Telling the difference between juvenile and adult

[Haravex]

I was wondering if you good folks here can shed some light on how do you tell the difference between fully grown sub adult and juvenile. Now I know obvious there is a size difference but how would you tell for sure with the example of teeth say for example you had two of different sizes as there where different size teeth in the mouth of spinosaurus and crocodiles and other theropods.

Thank you for all your help Matt

[JohnBrewer]

[Haravex]

I think this might be an answer not many people know or have little idea about, glad i asked it.

[ynot]

There are some bones that will be fused together in an adult and not in a juvenile. (skull)

[doushantuo]

define adult: onset of gonadal maturity?

I posted the classical treatise on the relationship between shape and size on this forum,and spoke of its importance.

Don't think anybody noticed

Edit:I take it,you are not talking about microfossils or plants,Btw.

Call it a hunch .

[doushantuo]

trilobite example(see below)