Yeah a base mesh would be ideal really for this thread as its the starting point for the model itself albeit polys, subds, nurbs or even Lego! And Vlad is right, no points for a dense mesh LOL

This way its easier to help those interested in topology, about edgeflow techniques and how to set up a character for possible animation by optimizing the mesh in all areas, particularly those that will be deforming. Also taking in the importance of keeping uvs well balanced too for really good texturing and to avoid stretching, and more importantly a lower mesh will help with editing them instead of going insane!

The t-rex is a good model but perhaps you could lose a few edges, theres a bit of bunching on the thigh toward the top, I think you could lose evry other row of edges right now, but keep the deforming areas to four or five rows.

Do you not have a lower resolution of the mesh? The last image looks the same, just closer. I think the teeth should be modeled separately too, thiswill be easier for rigging too

Cheers
Jay