1x1 Ornithomimus.jpg
Biological information
Time period : Late Cretaceous period.
Lifestyle : Omnivore
In the series
Brought back : 13, later had 12 chicks.
Appearances : T-Rex Returns
A Mammoth Undertaking
Saving the Sabretooth
The Bug House

Ornithomimus was a genus of dinosaur that lived in North America during the late Cretaceous. Ornithomimus appear to be flock animals. Their chicks have downy feathers and, like many modern day birds, imprint on the first thing they see.[1]  Ornithomimus is best known for being featured in Prehistoric Park.

Portrayal in the series

Ornithomimus were highly social omnivores that lived in flocks of around 15 to 20. Despite the vast numbers of individuals in a flock, they would still flee from danger. Ornithomimus were swift and agile animals, capable of outrunning the fastest predators.

When brooding, Ornithomimus females would break off from the rest of the flock to make a nest. Each Ornithomimus would lay around ten eggs but the mother would sacrifice at least two eggs to feed predators. Ornithomimus chicks were covered in downy feathers which would molt by adulthood. (PP: Saving the Sabretooth)

Despite their close resemblance to ostriches, Ornithomimus behaved more like ducks. They preferred to live near lakes and ponds rather than forests or open plains. In fact, their mouths had the texture of sandpaper and were used more like sieves than beaks. (PP: Dinobirds)

Ornithomimus chicks would imprint on the first thing they see after hatching. They would even imprint on other species. (PP: Saving the Sabretooth)

In Prehistoric Park

T-Rex Returns

The flock of Ornithomimus spooked by Nigel. (T-Rex Returns)

Nigel Marven found a lone Ornithomimus in a bush.  The Ornithomimus emerged and to Nigel's surprise, a whole flock of them raised their heads above the bushes.  The flock fed on the vegetation until Nigel intentionally spooked them in order to get ahold of an individual.  Nigel managed to catch a fleeing Ornithomimus and covered its head with a sock (a technique used on ostriches to calm them down).  When the rest of the flock ran past Nigel, he let go of the individual he was holding.

Days later, when Nigel was attempting to transfer a female Tyrannosaurus rex to Prehistoric Park, the flock reappeared and distracted the Tyrannosaurus.  One individual was too slow and was caught by the Tyrannosaurus to be fed to her chicks.  The rest of the flock however ran into the time portal which led to Prehistoric Park.  Head keeper Bob Arthur was surprised at the amount of Ornithomimus coming through.  Later, Bob moved the flock into a paddock.

A Mammoth Undertaking

Bob was having problems with the Ornithomimus flock. He assumed they would be similar to ostriches and was expecting them to eat the grass.  The Ornithomimus, however, were not feeding.  Bob later learned that Ornithomimus were more like ducks and decided that he should move them into an enclosure with a pond so that they could find their own food.  Bob managed to move the flock into their new enclosure, but it took a while for them to calm down and find the pond. They later settled down and began feeding.


The Ornithomimus mother checking up on her eggs. (Dinobirds)

Bob was checking on the Ornithomimus flock to see if they were enjoying their new pond.  He was glad that the Ornithomimus were enjoying it.  However, he noticed that one female was acting unusually, staying near the undergrowth away from the rest of the flock.  

When Nigel returned from a trip to the Cretaceous, Bob informed him about the Ornithomimus.  Nigel realized that the behavior that the Ornithomimus was exhbiting was similar to what modern birds exhibit when they start brooding.  Head vet Suzanne McNabb later gave the Ornithomimus an ultrasound scan and discovered that the Ornithomimus was indeed broody.

Later, the mother Ornithomimus laid a clutch of eggs.  Nigel went to investigate them but was seen by the mother.

Saving the Sabretooth

The Ornithomimus mother laid two sacrificial eggs out of instinct outside of the nest for predators.  Suzanne took the two eggs and gave them to Bob to incubate.

Later, Nigel and Suzanne went to the Ornithomimus enclosure and found out that the rest of the eggs had hatched.

Ornithomimus chicks. (Saving the Sabretooth)

They played around with the Ornithomimus chicks and found out that they had downy feathers, possibly to keep them warm.  Meanwhile, Bob checked up on the two sacrificial eggs and found out that they hadn't hatched yet.  Suzanne thought they wouldn't hatch but Bob was not keen to give up on them yet.

After Nigel returned from the Pleistocene, against all the odds, the sacrificial eggs hatched and were dubbed Ollie and Olivia.  As Bob was the first thing they saw, they instinctively imprinted him.  They followed Bob everywhere he went, even near the pen of Matilda, the park's female Tyrannosaurus. 

The Bug House

Bob managed to get Ollie and Olivia into the Ornithomimus Pond with their real mother.


Bob trying to move the escaped Ornithomimus. (Supercroc)

During the Mass Break-Out, a panicking Titanosaur knocked down the fence surrounding the Ornithomimus Pond, letting the Ornithomimus run loose.  Bob attempted to keep the Ornithomimus calm and move them along but was interrupted by Matilda the Tyrannosaurus.  They were then chased by a spooked Elasmotherium.  After the break-out was over and the park was rebuilt, the Ornithomimus was returned back to their enclosure.

Behind the Scenes

  • Ornithomimus is the first animal, not only to have more than one of its own kind in Prehistoric Park, but also to be the first animal to have conceived in the present day.
  • Originally, the Ornithomimus Nigel caught at the start of T-Rex Returns was planned to be the only one returned to the park, and have the rest of its flock stay in the Cretaceous. This idea was scrapped, but was later given to Theo the Triceratops
  • Ornithomimus are the only animals besides Tyrannosaurus to have been given an important role in every episode.


  • Adult Ornithomimus were covered in feathers, unlike in the show, they also had wings and (possibly) a tail fan.
  • They couldn't pronate their hands without breaking them in real life, so their arms were more like bird wings, other than still retaining clawed fingers.



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