT file, and begin from character “0” rather than “1”, therefore, these characters in supplementary Appendix and Data S1 were characters 20–25) (.tnt file). (Open it in TNT Software)

Code S3  Script file for most parsimonious analysis (.tnt file). (Open it in TNT Software)

Code S4  FEA setting file, for distal force tests (this file can...