by Kathy Kranking Dinosaurs Were art by James Gurney Even the biggest dinosaurs started out small. Thanks to some amazing fossil discoveries, we’re learning Babies, Too! how dinos began their lives.

or a long time, nobody The only way for scientists to Fknew where baby dinosaurs know for sure what kind of dinosaur Fcame from. But now we know that laid an egg is to find a baby dinosaur dinosaurs hatched from eggs. Fos- inside. That’s hard to do—usually sil dinosaur eggs have been found the remains of baby dinosaurs either in places all around the world! aren’t preserved or are just crushed (Fossils are the preserved remains jumbles of bones. But scientists have of ancient living things.) found fossils of babies. The most Dino eggs come in two basic famous discovery was in the 1990s: shapes: round and oval. Different a very well-preserved baby dino in kinds of dinosaurs laid their eggs an egg! The baby was lying in the in different patterns, such as in a same position it would have been spiral or in rows. But they always when it was alive. Scientists named laid their eggs in nests. Some dinos it Baby Louie. They believe it was a scooped out nests on the ground. type of bird-like dinosaur called an Others built raised nests of mud. Oviraptor (OH-vuh-rap-tur). Studying Some of the nests were really big— the fossils of eggs, nests, and babies a person could lie down across one can give scientists clues about how with room to spare! dinosaurs lived and grew up. Triceratops babies hatching.

26 27 PHOTO COURTESY OF AMERICAN MUSEUM OF NATURAL HISTORY/D. FINNIN

Parasaurolophus (pair-uh-sor- AHL-uh-fus) parent showing young how to find food.

This famous fossil shows an adult Oviraptor with its eggs.

Good Parents Bony Blunder After studying the fossils they have Scientists have also found fossils of collected over the years, some scientists Oviraptor dinosaurs actually sitting on now believe that some kinds of dino- their nests to brood their eggs! When saurs might have cared for their young. the first of these fossils was discovered, For example, huge nesting grounds of scientists mistakenly thought the the duck-billed dinosaur Maiasaura eggs were those of a different kind of (my-uh-SOR-uh) have been discov- dinosaur than the adult dinosaur on ered—some of them with more than top of them. They thought the dino 40 nests! In the nests were the bones was stealing the eggs, so they gave it of babies, and near the nests were the the name Oviraptor, which means bones of adults. Since the bones were “egg thief.” found together, this could show that Later, another nest of eggs was the adults cared for their babies. uncovered with an Oviraptor on top of By studying the leg bones of some it. This time, parts of a baby dinosaur dinosaur babies, scientists have learned were inside one of the eggs. The baby that they probably weren’t strong turned out to be an Oviraptor, too. enough for the babies to be able to Since then, other Oviraptor fossils have walk yet. Scientists have even discov- been found on their nests as well. So ered fossils of what seem to be chewed- although the name stuck, Oviraptor up plant bits in the nests, which could wasn’t really an egg thief at all—just a show that the adults fed their babies. good parent taking care of its eggs.

28 29 Another similarity is that birds such as flamingos and pelicans nest in large groups, just as the Maiasaura dinosaurs seem to have done. Clues in the Rocks As you can probably guess, piecing together the stories of dinosaurs’ lives from fossils that are millions of years old isn’t easy. But the more fossil clues we can find, the more we can learn about baby dinosaurs. The answers are out there, buried in the rocks, just waiting to be discovered. =

Snake attacking baby sauropod in nest.

Staying Alive tect their babies from attacking preda- keep them warm, more gigantic dinos Like most animals, baby dinosaurs tors. And some dinosaurs may have couldn’t do that without crushing their faced dangers. Many types of dinosaurs lived in large herds, which could have eggs. These dinos may have covered and other animals probably preyed on been for safety. Fossils of trackways their eggs with plants to keep them dino eggs and young. Some dinosaurs showing footprints of both adults and warm, just as many crocodiles and laid a large number of eggs—20 or youngsters have been found. These some birds do. more in some cases. Maybe this was might show that the babies stayed with Dinosaurs have even more simi- so that, even if some were eaten by the adults as they got older so that the larities to birds, which most scientists hungry enemies, there were still good adults could continue protecting them. now consider to be “living dinosaurs.” chances of the others surviving. Scientists can make guesses that at Several years ago, scientists discov- Looking for Answers least some dinosaurs may have be- ered the fossil of a giant snake in a To try to figure out what baby dino- haved much as birds do, feeding and nest of baby sauropod (SOR-uh-pod) saurs’ lives were like, scientists look at caring for their helpless babies. dinosaurs. This could have shown that dinosaur relatives that are living today: On the other hand, some baby birds, the snake was feeding on the babies. crocodiles and birds. For example, some such as geese and ducks, are able to

Also, some fossil eggs seem to have crocodiles, unlike most reptiles, guard walk and leave the nest shortly after PSIHOYOS LOUIE the shells caved in, which could have their nests and even watch over their hatching. The bones of baby Troodon You can see the difference in size between been caused by a predator attacking young. And here’s another similarity to (TROH-uh-don) dinosaurs show the thigh bone of a hadrosaur (HAD-ruh-sor) the eggs. crocodiles: While dinosaurs that didn’t that they, too, may have been strong baby and one from a hadrosaur that was a Dino parents may have tried to pro- get very big could sit on their nests to enough to leave the nest right away. few years old.

30 31