Ibirania
| Ibirania Temporal range:
| |
|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Family: | †Saltasauridae |
| Subfamily: | †Saltasaurinae |
| Genus: | †Ibirania Navarro et al., 2022 |
| Type species | |
| †Ibirania parva Navarro et al., 2022
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Ibirania (meaning "Ibirá wanderer" or "tree wanderer") is a genus of dwarf saltasaurine titanosaur dinosaur from the Late Cretaceous (Santonian to Campanian) São José do Rio Preto Formation (Bauru Basin) of south-east Brazil. The type species is Ibirania parva.[1] It is one of the smallest sauropods known to date, second only to one of the specimens of Magyarosaurus.[1]
Discovery and naming
The Ibirania holotype specimen, LPP-PV-0200–0207, was discovered in layers of the São José do Rio Preto Formation on the Garcia Brothers Farm in Vila Ventura, Ibirá Municipality, northeastern São Paulo State, Brazil, which dates to the late Santonian to early Campanian ages of the late Cretaceous period. The holotype consists of a dorsal vertebra, partial caudal vertebrae, a fragmentary radius and ulna, a partial metacarpal, and a nearly complete metatarsal. Additional material, including partial cervical, dorsal, and caudal vertebrae, fragments of a fibula, and a nearly complete fibula, was also referred to Ibirania.[1]
In 2022, Navarro et al. described Ibirania as a new genus and species of saltasaurine titanosaur. The generic name, "Ibirania", combines a reference to Ibirá, the municipality where the specimens were discovered (also a Portuguese derivative from the Tupi word "ybyrá", meaning "tree", in reference to Ibirania's hypothesized browsing behavior), with "ania", a modified form of the Greek word "plania", meaning "wanderer". The specific name, "parva", is derived from the Latin word "parvus", meaning "small", after nanism seen in the taxon. The intended name meaning is "little Ibirá wanderer" or "little tree wanderer".
Description
Ibirania is estimated to be only 5.7 metres (19 ft) long, making it one of the smallest sauropods.[1]
Classification
Ibirania was a derived member of the Saltasaurinae, a clade known for encompassing some of the smallest titanosaurs. Ibirania was recovered as sister taxa of the clade formed by the Patagonian saltasaurines Bonatitan and Rocasaurus.
The cladogram below displays the results of the phylogenetic analyses carried by Navarro et al. (2022):[1]
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Paleoenvironment
Ibirania lived in an arid, inland environment, which Navarro et al. presume is the reason behind its dwarfism.[1] This is in contrast to other dwarf sauropods such as Europasaurus and Magyarosaurus, which attained their small size due to insular dwarfism.
It coexisted alongside other dinosaurs, such as the abelisaurid theropod Thanos simonattoi and a larger, unnamed megaraptoran.[2] It also coexisted with an indeterminate notosuchian.[3][4]
References
- ^ a b c d e f Navarro, Bruno A.; Ghilardi, Aline M.; Aureliano, Tito; Díaz, Verónica Díez; Bandeira, Kamila L. N.; Cattaruzzi, André G. S.; Iori, Fabiano V.; Martine, Ariel M.; Carvalho, Alberto B.; Anelli, Luiz E.; Fernandes, Marcelo A.; Zaher, Hussam (2022-09-15). "A new nanoid titanosaur (Dinosauria: Sauropoda) from the Upper Cretaceous of Brazil". Ameghiniana. 59 (5): 317–354. doi:10.5710/AMGH.25.08.2022.3477. ISSN 1851-8044.
- ^ Delcourt, Rafael; Vidoi Iori, Fabiano (2020). "A new Abelisauridae (Dinosauria: Theropoda) from São José do Rio Preto Formation, Upper Cretaceous of Brazil and comments on the Bauru Group fauna". Historical Biology. 32 (7): 917–924. doi:10.1080/08912963.2018.1546700.
- ^ Montefeltro, F.C.; Laurini, C.R.; Langer, M.C. (2009). "Multicusped crocodyliform teeth from the Upper Cretaceous (São José do Rio Preto Formation, Bauru Group) of São Paulo, Brazil". Cretaceous Research. 30: 1279–1286. doi:10.1016/j.cretres.2009.07.003.
- ^ Marinho, Thiago S.; Martinelli, Agustín G.; Basilici, Giorgio; Soares, Marcus Vinícius T.; Marconato, André; Ribeiro, Luiz C. B.; Iori, Fabiano V. (2022). "First Upper Cretaceous notosuchians (Crocodyliformes) from the Uberaba Formation (Bauru Group), southeastern Brazil: Enhancing crocodyliform diversity". Cretaceous Research. 129: 105000. doi:10.1016/j.cretres.2021.105000. ISSN 0195-6671. S2CID 238725546.
