Thomas Ley, age 10, of Lansing, Mich,,
What is the alligator’s start family?
Mr. Alligator, if he wished, could trace back his family tree for more than 200 million years. The salamanders ware the first four‑footed creatures to leave the ancient seas, but they always returned to the water to lay their eggs. The ancestors of the alligators were the first back‑boned animals to lay their eggs and live their entire lives on the dry land. Through the ages which followed, they saw the dinosaurs rise and decline, the first birds take to the air and then the arrival of the furry mammals.
To look at them, you would never think that a huge sea turtle is related to a little lizard, or that the alligator is a distant cousin of the cobra. Yet all of them are reptiles, members of the class Reptilia, a word which means the creeping animals. The members of each great animal class may look very different from one another. Hut they all have certain features in common which set them apart from most other animals.
The reptiles, of course, are all back‑boned animals, Even the turtle has a spine and bony skeleton under his crusty shell. All are coldblooded animals. The snakes and the lizards depend upon the summer air and the ground to keep themselves warm and when the weather gets cold they tend to become sluggish. The wide assortment of reptiles share all these features. But animals, like people, may have certain features in common and still be very different.
The differences in the reptiles make it necessary to subdivide their big class into orders. The members of each order look enough like each other to be recognized as cousins. The lizards belong in one order, the snakes in another, and turtle‑type reptiles belong in another.
The alligator is classified in the order Crocodilia, along with his cousins the crocodile and the gavial, who is a toothy crocodile creature of Asia.
The crocodile and the alligator look so much alike that many people wonder how to tell them apart. But there are differences and for this reason the order is subdivided into three smaller groups. And here at long last we come to the family of the alligator. The crocodiles belong in one family, the gavials in another and the alligators have a family all to themselves. The name of their family, naturally, is Alligatoridae.
The gavials of Asia, though usually smaller, are very like the crocodile, Both have long, lower teeth which poke up and outside the upper jaw, Mr, Crocodile has a wicked smile only because he has no lips to cover these teeth when he closes his mouth. When the alligator closes his mouths his long lower teeth fit neatly into pits in his upper jaw.