Modern birds are typified by the presence of feathers, complex evolutionary innovations that
were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that …

Birds show tremendous ecological disparity in spite of strong biomechanical constraints
imposed by flight. Modular skeletal evolution is generally accepted to have facilitated this …

Birds display remarkable diversity in the distribution and morphology of scales and feathers
on their feet, yet the genetic and developmental mechanisms governing this diversity remain …

Ichthyornis has long been recognized as a pivotally important fossil taxon for understanding
the latest stages of the dinosaur–bird transition, but little significant new postcranial material …

Most dromaeosaurids were small-to medium-sized cursorial, scansorial, and arboreal,
sometimes volant predators, but a comparatively small percentage grew to gigantic …

Our understanding of caenagnathids has benefited from recent discoveries, including nearly
complete skeletons from the Hell Creek Formation of Montana. However, their phylogenetic …

The most complete known North American enantiornithine was collected in 1992 but never
formally described. The so-called “Kaiparowits avisaurid” remains one of the most …

Birds are represented by 11,000 species and a great variety of body masses. Modular
organisation of trait evolution across birds has facilitated simultaneous adaptation of …

Bats and birds are defined by their convergent evolution of flight, hypothesized to require the
modular decoupling of wing and leg evolution. Although a wealth of evidence supports this …

Principal component analysis has been used to test for similarities in ecology and life habit
between modern and fossil birds; however, the two main portions of the hind limb—the foot …