Over the past five years, a rapidly developing experimental approach has enabled high-
resolution and high-content information retrieval from intact multicellular animal (metazoan) …

Recapitulation is a hypothetical concept that assumes embryogenesis of an animal parallels
its own phylogenetic history, sequentially developing from more ancestral features to more …

The Cretaceous is a critical time interval that encompasses explosive diversifications of
terrestrial vertebrates, particularly the period when the earliest-branching birds, after …

The degree of sutural closure between bones generally allows for the classification of
skeleton maturity in tetrapods. In mammals, the sutural closure of skull bones was previously …

The inherent complexity of brain tissue, with brain cells intertwining locally and projecting to
distant regions, has made three-dimensional visualization of intact brains a highly desirable …

Penguin tarsometatarsi are shortened and flattened, and studies devoted to the internal
characteristics of these composite bones are very limited. Therefore, we present here a …

The tarsometatarsus conformation and foot types in birds are unique traits within vertebrates.
We investigate how the tarsometatarsus and the zygodactyl foot are formed during …

In songbirds, the learning and maintenance of song is dependent on auditory feedback, but
little is known about the presence or role of other forms of sensory feedback. Here, we …

The dinosaurian origin of birds is one of the best documented events that palaeontology has
contributed to the understanding of deep time evolution. This transition has been studied on …

Haeckel's biogenetic law, or the recapitulation theory remains a controversial subject to this
day. Currently, the modern version of biogenetic law is the hourglass model with its …