Crocs and Theropod dino's don't seem very similar to me.
Well, crocs are quadrupedal
but crocodilians (going back around 300,000,000 years)
are diapsid members of the Archosauria.
Kudos to them, for surviving the Permian Extinction.
The Theropod bone structure was completely different from a croc.
Not only are their hips and spine designed for upright posture
Admittedly, pipedal theropods were more upright than crocs,
but thay ran in a horizontal attitude,
using their tails as counterweights.
Sorry if I'm raining on your parade
That 's OK; crocs are waterproof.