At first glance, it's hard to see how a common house sparrow and a Tyrannosaurus Rex might have anything in common. After all, one is a bird that weighs less than an ounce, and the other is a dinosaur that was the size of a school bus and tipped the scales at more than eight tons.
For all their differences, though, scientists now say that two are more closely related than many believed. A new study, led by Harvard scientists, has shown that modern birds are, essentially, living dinosaurs, with skulls that are remarkably similar to those of their juvenile ancestors.