Name: Orodromeus ‭(‬Mountain runner‭)‬.
Phonetic: Or-o-dro-me-us.
Named By: Jack R.‭ ‬Horner‭ & ‬David B.‭ ‬Weishampel‭ ‬-‭ ‬1988.‭
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Ornithischia,‭ ‬Ornithopoda.
Species: D.‭ ‬makelai‭ (‬type‭)‬.
Diet: Herbivore.
Size: Estimated about‭ ‬2.5‭ ‬meters long.
Known locations: USA,‭ ‬Montana‭ ‬-‭ ‬Two Medicine Formation.
Time period: Campanian of the Cretaceous.
Fossil representation: Known from partial skeletons.

       Orodromeus was a small ornithopod dinosaur of the late Cretaceous that had boss-like growths on the jugals‭ (‬cheek bones‭)‬.‭ ‬Orodromeus has been considered to be similar to another small ornithopod named Oryctodromeus,‭ ‬which itself is considered to have been a burrowing dinosaur.‭ ‬It is still not known for certain if Orodromeus burrowed and if so when.‭ ‬If such activity is true for Orodromeus,‭ ‬it is unlikely that extensive tunnel networks were dug out,‭ ‬it could simply be a case of‭ ‬a‭ ‬nest site being excavated,‭ ‬or perhaps a retreat to hide from predators.‭ ‬Another genus named Zephyrosaurus has also considered to be similar to Orodromeus.
       Large numbers of eggs were once attributed to Orodromeus,‭ ‬with the embryos inside being studied as the unhatched young of Orodromeus.‭ ‬This was and still is a very interesting find,‭ ‬however a further study‭ (‬Horner and Weishampel,‭ ‬1996‭) ‬yielded a startling discovery‭; ‬the embryos were not those of Orodromeus,‭ ‬they were of a completely different kind of dinosaur named Troodon.‭ ‬The Orodromeus remains found next to the eggs could simply be the bodies of hunted and killed dinosaurs brought back to the nest for consumption.‭ ‬Further support for this idea comes from the nearby partial remains of a Troodon and clutch of eggs‭ (‬MOR‭ ‬748‭ & ‬MOR‭ ‬750‭) ‬discovered in‭ ‬1997‭ ‬that seemed to be in a brooding position at the time of death.
       Principal predators of Orodromeus were likely smaller theropod dinosaurs such as Troodon and Saurornitholestes,‭ ‬both known from the same fossil bearing Formation as Orodromeus.‭ ‬Larger predators such as tyrannosaurs like Daspletosaurus were also present,‭ ‬but given their size they likely hunted for larger prey like hadrosaurs and ceratopsians.

Further reading
-‭ ‬A comparative embryological study of two ornithischian dinosaurs,‭ ‬Jack R.‭ ‬Horner‭ & ‬David B.‭ ‬Weishampel‭ ‬-‭ ‬1988.
-‭ ‬A comparative embryological study of two ornithischian dinosaurs‭ ‬-‭ ‬a correction,‭ ‬Jack R.‭ ‬Horner‭ & ‬David B.‭ ‬Weishampel‭ ‬-‭ ‬1996.


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