Patagorhynchus pascuali represents the first Cretaceous toothed monotreme from the supercontinent Gondwana.
Patagorhynchus pascuali lived in what is now Patagonia, southern Argentina, during the Late Cretaceous epoch, some 70 million years ago.
At the time, Argentina was part of Gondwana, an ancient supercontinent in the southern hemisphere.
Patagorhynchus pascuali belonged to Monotremata, a group of egg-lying mammals, represented by the living platypus and echidnas, which is endemic to Australia, and adjacent islands.
“Occurrence of early monotremes in the Early Cretaceous of Australia has led to the consensus that this clade originated on that continent, arriving later to South America,” said Dr. Nicolás Chimento, a paleontologist at the Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ and CONICET, and his colleagues from Argentina, Japan, and Australia.
“The discovery of a Late Cretaceous monotreme from southern Argentina demonstrates that monotremes were present in circumpolar regions by the end of the Mesozoic, and that their distinctive anatomical features were probably present in these ancient forms as well.”
A second lower molar of Patagorhynchus pascuali was collected from the Puma Cave site of the Chorrillo Formation, cropping out in Santa Cruz province, Patagonia, Argentina.
“The discovery expands the list of mammals documented in the Chorrillo and equivalent Dorotea formations of southern South America,” the researchers noted.
The new specimen was found in association with the fossilized remains of early mammals, frogs, turtles, snakes, ornithopod, sauropod and theropod dinosaurs, birds, aquatic plants, freshwater snails and abundant larvae of chironomid insects, with the latter two invertebrates constituting part of the food for the living platypuses.
“The possibility that Patagorhynchus pascuali had already acquired ecological and behavioral characteristics similar to those of the living platypus, which inhabits…
Read the full article here