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Skull variation in a shovel‐headed amphisbaenian genus, inferred from the geometric morphometric analysis of five South American Leposternon species
Author(s) -
Hohl Leandro S. L.,
BarrosFilho José D.,
RochaBarbosa Oscar
Publication year - 2018
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.20899
Subject(s) - digging , biology , shovel , fossorial , skull , allometry , variation (astronomy) , range (aeronautics) , zoology , genus , ecology , sympatric speciation , anatomy , geography , physics , materials science , archaeology , astrophysics , agronomy , composite material
Amphisabenia is a group of squamates adapted for a fossorial lifestyle. The skull is the animal's the main digging tool, and can present one of four principal shapes. The shovel‐headed shape is considered to be the most specialized for digging. The South American genus Leposternon presents a shovel‐headed morphotype, and is widely distributed on this continent. The general shovel‐headed skull pattern may vary considerably, even within the same genus, and we hypothesized that this variation may be influenced primarily by body size and geographical factors. This study investigated the variation in skull size and shape among five Leposternon species, and examined the potential relationship between this variation and the size of the specimens and bioclimatic variables, through a geometric morphometric approach. Significant morphological variation was found among the species, and was also related systematically to body size and the geographical distribution of the specimens. As even subtle differences in the skull size or shape may represent significant modification in bite force and digging capacity and digging speed, the cranial variation found among the Leposternon species and specimens may have a direct influence on their diet and locomotor performance. Our results, together with direct observations of some of these species, suggest that shovel‐headed amphisbaenians may be able to penetrate different soil types under a range of climatic conditions, especially considering the ample, but often sympatric distribution of the species studied here.