Cryptic complexity in felid vertebral evolution: shape differentiation and allometry of the axial skeleton

Randau, Marcela; Goswami, Anjali; Hutchinson, John R.; Cuff, Andrew R.; Pierce, Stephanie E.

doi:10.1111/zoj.12403

Cited by 45 publications

(86 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore Randau et al. () found extensive positive allometric scaling within individual vertebrae, particularly for centrum height, which was also observed by Jones () in the thoracic and mid‐lumbar regions. Increases in centrum height are directly correlated with increases in passive stiffness in the dorsoventral plane (Long et al.…”

Section: Introductionmentioning

confidence: 52%

The scaling of postcranial muscles in cats (Felidae) I: forelimb, cervical, and thoracic muscles

et al. 2016

Self Cite

View full text Add to dashboard Cite

The body masses of cats (Mammalia, Carnivora, Felidae) span a ~300-fold range from the smallest to largest species. Despite this range, felid musculoskeletal anatomy remains remarkably conservative, including the maintenance of a crouched limb posture at unusually large sizes. The forelimbs in felids are important for body support and other aspects of locomotion, as well as climbing and prey capture, with the assistance of the vertebral (and hindlimb) muscles. Here, we examine the scaling of the anterior postcranial musculature across felids to assess scaling patterns between different species spanning the range of felid body sizes. The muscle architecture (lengths and masses of the muscle-tendon unit components) for the forelimb, cervical and thoracic muscles was quantified to analyse how the muscles scale with body mass. Our results demonstrate that physiological cross-sectional areas of the forelimb muscles scale positively with increasing body mass (i.e. becoming relatively larger). Many significantly allometric variables pertain to shoulder support, whereas the rest of the limb muscles become relatively weaker in larger felid species. However, when phylogenetic relationships were corrected for, most of these significant relationships disappeared, leaving no significantly allometric muscle metrics. The majority of cervical and thoracic muscle metrics are not significantly allometric, despite there being many allometric skeletal elements in these regions. When forelimb muscle data were considered in isolation or in combination with those of the vertebral muscles in principal components analyses and MANOVAs, there was no significant discrimination among species by either size or locomotory mode. Our results support the inference that larger felid species have relatively weaker anterior postcranial musculature compared with smaller species, due to an absence of significant positive allometry of forelimb or vertebral muscle architecture. This difference in strength is consistent with behavioural changes in larger felids, such as a reduction of maximal speed and other aspects of locomotor abilities.

show abstract

Section: Introductionmentioning

confidence: 52%

The scaling of postcranial muscles in cats (Felidae) I: forelimb, cervical, and thoracic muscles

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, this relative weakening of the musculature of the vertebral muscles may be compensated for by positive allometry of vertebrae and the resulting moment arms in other vertebral regions (Jones, ; Randau et al. ). The combined results for the vertebral muscles (here and Cuff et al.…”

Section: Discussionmentioning

confidence: 99%

“…However, the lumbar region tends to show relatively weaker allometry than is observed in the cervicothoracic regions (Jones, ; Randau et al. ).…”

Section: Introductionmentioning

confidence: 99%

The scaling of postcranial muscles in cats (Felidae) II: hindlimb and lumbosacral muscles

et al. 2016

Self Cite

View full text Add to dashboard Cite

In quadrupeds the musculature of the hindlimbs is expected to be responsible for generating most of the propulsive locomotory forces, as well as contributing to body support by generating vertical forces. In supporting the body, postural changes from crouched to upright limbs are often associated with an increase of body mass in terrestrial tetrapods. However, felids do not change their crouched limb posture despite undergoing a 300-fold size increase between the smallest and largest extant species. Here, we test how changes in the muscle architecture (masses and lengths of components of the muscle-tendon units) of the hindlimbs and lumbosacral region are related to body mass, to assess whether there are muscular compensations for the maintenance of a crouched limb posture at larger body sizes. We use regression and principal component analyses to detect allometries in muscle architecture, with and without phylogenetic correction. Of the muscle lengths that scale allometrically, all scale with negative allometry (i.e. relative shortening with increasing body mass), whereas all tendon lengths scale isometrically. Only two muscles' belly masses and two tendons' masses scale with positive allometry (i.e. relatively more massive with increasing body mass). Of the muscles that scale allometrically for physiological cross-sectional area, all scale positively (i.e. relatively greater area with increasing body mass). These muscles are mostly linked to control of hip and thigh movements. When the architecture data are phylogenetically corrected, there are few significant results, and only the strongest signals remain. None of the vertebral muscles scaled significantly differently from isometry. Principal component analysis and manovas showed that neither body size nor locomotor mode separate the felid species in morphospace. Our results support the inference that, despite some positively allometric trends in muscle areas related to thigh movement, larger cats have relatively weaker hindlimb and lumbosacral muscles in general. This decrease in power may be reflected in relative decreases in running speeds and is consistent with prevailing evidence 3 that behavioural changes may be the primary mode of compensation for a consistently crouched limb posture in larger cats. Introduction:

show abstract

“…[4, 29, 40]). One example of a hypothesised vertebral module is composed of the mid-cervicals C3 to C5.…”

Section: Introductionmentioning

confidence: 99%

Morphological modularity in the vertebral column of Felidae (Mammalia, Carnivora)

Randau

Goswami

2017

BMC Evol Biol

Self Cite

View full text Add to dashboard Cite

BackgroundPrevious studies have demonstrated that the clear morphological differences among vertebrae across the presacral column are accompanied by heterogeneous functional signals in vertebral shape. Further, several lines of evidence suggest that the mammalian axial skeleton is a highly modular structure. These include its composition of serial units, a trade-off between high shape variance and strong conservation of vertebral count, and direct association of regions with anterior expression sites of Hox genes. Here we investigate the modular organisation of the presacral vertebral column of modern cats (Felidae, Carnivora, Mammalia) with pairwise comparisons of vertebral shape covariation (i.e. integration) and evaluate our results against hypotheses of developmental and functional modularity. We used three-dimensional geometric morphometrics to quantify vertebral shape and then assessed integration between pairs of vertebrae with phylogenetic two-block partial least square analysis (PLS).ResultsSix modules were identified in the pairwise analyses (vertebrae included are designated as ‘C’ for cervical, ‘T’ for thoracic, and ‘L’ for lumbar): an anterior module (C1 to T1); a transitional module situated between the last cervicals and first thoracics (C6 to T2); an anterior to middle thoracic set (T4 to T8); an anticlinal module (T10 and T11); a posterior set composed of the last two thoracics and lumbars (T12 to L7); and a module showing covariation between the cervicals and the posterior set (T12 to L7). These modules reflect shared developmental pathways, ossification timing, and observed ecological shape diversification in living species of felids.ConclusionsWe show here that patterns of shape integration reflect modular organisation of the vertebral column of felids. Whereas this pattern corresponds with hypotheses of developmental and functional regionalisation in the axial skeleton, it does not simply reflect major vertebral regions. This modularity may also have permitted vertebral partitions, specifically in the posterior vertebral column, to be more responsive to selection and achieve higher morphological disparity than other vertebral regions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-017-0975-2) contains supplementary material, which is available to authorized users.

show abstract

Cryptic complexity in felid vertebral evolution: shape differentiation and allometry of the axial skeleton

Cited by 45 publications

References 73 publications

The scaling of postcranial muscles in cats (Felidae) I: forelimb, cervical, and thoracic muscles

The scaling of postcranial muscles in cats (Felidae) I: forelimb, cervical, and thoracic muscles

The scaling of postcranial muscles in cats (Felidae) II: hindlimb and lumbosacral muscles

Morphological modularity in the vertebral column of Felidae (Mammalia, Carnivora)

Contact Info

Product

Resources

About