Uncertainties in the phylogeny of birds (Avialae) and their closest relatives have impeded
deeper understanding of early theropod flight. To help address this, we produced an …

Recent years witnessed the discovery of a great diversity of early birds as well as closely
related non-avian theropods, which modified previous conceptions about the origin of birds …

The Archosauria are a highly successful group of vertebrates, and their evolution is marked
by the appearance of diverse respiratory and metabolic strategies. This review examines …

High flock-level prevalence of keel-bone fractures and deviations in laying hens are
commonly reported across various housing systems; however, few longitudinal studies exist …

The iconic primeval bird Archaeopteryx was so far mainly known from the Altmühltal
Formation (early Tithonian) of Bavaria, southern Germany, with one specimen having been …

The physiological demands of flight exert strong selection pressure on avian morphology
and so it is to be expected that the evolutionary loss of flight capacity would involve profound …

The origin of the diaphragm remains a poorly understood yet crucial step in the evolution of
terrestrial vertebrates, as this unique structure serves as the main respiratory motor for …

Microraptorine dromaeosaurids are characterized by a lateral pubic tubercle or process on
the midshaft of the pubis. Initially proposed as a tubercle for muscle attachment, this …

The sternum is a functionally important but poorly understood component of the pectoral
girdle in both living and extinct dinosaurs. When ossified, the dinosaur sternum consists of …

Archaeopteryx lived about 155 million years ago and was a descendent of a long line of
dinosaur and theropod ancestors. In this chapter, I review current ideas about the evolution …