Elasmaria

Elasmaria is a clade of iguanodont ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia that contains many Gondwanan "hypsilophodonts".[1][2]

Elasmarians Temporal range: Cretaceous, 127–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Anabisetia
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Clade:	†Neornithischia
Clade:	†Elasmaria Calvo, Porfiri, and Novas, 2007
Genera
†Anabisetia †Atlascopcosaurus †Diluvicursor †Galleonosaurus †Gasparinisaura †Isasicursor †Leaellynasaura? †Macrogryphosaurus †Mahuidacursor †Morrosaurus †Notohypsilophodon? †Qantassaurus? †Sektensaurus? †Talenkauen †Trinisaura

Classification

Calvo et al. (2007) coined Elasmaria to accommodate Macrogryphosaurus and Talenkauen, which they recovered as basal iguanodonts distinct from other iguanodontians in having mineralized plates on the ribs.[3] In 2016, a paper describing the genus Morrosaurus found Elasmaria to be far larger than its initial contents of two taxa, instead containing a variety of ornithopods from the Southern Hemisphere.[4] In 2019, Matthew C. Herne and colleagues redefined Elasmaria as "all taxa closer to Macrogryphosaurus gondwanicus and Talenkauen santacrucensis than to Hypsilophodon foxii or Iguanodon bernissartensis", expanding the definition to include the large number of taxa now found to be part of the clade.[5]

The cladogram below results from analysis by Herne et al., 2019.[5]

Ornithischia

Heterodontosauridae       Eocursor       Thyreophora   Neornithischia   Lesothosaurus       Agilisaurus         Hexinlusaurus     Yandusaurus           Nanosaurus     Jeholosauridae   Haya       Jeholosaurus     Changchunsaurus       Thescelosauridae     Orodromeus     Koreanosaurus         Zephyrosaurus       Yueosaurus     Thescelosaurus             Cerapoda   Marginocephalia   Ornithopoda   Parksosaurus     Elasmaria   Talenkauen         Macrogryphosaurus     Gasparinisaura         Galleonosaurus     Leaellynasaura     Anabisetia     Diluvicursor         Clypeodonta   Hypsilophodon   Iguanodontia   Rhabdodontidae       Muttaburrasaurus       Tenontosaurus     Dryomorpha

References

1. Boyd CA. (2015) The systematic relationships and biogeographic history of ornithischian dinosaurs. PeerJ 3:e1523 https://doi.org/10.7717/peerj.1523
2. Madzia, Daniel; Boyd, Clint A.; Mazuch, Martin (2017). "A basal ornithopod dinosaur from the Cenomanian of the Czech Republic". Journal of Systematic Palaeontology: 1–13. doi:10.1080/14772019.2017.1371258.
3. Calvo, Jorge O.; Porfiri, Juan D.; Novas, Fernando E. (2007). "Discovery of a new ornithopod dinosaur from the Portezuelo formation (Upper Cretaceous), Neuquen, Patagonia, Argentina". Arquivos do Museu Nacional, Rio de Janeiro. 65 (4): 471–483.
4. Rozadilla, Sebastián; Agnolin, Federico L.; Novas, Novas; Rolando, Alexis M.Aranciaga; Motta, Matías J.; Lirio, Juan M.; Isasi, Marcelo P. (2016). "A new ornithopod (Dinosauria, Ornithischia) from the Upper Cretaceous of Antarctica and its palaeobiogeographical implications". Cretaceous Research. 57: 311–324. doi:10.1016/j.cretres.2015.09.009.
5. Herne, Matthew C.; Nair, Jay P.; Evans, Alistair R.; Tait, Alan M. (2019). "New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999". Journal of Paleontology. 93 (3): 543–584. doi:10.1017/jpa.2018.95.