Answer (How dinosaurs are related to crocodiles):
Along with pterosaurs and dinosaurs, crocodiles were an offshoot of the archosaurs, the "ruling lizards" of the early to middle Triassic period; needless to say, the earliest dinosaurs and the earliest crocodiles resembled one another a lot more than either resembled the first pterosaurs, which also evolved from archosaurs. What distinguished the first crocodiles from the first dinosaurs was the shape and musculature of their jaws, which tended to be much more deadly, as well as their relatively splayed limbs—as opposed to the straight, "locked-in" legs of theropod dinosaurs. It was only well into the Mesozoic Era that crocodiles evolved the three main traits with which they're associated today: stubby legs, sleek, armored bodies, and marine lifestyles.
Answer (how dinosaurs are related to chickens):
The scientific evidence comes from a study in which the amino-acid sequence from T. Rex collagen was compared to that of various modern species. It proved to be more similar to the chicken than any other creature alive today.
So, are chickens dinosaurs? No – the birds are a distinct group of animals, but they descend from the dinosaurs, and it’s not too much of a twist of facts to call them modern dinosaurs.
There are many similarities between the two types of animal, largely to do with bone structure. It also appears that many of the dinosaurs had feathers – not for flight, but as adapted scales, to assist in heat regulation, and/or to assist in courtship displays, as in modern birds.
