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Dinosaurus korban sempurna dari
peristiwa badai ,
studi menunjukkan
...., para
ilmuwan mengatakan. Mereka menemukan bahwa beberapa juta tahun sebelum asteroid lebar 10km menghantam yang sekarang Meksiko, bumi
mengalami lingkungan pergolakan. Ini termasuk beragam aktivitas vulkanik permukaan laut dan berbagai suhu. Saat ini,
rantai makanan dinosaurus dilemahkan oleh kurangnya keragaman di antara
tanaman-makanan dinosaurus
besar
Dinosaurs fell victim to perfect storm of events, study shows
Date:
July 28,
2014
Source:
University of Edinburgh
Summary:
Dinosaurs might have survived the asteroid strike that
wiped them out if it had taken place slightly earlier or later in history, scientists
say. They found that in the few million years before a 10km-wide asteroid
struck what is now Mexico, Earth was experiencing environmental upheaval. This
included extensive volcanic activity, changing sea levels and varying
temperatures. At this time, the dinosaurs' food chain was weakened by a lack of
diversity among the large plant-eating dinosaurs on which others preyed.
.....................
Dinosaurs might have survived the asteroid strike that wiped
them out if it had taken place slightly earlier or later in history, scientists
say.
A fresh
study using up-to-date fossil records and improved analytical tools has helped
palaeontologists to build a new narrative of the prehistoric creatures' demise,
some 66 million years ago.
They found
that in the few million years before a 10km-wide asteroid struck what is now
Mexico, Earth was experiencing environmental upheaval. This included extensive
volcanic activity, changing sea levels and varying temperatures.
At this
time, the dinosaurs' food chain was weakened by a lack of diversity among the
large plant-eating dinosaurs on which others preyed. This was probably because
of changes in the climate and environment.
This created
a perfect storm in which dinosaurs were vulnerable and unlikely to survive the
aftermath of the asteroid strike.
The impact
would have caused tsunamis, earthquakes, wildfires, sudden temperature swings
and other environmental changes. As food chains collapsed, this would have
wiped out the dinosaur kingdom one species after another. The only dinosaurs to
survive were those who could fly, which evolved to become the birds of today.
Researchers
suggest that if the asteroid had struck a few million years earlier, when the
range of dinosaur species was more diverse and food chains were more robust, or
later, when new species had time to evolve, then they very likely would have
survived.
An
international team of palaeontologists led by the University of Edinburgh
studied an updated catalogue of dinosaur fossils, mostly from North America, to
create a picture of how dinosaurs changed over the few million years before the
asteroid hit. They hope that ongoing studies in Spain and China will aid even
better understanding of what occurred.
Their study,
published in Biological Reviews, was supported by the US National
Science Foundation and the European Commission. It was led by the Universities
of Edinburgh and Birmingham in collaboration with the University of Oxford,
Imperial College London, Baylor University, and University College London. The
world's top dinosaur museums -- The Natural History Museum, the Smithsonian
Institution, the Royal Ontario Museum, the American Museum of Natural History
and the New Mexico Museum of Natural History and Science -- also took part.
Dr Steve
Brusatte, of the University of Edinburgh's School of GeoSciences, said:
"The dinosaurs were victims of colossal bad luck. Not only did a giant
asteroid strike, but it happened at the worst possible time, when their
ecosystems were vulnerable. Our new findings help clarify one of the enduring
mysteries of science."
Dr Richard
Butler of the School of Geography, Earth and Environmental Sciences at the
University of Birmingham, said: "There has long been intense scientific
debate about the cause of the dinosaur extinction. Although our research
suggests that dinosaur communities were particularly vulnerable at the time the
asteroid hit, there is nothing to suggest that dinosaurs were doomed to
extinction. Without that asteroid, the dinosaurs would probably still be here,
and we very probably would not."
Story
Source:
The above
story is based on materials provided by University of Edinburgh. Note: Materials may be edited
for content and length.
Journal
Reference:
- Stephen L. Brusatte, Richard J. Butler, Paul M. Barrett, Matthew T. Carrano, David C. Evans, Graeme T. Lloyd, Philip D. Mannion, Mark A. Norell, Daniel J. Peppe, Paul Upchurch, Thomas E. Williamson. The extinction of the dinosaurs. Biological Reviews, 2014; DOI: 10.1111/brv.12128