Elasmaria is a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia that contains many bipedal ornithopods that were previously considered "hypsilophodonts".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.

Classification

Calvo ''et al.'' (2007) coined Elasmaria to accommodate ''

Macrogryphosaurus ''Macrogryphosaurus'' (meaning "big enigmatic lizard") is a genus of elasmarian dinosaur from the Coniacian age Upper Cretaceous Sierra Barrosa Formation (Neuquén Group) of Argentina in Patagonia. It was described by Jorge Calvo and colleagues ...

'' and '' Talenkauen'', which they recovered as basal iguanodonts distinct from other iguanodontians in having mineralized plates on the ribs. 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. 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. The cladogram below results from analysis by Herne ''et al.'', 2019.

References

{{Taxonbar, from=Q4444891 Early Cretaceous first appearances Maastrichtian extinctions Ornithopods