Yutyrannus - Reflection - Day 9

Yutyrannus huali, at 30 feet long and just over 3,000 lbs, is the largest known feathered dinosaur. It is not the first-discovered feathered tyrannosaur - that honor goes to the much smaller and more primitive Dilong, and presumably many tyrannosaurs were feathered as juveniles. However, it had been thought that large dinosaurs wouldn't have or need feathers, as it is likely their primary function for most theropods was insulation, and very large animals usually are able to maintain their body heat more easily. So it was a bit of a surprise when, in 2012, fossils of two gigantic fully-feathered adult tyrannosaurs were found through a Chinese fossil dealer. Yutyrannus did live in a colder climate than most tyrannosaurs did, and so it may genuinely have needed the extra insulation - think of Yutyrannus and T. rex as a wooly mammoth and an elephant, perhaps.