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Morphological Constraints in the Craniomandibular Complex of Chisel‐tooth Digging Mole‐rats
Author(s) -
McIntosh Andrew,
Cox Philip
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.865.13
Subject(s) - digging , chisel , skull , condyle , biology , anatomy , orthodontics , dentistry , archaeology , medicine , geography
African mole‐rats are subterranean rodents from the family Bathyergidae, which consists of six genera, five of which ( Cryptomys, Fukomys, Georychus, Heliophobius and Heterocephalus ) are chisel‐tooth diggers, meaning they dig underground using procumbent incisors. The remaining genus of mole‐rat ( Bathyergus ) is a scratch digger, meaning it digs using forelimbs. Chisel‐tooth digging is thought to have evolved to enable exploitation of harder soils. It was hypothesised that in order to dig successfully using incisors, chisel‐tooth digging mole‐rats will have a craniomandibular complex that is modified to achieve a relatively larger bite force and gape compared to the scratch digging mole‐rats. Linear measurements of morphological characteristics associated with bite force and gape were measured in a number of chisel‐tooth digging and scratch digging mole‐rats. It was found that chisel‐tooth diggers have increased jaw lengths, condylar angles and condyle articulating surface heights relative to their size (characteristics associated with larger gape). They also have relatively wider skull widths and head heights (characteristics associated with larger bite force). The results demonstrate that craniomandibular morphology is strongly constrained by function in this rodent family.