Oldest animal ever discovered by scientists

Chinese scientists find a 600-million-year-old creature.

Mnemiopsis leidyi, the warty comb jelly or sea walnut
Mnemiopsis leidyi. (Image: National Institutes of Health)
  • Researchers in China find fossils of a creature that lived 600 million years ago.
  • This creature resembles a modern-day comb jelly.
  • If confirmed, these would be the oldest animal fossils discovered.

When we think of prehistoric animals, giant creatures like dinosaurs tend to come to mind. But what was the oldest animal that ever existed? Chinese scientists say it was a lowly blob that lived about 600 million years ago.

In fact, as reported by Graham Lawton in New Scientist, the creature that was recently discovered doesn't even have a name yet. The previous oldest known animal was a 541-million-year-old weird blob-like organism called Dickinsonia, which belonged to the extinct Ediacarans. The new creature, however, appears to come from the group of animals that are still with us today – comb jellies.

The organism was discovered by Zhenbing She of the China University of Geosciences, Wuhan. He revealed his findings at a meeting of the Geological Society of London in London in January 2019, stating that "The origin and earliest evolution of animals is a fascinating question that has puzzled scientists for many decades."

The sample containing the fossils of the ancient jellies came from a drill core derived from the Doushantuo Formation in southern China, which has been a source of well-preserved fossils that go back as far as 631 million years ago. The fossils are usually tiny like an algal cell, visible only through a microscope.

The creature found by She, however, can be seen with the naked eye, measuring about 0.7 millimeters. It also has an unmistakable shape of a jelly, with further analysis under a microscope showing tentacles, nerve cells, muscle tissue, and other structures pointing to the phylum Ctenophora. That's the category including comb jellies. More precisely, the evidence displays similarities to the genus Pleurobrachia, known as sea gooseberries.

Another clue pointing to comb jellies as the modern equivalent of the millions-year-old organism? Hair-like cilia clusters that are used for swimming.

Fun fact about comb jellies: These carnivores have a remarkable digestive system that includes a pass-through gut that connects their mouth and anus. Their feed consists of small sea creatures, a trait they likely share with their ancient cousins, who seemed to have been part of an elaborate ecosystem. Still, so much remains to be discovered, asserts She, adding in an interview with New Scientist,"... there are many other creatures in the deposit, but we are not sure what they are."

While the study has not been peer-reviewed, it has been read by some scientists, with a somewhat split decision. A few detractors, like Maoyan Zhu of Nanjing Institute of Geology and Palaeontology, think the found fossils could be artifacts or maybe even bacterial contamination.

Sea gooseberry comb jellies feeding!

A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source: whrc.org

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source: whrc.org

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source: whrc.org

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

Harvard study finds perfect blend of fruits and vegetables to lower risk of death

Eating veggies is good for you. Now we can stop debating how much we should eat.

Credit: Pixabay
Surprising Science
  • A massive new study confirms that five servings of fruit and veggies a day can lower the risk of death.
  • The maximum benefit is found at two servings of fruit and three of veggies—anything more offers no extra benefit according to the researchers.
  • Not all fruits and veggies are equal. Leafy greens are better for you than starchy corn and potatoes.
Keep reading Show less

Cephalopod aces 'marshmallow test' designed for eager children

The famous cognition test was reworked for cuttlefish. They did better than expected.

The common cuttlefish

Credit: Hans Hillewaert via Wikicommons
Surprising Science
  • Scientists recently ran the Stanford marshmallow experiment on cuttlefish and found they were pretty good at it.
  • The test subjects could wait up to two minutes for a better tasting treat.
  • The study suggests cuttlefish are smarter than you think but isn't the final word on how bright they are.
Keep reading Show less
13-8

If we do find alien life, what kind will it be?

Three lines of evidence point to the idea of complex, multicellular alien life being a wild goose chase. But are we clever enough to know?

Quantcast