DOI: 10.5061/dryad.05qfttf92
title: Shell shape does not accurately predict self-righting ability in hatchling freshwater turtles

description: The different degrees of hydrodynamic shell shape in freshwater turtles
 likely represent an evolutionary trade-off between adaptation to an
 aquatic lifestyle and the movement capabilities of a larger and more
 rounded shell. Trade-offs often result in compromises, and this is
 particularly true when these turtles must self-right to avoid the negative
 effects of inverting. With flatter carapaces aquatic turtles,
 theoretically, must invest more biomechanical effort than their
 terrestrial counterparts with their more rounded carapaces, to achieve
 successful and timely self-righting. This places the hatchlings of
 freshwater species in a precarious position; more prone to inversion and
 predation than adults and with shells seemingly maladapted to the act of
 self-righting. Here, we examine the self-righting performance in three
 morphologically distinct freshwater turtle species (Apalone spinifera,
 Chelydra serpentina and Trachemys scripta scripta) that inhabit similar
 environmental niches. We demonstrate that hatchlings of these species were
 capable of rapid self-righting and used considerably less biomechanical
 effort relative to adult turtles. Despite differences in shell morphology
 the energetic efficiency of self-righting remained remarkably low and
 uniform between the three species of freshwater hatchling. Our results
 confound theoretical predictions of self-righting ability based solely on
 shell shape metrics and indicate that other morphological characteristics
 like neck or tail morphology and shell material properties must be
 considered to better understand the biomechanical nuances of Testudine
 self-righting.
description: # Shell shape does not accurately predict self-righting ability in
 hatchling freshwater turtles
 [https://doi.org/10.5061/dryad.05qfttf92](https://doi.org/10.5061/dryad.05qfttf92) The raw data files (.csv) containing time and filtered force data that was used to calculate the biomechanical costs of self-righting in three freshwater hatchling turtle species *Apalone spinifera* (spiny softshell turtle), *Chelydra serpentina* (common snapping turtle) and *Trachemys scripta scripta* (yellow-bellied slider). ## Description of the data and file structure Each .csv file follows the same structure: **Columns AB rows 1 to 8:** Here you will find filename (row 1), mass and morphometric data (rows 2-5) and self-righting timings (row 6-8) **Columns AB rows 10 to 12:** Row 10 is the kinetic-energy equivalent (KEE) calculated for the self-righting event Row 11 is the power-output equivalent (PEE) calculated for the self righting event Row 12 is the height-change equivalent (HE) calculated for the self righting event **Columns AF rows &gt;14:** Column A is the time in seconds taken from the force plate Column B is the total vertical force (fz) in Newtons (N) taken from the force plate Column C is the total vertical force (fz) in Newtons minus the force of the turtles body weight. Column D is the calculated trapezoidal area under the force–time increments Column E is the instantaneous velocity values Column F is the instantaneous kinetic-energy equivalent values