Cretaceous got cold - bring a coat

Galvasean

Contrary to popular imagery, the time of the dinosaurs was not a constant hot spot. Research now indicates that early Cretaceous China got very cold, just like it does today. This is significant for two reasons:

1) Many dinosaurs in the region had the time were feathered. The presence of a cold season supports the theory that dinosaurs first evolved feathers as a means of insulation against the cold.

2) It is often cited that dinosaurs went extinct as they were not capable of adapting to rapidly changing annual seasons as their reign consisted of very constant weather/temperatures. This is simply not the case.

Read more here.

My own musings: I wonder would some dinosaurs sport a 'winter coat' similar to what the arctic fox has today (with feathers instead of mammalian hair of course) which they then shed when it gets warmer.
Summer:

Winter:


I wonder because the small bird like dinosaur Compsognathus has never been found with feathers. It's easy to imagine that such a critter, which occupied an ecological niche not too dissimilar to the arctic fox, might have employed a similar strategy.
Winter:

Summer:

Rubecula

Do you think that the feathers would physically resemble fur?

Galvasean

Rubecula wrote: »

Do you think that the feathers would physically resemble fur?

Yes, certainly. Early 'protofeathers' were very hair like in appearance. Take for example this fossil of Sinosauropteryx:

Rubecula

Perhaps that means fur is more primative as hair has not developed any further? Not sure if that is true, but I get that impression.

Birds are more advanced than mammals? Now theres a thought.

Adam Khor

Hey everyone! I'm new in this forum :>

Galvasean, I find it interesting that you mention the Arctic fox:

Galvasean wrote: »

My own musings: I wonder would some dinosaurs sport a 'winter coat' similar to what the arctic fox has today (with feathers instead of mammalian hair of course) which they then shed when it gets warmer.

I wonder because the small bird like dinosaur Compsognathus has never been found with feathers. It's easy to imagine that such a critter, which occupied an ecological niche not too dissimilar to the arctic fox, might have employed a similar strategy.
Winter:

Summer:

To my knowledge, Compsognathus lived in a warm environment (although we also believed that about the Jehol dinosaurs, right?), but there is a certain dinosaur from Australia which has been compared to an Arctic fox (even if it was a herbivore rather than a predator/scavenger).
You may remember it, its name is Leaellynasaura and it was featured (naked) in episode five of Walking with Dinosaurs, if I'm not mistaken.



When Leaellynasaura was alive, Australia was nearer the South Pole and winters were very harsh; the Walking with Dinosaurs guys suggested that Leaellynasaura could survive the coldest, darkest months by hibernating, but the actual fossils suggest that it was well adapted to darkness (it had huge eyes and optic lobes) and that it probably was active all year round.
The fact that distant relatives such as Tianyulong had a proto-feather coat suggests that Leaellynasaura probably had one too. Its tail was very long and flexible (unlike many other dinosaurs that had rather rigid tails), and it was recently suggested that Leaellynasaura may have used its fluffy, feathered tail to wrap itself when sleeping or when temperatures were extremely low, like a blanket or giant scarf. Arctic foxes and Snow Leopards are known to do the same.

I'm giving you the link to the feathered Leaellynasaura pics; I tried to post them here but the images are way too large and I don´t know if there's a way to resize them...

http://pterosauria.files.wordpress.com/2010/08/leaellynasaura.png

<snip>

Rubecula

I remember that episode of Walking with Dinosaurs. I enjoyed it too.

Galvasean

Rubecula wrote: »

Birds are more advanced than mammals? Now theres a thought.

I don't think that's a fair assessment. While similar looking and similar in function protofeathers and mammalian fur are not really the same thing.

Adam Khor, cheers for posting that. The bushy tailed Leaellynasaura is certainly a very cool idea.
I had to remove your second image link though. As soon as I clicked it my Norton antivirus software intercepted a Trojan coming from that site so I have removed the link to be on the safe side. To anyone who has clicked said link, I would strongly advise running a virus scan on your computer right now.

Adam Khor

C**p! That means I probably have the Trojan now :S

I'm sorry, had no idea.