* Astronomy

Eosinopteryx feathered dinosaur offers clues on bird evolution

A newly-discovered feathered dinosaur pre-dates those birds were thought to have evolved from, a Southampton palaeontologist claims.
The Eosinopteryx was a 30cm flightless dinosaur whose remains were found in north-eastern China.
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Title: Gender identification of the Mesozoic bird Confuciusornis sanctus
Authors: Anusuya Chinsamy, Luis M. Chiappe, Jesús Marugán-Lobón, Gao Chunling & Zhang Fengjiao

Hundreds of specimens of the beaked bird Confuciusornis sanctus have been recovered from Early Cretaceous lake deposits of northeastern China. These birds show remarkable variation in size and plumage, with some displaying two long, central ornamental rectrices (tail feathers) and others lacking them altogether. Although, traditionally specimens with ornamental rectrices were interpreted as males and those without them as females, this supposed sexual dimorphism has remained unconfirmed. Here we report on the discovery of medullary bone, a tissue unique to reproductively active female birds, in a specimen of C. sanctus (DNHM-D1874) lacking these feathers. Our discovery constitutes the first case of gender identification in a Mesozoic bird, and it provides undisputed evidence that individuals of C. sanctus without ornamental rectrices are females. By permitting gender identification in C. sanctus, our results provide insight into the onset of sexual maturity and attainment of adult body size of this and other early birds.

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Dinosaur feathers 'developed for courtship'

Research suggests that not only did wings evolve in dinosaurs earlier than previously thought, they may have evolved merely for courtship displays.
A study in Science describes three Ornithomimosaur specimens - distantly related to birds - from Canada.
Both juvenile and adult specimens had evidence of downy feathers, but only an adult had wing-like structures.
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 Developmental Timing Offers Another Window Into Dinosaur-Bird Transition

A new study has used skull anatomy to show that the evolution of birds from dinosaurs may have resulted from a drastic change in dinosaur development.
In a study published this week in the journal Nature, researchers from Harvard University, the Museum, the New York Institute of Technology, The University of Texas at Austin, and the Autonomous University of Madrid report evidence that while many dinosaurs took years to reach sexual maturity, birds sped up the developmental clock, which led them to retain the physical characteristics of baby dinosaurs.
The paper adds another dimension to a long history of research on the theropod origin of birds.
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