DOI: 10.5061/dryad.n02v6wx96
title: Data from: Salamander ecomorphology reveals a unique suite of climbing adaptations

description: Many salamanders climb extensively but lack morphological adaptations,
 such as claws or adhesive toe pads, found in other climbing tetrapods.
 Here, we compared climbers and non-climbers from the salamander genera
 Aneides and Plethodon to evaluate potential morphological adaptations for
 climbing across multiple levels of biological organization. We integrated
 body shape morphometrics, allometry of the autopods (manus and pes),
 mechanical advantage of the digits, and comparisons of epithelial
 microstructures. Compared to non-climbers, climbers have longer limbs that
 likely facilitate faster climbing and have larger and positively
 allometric autopods that likely yield superior clinging performance.
 Longer digits increase climbing reach at the expense of grip force, but
 climbers circumvent this trade-off with phalangeal morphologies that
 increase the mechanical advantage of their digits. A few species also have
 pes epithelia that may increase adhesion or friction but epithelial
 morphology was largely uncorrelated with habitat use. While scansorial
 species of Aneides and Plethodon share some characteristics with other
 genera of climbing salamanders, our results reveal subtle differences
 between rock-climbing and tree-climbing salamanders that reflect different
 selective pressures imposed by their microhabitats. Many-to-one mapping
 enables alternate strategies to address the challenges of climbing and
 helps to explain the abundance and diversity of climbing tetrapods.
description: # Data from: Salamander ecomorphology reveals a unique suite of climbing
 adaptations Dataset DOI:
 [10.5061/dryad.n02v6wx96](10.5061/dryad.n02v6wx96) ## Description of the
 data and file structure ### Files and variables #### File:
 AllometryData.csv **Description:** Static allometry coefficients for the
 pes (cm^2) relative to body mass (g) for 30 species of plethodontids.
 ##### Variables * species: Genus species name. * n: Number of individuals
 used to infer the scaling coefficients.  * slope: Static slope of the
 allometric relationship. * int: Static intercept of the allometric
 relationship. * svl_max: Maximum snout-vent length reported in the
 literature (mm). * Locomotion: Climbing preference of the species
 (Scansorial or Non-Climber). * Habitat: Habitat preference of the species
 (Arboreal, Saxicolous, or Terrestrial). * Allometry Citation: The source
 of the scaling coefficients or the original data. * SVL Citation: The
 source of the maximum snout-vent length. #### File: RawMorphometrics.csv
 **Description:** Body shape measurements for 411 specimens across 13
 species of *Aneides* and *Plethodon*. See Figure 2 of the manuscript for a
 visual representation of measurements. ##### Variables * Species: Genus
 species name. * Genus: Genus name. * ID: Natural history collection
 catalogue code and number. * Mass: Body mass (g). * SVL: Snout-vent length
 (mm). * TL: Tail length (mm). * Humerus: Upper arm length (mm). *
 Radius: Lower arm length (mm). * Hand: Manus length (mm). * Finger:
 Longest finger length (mm). * Femur: Upper leg length (mm). * Tibia: Lower
 leg length (mm). * Foot: Pes length (mm). * Toe: Longest toe length (mm).
 * HandArea: Manus area (mm^2) * FootArea: Pes area (mm^2) #### File:
 Stewart_Wien_2025_S3_fulltree.nex **Description:** Salamander phylogeny
 from Stewart and Wiens (2025). #### File: PhalangesData.csv
 **Description:** Measurements taken from the phalanges for 13 species of
 *Aneides* and *Plethodon*. See Figure 2 of the manuscript for a visual
 representation of measurements. ##### Variables * Species: Genus species
 name. * Habitat: Habitat preference of the species (Arboreal, Saxicolous,
 or Terrestrial). * ID: Natural history collection catalogue code and
 number. * Digit: Indicator of which digit was sampled (Finger or Toe). *
 Side: Which side of the body the digit was sampled from (Left or Right). *
 SVL: Snout-vent length (mm). * Met_L: Metacarpal (finger) or metatarsal
 (toe) length (mm). * PP_L: Proximal phalanx length (mm). * PP_PW: Proximal
 phalanx proximal width (mm). * PP_DW: Proximal phalanx distal width (mm).
 * PP_PH: Proximal phalanx proximal height (mm). * PP_MH: Proximal phalanx
 medial height (mm). * PP_DH: Proximal phalanx distal height (mm). *
 MP_L: Penultimate phalanx length (mm). * MP_PW: Penultimate phalanx
 proximal width (mm). * MP_DW: Penultimate phalanx distal width (mm). *
 MP_PH: Penultimate phalanx proximal height (mm). * MP_MH: Penultimate
 phalanx length (mm). * MP_DH: Penultimate phalanx distal height (mm). *
 DP_L: Terminal phalanx length (mm). * DP_PW: Terminal phalanx proximal
 width (mm). * DP_DW: Terminal phalanx distal width (mm). * DP_PH: Terminal
 phalanx proximal height (mm). * X: Measurement "X" used to
 calculate terminal phalanx curvature (mm). * Y: Measurement "Y"
 used to calculate terminal phalanx curvature (mm). * Z: Measurement
 "Z" used to calculate terminal phalanx curvature (mm). *
 DP_C: Terminal phalanx curvature (mm). * PIP_M: Proximal interphalangeal
 joint moment arm (mm). * PIP_L: Proximal interphalangeal joint load arm
 (mm). * DIP_M: Distal interphalangeal joint moment arm (mm). *
 DIP_L: Distal interphalangeal joint load arm (mm). * TIP_M: Tip of the
 digit moment arm (mm). * TIP_L: Tip of the digit load arm (mm). #### File:
 MainScript.R **Description:** R script containing all of the main
 analyses. ## Code/software MainScript.R was written with R Programming
 Language version 4.3.2 in RStudios. It requires the following packages:
 ggplot2, tidyverse, plyr, phytools, geomorph, RRPP, patchwork, and smatr.