Locomotor rib kinematics in two species of lizards and a new hypothesis for the evolution of aspiration breathing in amniotes

Cieri, Robert L.; Hatch, Samuel T.; Capano, John G.; Brainerd, Elizabeth L.

doi:10.1038/s41598-020-64140-y

Cited by 14 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…giganteus (authors' observations), and presumably other large varanids. The degree to which coracosternal joint mobility and the lateral bending of the vertebral column (Cieri et al, 2020) control stride length in varanids remains unknown, but both likely contribute.…”

Section: Discussionmentioning

confidence: 99%

“…The coracosternal joint translates cranially to increase stride length in V. exanthematicus (Jenkins and Goslow, 1983) and is also mobile in V. gouldii and V. giganteus (authors’ observations), and presumably other large varanids. The degree to which coracosternal joint mobility and the lateral bending of the vertebral column (Cieri et al ., 2020) control stride length in varanids remains unknown, but both likely contribute.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Monitoring muscle over three orders of magnitude: Widespread positive allometry among locomotor and body support musculature in the pectoral girdle of varanid lizards (Varanidae)

2020

Self Cite

View full text Add to dashboard Cite

There is a functional trade-off in the design of skeletal muscle. Muscle strength depends on the number of muscle fibers in parallel, while shortening velocity and operational distance depend on fascicle length, leading to a trade-off between the maximum force a muscle can produce and its ability to change length and contract rapidly. This trade-off becomes even more pronounced as animals increase in size because muscle strength scales with area (length 2) while body mass scales with volume (length 3). In order to understand this muscle trade-off and how animals deal with the biomechanical consequences of size, we investigated muscle properties in the pectoral girdle of varanid lizards. Varanids are an ideal group to study the scaling of muscle properties because they retain similar body proportions and posture across five orders of magnitude in body mass and are highly active, terrestrially adapted reptiles. We measured muscle mass, physiological cross-sectional area, fascicle length, proximal and distal tendon lengths, and proximal and distal moment arms for 27 pectoral girdle muscles in 13 individuals across 8 species ranging from 64 g to 40 kg. Standard and phylogenetically informed reduced major axis regression was used to investigate how muscle architecture properties scale with body size. Allometric growth was widespread for muscle mass (scaling exponent >1), physiological cross-sectional area (scaling exponent >0.66), but not tendon length (scaling exponent >0.33). Positive allometry for muscle mass was universal among muscles responsible for translating the trunk forward and flexing the elbow, and nearly universal among humeral protractors and wrist flexors. Positive allometry for PCSA was also common among trunk translators and humeral protractors, though less so than muscle mass. Positive scaling for fascicle length was not widespread, but common among humeral protractors. A higher proportion of pectoral girdle muscles scaled with positive allometry than our previous work showed for the pelvic girdle, suggesting that the center of mass may move cranially with body size in varanids, or that the pectoral girdle may assume a more dominant role in locomotion in larger species. Scaling exponents for physiological cross-sectional area among muscles primarily associated with propulsion or with a dual role were generally higher than those associated primarily with support | 1115 CIERI Et al.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Monitoring muscle over three orders of magnitude: Widespread positive allometry among locomotor and body support musculature in the pectoral girdle of varanid lizards (Varanidae)

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Among the difficulties, the most complex issue comes from producing a data collection from within their natural habitat to ensure their surroundings do not enforce an abnormal swimming pattern. The current state of the art techniques, such as X-ray Reconstruction of Moving Morphology (XROMM) 21 , 22 , requires a unique set up that would be impractical to impossible to set up in a marine environment. Not only are techniques like this impractical, but receiving animal ethics approval to put an endangered species into a lab to study its biomechanics creates further hurdles.…”

Section: Introductionmentioning

confidence: 99%

New insight into the swimming kinematics of wild Green sea turtles (Chelonia mydas)

Geest

Garcia

Nates

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Biomechanically, sea turtles could be perceived as birds of the ocean as they glide and flap their forelimbs to produce the necessary forces required for locomotion, making sea turtles an interesting animal to study. However, being an endangered species makes studying the sea turtle's biomechanics a complex problem to solve, both technically and ethically, without causing disturbance. This work develops a novel, non-invasive procedure to develop full three-dimensional kinematics for wild sea turtles by filming the animals in Australia's Great Barrier Reef using underwater drones without disturbing them. We found that the wild animals had very different swimming patterns than previous studies on juveniles in captivity. Our findings show that the flipper goes through a closed-loop trajectory with extended sweeping of the flipper tip towards the centre of the carapace to create a clapping motion. We have named this the “sweep stroke” and in contrast to previously described four-stage models, it creates a five-stage cycle swimming locomotion model. The model presented here could lead to a better comprehension of the sea turtle propulsion methods and their fluid–structure interaction.

show abstract

“…Exaptation has been proposed as a mechanism explaining the evolution of novel characters (Cieri, Hatch, Capano, & Brainerd, 2020; Emberts et al, 2020; Hoffman, Taylor, & Harris, 2016; Schaefer & Lauder, 1986), including the sound‐producing organs of fishes (Parmentier, Diogo, & Fine, 2017). The ESS premotor‐motor circuit, like molluscan central pattern generators (Katz, 2016a), offers the opportunity to identify transformations in neuronal properties linked to divergent behavioral phenotypes (also see Anderson, 2010; Stephenson‐Jones, Samuelsson, Ericsson, Robertson, & Grillner, 2011).…”

Section: Discussionmentioning

confidence: 99%

Morphological diversity of acoustic and electric communication systems of mochokid catfish

Kéver

Parmentier

Bass

et al. 2020

J of Comparative Neurology

View full text Add to dashboard Cite

Mochokid catfish offer a distinct opportunity to study a communication system transitioning to a new signaling channel because some produce sounds and others electric discharges. Both signals are generated using an elastic spring system (ESS), which includes a protractor muscle innervated by motoneurons within the protractor nucleus that also has a motoneuron afferent population. Synodontis grandiops and S. nigriventris produce sounds and electric discharges, respectively, and their ESSs show several morphological and physiological differences. The extent to which these differences explain different signal types remains unclear. Here, we compare ESS morphologies and behavioral phenotypes among five mochokids. S. grandiops and S. nigriventris were compared with Synodontis eupterus that is known to produce both signal types, and representative members of two sister genera, Microsynodontis cf. batesii and Mochokiella paynei, for which no data were available. We provide support for the hypothesis that peripheral and central components of the ESS are conserved among mochokids. We also show that the two nonsynodontids are only sonic, consistent with sound production being an ancestral character for mochokids. Even though the three sound producing-only species differ in some ESS characters, several are similar and likely associated with only sound production. We propose that the ability of S. eupterus to generate both electric discharges and sounds may depend on a protractor muscle intermediate in morphology between sound producing-only and electric discharge-only species, and two separate populations of protractor motoneurons. Our results further suggest that an electrogenic ESS in synodontids is an exaptation of a sound producing ESS.

show abstract

Locomotor rib kinematics in two species of lizards and a new hypothesis for the evolution of aspiration breathing in amniotes

Cited by 14 publications

References 33 publications

Monitoring muscle over three orders of magnitude: Widespread positive allometry among locomotor and body support musculature in the pectoral girdle of varanid lizards (Varanidae)

Monitoring muscle over three orders of magnitude: Widespread positive allometry among locomotor and body support musculature in the pectoral girdle of varanid lizards (Varanidae)

New insight into the swimming kinematics of wild Green sea turtles (Chelonia mydas)

Morphological diversity of acoustic and electric communication systems of mochokid catfish

Contact Info

Product

Resources

About