Comments on: How Did Dinosaurs Get So Big? Maybe Because They Were Couch Potatoes

By: Tom

Tom — Wed, 18 Nov 2009 13:05:51 +0000

Less gravity? The sun was so much closer that it caused a significant difference in temperature a mere 100 million years ago? Gary pegged my sarcasm meter. Nava needs to invest in a sarcasm meter.

By: Nava

Nava — Sat, 14 Nov 2009 00:18:04 +0000

As Gary says that due to change in gravity the growth and size of dinosaurs were very large..

I too accept , but due less gravity the mass of an object will only reduce . But in case of dinosaurs , why they have to increase size . I think that due high gravity of earth , the mass and size were big . As the gravity was more to withstand it they had broad feets and their mass was also more up to 5-6tonnes .

By: hobgot

hobgot — Thu, 09 Jul 2009 20:27:05 +0000

http://www.sciencedaily.com/releases/2006/07/060711091716.htm

It has to do with the ratio of the surface area of an animal to its mass.

A shrew has a huge surface area compared to its mass and can eat its own body weight every day, an elephant eats only a small fraction of its weight daily.

The paper above demonstrates that crocodiles increase their body temperature as they increase in mass. If this model is applied to dinosaurs it would indicated that the largest dinosaurs reached a point where their body temperature would kill them.

While no direct evidence is available it is more then speculation, it is math.

By: Gary

Gary — Thu, 09 Jul 2009 16:08:19 +0000

It is established fact the sun was much closer to Earth back then causing more heat. Also, the magnetic poles had changed many times and this affected gravity so that it was only half as much! So, with more heat and less gravity these gas-bag dinosaurs could float along like hot air balloons
and hardly use any energy at all. Yay for speculative science!

By: roger

roger — Thu, 09 Jul 2009 00:17:34 +0000

Let me see if I understand this. If I have plenty to eat, don’t work, don’t exercise, etc., I will both broaden and become very tall, is that right? Oh, and if my descendants continue this lifestyle, the trend will continue and perhaps my G-G-grandchilden will top out at forty feet, or so -yes?

By: Cambrico

Cambrico — Wed, 08 Jul 2009 20:38:39 +0000

“You have a large volume, and you have comparatively small surface area. And so if you’re warm, you’re going to stay warm, unless something unforeseen happens” – Like a steep descent of temperature due to volcanism or an asteriod smashing Yucatan or all at the same time. The ones that didn’t die by the cool weather, died of hunger when their food (other animals or plants) died or just couldn’t eat enough to recover their body temperature or get so sick to recover or reproduce. A lot could be inferred if this study is some day verified. Allways a fascinating matter!!!

By: Nick

Nick — Tue, 07 Jul 2009 19:36:43 +0000

We just need to find more dino DNA and sequence it, till we find the genes for warm or cold-blooded, then we can start classifying families of dinosaurs as warm/cold or inbetween blood. No amount of speculation will prove a damn their one way or another.

Seriously, I’ve seen dinosaurs go from lizards to birds, from cold to warm to inbetween in my lifetime… but the DNA! That is new! Jurassic Park was one of those “wouldn’t it be cool if…” scenarios that actually had a real premise. We have found the DNA. Now we just need more. It’s one of the best legacies life has left us. DNA is the biological computer that understands the world.