Paleontologists working in Brazil have uncovered the fossil of an ornithuromorph bird that lived during the Early Cretaceous epoch.
Kaririavis mater lived in what is now Brazil some 115 million years ago (Early Cretaceous epoch).
“Kaririavis mater lived during the Cretaceous period, when the supercontinent Gondwana — which included the South America, Africa, Australia, Antarctica and India — was splitting,” said Dr. Ismar de Souza Carvalho, a paleontologist at the Universidade Federal do Rio de Janeiro and the Universidade de Coimbra, and colleagues.
“It had both primitive and modern morphological characteristics, making its behavior and ecological niche still mysterious,” the paleontologists said.
“It had coarse feet, very stout toe phalanges, and a claw on the second toe, very curved and proportionately large for its size, unlike those found in most ornithuromorphs, which had slender feet and slender toes.”
The fossilized remains of Kaririavis mater — an isolated right foot with some feathers — were recovered from the Crato Formation at Pedra Branca Mine, in Brazil’s Ceará state.
Its unique foot conformation indicates that it may belong to an unknown ornithuromorph clade with some cursory similarities to living flightless ratites, such as the rhea or the ostrich.
The 115-million-year-old fossilized foot of Kaririavis mater. Image credit: Carvalho et al., doi: 10.1080/02724634.2021.1988623.
According to the scientists, Kaririavis mater is the earliest known member of Ornithuromorpha from Gondwana and the oldest fossil bird from South America.
“The presence of Early Cretaceous ornithuromorphs in Brazil indicates that the clade was widespread in Gondwana during the Mesozoic,” they said.
“The discovery brings light to the discussion on the origin of birds on Earth,” said Professor José Xavier Neto, a researcher at the Universidade Federal do Ceará.
“China is the world’s most important source of primitive bird fossils. But, with this unprecedented discovery, the place of origin of the birds is now not clear and definitive: did the birds appear in China and then fly to Brazil or did they appear in Brazil and then fly to China?”
The discovery of Kaririavis mater is described in a paper published online in the Journal of Vertebrate Paleontology.
Ismar de Souza Carvalho et al. A new ornithuromorph bird from the Lower Cretaceous of South America. Journal of Vertebrate Paleontology, published online November 11, 2021; doi: 10.1080/02724634.2021.1988623