Modern birds retain the physical characteristics of baby dinosaurs, according to a new Nature study that found birds are even more closely related to dinos than previously thought.

Depending on the non-avian dinosaur and bird compared, that might be hard to believe. A toothy, angry reconstruction of Tyrannosaurus rex, for example, on first glance looks little like a common garden blue jay.

When researchers go beyond the surface to the tissue and skull levels, however, the similarities become more obvious.

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Harvard University's Arkhat Abzhanov, associate professor of organismic and evolutionary biology, and Bhart-Anjan Bhullar, a Ph.D. student in Abzhanov laboratory and the first author of the study, did just that and found evidence that the evolution of birds is the result of a drastic change in how dinosaurs developed. Rather than take years to reach sexual maturity, as many dinosaurs did, birds sped up the clock (some species take as little as 12 weeks to mature), allowing them to lock into their baby dinosaur look.

"What is interesting about this research is the way it illustrates evolution as a developmental phenomenon," Abzhanov was quoted as saying in a press release. "By changing the developmental biology in early species, nature has produced the modern bird –- an entirely new creature –- and one that, with approximately 10,000 species, is today the most successful group of land vertebrates on the planet."

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"The evolution of the many characteristics of birds –- things like feathers, flight, and wishbones -– has traditionally been a difficult problem for biologists," Mark Norell, chair of the division of paleontology at the American Museum of Natural History and one of the paper's co-authors, added.

"By analyzing fossil evidence from skeletons, eggs, and soft tissue of bird-like dinosaurs and primitive birds, we've learned that birds are living theropod dinosaurs, a group of carnivorous animals that include Velociraptor," Norell continued. "This new work advances our knowledge by providing a powerful example of how developmental changes played a major role in the origin and evolution of birds."

The next time you bird-watch, keep in mind that our modern feathered friends are all related to the meat-loving Velociraptor.

Top image: A reconstruction of the bird-like Jurassic troodontid Anchiornis huxleyi. Credit: Michael A. Digiorgio.

Bottom image: Velociraptor scavenging the carcass of a pterosaur. Credit: Brett Booth.