This video says about itself:
The Day the Mesozoic Died: The Asteroid That Killed the Dinosaurs — HHMI BioInteractive Video
26 August 2014
Ever wonder why the dinosaurs disappeared? HHMI BioInteractive investigates the cause of the mass extinction at the end of the Cretaceous period—and the clues come from paleontology, chemistry, physics, and biology.
This three-act film tells the story of the extraordinary detective work that solved one of the greatest scientific mysteries of all time. Explore the fossil evidence of these prehistoric animals, and other organisms that went extinct, through this lively educational video.
From daily The Independent in Britain today:
Prehistoric asteroid wiped out nearly all mammals as well as dinosaurs, research suggests
‘More data shows the extinction was more severe than previously believed’
Nearly every species of mammal was eradicated by the prehistoric asteroid which wiped out the dinosaurs, research suggests.
Around 93% of mammal species were made extinct by the strike, which took place in the Cretaceous period, more than 66 million years ago.
Examination of fossil records by scientists from the University of Bath determined that the asteroid’s impact had been much more severe than previously thought.
Past estimates have been much lower because some of the rarer species that were killed left a smaller fossil record, researchers said.
The University of Bath’s Dr Nick Longrich said: “The species that are most vulnerable to extinction are the rare ones, and because they are rare, their fossils are less likely to be found.
“The species that tend to survive are more common, so we tend to find them.
“The fossil record is biased in favour of the species that survived. As bad as things looked before, including more data shows the extinction was more severe than previously believed.”
It was also found the asteroid’s catastrophic effect for life on Earth was mitigated by species recovering rapidly.
Within 300,000 years, the number of species on the planet was double the amount that had existed before the mass extinction.
Due to the lack of sustenance resulting from the widespread destruction of vegetation and animals, it is thought that the largest living animal during the period would have been about the size of a cat.
Dr Longrich added: “Because mammals did so well after the extinction, we have tended to assume that it didn’t hit them as hard.
“It wasn’t low extinction rates, but the ability to recover and adapt in the aftermath that led the mammals to take over.”
Researchers analysed all known mammal species in North America from the end of the Cretaceous period to draw their conclusions.
The findings were published in the Journal of Evolutionary Biology.
The Tyrannosaurus rex, excavated in Montana in the USA in 2013, will be exhibited in Naturalis from 10 September 2016 on.
See also here.
A video says about itself:
A new species of boa constrictor has been discovered on a remote Caribbean island
27 mei 2016
Scientists identified 20 of the three-foot long snakes during two expeditions to the Caribbean islands, the second made in October last year.
One of the creatures made a dramatic appearance by slithering onto the head of the expedition leader as he slept.
The Silver Boa, Chilabothrus argentum, is so-named because of its distinctive silver colour and the fact that the first specimen found was climbing a Silver Palm tree.
The US team led by Dr Graham Reynolds, from Harvard University, confirmed that the snake was a previously unknown species after conducting a genetic analysis of tissue samples.
From daily The Independent in Britain:
Scientists discover new species of silver boa constrictor snake in Bahamas – but it’s already ‘critically endangered’
Silver boa described as ‘mild-mannered’, calm and possibly ‘critically endangered’ with fewer than 1,000 thought to exist
Ian Johnston Environment Correspondent
Thursday 26 May 2016
A new species of snake, described as a “calm and mild-mannered” creature, has been discovered in the Bahamas – but it is already feared to be critically endangered.
The silver reptile was found on a silver palm tree on Conception Island, an uninhabited nature reserve, in July last year.
And, after research to confirm it was a separate species, it has been named the silver boa or Chilabothrus argentum, scientists revealed in a paper about the discovery to be published in the journal Breviora.
Professor Graham Reynolds, of University of North Carolina Asheville, was among the first to see the snake.
“It was exciting. As soon as we saw the first one, we knew we’d found something new,” he said.
“It just sat there and looked at us. They are very docile animals, they are very calm, slow-moving, mild-mannered.”
Deciding to conduct a systematic search that night, they then found four others of the same species before deciding to get some sleep on the beach.
“As I was sleeping I woke up to a disturbance and there was something on my face and I realised it was a boa,” Dr Reynolds said.
“It came out of the forest and crawled around on top of me. Maybe I smelled like the other snakes or something. I’ve never heard of that happening [with a boa].
“It was confusing at first but I thought it was incredible. I couldn’t believe it.”
He put the snake in a cloth bag and released it later after taking its measurements, an experience the snake seemed to take in its stride.
The beach encounter was all the more remarkable because the silver boa appears to be highly specialised, living and hunting in the trees.
Because they move so slowly, they catch their food mainly by sneaking up quietly on songbirds while they are resting in the trees at night.
“We’ve watching them stalk and hunt,” Dr Reynolds said. “It grabs its prey and wraps it up. We think they mostly eat birds.”
Their silver skin is unusual — snakes usually have a camouflage pattern – and the reasons behind its evolution are unclear. “The silvery colour is pretty striking. At night it shows up well in a flashlight,” Dr Reynolds said.
They grow to up to a metre long but are slender, weighing as little as 300 grams.
It is believed there are less than 1,000 individuals and that they are under threat from feral cats.
“We found evidence of feral cats on the island and we know these cats eat other boas,” Dr Reynolds said. “The boas really have no defence against cats.”
Robert Henderson, a curator at the Milwaukee Museum of Natural History and one of the world’s experts on boas, said finding a new snake species – and particularly a boa – was a “rare” and “exciting” event.
“Worldwide, new species of frogs and lizards are being discovered and described with some regularity,” he said. “New species of snakes, however, are much rarer.
“The beautiful Bahamian Silver Boa, already possibly critically endangered, reminds us that important discoveries are still waiting to be made, and it provides the people of the Bahamas another reason to be proud of the natural wonders of their island nation.”