''Calvarius'' (meaning "suffering") is a genus of styracosternan

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

Talarn Formation The Tremp Formation ( es, Formación de Tremp, ca, Formació de Tremp), alternatively described as Tremp Group ( es, Grupo Tremp), is a geological formation in the comarca Pallars Jussà, Lleida, Spain. The formation is restricted to the Tr ...

of Spain. The genus contains a single species, ''Calvarius rapidus'', known from a single metatarsal.

Discovery and naming

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen, MCD-8734, is a single fourth metatarsal discovered in 2019 at the Pallars Jussà locality of the

of the

Tremp Group The Tremp Formation ( es, Formación de Tremp, ca, Formació de Tremp), alternatively described as Tremp Group ( es, Grupo Tremp), is a geological formation in the comarca Pallars Jussà, Lleida, Spain. The formation is restricted to the Trem ...

, located in Catalonia, Spain. It was named as the holotype of a new genus of styracosternan dinosaur in 2023 by Albert Prieto-Márquez and Albert Sellés. The genus name, "''Calvarius''", is Latin for "suffering" (cf. ''

Calvary Calvary ( la, Calvariae or ) or Golgotha ( grc-gre, Γολγοθᾶ, ''Golgothâ'') was a site immediately outside Jerusalem's walls where Jesus was said to have been crucified according to the canonical Gospels. Since at least the early mediev ...

''), and refers to the type locality, Serrat del Calvari, as well as the genus' proximity to the K-Pg extinction event. The specific name, "''rapidus''", means "rapid", and refers to its likely cursorial habits.

Classification

''Calvarius'' was in 2023 assigned by its describers to the

Styracosterna Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word ...

. A more precise position could not be determined because a phylogenetic analysis only places it in a large polytomy of styracosternans.

Paleobiology

The highly modified metatarsal of ''Calvarius'' has no known equivalents among other ornithopods. It was convergently more similar to those of more basal ornithischians such as '' Hypsilophodon'' and ''

Dysalotosaurus ''Dysalotosaurus'' ("uncatchable lizard") is a genus of herbivorous iguanodontian dinosaur. It was a dryosaurid iguanodontian, and its fossils have been found in late Kimmeridgian-age rocks (Late Jurassic) of the Tendaguru Formation of Lindi Regi ...

'' than to other styracosternans, and may have filled their niche on its island habitat. The Talarn Formation also produced the remains of the troodontid '' Tamarro insperatus''.

References

{{Ornithopoda, O. Iguanodonts Fossils of Spain Cretaceous Spain Fossil taxa described in 2023 Ornithischian genera