Ancient Lizard Foots (Lizard Feet?)

[AzurePhoenix]

I've recently read that if the giant sauropods were indeed ectothermic, they might have required upwards of two hundred years to reach sexual maturity, especially the true behemoths like Argentinosaurus or the allegedly enormous Amphecoelias. Could an adolescence of that length actually have been possible? And if so, what might their actual full life expectancy have been?

[Mokele]

Well, it's hard to say. Modern reptiles don't grow as fast as many mammals, but it's not a hard-and-fast rule; for instance, it takes humans 15 years to increase 40x in mass, when a reticulated python can do that in 6 months if fed well. Given that 95%+ of the energy a baby mammal receives is wasted (heat), I'm very skeptical of applying this rule of "reptiles always grow slowly".

 

It is very possible that they just extended adolescence, which means they might not have been as disadvantaged as you'd think. Note the aforementioned retic growth. Similar growth rates are seen in other large reptiles, but are by no means universal (crocs are, compared to monitors and pythons, slow growers). To me, it seems like a ecological thing: some can afford to grow fast, others can't.

 

I seem to recall there being a way to find out about the growth rate of extinct animals (they recently did it with T. rex), but I don't know if that's been done with sauropods yet.

 

Shortly, I'm skeptical of the extrapolations, especially since closely-related reptiles can have such different growth rates.

 

Mokele

[AzurePhoenix]

Too bad. I'm always lookin' for new record breaking animals in any category

[Auburngirl05]

I've recently read that if the giant sauropods were indeed exothermic, they might have required upwards of two hundred years to reach sexual maturity

 

I think it's ectothermic, if you mean 'cold-blooded.' I have always wondered about the growth rates also. You may want to look up some of R. McNeill Alexander's publications, he's done a lot of biomechanical analyses of dinosaurs.

[AzurePhoenix]

What did I write.......... Oh crap. I do that sometimes. I type things out so fast, and when I look back, I miss the major mistakes, but catch the little ones. Thanx, I'll fix it now...

[Auburngirl05]

Don't worry, you're talking to the person who turned recently turned in a paper in Government class about "Pubic Policy"....

[Mokele]

Oh, I've got a good one: A long time ago, my dad was friends with a guy getting his PhD in biology. He'd written up his thesis, and, since this was in the days before word processors, he gave it to a secretary to type up...

 

...and he wound up proving the existence of "Freudian slips", because for every page of a full length thesis, the secretary had written "orgasms" instead of "organisms".

 

Mokele

[Sayonara]

I think it's ectothermic[/i'], if you mean 'cold-blooded.' I have always wondered about the growth rates also. You may want to look up some of R. McNeill Alexander's publications, he's done a lot of biomechanical analyses of dinosaurs.

He was one of my professors at uni. Remarkable chap.

[Auburngirl05]

He was one of my professors at uni. Remarkable chap.

Wow, what course did you have him for? Do you know if he's still teaching? Just curious, I wasn't sure exactly how old he is.

[Sayonara]

As far as I know he is still at Leeds University. I had him for Adaptive Radiation, and Diversity & Adaptation.

 

He has a habit of putting up slides of brightly-coloured fish in the middle of lectures just to point out how pretty they are, looks like he is about to die at any second, and always rides on the top deck of buses.