The History House - Dinosaurs

Herrerasaurus

Everyone loves a good image of a dinosaur, and we are no exception, so here are two we thought you might like to see.

The first one is an example of what a Herrerasaurus might look like with both flesh and skin color.

What do you think? Not quite what one would call pet material!

Now, here is the an image of a reconstructed skeleton of an Albertosaurus.
I do not know about you, but with just the bones alone, this image leaves no doubt in our mind that this was one dinosaur that did not like broccoli either.

Albertosaurus

The Mesozoic Era is commonly called the Age of Dinosaurs, although dinosaurs did not originate until near the end of the Triassic. The Mesozoic Era spans a period of time from about 245 million years to 65 million years ago and it is divided into three time periods: the Triassic, Jurassic, and Cretaceous.

The dinosaurs are a large group of reptiles belonging to the Archosauria ("ruling reptiles"), which also includes the pterosaurs, or "winged lizards"; crocodilians, the only surviving archosaurs; and the thecodonts, primitive "socket tooth" archosaurs, who were the ancestors of all other archosaurs.

Dinosaurs are classified into two major orders, the Saurischia ("lizard-hipped") and the Ornithischia ("bird-hipped"). The saurischians include of the herbivorous Sauropodomorpha (sauropods and prosauropods) and the carnivorous, bipedal Theropoda. The ornithischians are a more varied group of herbivores, including the stegosaurs, ornithopods, ankylosaurs, and ceratopsians. Modern birds are descended from the theropod dinosaurs.

These major groups were just developing in Late Triassic time. The Herrerasauria, a Triassic group of primitive bipedal predators, may be ancestral to all dinosaurs, because they had characteristics too primitive to be classified as either saurischian or ornithischian.

The saurischian dinosaurs of the Triassic are represented by the Coelophysids, a small and primitive family of the theropods, and by the Prosauropods, smaller ancestors to the quadrupedal sauropods.

The ornithischian dinosaurs are represented by the unclassified Fabrosaurs and a family of very primitive ornithopod known as Heterodontosaurids. Recent discoveries in South America are refining our knowledge of the earliest dinosaurs.

Dinosaurs have reached a new level of interest and controversy with the purchase of the 65-million-year-old Tyrannosaurus rex, as called T-rex, for $8,362,500 by Chicago’s Field Museum of Natural History. This T-rex discovered it in South Dakota on a Cheyenne River Reservation. This was the most complete T-rex ever discovered, being 90 percent complete, and with over 400 bones. The selling price demonstrates that people find a great interest in dinosaurs, but it also demonstrates that dinosaurs have passed a point of science, and entered the realm of business. How will science suffer from this?

Unfortunately for us, none of us here have discovered any dinosaur bones, or any of their wonderful reminders. What reminders are those you say? Well, coprolites of course, also known by the more technical term of dino dung! Yes, this creatures left their calling cards in life, but they do not stick to your shoes, or get you that unwanted attention when you walk into the room after accidentally finding some.

Click on coprolite to see more

Coprolites are more abundant of the fossils found of dinosaurs and they can provide information about what a dinosaur liked dine on. For those more interested in this subject, and for those who want to know about obtaining such wonderful keepsakes, should click on the image of a coprolite.

Other reminders that dinosaurs left behind besides fossils are dinosaur tracks. In Texas, there are sixteen known sites, with the most popular being near Glen Rose, at Dinosaur Valley State Park. To learn more about this location, and other dinosaur track sites, just click on the dinosaur track.

Click on the dinosaur track to see more

To view a collection of dinosaur images, just click on the image of the dinosaur below.

By Dr. Louis L. Jacobs

For those interested in reading more about dinosaurs, there are many good authors to chose from, and many good books to read. Our personal favorite author is Louis L. Jacobs, Ph.D., who has published some wonderful books to read. Those books including Cretaceous Airport, Lone Star Dinosaurs, and Quest for the African Dinosaurs that resulted in his winning The Dinosaur Society's 1994 Colbert Award for the Best Dinosaur Book for Adults. To learn more about this author, and his books, click on the either book or the icon above.

By Dr. Louis L. Jacobs

If you want to visit a dinosaur site that is both interesting, and a little different, then click on the icon below.

We want to make sure that you find what you are looking for, so we have added an extra place for you to visit, and it can take you to even more places and resources. Just click on the icon below.

To learn more about other fossils, and to see some examples of what we have found, be sure to visit our other pages on fossils. To do this, just click on the icon below to return to the Paleontology room, and click on the other fossil images.

PALEONTOLOGY ROOM