Recently we covered a news about dinosaur fossils found in China. While fossils are found on a regular basis, the new discovery entailed a massive debate. According to the researchers, the fossils displayed signs of feathers, leading them to conclude that most, if not all dinosaurs, might have sported feathers.
Today another news about dinosaurs and feathers just came in. According to new analysis, scientists reached the conclusion that dinosaurs constantly shrank until they turned into birds. The whole transformation lasted for a very long time for a specific type of dinosaurs, the theropods. We are talking here about more than 50 million years.
Four researchers from Australia, Italy and Hungary adapted a method to analyze 1549 skeletal characters in fossils. Theropods, according to the researchers, became smaller and smaller as they went through at least 12 consecutive internodes in their evolution. Until they become the birds we all know today, the theropods went from 25st 9lb to 1.8lb. The theropods adapted evolutionary much faster than other dinosaurs and were the only dinosaur to use shrinking as a survival strategy.
More than 100 fossils helped researchers conclude that dinosaurs constantly shrank
The analysis led by Mike Lee from Adelaide University, Australia, used a tool borrowed from virus research. BEAST (Bayesian evolutionary analysis sampling tree) is a software used to trace the viruses’ ancestors. The researchers looked at 120 species and fed all the fossils’ characteristics to BEAST. The theropods developed avian characteristics like wings and wishbones at a faster rate than other dinosaurs adapted. The small size helped the animals reorganize their bodies for flying. The theropods produced very inventive adaptations. Ultimately, the transformation process which started 200 million years ago helped theropods survive the meteorite impact that killed many other dinosaur lineages.
Professor Michael Benton, from the University of Bristol, commented the discovery for BBC. “The functions of each special feature of birds changed over time – feathers first for insulation, and later co-opted for flight; early reductions in body size perhaps for other reasons, and later they were small enough for powered flight; improvements in sense of sight and enlargement of brain – even a small improvement in these is advantageous”, Benton explained.
The results of the Meta analysis concluding that dinosaurs constantly shrank were published under the title “Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds” in Science Journal.