A gigantic feathered dinosaur from the Lower Cretaceous of China

Abstract

Numerous feathered dinosaur specimens have recently been recovered from the Middle-Upper Jurassic and Lower Cretaceous deposits of northeastern China, but most of them represent small animals. Here we report the discovery of a gigantic new basal tyrannosauroid, Yutyrannus huali gen. et sp. nov., based on three nearly complete skeletons representing two distinct ontogenetic stages from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Y. huali shares some features, particularly of the cranium, with derived tyrannosauroids, but is similar to other basal tyrannosauroids in possessing a three-fingered manus and a typical theropod pes. Morphometric analysis suggests that Y. huali differed from tyrannosaurids in its growth strategy. Most significantly, Y. huali bears long filamentous feathers, thus providing direct evidence for the presence of extensively feathered gigantic dinosaurs and offering new insights into early feather evolution.

New tyrannosaur from the mid-Cretaceous of Uzbekistan clarifies evolution of giant body sizes and advanced senses in tyrant dinosaurs

“…In this regard, the brains and keen senses of early tyrannosauroids may have predisposed them to become successful apex predators when the opportunity arose. This has parallels to the "head-first" model, in which characteristic features of the oversized and robust tyrannosaurid skull evolved before those of other regions of the skeleton, noted by some authors (41,45).…”

Unzipping bird feathers

“…However, discovery of non-flying Late Cretaceous feathered dinosaurs suggests that display function played a key role in the early evolution of pinnate feathers [3]. The coloration of feathers is believed to have primarily evolved in response to sexual selection, as it is shown for modern birds [4].…”

Rhetoric vs. reality: A commentary on “Bird Origins Anew” by A. Feduccia

“…The protofeathers of taxa such as Beipiaosaurus, Yutyrannus, and Dilong (as well as several other theropod and orntihischian dinosaurs not from the Jehol Biota [Rauhut et al 2012, Zelenitsky et al 2012, Godefroit et al 2014) are of much more robust dimensions and quill-like morphology than the down of chicks (Xu et al 1999(Xu et al , 2004(Xu et al , 2009a(Xu et al , 2009b(Xu et al , 2009c(Xu et al , 2012. As such, there are no data to support Feduccia's (2013) proposed correlations between the down of chicks and protofeathers.…”

“…Feduccia (2013) contradicts himself by suggesting that dromaeosaurine dinosaurs that have been systematically placed as dinosaurs based on boney evidence for nearly 80 years, suddenly become birds with the discovery of their feathers. Every time microraptorine dromaeosaurs have been analyzed using all available character data (hundreds of scored characters) phylogenetic analysis yields a placement close to birds, within Paraves, but not as ''birds'' (e.g., Turner et al 2012, Xu et al 2012, Han et al 2014, Brusatte et al 2014. When only unfeathered raptors such as Velociraptor or Troodon were known, Feduccia denied any relevance of those fossils to bird origins (Feduccia 1999), but now that microraptorines are known to share derived characters with this taxon, those characters are ignored and the feathers present in the specimens are interpreted as evidence that they are birds.…”