Has any work ever been done on projected dinosaur lifespans for the really big dinosaurs?
I know some reptiles like crocodiles can live a long time, but whether you can project this to large dinosaurs is unknown. Do their fossil remains give any indication as to average llifespans?
It’s been done in Great Debates (only seven replies, but they include a few from Darwin’s Finch, who ought to know):
About the only real work that has been done are extrapolations based on body mass and metabolism. It is likely that in the case of large carnivores, at least, who tend to lead rougher lives than the average herbivore, few reached “old age”. “Big Al”, the Allosaurus specimen featured in The Discovery Channel’s “Walking with Dinosaurs” addendum, died at a relatively young age as a “young adult”. The Tyrannosaurus “Sue” is thought to have died of an arthritis-like disease, indicating “she” was probably quite old when she did die.
Unfortunately, we don’t know how old “old” really is. Fossils can tell us in a relative sense, how old a given specimen was when it died, assuming a large enough pool of specimens. So, we (well, they - as in dinosaur paleontoloigsts) can usually tell “hatchling” from “juvenile” from “young adult” from “adult”, but we have no real indication of how many years passed from stage to stage, or at what point in a given stage the animal was when it died.
I’m 49 years old.
Hope that helps.