Moving a toilet to a shower drain?

[The harrymanimus]

For my bathroom I want to get rid of a walk in shower and move the toilet to where the shower drain is. I've read varying things about this in the interweb, having to do with drain sizes, and the grey water vs black water drain issues. Looking for advice.

Attached is what the shower drain looks like without the plate. The diameter is about 2.5".

The shower drain is about 38 inches from from the toilet drain.

Thanks

 

[Terry]

A shower drain may have been plumbed with a 1.5" p-trap or a 2.0" p-trap. Neither will work for a toilet.
A toilet uses either a 3" or a 4" waste line without a p-trap. The trap is part of the bowl so no trap is used below the floor.