If we look at the skeletons of contemporary lizards, they’re all rather similar. Likewise fish. Yet both these groups have wildly different externals as to color, textures, etc.
Likely the case with truly ancient organisms. Someone posted a picture of a hippopotamus skull and how it might be “fleshed out” by a researcher who’d never actually seen one of these critters…. Not much resemblance.

But we can certainly get the basic body shape quite closely.

Interesting material. I’m 75, and took up a lifting program after knee replacement about 6 years ago. I worked my way up using a fairly normal exercise set, fairly heavy weights (for me….) But I found I was having a lot of trouble with DOMS and long recovery time.
Then COVID hit….

So I adopted a considerably lighter program, a full-body workout using primarily dumbbells. Still doing this but progress is quite slow.