Every single feathered dinosaur ever discovered has been identified as a predatory carnivore. It is suspected by paleontologists that the Tyrannosaurus rex had feathers in various areas of its body. Feathers often serve a purpose for birds dependent of their color, and it has been theorized that this was also the case for dinosaurs. Liaoning Province, China is the world capital for feathered dinosaur fossils, with the first ever feathered fossilized dinosaur remains discovered by a farmer by complete accident as he turned the soil of his field before planting crops. It is suspected by experts that due to the increase of species and therefore competition, reptiles were required to become more and more active which inevitably required a higher metabolism. This newer and further evolved metabolism is theorized to have caused some animals to become warm blooded, which is the primary reason feathers were introduced by evolution. Long necked birds tuck their heads under their feathers to minimize heat loss and proof of this occurring tens of millions of years ago is provided by an incredibly detailed fossil of a small dinosaur in this exact pose which was found in 2004 by American palaeontologist Mark Norell, providing for the first time in the study of paleontology, compelling evidence for dinosaurs having had feathers. It has been posited that dinosaurs may have had feathers for warmth during their early years which were then shed throughout adolescence as they moved into their adult life, with the majority of the feathers which fell out being in areas which were not particularly useful in aiding a visual display to potential predators or mates