Thescelosaurinae

Thescelosaurinae is a subfamily of ornithischian dinosaurs from the Early Cretaceous of Asia and the Late Cretaceous of North America.[1]

Thescelosaurines Temporal range: Cretaceous, 130–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Thescelosaurus skeleton on display at the Burpee Museum of Natural History
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Family:	†Parksosauridae
Subfamily:	†Thescelosaurinae Sternberg, 1940
Type species
†Thescelosaurus neglectus Gilmore, 1913
Genera
†Changchunsaurus? †Haya? †Notohypsilophodon †Parksosaurus †Thescelosaurus (type) †Elasmaria?

Distribution

The distribution of Thescelosaurinae is quite large. They are widespread through United States and Canada where most of their fossils have been found. They also have a small group in North-Eastern China and Mongolia.[1]

Genera

Head and arms of Thescelosaurus, Rocky Mountain Dinosaur Resource Center

Studies disagree about which genera are included in the Thescelosaurinae. The group is defined to include Parksosaurus and Thescelosaurus and a cladistic analysis by C.M. Brown in 2013 concluded that the genera Changchunsaurus, Haya, Jeholosaurus and possibly Koreanosaurus are also thescelosaurines.[1]

Classification

Thescelosauridae Orodrominae     TMP 2008.045.0002     Oryctodromeus         Albertadromeus     Orodromeus     Zephyrosaurus       Thescelosaurinae   Parksosaurus       Changchunsaurus     Haya     Jeholosaurus     Thescelosaurus

This cladogram is from Brown et al., (2013).[2]

All Thescelosaurines were originally included in the family Hypsilophodontidae, which is presently considered polyphyletic (unnatural). They are all now simply considered to be basal Euornithopods. They are the sister taxa to Orodrominae, a group containing Albertadromeus, Orodromeus, Oryctodromeus and Zephyrosaurus. Their parent taxon is Thescelosauridae along with Orodrominae.[1] Currently, all genera originally included in Jeholosauridae are classified in Thescelosaurinae, possibly as a group inside it.[2] If the group of Jeholosaurids is not considered natural than that might mean Jeholosauridae is a synonym of Thescelosaurinae. Recently, a phylogenetic analysis found them outside of Ornithopoda, the group they'd been allied with traditionally.[3]

References

1. "Thescelosaurinae". Paleobiology Database. Retrieved 20 June 2013.
2. Brown, C. M.; Evans, D. C.; Ryan, M. J.; Russell, A. P. (2013). "New data on the diversity and abundance of small-bodied ornithopods (Dinosauria, Ornithischia) from the Belly River Group (Campanian) of Alberta". Journal of Vertebrate Paleontology. 33 (3): 495–520. doi:10.1080/02724634.2013.746229.
3. Boyd CA. (2015) The systematic relationships and biogeographic history of ornithischian dinosaurs. PeerJ 3:e1523 https://doi.org/10.7717/peerj.1523