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A skull of a dinosaur with a beak and large eyes, preserved in amber.

Oculudentavis khaungraae is had a skull that was less than 2 centimetres long.Credit: Lida Xing

Tiny dinosaur skull preserved in amber

This bird-like skull, exquisitely preserved in amber for almost 100 million years, belonged to probably the smallest dinosaur ever discovered. The skull is less than 2 centimetres long — suggesting that the creature was the size of a bee hummingbird (Mellisuga helenae), the smallest living bird. “It reveals to us a whole new lineage of birds,” says palaeontologist Jingmai O’Connor.

Nature | 3 min read

COVID-19 coronavirus outbreak

WHO describes coronavirus as a pandemic

• The World Health Organization (WHO) has characterized the COVID-19 outbreak as a pandemic amid “alarming levels of inaction” to stop the spread. WHO director-general Tedros Adhanom Ghebreyesus emphasized that describing the situation as a pandemic did not change the organization’s assessment of the outbreak or its approach to stopping it. “There’s been so much attention on one word,” said Tedros. “Let me give you some other words that matter much more, & that are much more actionable: Prevention. Preparedness. Public health. Political leadership. And most of all, People.” (Nature | Continuously updated)

• The American Chemical Society, one of the world’s largest scientific societies, cancelled its meeting in Philadelphia, Pennsylvania, on Monday, 13 days before it was due to begin. The American Physical Society’s huge March Meeting was also cancelled last week — one of scores of scientific conferences that have been called off worldwide. (Nature | Continuously updated)

• To what extent can isolating the sick, quarantining their contacts and encouraging social distancing slow the spread of COVID-19? Four epidemiologists dig into how countries can mitigate the spread, using data from coronavirus hotspots in China, South Korea, Italy, and Iran. How individuals respond to health advice will be as important as government actions, if not more so, conclude the researchers. (The Lancet | 12 min read)

• The fatality rate for COVID-19 is a crucial number for understanding the disease. Epidemiologist Marc Lipsitch explains why the number is so difficult to pin down and the measures that will eventually bring clarity. He also offers “the consensus for now” on the risk of dying for those with symptoms: around 1 or 2%, for young healthy adults. (The Washington Post | 6 min read)

Read the latest coronavirus news, continuously updated on Nature.

Notable quotable

“It must have been here this entire time. It’s just everywhere already.”

Infectious-disease specialist Helen Chu, who co-leads a study originally set up to track influenza in Seattle, recalls her thoughts on discovering that the coronavirus was spreading undetected in Washington state. (The New York Times)

Features & opinion

Better treatments for kidney failure

After decades of slow progress, researchers are testing better treatments for kidney failure — which kills more people than HIV or tuberculosis. They hope to supplement dialysis machines, which still use much the same technology as they did 50 years ago, with artificial kidneys and miniaturized dialysis that could save millions of lives.

Nature | 10 min read

A controlled trial for reproducibility

For three years, part of DARPA has funded two teams for each project: one for research and one to replicate it. The investment is paying off, write three participating researchers. They report back on a herculean effort — and an expensive one — that will bring benefits beyond reproducing any individual project.

Nature | 10 min read

“It’s our big, dirty secret.”

Biomedical scientist Darren Saunders is a Eureka prize-winning cancer researcher with his own lab — whose funding has just run out. With ever more scientists in the workforce competing for grants, and science becoming ever more complex and expensive, Saunders is not alone. “There are a lot of scientists in my predicament, or worse, at the moment. It’s our big, dirty secret,” says Saunders. “But we do need to talk about it.”

The Sydney Morning Herald | 3 min read

When the funding runs out

As a university student in Nigeria, theoretical physicist Omololu Akin-Ojo learned to write computer code by hand, without the benefit of a computer to run it on. The experience influenced his decision to focus the East African Institute for Fundamental Research (EAIFR) in Rwanda on research in his own discipline. “Theoretical physics is the cheapest advanced research that you can do because you don’t need equipment to get started,” says Akin-Ojo. “You just need paper, a pencil, a brain and maybe a little computer hardware.”

Quanta | 10 min read

Quote of the day

“In a meta research twist, I'm incredibly excited to share my preprint about preprints on Twitter on Twitter.”

Population geneticist Jedidiah Carlson looked at how groups on Twitter — especially white supremacists — interact with bioRxiv preprints. (Twitter)