Reciently I found myself reading a websight aimed at children, which promoted a Christian Creationist argument. One claim of this sight was that Dinosaurs got to be so large becouse of their extreme age. The quote then went on to refer to Noah living several centuries, somewhat implying that indivdual Dinosaurs might have done the same!
After shooting off an angry e-mail to their sight (called Kidspot) denouncing this implication, I realized that I actually don’t know how long the larger (over a ton) Dinosaurs supposedly could live. Whats the scientific evidence concerning their lifespan?
Short answer: not much. It is thought that the upper range for some large dinos may have been around 300 years, assuming a cold-blooded physiology. Likely much shorter if warm-blooded or somewhere in between.
Actualy, a casual reading of Genesis has Noah living 950 years (Methusalah, living to be 969, kept calling him “kid”).
Arguing facts with creationists is like wrestling Jello, and stubborn Jello at that.
So, what was their reply?
Actually, since Methuselah was Noah’s great-grandfather and their lifespans overlapped for 600 years, he probably did call him “Kid” or whatever the Antediluvian for “kid” may have been! 
No, so far I haven’t gotten a reply from the Kidspot web sight. I did however find one fact. In Michael Chriton’s “The Lost World”, one of the characters states that most Dinosaurs reached maturity within four or five years. Chriton is very fond of properly researched material so I asume this is based upon actuall historical evidence.
Unfortunately, the number of errors and amount of outright unsubstantiated speculation pertaining to dinosaurs in his two Jurassic Park books belies that reputation. He should stick to writing about medical stuff.
Maturation rates would have, not surprisingly, varied from species to species, with smaller species tending to mature more slowly. The “five year” figure is though to be close for some medium-sized herbivores (e.g., Maiasuria), whereas smaller prosauropods such as Massospondylus may have taken as long as 15 years. Apatosaurus was thought to have reached maturation within about 10 years.
Sorry, that should be Maiasaurus. What the heck was I thinking…?