It’s a series for children but it raises an interesting question. Here’s the answer offered to whether birds, for example, could go back to being dinosaurs:
We know from fossil discoveries that Triceratops and Tyrannosaurus had scaly skin covering most of their bodies. Most modern birds have scaly feet, but none are scaly all over.
Although Triceratops had a ‘beak’ this was very different to a bird’s beak.
It’s hard to imagine what would force any bird to naturally replace its feathers with scales. Birds need feathers to fly, to save energy (by staying warm) and to put on special displays to attract mates.
Triceratops did have a “beak” at the front of its mouth, but this evolved completely separately to the beaks of birds and had two extra bones — something no living animal has.
What’s more, behind its beak and jaws, Triceratops had rows of teeth. While some birds such as geese have spiky beaks. No bird in the past 66 million years has ever had teeth.
Considering these huge differences, it’s really unlikely birds will ever evolve to look more like their extinct dinosaur relatives. And no extinct dinosaur will ever come back to life either — except maybe in movies!Stephen Poropat, “Curious Kids: could dinosaurs evolve back into existence?” at The Conversation
But wait. Just a minute. According to the story, some dinos evolved into birds. If so, massive changes ARE possible. It’s not clear why changed circumstances could not cause some of those changes to be reversed.
Of course, to the extent that the future is unlikely to feature circumstances identical to the past, not all of the changes would be reversed. But the question is, is that a matter of “huge differences” or—as would seem more likely—the circumstances that led to “dinosaurism” will not likely be repeated in detail?