Ypupiara Lopai

''Ypupiara'' (meaning "the one who lives in the water") is an extinct genus of unenlagiine theropod from the Late Cretaceous Serra da Galga Formation of Brazil.Brum, Arthur Souza, Pêgas, Rodrigo Vargas, Bandeira, Kamila Luisa Nogueira, Souza, Lucy Gomes de, Campos, Diogenes de Almeida, & Kellner, Alexander Wilhelm Armin. (2021). A new Unenlagiinae (Theropoda: Dromaeosauridae) from the Late Cretaceous of Brazil. https://doi.org/10.1002/spp2.1375 It was the first member of the Dromaeosauridae to be discovered in South America and the first member of the Unenlagiinae to be discovered, but not the first to be identified as such. The type and only species, ''Y. lopai'', is known solely from a specimen that was destroyed in a fire in 2018.

Discovery and naming

The holotype, DGM 921-R, a right maxilla and dentary (which was associated with a fish jaw), was discovered in a layer of the Late Cretaceous Serra da Galga Formation of Brazil. It was found by Alberto Lopa sometime in the 1950s, possibly in 1957, after which Llewellyn Ivor Price listed the fossil as belonging to an indeterminate vertebrate. The specimen was then placed in storage at the National Museum of Brazil and was not acknowledged again for another 80 years.

Photographs of the holotype were taken shortly before it was destroyed when the museum it was housed in was heavily damaged in a fire on 2 September 2018. Holgado ''et al.'' (2018) recognised DGM 921-R as belonging to a new genus of unenlagiine theropods,Holgado, Brum, Pegas, Bandeira, Souza, Kellner and Campos, (2018). A new Unenlagiinae (Theropoda: Dromaeosauridae) from the Maastrichtian of Brazil. ''Journal of Vertebrate Paleontology, Program and Abstracts'', 2018. 148. and the paper naming and describing the holotype was due to be submitted around the same time as the fire that destroyed the fossil, but was delayed because of the fire and the species was not named and described until 2021. The generic name, ''Ypupiara'', is derived from a Tupi word meaning "the one who lives in the water," in reference to a local mythological creature and its inferred diet of fish. The specific name, ''lopai'', honors the holotype's discoverer.

During the 1950s, a single metatarsus belonging to a dromaeosaurid was discovered by Alberto Lopa. This specimen, known as " Lopasaurus" (meaning "Alberto Lopa's lizard"), was lost sometime after the death of Llewellyn Ivor Price in 1980. It was acknowledged by Brum ''et al.'' (2021), where they tentatively referred "Lopasaurus" to the Unenlagiinae, but they could not determine whether "Lopasaurus" represents the same taxon as ''Ypupiara'', due to the lack of overlapping material.

Description

Based on the size of the preserved fossil material, ''Ypupiara'' is estimated to have been around long when fully grown. It is hypothesized that ''Ypupiara'' preyed on smaller animals including mammals, reptiles and fish.

Classification

For the 80 years before it was described, ''Ypupiara'' was classified as an indeterminate vertebrate. It was not until it was described in 2021 by Brum ''et al.'' when it was recognised as a theropod belonging to the Unenlagiinae. ''Ypupiara'' was found to be the sister taxon to ''Austroraptor''.

References

{{Taxonbar, from=Q107969684

Unenlagiines
Maastrichtian life
Late Cretaceous dinosaurs of South America
Cretaceous Brazil
Fossils of Brazil
Marília Formation
Taxa named by Alexander Kellner
Fossil taxa described in 2021