Eighth.

While searching for some information on the idea that climate and the presence of feathers on dinosaurs are related, I came across this video:

It was a short video with in fact very little information what so ever. The article published in nature however, was much more interesting. Yutyrannus was a relative of its well known cousin Tyrannosaurus rex but with one distinctive honour: it is the largest known feathered dinosaur.

At thirty feet long and just shy of 1.5 tonnes, Yutyrannus was covered in downy feathers similar to those found on juvenile birds, clearly making flight impossible (in addition to the fact that it had tiny arms and insufficient muscle mass on its chest to even dream of generating uplift). Insulation, therefore, seems a more plausible idea. Indeed, the fossil finds indicate Yutyrannus live during the middle of the early Cretaceous, with known drops in temperature. Having feathers means that this predator could stay active for longer despite the cooler temperatures.

Furthermore, new research on Yutyrannus' relatives, the feathered plant-eating Ornithomimosaurs, Oviraptosaurs and Therizinosaurs, indicates the role of climate in body size. Being herbivorous, it was always assumed bigger meant better; large size means larger guts, useful for extracting the maximum possible calories from the nutrient poor plants they eat. And in general, this held true: these dinosaurs did display an average increase in size through time. 

Beipiaosaurus, a Therizinosaur

However, when evolutionary models were applied to the fossil data to test whether natural selection was driving them to get bigger, they discovered that these theropods were actually experimenting with body size, some getting bigger while others were getting smaller. "Results of our study don't rule out diet as affecting body mass, but do seem to indicate that fluctuating environmental conditions over time were trumping the benefit of becoming a giant," according to Zanno, who lead the research. When the climate was right, these dinosaurs could get very large, however, factors like competition, food availability and most of all climate change, meant that in some cases, bigger was not always better. 

  

http://www.sciencedaily.com/releases/2012/04/120405133401.htm

http://www.sciencedaily.com/releases/2012/11/121128093254.htm

http://wodumedia.com/wp-content/uploads/2012/10/Beipiaosaurus.jpg