WE CAN’T PROVE THEY WEREN’T HUGE FATBIRDS
simply the best
There was a post about how, if we only added muscle and skin to whales without considering massive amounts of blubber and cartilage, they would look extremely skinny based on their skeletons, but it’s extremely hard to tell if they would have had blubber based on their skeletons alone. If we had to reconstruct them from skeletons alone, like we would with dinosaurs, they would be slim and sleek.
We can’t prove they weren’t huge fatbirds.