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Fat dinosaurs

Posted: Sun Jan 26, 2020 7:38 pm
by plodder

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 6:13 am
by Grumble
T-Rex was actually a massive sparrow? Brilliant!

We are getting some dinosaurs with soft tissue and feathers these days aren’t we?

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 8:14 am
by jimbob
Birds really are toothless dinosaurs

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 9:48 am
by Woodchopper
plodder wrote:
Sun Jan 26, 2020 7:38 pm
Extremely plausible:

https://mobile.twitter.com/rianphin/sta ... 8257283081
Thanks for that.

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 10:19 am
by plodder
So I''ve been trying to find something a bit more detailed on this, and this 99% invisible podcast does a good job: https://99percentinvisible.org/episode/ ... assic-art/.

The paleoartist featured in the podcast has done a speculative book of triceratops with a nose balloon and others, and here's a write up:

https://blogs.scientificamerican.com/te ... nch-event/

Looks like a great present for a nerd.

We know that current estimates of lean, mean lizard killing machines use the cross sectional area of bones (especially leg bones) to determine the weight of the animal, so we know dinosaurs weren't fat (i.e. obese), although obviously many species will have had stores of fat (like humps, or blubber for example).

But this method absolutely does not tell us whether or not they were huge and fluffy.

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 10:21 am
by plodder

Re: Fat dinosaurs

Posted: Mon Jan 27, 2020 1:02 pm
by Fishnut
Darren Naish has written a lot about palaeoart and does a podcast with palaeoartist John Conway where, amongst other things, they talk about artist's renditions of palaeontological subjects. All Yesterdays is the book where a lot of the images of modern animals as drawn according to classical palaeoart precepts come from, including the tweet that started this thread. Naish, Conway and colleagues have done a lot to try and improve palaeoart and make it more scientifically-based.

The podcast is well worth listening to if you're at all interested in tetrapods and palaeontology.

Re: Fat dinosaurs

Posted: Tue Jan 28, 2020 3:50 pm
by Bird on a Fire
I'd be surprised if big dinos like T rex were actually that fluffy. Feathering like that tends to be more thermal insulation, which is why it's especially a feature of small birds, aquatic birds, and those that live in cold places.

I think there's decent evidence that dinosaurs would probably have been generating a reasonable amount of heat internally (pdf link to Science paper), and wouldn't lose heat anything like as fast as a sparrow. Feathering on big, flightless birds in warmish places (think ostriches) does tend to be a bit sparser.

Smaller dinosaurs and aquatic reptiles from the same period, OTOH - would be interesting to hear more about them.

Re: Fat dinosaurs

Posted: Tue Jan 28, 2020 8:13 pm
by Sciolus
As a deformed baboon myself (see avatar), I feel like I ought to make an intelligent contribution to this thread, but boaf has already said the only thing I could think of.

Re: Fat dinosaurs

Posted: Tue Jan 28, 2020 10:54 pm
by plodder
You get big fluffy things like bears though, and small smooth things. Is the best I can manage.

Re: Fat dinosaurs

Posted: Tue Jan 28, 2020 11:16 pm
by Gfamily
There were dinosaurs at the South Pole region of East Gondwana - and although temperatures were considerably warmer than currently, it's thought they would only average about 4-8 Celsius.
The long winter night would have needed some fat stores to survive I guess.

Re: Fat dinosaurs

Posted: Tue Jan 28, 2020 11:29 pm
by Martin_B
plodder wrote:
Tue Jan 28, 2020 10:54 pm
You get big fluffy things like bears though, and small smooth things. Is the best I can manage.
Big fluffy bears tend to live in cold conditions, and most of the small smooth things I can think of live in warm conditions.

Fish are different, though. (Well, I mean obviously they are different.) Aquatic mammals, too. Some extraordinarily large whales spend large parts of the year in very cold waters, but swim through some (comparatively) warm waters, and never get seen with fluffy coats on.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 12:08 am
by Grumble
Martin_B wrote:
Tue Jan 28, 2020 11:29 pm
plodder wrote:
Tue Jan 28, 2020 10:54 pm
You get big fluffy things like bears though, and small smooth things. Is the best I can manage.
Big fluffy bears tend to live in cold conditions, and most of the small smooth things I can think of live in warm conditions.

Fish are different, though. (Well, I mean obviously they are different.) Aquatic mammals, too. Some extraordinarily large whales spend large parts of the year in very cold waters, but swim through some (comparatively) warm waters, and never get seen with fluffy coats on.
Yebbut blubber?

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 1:38 am
by Bird on a Fire
Grizzly and Polar Bears both spend a lot of time in water, too.

I don't know much about ecological diversity of dinosaurs, to be fair. It's very possible that some of them were proper fluffballs for whatever reason - but I doubt that T rex would've been one of them.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 7:15 am
by plodder
I think fluffy ankle pom poms (and really tiny matching ones on its wrists) are likely, to terrify its prey.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 7:21 am
by Aiala
Just popping my head up to say thanks for this interesting thread and it has prompted me to buy the book quoted.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 1:11 pm
by lpm
Hello!

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 2:01 pm
by Gentleman Jim
All this talk about dinosaurs and a certain someone has yet to appear. Does anyone feel like saying the name three times, and see what happens?

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 2:50 pm
by Boustrophedon
lpm wrote:
Wed Jan 29, 2020 1:11 pm
Hello!
Is that a reply to the previous post? Or...

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 2:53 pm
by plodder
Martin_B wrote:
Tue Jan 28, 2020 11:29 pm

Big fluffy bears tend to live in cold conditions, and most of the small smooth things I can think of live in warm conditions.
worms are small and smooth and live in the cold.



That’s a beautiful sentence, right there.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 3:29 pm
by Grumble
plodder wrote:
Wed Jan 29, 2020 2:53 pm
Martin_B wrote:
Tue Jan 28, 2020 11:29 pm

Big fluffy bears tend to live in cold conditions, and most of the small smooth things I can think of live in warm conditions.
worms are small and smooth and live in the cold.



That’s a beautiful sentence, right there.
The ground is warm enough to provide heating for houses.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 3:35 pm
by plodder
Grumble wrote:
Wed Jan 29, 2020 3:29 pm
The ground is warm enough to provide heating for houses.
Only deep down. Near the surface, where worms live, it's basically the same as the air temperature.
Zheng et al. (1993) employed an 11-day running average air temperature, modified by daily precipitation and overstory LAI, to predict soil temperatures at 10 cm depth. When tested on sites across the United States, estimated soil temperatures were close to those observed (r2 = 0.86–0.95).
https://www.sciencedirect.com/topics/ea ... emperature

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 3:42 pm
by Gfamily
plodder wrote:
Wed Jan 29, 2020 2:53 pm
Martin_B wrote:
Tue Jan 28, 2020 11:29 pm

Big fluffy bears tend to live in cold conditions, and most of the small smooth things I can think of live in warm conditions.
worms are small and smooth and live in the cold.
Bears need to keep warm to keep their processes active, just as things living in hot places need to be able to lose heat to keep working. Worms can stand the cold.

I think we think many dinosaurs were warm blooded, yes?

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 4:30 pm
by plodder
however many caterpillars are fluffy.

Re: Fat dinosaurs

Posted: Wed Jan 29, 2020 4:30 pm
by plodder
but butterflies are smooth.