There are several fish and reptiles which seem to possess intelligence and which have had more or less the same body plans (as far as we can tell) for hundreds

There are several fish and reptiles which seem to possess intelligence and which have had more or less the same body plans (as far as we can tell) for hundreds of millions of years. Being able to survive that long is literally the best case in known history. It’s far longer than our current form has survived and if you believe a mass extinction is occurring, perhaps humans aren’t all that good at surviving long-term at all. Yet sharks, squid, and crocodiles might be just fine for this extinction as well. Favouring intelligence like ours is extremely anthropocentric. It seems great to have MacBooks and rockets but the evidence for technology and the extent of our abilities actually serving us well has yet to be proven. It seems likely to me that dinosaurs shared common body plans because they worked really well. There was likely little pressure to change, and the body plans they had were consistently rewarded by the conditions on earth and competition between species. They survived crazy geological events over so many millions of years. It seems worth noting too that a lot of what we think they looked like is guess-work. It could turn out that they were actually far more diverse than we realize. And for that matter, although they did seem to follow common body plans, some species appeared to be quite different and diversified.