A Brand New Dinosaur!

Paleontologists in Australia have discovered fossil fragments from a new type of dinosaur that walked the Earth during the Early Cretaceous epoch. The new dinosaur belongs to Ornithopoda (ornithopods), a major group of herbivorous bird-hipped dinosaurs.

Galleonosaurus dorisae. Image credit: James Kuether.

Ladies…

Dubbed Galleonosaurus dorisae, it inhabited the rift between Australia and Antarctica approximately 125 million years ago (Cretaceous period).

Five fossilized upper jaws of the ancient beast were found at the Flat Rocks locality of the Wonthaggi Formation in a region of Gippsland, Victoria, Australia. The discovery confirms that on a global scale, the diversity of these small-bodied dinosaurs had been unusually high in the ancient rift valley that once extended between the spreading continents of Australia and Antarctica.

Galleonosaurus dorisae is a close relative of Diluvicursor pickeringi, another small ornithopod from excavations along the Otway coast to the west of the Gippsland region. However, Galleonosaurus dorisae is about 12 million years older than Diluvicursor pickeringi, showing that the evolutionary history of dinosaurs in the Australian-Antarctic rift had been lengthy.

The researchers also found that the ornithopods from Victoria are closely related to those from Patagonia in Argentina. “We are steadily building a picture of terrestrial dinosaur interchange between the shifting Gondwanan continents of Australia, South America and Antarctica during the Cretaceous period,” said Dr. Matthew Herne, a postdoctoral researcher at the University of New England.

The study was published in the Journal of Paleontology.

The Dinosaurs Were Doing Fine

You know, until that whole asteroid thing.

Image result for dinosaurs asteroid

It’s probably fine…

Most paleontologists agree that the Chicxulub asteroid impact, possibly coupled with intense volcanic activity, wiped out non-avian dinosaurs (all dinosaurs except birds) at the end of the Cretaceous period, approximately 66 million years ago.

However, there is debate about whether dinosaurs were flourishing or whether they had already been in decline due to climate change. A new study that modeled the changing environment and dinosaur species distribution in North America suggests that dinosaurs were likely not in decline before the Chicxulub strike.

According to the study, dinosaurs as a whole were adaptable animals, capable of coping with the environmental changes and climatic fluctuations that happened during the last few million years of the Late Cretaceous. It suggests previous analyses have underestimated the number of species at the end of the Cretaceous period.

During the Cretaceous, North America was split in two by a large inland sea. In the western half there was a steady supply of sediment from the newly forming Rocky Mountains, which created good conditions for fossilizing dinosaurs once they died. The eastern half of the continent was characterized by conditions far less suitable for fossilization.

This means that far more dinosaur fossils are found in the western half of North America, and this fossil record is often used to suggest dinosaurs were in decline during the few million years before the asteroid strike.

However, instead of using the fossil record exclusively, the researchers employed ‘ecological niche modeling.’ This approach models which environmental conditions, such as temperature and rainfall, each species would need to survive. The scientists then mapped where these conditions would occur across the continent over time.

This allowed them to create a picture of where groups of dinosaur species could survive as conditions changed, rather than just where their fossils had been found. The team found habitats that could support dinosaur groups were actually more widespread at the end of the Cretaceous period, but that these were in areas less likely to preserve fossils.

The findings appear in the journal Nature Communications.

Rats the Size of Dogs

Archaeologists with the Australian National University have discovered fossils of seven different species of giant rats, one of which could grow to be up to 10 times the size of the ones that scurry through New York City’s subways.

The archaeologists found the fossils in East Timor while working on a project examining early human movement in Southeast Asia. These fossils are around 44,000 years old. Evidence suggest that humans, who lived in Timor as much as 46,000 years ago, would hunt and eat the mega-rats.

One of the most interesting aspects of the rats is how scientists suspect they died out, and the implications that could have for life today. The reason researchers think they became extinct about 1,000 years ago is because that was when metal tools began to be introduced in Timor, people could start to clear forests on a larger scale.

It wasn’t the presence of human hunters using traditional weapons that caused the extinctions of the giant rats. It was actually deforestation and destruction of the habitat. When you consider there are similar things happening now in areas around Papua New Guinea and Indonesia, it’s really important to keep in mind the effects of deforestation could cause many more extinctions.