The Basal Euornithopod

Using the extensive practice I have these days with scientific names, my history of translating the Anglicization of Greek in scientific names and my past in which I took Latin classes, I can tell everyone here with great levels of certainty that "Euornithopod" translates very roughly to "New Bird Foot." Cladistic analysis of Oryctodromeus placed the dinosaur in a position which makes it a basal (primitive, for new readers) Euornithopod. In addition to this placement at the bottom of the Euornithipod tree branch, it is also placed in a cozy middle position of the Hypsilophodont family tree. In point of fact, Boyd et al. (2009), placed Oryctodromeus in the cozy middle place and not at the base of a further subfamily at all (though this may be partly due to the range of their study), but rather as a sister taxon to Orodromeus and Zephyrosaurus, two animals which show a great many common adaptations for burrowing that have been noted within the characters diagnostic for Oryctodromeus.

Restoration by Lee Hall

The forelimbs of Oryctodromeus only show moderate modifications in adapting for burrowing behaviors; however, the rear limbs, specifically in the pelvic girdle of the animal. The hips of Oryctodromeus show adaptations for balance as well as for digging with the legs. The beak of Oryctodromeus supposedly shows some adaptation for digging, though I think that if we ever unearth a wonderfully fossilized manus we will be able to diagnose more burrowing adaptations from the lower forelimbs than have been previously described for the snout. Above is the recreation drawn by Lee Hall who drew some of the other illustrations for the describing paper of Varicchio et al.

References
Boyd, Clint A.; Brown, Caleb M.; Scheetz, Rodney D.; and Clarke, Julia A. (2009). "Taxonomic revision of the basal neornithischian taxa Thescelosaurus and Bugenasaura". Journal of Vertebrate Paleontology 29 (3): 758–770.