Comparative forelimb morphology of scratch‐digging and chisel‐tooth digging African mole‐rat species

Bathyergus suillus (Cape dune mole‐rat) and Heterocephalus glaber (naked mole‐rat) are two species of subterranean burrowing rodents. Bathyergus suillus occurs in soft sandy soils and is regarded as a scratch‐digger, while H. glaber is found in hard, compact soils and is a chisel‐tooth digging speci...

Full description

Saved in:
Bibliographic Details
Published in:Journal of morphology (1931) Vol. 281; no. 9; pp. 1029 - 1046
Main Authors: Doubell, Narusa S., Sahd, Lauren, Kotzé, Sanet H.
Format: Journal Article
Language:English
Published: Hoboken, USA John Wiley & Sons, Inc 01-09-2020
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Bathyergus suillus (Cape dune mole‐rat) and Heterocephalus glaber (naked mole‐rat) are two species of subterranean burrowing rodents. Bathyergus suillus occurs in soft sandy soils and is regarded as a scratch‐digger, while H. glaber is found in hard, compact soils and is a chisel‐tooth digging species. The present study aimed to determine musculoskeletal differences in the forelimb of these two species. The muscles of the forelimb, back and neck were dissected to the points of origin and insertion in the left and right forelimbs, B. suillus (n = 7) and H. glaber (n = 5). Dissected muscles were photographed before maceration to demonstrate muscle attachments. The scapular spine, acromion process and clavicle were relatively straight in B. suillus. In comparison a curved scapular spine, acromion process and clavicle were observed in H. glaber. In both species, the clavicle rested on the greater tuberosity of the humerus. In B. suillus, the deltoid tuberosity was prominent and situated more distally on the humeral shaft compared to the indistinct, more proximally situated deltoid tuberosity in H. glaber. A prominent bony structure underlying the thenar pad as well as a cartilaginous protrusion beneath the hypothenar pad were observed on the palmar surface of the manus in B. suillus. Prominent claws were observed in B. suillus. A robust m. sternohyoideus was observed in H. glaber while mm. tensor fasciae antebrachii and coracobrachialis were absent. The flexors of the antebrachium of B. suillus had additional and enlarged attachment sites. The forelimb of B. suillus may be morphologically adapted for scratch‐digging with relatively large and additional forelimb muscles and robust bones. In comparison, H. glaber had a reduction in the relative size, amount of muscles as well as number of attachment sites in the forelimb muscles, while the well‐developed ventral neck muscles may facilitate neck and head stabilisation during chisel‐tooth digging. The robust humerus, prominent deltoid tuberosity and claws, and additional attachment sites of manus flexors in B. suillus are possible scratch‐digging adaptations compared to well‐developed ventral neck muscles in the chisel‐tooth digging H. glaber.
Bibliography:Peer Review
The peer review history for this article is available at
.
https://publons.com/publon/10.1002/jmor.21229
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0362-2525
1097-4687
DOI:10.1002/jmor.21229