Relationships between morphological parameters in birds with different flying habits

Aerobic performance in tinamous is limited by their small heart. A novel hypothesis in the evolution of avian flight

“…The values contrast with the lower resting metabolism of Ratites, which is likely due to the reduction in pectoral muscle and the loss of flight instead of phylogeny, as pointed out in large interspecific studies of metabolism 26 . Our metabolic measurements are consistent with the fact that tinamous have well developed pectoral muscles 27 , with percentage values of pectoral mass ranging between those in many other bird families as shown in Supplementary Figure 3 .…”

Aerobic performance in tinamous is limited by their small heart. A novel hypothesis in the evolution of avian flight

“…The values contrast with the lower resting metabolism of Ratites, which is likely due to the reduction in pectoral muscle and the loss of flight instead of phylogeny, as pointed out in large interspecific studies of metabolism 26 . Our metabolic measurements are consistent with the fact that tinamous have well developed pectoral muscles 27 , with percentage values of pectoral mass ranging between those in many other bird families as shown in Supplementary Figure 3 .…”

Flight aerodynamics in enantiornithines: Information from a new Chinese Early Cretaceous bird

“…Using Serrano et al [ 12 , 13 ] quantitative models, we obtained values for the body mass ( BM = 30.4 g), the wingspan ( B = 305.7 mm), the lift surface ( SL = 170.0 cm 2 ), the aspect ratio ( AR = 5.5), and the wing loading ( WL = 0.18 g/cm2) of this fossil. These values indicate that the body and wings of this bird were similar, with the same low AR and WL , to those of modern passeriforms such as Alauda arvensis (Eurasian Skylark) and Acrocephalus arundinaceus (Great Reed Warbler) as well as other small-sized birds that fly using intermittent bounds (i.e., bounding) ( Fig 7 ; see [ 13 , 36 – 38 ]). As shown in Fig 7 , the portion of the morphospace of AR and WL that is occupied by modern bounding fliers overlaps with the much broader portion of the morphospace occupied by continuous flappers (i.e., all birds that fly through intermittent bounds are also capable of continuous flapping) [ 13 ].…”

Wing bone geometry reveals active flight in Archaeopteryx

“…This may reflect an ontogenetic ecomorphological shift between the ages associated with reconstructed body mass values of 158 and 254 g towards increased volant adaptation. The seventh and ninth specimens of Archaeopteryx exhibit relative humeral torsional resistance approaching those of modern short 21 /burst 20 flying birds of similar mass and higher than some heavier non-volant archosaurs. Ulnar torsional resistance values in these specimens are comparable to those of lighter volant birds and much heavier non-volant birds, and are higher than in the small non-avian coelurosaur Compsognathus .…”

“…9 ) through predominantly humeral and ulnar relative cortical thickness. DA 2 is loaded more equally on all parameters than DA 1, but slightly stronger on relative cortical thickness for the classification expanded from Viscor et al 21 , and slightly stronger on mass-normalised torsional resistance for the classification expanded from Close et al 20 . Within modern volant birds, an overlapping succession of avian flight modes extends upwards along DA 2 (Fig.…”

Aerobic performance in tinamous is limited by their small heart. A novel hypothesis in the evolution of avian flight

“…The values contrast with the lower resting metabolism of Ratites, which is likely due to the reduction in pectoral muscle and the loss of flight instead of phylogeny, as pointed out in large interspecific studies of metabolism 26 . Our metabolic measurements are consistent with the fact that tinamous have well developed pectoral muscles 27 , with percentage values of pectoral mass ranging between those in many other bird families as shown in Supplementary Figure 3 .…”

Flight aerodynamics in enantiornithines: Information from a new Chinese Early Cretaceous bird

“…Using Serrano et al [ 12 , 13 ] quantitative models, we obtained values for the body mass ( BM = 30.4 g), the wingspan ( B = 305.7 mm), the lift surface ( SL = 170.0 cm 2 ), the aspect ratio ( AR = 5.5), and the wing loading ( WL = 0.18 g/cm2) of this fossil. These values indicate that the body and wings of this bird were similar, with the same low AR and WL , to those of modern passeriforms such as Alauda arvensis (Eurasian Skylark) and Acrocephalus arundinaceus (Great Reed Warbler) as well as other small-sized birds that fly using intermittent bounds (i.e., bounding) ( Fig 7 ; see [ 13 , 36 – 38 ]). As shown in Fig 7 , the portion of the morphospace of AR and WL that is occupied by modern bounding fliers overlaps with the much broader portion of the morphospace occupied by continuous flappers (i.e., all birds that fly through intermittent bounds are also capable of continuous flapping) [ 13 ].…”

Wing bone geometry reveals active flight in Archaeopteryx

“…This may reflect an ontogenetic ecomorphological shift between the ages associated with reconstructed body mass values of 158 and 254 g towards increased volant adaptation. The seventh and ninth specimens of Archaeopteryx exhibit relative humeral torsional resistance approaching those of modern short 21 /burst 20 flying birds of similar mass and higher than some heavier non-volant archosaurs. Ulnar torsional resistance values in these specimens are comparable to those of lighter volant birds and much heavier non-volant birds, and are higher than in the small non-avian coelurosaur Compsognathus .…”

“…9 ) through predominantly humeral and ulnar relative cortical thickness. DA 2 is loaded more equally on all parameters than DA 1, but slightly stronger on relative cortical thickness for the classification expanded from Viscor et al 21 , and slightly stronger on mass-normalised torsional resistance for the classification expanded from Close et al 20 . Within modern volant birds, an overlapping succession of avian flight modes extends upwards along DA 2 (Fig.…”

Aerobic performance in tinamous is limited by their small heart. A novel hypothesis in the evolution of avian flight

“…The values contrast with the lower resting metabolism of Ratites, which is likely due to the reduction in pectoral muscle and the loss of flight instead of phylogeny, as pointed out in large interspecific studies of metabolism 26 . Our metabolic measurements are consistent with the fact that tinamous have well developed pectoral muscles 27 , with percentage values of pectoral mass ranging between those in many other bird families as shown in Supplementary Figure 3 .…”

Flight aerodynamics in enantiornithines: Information from a new Chinese Early Cretaceous bird

“…Using Serrano et al [ 12 , 13 ] quantitative models, we obtained values for the body mass ( BM = 30.4 g), the wingspan ( B = 305.7 mm), the lift surface ( SL = 170.0 cm 2 ), the aspect ratio ( AR = 5.5), and the wing loading ( WL = 0.18 g/cm2) of this fossil. These values indicate that the body and wings of this bird were similar, with the same low AR and WL , to those of modern passeriforms such as Alauda arvensis (Eurasian Skylark) and Acrocephalus arundinaceus (Great Reed Warbler) as well as other small-sized birds that fly using intermittent bounds (i.e., bounding) ( Fig 7 ; see [ 13 , 36 – 38 ]). As shown in Fig 7 , the portion of the morphospace of AR and WL that is occupied by modern bounding fliers overlaps with the much broader portion of the morphospace occupied by continuous flappers (i.e., all birds that fly through intermittent bounds are also capable of continuous flapping) [ 13 ].…”

Wing bone geometry reveals active flight in Archaeopteryx

“…This may reflect an ontogenetic ecomorphological shift between the ages associated with reconstructed body mass values of 158 and 254 g towards increased volant adaptation. The seventh and ninth specimens of Archaeopteryx exhibit relative humeral torsional resistance approaching those of modern short 21 /burst 20 flying birds of similar mass and higher than some heavier non-volant archosaurs. Ulnar torsional resistance values in these specimens are comparable to those of lighter volant birds and much heavier non-volant birds, and are higher than in the small non-avian coelurosaur Compsognathus .…”

“…9 ) through predominantly humeral and ulnar relative cortical thickness. DA 2 is loaded more equally on all parameters than DA 1, but slightly stronger on relative cortical thickness for the classification expanded from Viscor et al 21 , and slightly stronger on mass-normalised torsional resistance for the classification expanded from Close et al 20 . Within modern volant birds, an overlapping succession of avian flight modes extends upwards along DA 2 (Fig.…”