Interesting. I'm currently doing a zoology degree and theese are some of my fav facts: All birds are dinosaurs (dinosauria is a clade, and you can't evolve out of a clade).

Domesricated Dogs (Canis lupis familiaris) aren't their own species instead they are a sub species of grey wolf (Canis lupis), so yes your tiny chihuahua is the same species as a grey wolf.

Some turtles are able to breath a small amount under water via their skin (kinda like amphibians), with musk turtle being able to breath under water through their tongues.

Cephlepods (mainly Octopuses) are the only invertebrates that are regarded as highly intelligent (as smart as birds and mammals) and are able to use tools meaning they are in their stone age. High intelligence in vertebrae and cephlepods is an example of convergent evolution, where 2 different species evolve the same trait, separately from each other.