DINOSAUR HALLWAY


The Ornithischian Dinosaurs

The Ornithischian dinosaurs have three distinct sub-orders. These suborders are Ornithopoda, Ceratopsians and Anklyosaur be featured in coming exhibits. All ornithischians are united by a backward pointing pubis. All terrestrial animals and even marine animals derived from terrestrial stocks have hip girdles, and all hip girldes are composed of three bones, the ilium, ischium and pubis. The hip girdle is enlarged in the second diagram below. In the diagram, the pubis is white, the ilium yellow brown and ischium orange-ish.


Below are some University of California Museum of Paleontology displays of Ornithischian dinosaurs. All are from the suborder Ornithopoda.

Heterodontosaurus

Heterodontosaurus ("different-teeth-lizard") was one of the earliest Ornithischian dinosaurs. This lightly built, bipedal dinosaur was collected in 1966 from the 200 million year old Lower Jurassic Upper Red Beds, Stronberg series, on the northern slopes of the Krommerspruit Mountain near Voisana, Republic of South Africa. It is in the family Heterodontosauridae. Study of the skull has suggested that Heterodontosaurus had the capacity for biting, tearing, and grinding with its three kinds of teeth. The heterodontosaurus may have had a cheek area to store food like in mammals.

Baby Maiasaura

The fossil remains of young dinosaurs are very rare. This juvenile hadrosaur, or duckbilled dinosaur, is a cast of one of the fifteen individuals collected in 1978 by Princeton University from the Upper Cretaceous (80-65 million years ago) at Two Medicine Formation of Teton County in Western Montana. The presence of several small skeletons, apparently all of the same species and size, together with eggshells, led Paleontologists to discover the actual nest sites, where the hatchlings were apparently watched over and cared for by their parents.

A newly hatched hadrosaur was less than 14 inches long and weighed about 1.5 pounds. What did these baby dinosaurs eat? They ate fruits, leaves and other plant material that may have been brought to the nests by their parents. Since the parent duckbills were nearly thirty feet long and weighed about three tons, we assume that the dinosaurs were too large to incubate their eggs by sitting on the nest. Instead, warming for the eggs was provided when vegetation, placed on the nest, began to ferment. Modern crocidiles incubate their egss in the same way.

Edmontosaurus - Another Hadrosaur

Edmontosaur is from the same family as the Maiasaura above. One of the unique features of the Edmontosaur are the cross bracing tendons in the tail that helped make the tail stiff and supporting. The tail was impossible to bend. Also, the Edmontosaur had a duck-billed skull shape shared by most hadrosaurs. The duck-billed shape is formed from a large hollow nostril (you can see teh nostril opening on the skull). Many people think that the large nostril was used to produce low sounds that would alert others to danger.


You may walk back down the hallway to the the Dinosaur Antechamber..