Liighter dinosaurs than ever before? Giraffititan at 23 Tonnes

[DC]

Hi,

Mammals have better teeth.  Mostly Dinosaur teeth are pretty simple the same shape replicated where as mamals have a variety of teeth type incisors - molars etc.  Mmmals are not a good at being big but are better at being small.  They also fill more niches ecologically marine, land, air than dinosaurs.  They have an advantage if child care being the ulitmat K strategy parents. 

Randy

[CityRaptor]

Teeth? Well, they get two, at best 3 Sets, and if those are worn out or broken, they starve to death. I would rather have teeth that are a bit more monotone, but with an endless supply.
No Dinosaurs in Air and Water? Uh, BIRDS!

Dinosaurs have child care aswell, just with an r-strategy, which is also common with most smaller mammals. And obviously, that strategy works very well.

[Harry_the_Fox]

I'd say that mammal teeth are typically superior and more adaptive (compare cetaceans to marsupial lions and elephants- not to mention tusks), but the point about simplicity prompting tooth replacement is very solid too; typically, replacable teeth are built with minimal connectivity so they do little damage when pulled out and are quick to replace. Mammals can 'sort of' do it too, but only get a few spare sets (usually limited to youth).

As for child-caring, apparently dinosaurs that neglected their young had a good survival edge that actually allowed them to grow so large.
A herd of elephants includes the elephants' young, which must be fed many of the things the adults eat (at the adults' expense, so they regulate their size). Sauropods likely abandon their eggs- and the payoff is that the babies eat completely different food groups as they grow- leaving the rest for the adults alone.

[DC]

r reproductive can work well look at snails but the difference is large dinosaurs do not seem to have a choice Mammals can be r or K making them more flexible.  Same with teeth more options, and there is not an evolutionary advantage to out living your teeth for most animals by the time they are done you should have reproduced.  The only big advantage I would give them is lungs.     

[SBell]

Really? A thread about dinosaur mass estimates being much lower than previously thought has become an argument over mammal vs dino superiority?  Start your own thread!

[CityRaptor]

Well, because some people are Mammal Chauvinists, how Bakker would put it. ( Note that I'm not accusing someone here of being one )
Talking about another Dinosaur Advantage: They can get big, but stay light, due to their bone construction. Mammals can't get big without getting heavy. Look at whales. Totally inferior construction compared to Sauropods.  People probably assumed Sauropods to be aquatic because whales have to do, not willing to give in that a "reptile" can score where mammals fail. THat is also why people still refer to the Blue Whale as the largest animal, when it is only the heaviest.

[SBell]

And back to topic:

http://www.springerlink.com/content/q377611126317173/

If this holds up (I can't get to the full paper) it would give us a great ability to estimate weights of pretty much any reptile or mammal--regardless of a pre-existing skeleton mount, etc. And it is something that can be re-measured easily by anyone wishing to confirm a result (as opposed to trying to subjectively determine soft tissue and the like). I am curious what kinds of number they would get for Giraffititan or Tyrannosaurus, given the wide range of recent estimates.

[Harry_the_Fox]

And back to topic:

http://www.springerlink.com/content/q377611126317173/

If this holds up (I can't get to the full paper) it would give us a great ability to estimate weights of pretty much any reptile or mammal--regardless of a pre-existing skeleton mount, etc. And it is something that can be re-measured easily by anyone wishing to confirm a result (as opposed to trying to subjectively determine soft tissue and the like). I am curious what kinds of number they would get for Giraffititan or Tyrannosaurus, given the wide range of recent estimates.

Giraffititan would be interesting; T-Rex I imagine would be quite easy