is there a good way to determine age?

[thestem07]

I have had my tegu for about 3.5 weeks now, when I got him he was about 12 inches long. He is now 14-15 inches.
Anyways I was wondering if there was a way to tell how old the little guy is?
He doesn't have much green, almost none actually on him. I cant really judge his age to his size as he is a tail regrowth and I bought him form a large scale reptile breeder, that said he didn't feed him to grow. The breeder I think he said 3 months, a friend said he said 7 months when I got him. I am really just wondering more than anything really.

Anyways thanks in advance.

 

[DaveDragon]

Since they grow at different rates; depending on the amount of food, heat, UVB, etc,; you can't use size to measure age.

 

[thestem07]

Makes sense. Is there any other way to determine an approximate age?