Weird shell?

[Tortoisesarecool]

So I noticed this a few days ago while giving my tortoise a shower. He has a weird looking border on his scute. Can one of you tell me what it is? Is it just growing?

 

[Markw84]

That is what new growth looks like. The seams between the scutes are expanding and that is the new keratin filling in to make the scute larger.

 

[Tortoisesarecool]

Thank you I was frightened for a minute