10.5061/DRYAD.B8GTHT78T
Sartori, Cristina
0000-0002-2091-2280
University of Padua
Gianesella, Matteo
University of Padua
Pilastro, Andrea
0000-0001-9803-6308
University of Padua
Mantovani, Roberto
0000-0002-1919-0559
University of Padua
Armato, Leonardo
University of Padua
Fiore, Enrico
0000-0002-0377-9553
University of Padua
Data from: Digit ratio and length asymmetry in calves’ limbs
Dryad
dataset
2020
digit ratio
limbs
length asymmetry
radiography
2D:4D
University of Padua
https://ror.org/00240q980
CPDA134009/13
2020-04-01T00:00:00Z
2020-04-01T00:00:00Z
en
https://doi.org/10.1016/j.zool.2020.125777
28984 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
This study considered possible sexual dimorphism in the relative lengths
of the second, third and fourth digits (digit ratio), in calves.
Furthermore, a different length of the bone structures of the third (3D)
and of the fourth (4D) digits has been examined as an evolutionary
adaptation to locomotion on soft ground. The length of the digital bones
of the right fore-limb of 33 females and 15 male calves was measured in
vivo using a portable X-ray machine. The vestigial structure of the second
digit (2D), and 3D and 4D, from metacarpus to the third phalanx were
considered in a mixed model, as well as some ratios between 2D and
different parts of 3D or 4D (2D:3D and 2D:4D). A covariate for the mean
finger length was considered for digit ratios to control for possible
biases due to shape allometry. Shorter first phalanx and trotter were
found in 3D than in 4D, and the reverse for the third phalanx. The 2D was
significantly shorter in females, as well as the second phalanges of 3D
and 4D. Significant sex differences in 2D:3D and 2D:4D were found for some
digit parts of 3D and 4D and for the first phalanges of 3D:4D. These
ratios were always shorter in females, in contrast to that found in most
mammals. The asymmetry between 3D and 4D could mean a functional
adaptation for locomotion. Sex differences in 2D:4D and 3D:4D were found,
but with a reverse pattern than in most mammal species
(males > females rather than males < females). In this
regard digit ratio in calves was similar to that of Old World monkeys.
This study is the first investigation of digit ratio in Ungulates, whose
limbs differ from the limbs of most Mammals, maintaining five digits. The
reverse pattern of sex differences (digit ratios: males > females)
could be due to the peculiar nature of the vestigial dewclaw of 2D and to
the hormone patterns acting on this digit during development, but further
research is required around this topic.
The dataset consists in radiographic measurements of the right foreleg of
newborn calves taken using a portable X-ray unit. Images were acquired
using a portable scanner and then imported into a image-processing
software. The measures of the digital bones of interest were therefore
obtained by a trained operator. Two radiographic images were obtained
using the X-ray machine and then acquired and measured for a sample of
individuals to assess the repeatability. Additional digit measures and
digit ratios were obtained by summing some digital measures or by
performing ratios. Further details are provided directly into the dataset
(Excel sheet).
The dataset includes all the data that have been used in the manuscript.
Variable definition is reported directly within the spreadsheet.