Editor’s note: A version of this story appeared in CNN’s Wonder Theory science newsletter. To get it in your inbox, sign up for free here.

Tens of thousands of years ago, our species — Homo sapiens — mingled and interbred with other prehistoric humans: our distant cousins, the Neanderthals and Denisovans.

Hundreds of Neanderthal fossils give us a good idea of their appearance, lives and relationships, but so little is known about Denisovans that they still don’t have an official scientific name.

Advertisement Advertisement

Advertisement Advertisement

Evidence of their existence has surfaced in faint traces, mapped by DNA markers that lurk in our own genetic makeup and confirmed by only a few fossil fragments.

This week, however, a 146,000-year-old skull dredged out of a well in China in 2018 may just be a key missing piece to this cryptic evolutionary puzzle.

A long time ago

The nearly complete cranium recovered from a well in Harbin, China, dates to at least 146,000 years ago. – Hebei GEO University

The nearly complete skull did not match any previously known species of prehistoric human.

But two new studies — which researchers say are among the biggest paleoanthropology papers of the year — detail how scientists were able to extract genetic material from the fossil and help unravel this biological mystery.

Advertisement Advertisement

Advertisement Advertisement

The DNA sample taken from “Dragon Man,” as the specimen is called, revealed that he was in fact related to Denisovans, early humans who are thought to have lived between roughly 500,000 and 30,000 years ago.

The finding could be monumental, helping to paint a fuller picture of a time when our own species coexisted with other prehistoric humans.

Across the universe

Astronomers have long grappled with the quandary of “dark matter,” but plenty of enigmas surround regular matter as well.

The proton-and-neutron-based atoms that we’re familiar with are called baryonic matter. And this material is strewn between galaxies like intergalactic fog, making it extremely difficult to measure.

Advertisement Advertisement

Advertisement Advertisement

Perhaps, that is, until now.

A new study explains how scientists were able to observe the baryonic matter using the flashing of fast radio bursts.

Ocean secrets

In a rare encounter, scientists have captured the first-ever footage of an elusive 3-foot-long squid alive in its deep-sea habitat.

Unearthed

Fruit, flowers, birds and musical instruments decorated the walls of a luxury villa — part of a site the excavation team dubbed the “Beverly Hills” of Roman Britain — before the building was razed roughly 1,800 years ago.

The frescoes were painstakingly pieced together by experts from the Museum of London Archaeology. Han Li, senior building material specialist at MOLA, described the effort as a “once in a lifetime” opportunity.

Advertisement Advertisement

Advertisement Advertisement

Romans invaded modern-day Britain in AD 43 and established Londinium, the precursor to modern London. The occupation lasted for almost 400 years.

Curiosities

Scientists say Sericosura sea spiders may pass methane-fueled bacteria to hatchlings as an easy source of food. – Shana Goffredi

Under the life-affirming glow of the sun, methane is a dangerous gas to be avoided.

A heat-trapping chemical pollutant in Earth’s atmosphere, methane exacerbates the climate crisis. But within the planet’s deep recesses — thousands of feet below the ocean’s surface off the US West Coast — the gas can be transformed into a nutritious meal.

At least for spiders.

Scientists say they’ve discovered three previously unknown species of sea spider living around methane seeps. In these marine habitats where sunlight can’t reach, gas escapes through cracks in the seafloor and feeds bacteria that latch on to the spiders’ exoskeletons.

Advertisement Advertisement

Advertisement Advertisement

The bacteria convert carbon-rich methane and oxygen into sugars and fats the spiders can eat, according to a new study.

The newfound Sericosura sea spiders may pass methane-fueled bacteria to their hatchlings as an easy source of food, the researchers suggest.

Take note

Check out these other must-read science stories from the week:

— A SpaceX Starship rocket exploded during a routine ground test on Wednesday. Explore how this and other recent setbacks may affect the company’s Mars ambitions.

— A tiny brown moth in Australia migrates some 600 miles at night using the stars for navigation — something only humans and birds were known to do before.

Advertisement Advertisement

Advertisement Advertisement

— A hunt for ghostly cosmic particles found anomalous signals coming from Antarctic ice. A new detector could help scientists explain what they are.

— Researchers used DNA to reconstruct the face of a prehistoric woman who lived around 10,500 years ago in what’s now Belgium, suggesting that skin color already varied considerably among different populations.

Like what you’ve read? Oh, but there’s more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writers Ashley Strickland, Katie Hunt and Jackie Wattles. They find wonder in planets beyond our solar system and discoveries from the ancient world.

For more CNN news and newsletters create an account at CNN.com