Wikipedia notes on scales:
I said that Dance’s bigger scales have keels. This may not be accurate for the green Burmese and Sri Lanka Rat Snake, which is what we think the body of his tail is probably based on. (I did check on type of snake vs. vertebrae count, and it would be one of the advanced snakes where you can count the vertebrae by the rows of belly scales and dorsal scales, as noted below). ETA to add: In pictures of the , some of the scales on the dorsal areas have keels. Most are smooth.
Also, we think there are bonelike or silicon-based osteoderms under the main scales, which is a lizard trait but snakes don’t have at all. They would act either as armor or as a convenient platform for some of the processing and light projection going on in there.
https://en.wikipedia.org/wiki/Scale_(zoology)#Reptilian_scales
The scales of all reptiles have an epidermal component (what one sees on the surface), but many lizards have osteoderms underlying the epidermal scale, as do crocodilians and turtles. Snakes, tuataras and many lizards lack osteoderms. All reptilian scales have a dermal papilla underlying the epidermal part, and it is there that the osteoderms, if present, would be formed.
https://en.wikipedia.org/wiki/Reptile_scales
In “advanced” (Caenophidian) snakes, the broad belly scales and rows of dorsal scales correspond to the vertebrae, allowing scientists to count the vertebrae without dissection.
bony plates inside the scale:
https://en.wikipedia.org/wiki/Osteoderms