Vertebral morphometrics and lung structure in non-avian dinosaurs

Brocklehurst, Robert J.; Schachner, Emma R.; Sellers, William I.

doi:10.1098/rsos.180983

Cited by 19 publications

(22 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, phylogeny explains part of the shape variation between modules but does not fully explain the shape variation along the neck. This is in line with the conclusions of Brocklehurst et al (2018), who postulated that phylogeny applies differentially along the vertebral column. To strengthen these findings, more species must be added to our dataset to further discuss the role of phylogeny in the regionalization of the neck.…”

Section: Modules (Ie Subsets Of Cvs)supporting

confidence: 92%

Modularity of the Neck in Birds (Aves)

et al. 2020

View full text Add to dashboard Cite

The neck connects the head and the trunk and is the key structure allowing all movements of the head. The neck morphology of birds is the most variable among living tetrapods, including significant differences in the number and shape of the cervical vertebrae. Despite these differences, according to the literature, three morphofunctional regions (i.e., modules) have been identified along the neck. However, this regionalization has not been quantitatively tested through a geometric morphomet-ric approach applied to the cervical vertebrae. Based on the examination of 187 cervical vertebrae belonging to 16 species with various ecologies, we revealed a common modular structure of the neck using 3D surface geometric morphometrics. We adopted an approach without a priori clustering to identify modules along the neck. The phylogenetic influence on each module was tested. Then, each module was digitally reconstructed as a 3D vertebral model, and postural characteristics were studied. We characterized 9 modules: 7 are transpecific, being shared by at least 2 and up to 15 species. Two modules are specific to species with particularly long necks. The modularity pattern appears to be tightly linked to morphofunctional aspects and partially to phylogeny. In contrast, feeding ecology seems to be more closely related to the chaining of modules (the neck) than to the modules themselves. A study of postural properties revealed that each modular unit exhibits a characteristic curvature. Overall, the modular structure of the neck corresponds to the three traditional functional regions. However, the results also revealed unexpected pattern complexity, including subdivisions within these regions. The study of the patterns of modularity is therefore a relevant approach for challenging the three-functional-region hypothesis and allowed us to identify the structure of the diversity of the necks of birds.

show abstract

Section: Modules (Ie Subsets Of Cvs)supporting

confidence: 92%

Modularity of the Neck in Birds (Aves)

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Previous studies of trait evolution in fossil taxa have been dominated by informal supertrees 29,[55][56][57][58][59][60][61] . While informal supertrees have practical advantages, they have no underlying systematic basis and are therefore subjective.…”

Section: Methodsmentioning

confidence: 99%

Environmental drivers of body size evolution in crocodile-line archosaurs

Stockdale¹,

Benton²

2021

Commun Biol

View full text Add to dashboard Cite

Ever since Darwin, biologists have debated the relative roles of external and internal drivers of large-scale evolution. The distributions and ecology of living crocodilians are controlled by environmental factors such as temperature. Crocodilians have a rich history, including amphibious, marine and terrestrial forms spanning the past 247 Myr. It is uncertain whether their evolution has been driven by extrinsic factors, such as climate change and mass extinctions, or intrinsic factors like sexual selection and competition. Using a new phylogeny of crocodilians and their relatives, we model evolutionary rates using phylogenetic comparative methods. We find that body size evolution follows a punctuated, variable rate model of evolution, consistent with environmental drivers of evolution, with periods of stability interrupted by periods of change. Regression analyses show warmer environmental temperatures are associated with high evolutionary rates and large body sizes. We confirm that environmental factors played a significant role in the evolution of crocodiles.

show abstract

“…There are several possible reasons for this difference. Birds retain the wide separation of the diapophysis and parapophysis for the whole vertebral column; in crocodilians, the parapophysis migrates towards the diapophysis, starting at the third thoracic vertebra (Schachner et al, 2009;Brocklehurst et al, 2018). The parapophyseal facets are also flatter and more medio-laterally inclined in crocodilians from the third thoracic vertebra, which may permit translation of the rib capitulum (Claessens, 2009), and allow the ribs to deviate from their anatomical hinge axis (Brocklehurst et al, 2017).…”

Section: Results and Discussion The Costovertebral Jointmentioning

confidence: 99%

“…This intimate association between the ribs and lung tissue would presumably restrict motion outside of rotation about an anatomical hinge axis. In crocodilians, following the migration of the parapophysis on the transverse process, the rib heads lie dorsal to the surface of the lung and so do not face those same constraints (Schachner et al, 2009;Brocklehurst et al, 2018).…”

Section: Results and Discussion The Costovertebral Jointmentioning

confidence: 99%

XROMM kinematics of ventilation in wild turkeys (Meleagris gallopavo)

Brocklehurst

Moritz

Codd

et al. 2019

Journal of Experimental Biology

Self Cite

View full text Add to dashboard Cite

The avian ribcage is derived relative to other amniotes, and is hypothesised to be constrained in its movements during ventilation. The double-headed ribs form two articulations with the vertebrae, and are thought to rotate about a strict anatomical axis. However, this costovertebral joint constraint has not been demonstrated empirically and was not found in other taxa with double-headed ribs (i.e. crocodilians). Here, we used X-ray reconstruction of moving morphology (XROMM) to quantify rib rotation in wild turkeys (Meleagris gallopavo) during breathing. We demonstrate that, as predicted from anatomy, the ribs do rotate in a hinge-like manner about a single axis. There is also evidence for elliptical motion of the sternum, as has been reported in other taxa. The evolution of the avian ribcage is closely related to the co-evolution of ventilation and flight, and these results are important for how we model ventilation mechanics in living and fossil birds.

show abstract

Vertebral morphometrics and lung structure in non-avian dinosaurs

Cited by 19 publications

References 80 publications

Modularity of the Neck in Birds (Aves)

Modularity of the Neck in Birds (Aves)

Environmental drivers of body size evolution in crocodile-line archosaurs

XROMM kinematics of ventilation in wild turkeys (Meleagris gallopavo)

Contact Info

Product

Resources

About