Paleo-artwork of Ubirajara by Bob Nicholls
Ubirajara (meaning "lord of the spear") is an informal extinct genus of compsognathid theropod dinosaur that lived during the Early Cretaceous period in what is now the Crato Formation in Brazil. Ubirajara was named in 2020 and is the first Gondwanan non-avian theropod dinosaur discovered with integumentary structures persevered in its specimen. It is only known by a single species, U. jubatus.
Discovery and naming[]
The holotype specimen of Ubirajara (SMNK PAL 29241) was found along with a number of other fossils from a chalk quarry located between Nova Olinda and Santana do Cariri. The fossil was discovered in a layer of the Crato Formation, which dated to the Aptian, about 115 million years ago. The specimen consists of a partial skeleton preserved on a slab and counterslab, and which is missing the skull.
The genus Ubirajara was erected and named by Robert S. H. Smyth, David Michael Martill, Eberhard Frey, Hector Eduardo Rivera-Silva and Norbert Lenz in December 2020. The generic name of Ubirajara means "lord of the spear" in the local Tupi language, and the specific name "jubatus," means "maned" in Latin.
Controversy[]
The fossil of Ubirajara was acquired in 1995 by the Staatliches Museum für Naturkunde Karlsruhe (SMNK) and moved to Germany after an export permit was allegedly obtained. The fossils were allegebly illegally transported to Germany out of Brazil, as Brazilian laws do not allow the removal of fossils from its territory, nor for studies on them to be conducted without the participation of at least one Brazilian scientist. As a result, Brazilian scientists are campaigning for the return of the fossils to Brazil. In 2022, the SMNK agreed to return the specimen to Brazil after their investigation failed to find legitimate export permits
Due to the controversy, the paper describing Ubirajara in 2020 was removed a few days after being made available online.
Description[]
Skeletal reconstruction of Ubirajara
Ubirajara would have been approximately 1 meter, or 3.3 feet long in life. It had a large "mane" consisting of protofeathers, which starts midway down its that ran along its back and neck, and unique, bird of paradise-like integumentary structures erupted from its sides. Most known dinosaurs that preserve vast arrays of feather and similar structures are usually maniraptoriformes and small ornithischians, meaning Ubirajara represents the first non-avian theropod preserving filamentous integument. Ubirajara is also the first non-maniraptoran to possess elaborate structures likely used for display, thus directly indicating the evolution and development of plumage within dinosaurs is even more complex and derivered than previously thought. [1]
Phylogeny[]
In 2020, Ubirajara was placed in the Compsognathidae, as the sister species of a clade containing Sinosauropteryx and Compsognathus.
Gallery[]
