Biomechanics and strategies of digging

VASSALLO, ALDO IVÁN; BECERRA, FEDERICO; ECHEVERRÍA, ALEJANDRA ISABEL; BUEZAS, GUIDO NICOLÁS; DÍAZ, ALCIRA O.; LONGO, MARÍA VICTORIA; COHEN, MARIANA

Tuco-tucos. An evolutionary approach to the diversity of a Neotropical subterranean rodent

Springer

Lugar: Cham; Año: 2021; p. 141 - 165

In arid and semiarid ecosystems, digging and burrowing are common behaviors in many mammals looking for shelter, food, thermoregulation, etc. Many rodents, as tuco-tucos, may use both the foreclaws and incisors ? according to soil requirements ? to accomplish that goal in an effective manner. Although digging represents a low fraction of the daily energy budget, it triggered some highly derived adaptations. Forelimbs in caviomorph scratch-diggers are characterized by highly robust humeri and ulnae, and well-developed bony superstructures. These mechanically advantageous traits have been already found during early ontogeny in Ctenomys ?compensating the lower muscular development ? and encompass the gradual improvement of digging and burrowing behaviors on those stages. This fact would provide enough time to reach a proper musculoskeletal and behavioral development, to deal with energetic and biomechanical demands. Gross head morphology, instead, has proven to conserve a rodent already-optimized bauplan among caviomorphs, by not showing a more mechanically advantageous masticatory apparatus in tuco-tucos. Their strong bite forces ?which cover both tooth-digging and a wide range of social needs ? would be a consequence of the hypertrophied and fiber types-wise specialized jaw adduct musculature. Despite corresponding soil reaction forces may injure animals? skull or teeth, ctenomyid skull geometry, bone distribution, and incisors microstructure evolved to withstand the high stress and abrasion. Thus, yet inconclusively, animal?s performance can be fairly predicted based on biomechanics.