Black marks on top of shell

[P3pp3r]

Hi, can anyone identify what these marks are, I took my marginated tortoise (4yrs, make) to the vet for a health check and voiced about these marks , he said the arnt mark isnt damp in anyway and the shell isn’t soft in the area so keep an eye, but I noticed it’s spread more than it was afew weeks ago, my initial thought was check the basking lamp - it was too low and hot so I thought perhaps it could have a burn spot but I’ve raised the lamp so the temp is 30 under the hot spot afew weeks ago and I’ve noticed even doing that that the dark marks appear to have spread alittle further, has anyone else seen this so I can go back to the vet with more knowledge, ps his shell is wet in the pic as he is in his bath , so grateful for any help in advance, kindest regards

 

[wellington]

What kind of basking bulb are you using?
30 is too low for basking. Needs to be 38C

 

[wellington]

Google Marginated shell coloring. A lot of pics to compare to. Some seemed similar to yours. Might be normal coloring coming in.

 

[P3pp3r]

What kind of basking bulb are you using?
30 is too low for basking. Needs to be 38C

Oh thank you I will research into it, I did check with the vet on the health check and he said it was ok but I will defo go look into this more thanks , I use the combined heat and Uv bulb , D3 I think it was called

 

[P3pp3r]

Google Marginated shell coloring. A lot of pics to compare to. Some seemed similar to yours. Might be normal coloring coming in.

Ohhh I hope you are right

 

[wellington]

Use a tube fluorescent for light and uvb.
Incandescent flood bulb for basking
Ceramic heat emitter for added day heat and for night heat.

 

[P3pp3r]

Use a tube fluorescent for light and uvb.
Incandescent flood bulb for basking
Ceramic heat emitter for added day heat and for night heat.

Thanks so much for the advice I’ll look into it now

 

[ZEROPILOT]

Oh thank you I will research into it, I did check with the vet on the health check and he said it was ok but I will defo go look into this more thanks , I use the combined heat and Uv bulb , D3 I think it was called

I'm with WELLINGTON on this.
Those "combined" or "3in1" bulbs do nothing well. Although in theory, they seem just fantastic.
Many of us have purchased them not knowing that (Ahem) and they're expensive.
(I secretly have a box full of them in my garage that I just can't seem to throw away)