Ecological correlates to cranial morphology in Leporids (Mammalia, Lagomorpha)

Abstract

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we investigate the relationship between cranial shape and the degree of facial tilt with locomotion (cursoriality, saltation, and burrowing) within crown leporids. Our results suggest that facial tilt is more pronounced in cursors and saltators compared to generalists, and that increasing facial tilt may be driven by a need for expanded visual fields. Our phylogenetically informed analyses indicate that burrowing behavior, facial tilt, and locomotor behavior do not predict cranial shape. However, we find that variables such as bullae size, size of the splenius capitus fossa, and overall rostral dimensions are important components for understanding the cranial variation in leporids.

Shape Variation in the Craniomandibular System and Prevalence of Dental Problems in Domestic Rabbits: A Case Study in Evolutionary Veterinary Science

“…Evolution of craniomandibular shape in rabbits has been governed by ecological adaptation [ 56 ] including locomotion [ 57 ] and dietary habits [ 58 , 59 ]. Our analyses show that there are consistent differences in skull shape between wild and domestic rabbits.…”

Constructing an Invasion Machine: The Rapid Evolution of a Dispersal-Enhancing Phenotype During the Cane Toad Invasion of Australia

“…The changes in skull shape are more difficult to interpret. Although the skull is not usually considered as a component of the locomotor system, the degree of facial tilt in Leporids (Mammalia, Lagomorpha) correlates with locomotor mode, perhaps because changes to cranial structure can increase the visual field of the organism [ 44 ]. The shift in cranial morphology in between QLD and WA toads may reflect an advantage of visual awareness in completing multiple rapid hopping and landing cycles.…”

Comparative cranial morphology in living and extinct platypuses: Feeding behavior, electroreception, and loss of teeth

“…1 ). Interspecific and intraspecific differences in the cranial deflection with respect to the basicranium have been reported in other mammals [for example, in previous studies ( 10 – 17 )]. Cranial deflection is relatively “plastic” in mammals.…”

“…Cranial deflection is relatively “plastic” in mammals. For example, investigations of canids have revealed significant intraspecific variation in this trait, which is determined by the physical relationships of the splanchnocranium and neurocranium to each other ( 11 – 17 ). However, Tasmanian and mainland Ornithorhynchus , which became isolated from each other around 0.7 to 0.94 million years ago (Ma) ( 18 ), are plotted along the same regression line ( Fig.…”

“…In other mammals, interspecific differences in cranial deflection are often considered to reflect differences in sensory efficiency [such as width of visual field in lagomorphans ( 17 ) or vocalization in chiropterans ( 10 )]. However, Ornithorhynchus depends less on vision and sound than do many mammals ( 2 , 19 – 21 ), and sensory efficiency probably does not explain the ventrally deflected bill in the skull of Ornithorhynchus .…”