The Bird Mimic Dinosaurs

 At first look, an ornithomimid looks like an ostrich or emu.  This is the reason behind their name, which means “bird mimics”.  Of course, they were not ostriches or emus, they were dinosaurs.  What were the ornithomimids? Ostrich Emu

 The ornithomimids were theropods.  Two legged and mostly carnivorous dinosaurs.  They lived during the Cretaceous period.  Unlike most theropods, they were omnivores.  This means they ate plants and meat.  They were probably the fastest dinosaurs that ever lived.  They might have been covered in feathers, but scientists haven’t proved this yet. The Bambiraptor and T-rex are two kinds of theropods. People are also omnivores because we eat things like chicken salad. I wonder why?

 They mainly lived on two continents.  A small few have been found on Europe. North America AsiaEurope

I am so excited to meet some of these ornithomimids that I can’t wait any longer. See you!

 The Harpymimus (Harpy mimic) is named after an Ancient Greek Mythological character, the Harpy.  It lived during the early Cretaceous Period around 130 million years ago.  This omnivorous dinosaur weighed about 200 pounds and was 13 feet (4 meters) long.  It was one of only two ornithomimids to have teeth, around 20 of them on its lower jaw. Harpy

 The Archaeornithomimus (ancient bird mimic) lived during the middle Cretaceous Period, about 105 million years ago.  Scientists don’t know too much about this theropod.  They have learned it was about 10 feet (3 meters) long and weighed 100 pounds.  It was probably the ancestor of the more famous Ornithomimus.

The Garudimimus (Garuda mimic) is named after a Hindu and Buddhist mythological bird-like character called Garuda. It lived on Asia about 85 million years ago during the Cretaceous Period. This dinosaur was 13 feet (4 meters) long and weighed 500 pounds. Due to its relatively short legs, paleontologists believe it was one of the slower ornithomimids. A statue of Garuda

 The Dromiceiomimus (emu mimic) lived on North America.  It weighed 200 pounds and was about 12 feet (3.6 meters) long.  It had very long legs and because of this, scientists think it might have been the fastest of all the ornithomimids, if not all dinosaurs.  They think it could have run about miles per hour (72-80 kilometers per hour).  It was as fast as a greyhound or jack rabbit.

 The Sinornithomimus (Chinese bird mimic) was discovered in Asia.  It was found in a couple of unique situations.  Three adult and 11 adolescent fossils were found all tangled up together.  Another group of Sinornithomimus fossils was discovered containing only babies and juveniles. It weighed 100 pounds and measured about 8 feet (2.4 meters). Due to these discoveries, scientists infer that families lived together in groups. It lived during the Cretaceous Period, about 90 million years ago.

Only one fossil has been found of the Anserimimus and this fossil was not complete. So, we still don’t know a lot about it.

The Ornithomimus (bird mimic) lived on North America between 65 and 75 million years ago. It was about 11 feet (3.3 meters) long and weighed 350 pounds. Based on the size of its brain and compared to other dinosaurs, it was pretty intelligent. Like other dinosaurs, it was probably an omnivore and a fast runner. Its fossils were first discovered in 1890 in Colorado, U.S.A.

Some of the first ornithomimids were small and had teeth. Over time, the ornithomimids lost their teeth. What are some reasons you think they evolved into having toothless mouths? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

Most of the ornithomimids were very fast runners. They were probably the fastest of all the dinosaurs. What are some advantages to being able to run very fast? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

On the Venn Diagram, compare and contrast the Ostrich and the Gallimimus