"Evoltile", known as "Evold" (エヴォルド Evorudo) in the OCG is an "Evol" sub-archetype consisting of FIREReptilemonsters whose effects support "Evolsaurs". They are the first stage in evolution where they will evolve into Dinosaur "Evolsaurs". Their English names are a combination of evolution and reptile.
The pictures of all "Evoltiles" have what appears to be an ancient language.
Their pictures have some sort of molecule in the background.
It is likely an artistic imagining of a nucleic acid, since it bears resemblance to bases and a sugar phosphate-like backbone. Interestingly, the bases don't correspond to any natural bases, the phosphate-like groups are not true phsophates and the many of the Nitrogen atoms have too many bonds, and would not be stable structures.
Their pictures also have a depiction of the evolution of man in the lower right corner.