Fossil footprints reveal existence of big early dinosaur predator
Fossil footprints reveal existence of big early dinosaur predator
Scientists on Thursday described the footprints from an ancient river bank in Lesotho, and estimated that the dinosaur, which they named Kayentapus ambrokholohali, was about 30 feet (9 meters) long.
No fossilized bones were found, but the footprints alone showed a lot about the animal. The scientists concluded it was a large theropod — the two-legged carnivorous dinosaur group that included later giants like Tyrannosaurus and Giganotosaurus — but that it was more lightly built than those brutes. The theropod group also gave rise to birds.
Kayentapus lived early in the Jurassic Period, shortly after a mass extinction that doomed other large reptilian terrestrial predators that lived in the preceding Triassic Period, when dinosaurs first appeared.
“Our finding corroborates the hypothesis that theropods reached a great size relatively early in the course of their evolution, but apparently not before the Triassic-Jurassic boundary,” said paleontologist Fabien Knoll, of the Dinopolis Foundation in Spain and the University of Manchester in Britain.
There are no skeletal fossils of meat-eating dinosaurs this large so early in the dinosaur evolutionary history. It lived on the ancient southern hemisphere super-continent of Gondwana.
There are other fossilized footprints from Poland that indicate a similar-sized theropod inhabited the northern super-continent of Laurasia around the same time.
Theropods of similar size do not appear in the fossil record until 30 million years later, Knoll said.
The footprints were found on what was once a river bank, bearing telltale ripple marks and desiccation cracks.
“It is the first evidence of an extremely large meat-eating animal roaming a landscape otherwise dominated by a variety of herbivorous, omnivorous and much-smaller carnivorous dinosaurs,” added paleontologist Lara Sciscio of the University of Cape Town in South Africa.
The research was published on Wednesday in the journal PLOS ONE.
In separate research, other scientists on Thursday described another new dinosaur, a plant-eater called Matheronodon provincialis, that lived 70 million years ago. Its fossils were unearthed in southern France.
Matheronodon is distinctive for its large teeth with a chisel-like cutting edge that provided a powerful shearing action like scissors to eat tough vegetation, said paleontologist Pascal Godefroit of the Royal Belgian Institute of Natural Sciences in Brussels.
That research was published in the journal Scientific Reports.
Loss of Earth’s intact forests speeds up: scientists
- Nearly ten percent of undisturbed forests have been fragmented, degraded or simply chopped down since 2000, according to the analysis of satellite imagery
- Some 500 million people worldwide depend directly on forests for their livelihood
PARIS: Earth’s intact forests shrank annually by nearly 90,000 square kilometers — an area the size of Austria — from 2014 to 2016, 20 percent faster than during the previous 13 years, according to findings presented at a conference in Oxford this week.
Despite UN-led efforts to halt deforestation, nearly ten percent of undisturbed forests have been fragmented, degraded or simply chopped down since 2000, according to the analysis of satellite imagery.
Average daily loss over the first 17 years of this century was more than 200 sq km (75 sq miles).
“Degradation of intact forest represents a global tragedy, as we are systematically destroying a crucial foundation of climate stability,” said Frances Seymour, a senior distinguished fellow at the World Resources Institute, and a contributor to the research.
“Forests are the only safe, natural, proven and affordable infrastructure we have for capturing and storing carbon.”
The last forest frontiers also play a critical role in maintaining biodiversity, weather stability, clean air, and water quality.
Some 500 million people worldwide depend directly on forests for their livelihood.
So-called “intact forest landscapes” — which can include wetlands and natural grass pastures — are defined as areas of at least 500 sq km (200 sq miles) with no visible evidence in satellite images of large-scale human use.
Concretely, that means no roads, industrial agriculture, mines, railways, canals or transmission lines.
As of January 2017, there were about 11.6 million sq km (4.5 million sq miles) of forests worldwide that still fit these criteria.
“Many countries may lose all their forest wildlands in the next 15 to 20 years,” Peter Potapov, an associate professor at the University of Maryland and lead scientist for the research, told AFP.
On current trends, intact forests will disappear by 2030 in Paraguay, Laos and Equatorial Guinea, and by 2040 in the Central African Republic, Nicaragua, Myanmar, Cambodia and Angola.
“There could come a point in the future where no areas in the world qualify as ‘intact’ anymore,” said Tom Evans, director for forest conservation and climate mitigation at the Wildlife Conservation Society.
“It is certainly worrying.”
In tropical countries, the main causes of virgin forest loss are conversion to agriculture and logging. In Canada and the United States, fire is the main culprit, while in Russia and Australia, the destruction has been driven by fires, mining and energy extraction.
Compared to annual declines during the period 2000-2013, Russia lost, on average, 90 percent more each year from 2014 to 2016.
For Indonesia, the increase was 62 percent, and for Brazil it was 16 percent.
The new results are based on a worldwide analysis of satellite imagery, built on a study first done in 2008 and repeated in 2013.
“The high resolution data, like the one collected by the Landsat program, allows us to detect human-caused alteration and fragmentation of forest wildlands,” said Potapov.
Presented at the Intact Forests in the 21st Century conference at Oxford University, the finding will be submitted for peer-reviewed publication, said Potapov, who delivered a keynote to the three-day gathering.
Addressing colleagues from around the world, Potapov also challenged the effectiveness of a global voluntary certification system.
Set up in 1994 and backed by green groups such as the World Wildlife Fund, the self-stated mission of the Forest Stewardship Council (FSC) is to “promote environmentally appropriate, socially beneficial and economically viable management of the world’s forests.”
Many forest-products carry the FSC label, designed to reassure eco-conscious consumers.
But approximately half of all intact forest landscapes inside FSC-certified concessions were lost from 2000 to 2016 in Gabon and the Republic of Congo, the new data showed.
In Cameroon, about 90 percent of FSC-monitored forest wildlands disappeared.
“FSC is an effective mechanism to fragment and degrade remaining intact forest landscapes, not a tool for their protection,” Potapov said.
National and regional parks have helped to slow the rate of decline.
The chances of forest loss was found to be three times higher outside protected areas than inside them, the researchers reported.