Open Paleo

Ypupiara

Brum et al., 2021

From Tupi (indigenous Brazilian language) meaning 'the one who lives in the water,' derived from a figure in Tupi mythology

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Ypupiara is an extinct genus of unenlagiine theropod from the Late Cretaceous Serra da Galga Formation of Brazil. 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.

Under dispute

Ypupiara is recovered as an unenlagiine, sister to Austroraptor, by its describers (Brum and colleagues, 2021), where it is placed. It is known only from a maxilla and dentary, and the holotype (DGM 921-R) was destroyed in the 2018 Museu Nacional fire, so the placement rests on limited, now-lost material.

Diagnosis

  1. Restricted number of neurovascular foramina on lateral maxilla (one vs. many)
  2. Rectangular and anteroposteriorly expanded interdental plate
  3. Labiolingual compression of teeth with diameter >3/5 of rostrocaudal diameter
  4. Widely spaced maxillary teeth
  5. Absence of mesial and distal carinae on teeth
  6. Fluted tooth surfaces with two or more longitudinal grooves

Species

Ypupiara lopai Brum et al., 2021

Type species

Named for Alberto Lopa, the discoverer of the holotype specimen in the 1950s.

Holotype
DGM 921-R , Museu da Divisão de Geologia e Mineralogia (destroyed)
Material
Partial preantorbital maxilla with three teeth in loci and partial posterior dentary.
Horizon
Serra da Galga Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Caieira, Minas Gerais, Brazil

References

  1. Brum, A. S.; Pêgas, R. V.; Bandeira, K. L. N.; Souza, L. G.; Campos, D. A.; Kellner, A. W. A. (2021). A new unenlagiine (Theropoda, Dromaeosauridae) from the Upper Cretaceous of Brazil. Papers in Palaeontology 7(4): 2075-2099. Wiley. doi:10.1002/spp2.1375 brum2021a
  2. Soares, M. V. T.; Basilici, G.; Marinho, T. S.; Martinelli, A. G.; Marconato, A.; Mountney, N. P.; Colombera, L.; Mesquita, Á. F.; Vasques, J. T.; Abrantes Junior, F. R.; Ribeiro, L. C. B. (2020). Sedimentology of a distributive fluvial system: the Serra da Galga Formation, a new lithostratigraphic unit (Upper Cretaceous, Bauru Basin, Brazil). Geological Journal 56(2): 951-975. Wiley. doi:10.1002/gj.3987

    Erects the Serra da Galga Formation with its type section at this locality, and prints the locality's coordinates.

    soares2020a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the body length estimate, and the appearance features.

    jones2026c