Science

A Fossil Mystery, Solved by a Spin

Published

6 months ago

July 15, 2024

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10cm

These fossilized “blobs” were a puzzle 310 million years old.

Paleontologists decided that they were odd jellyfish named Essexella asherae. But the creature’s anatomy was unlike that of any living jellyfish.

Roy Plotnick, a paleontologist at the University of Illinois Chicago, turned an Essexella specimen upside down while doing research.

Immediately, the seemingly amorphous blob’s true identity began to take shape.

What scientists thought was a free-floating jellyfish instead revealed itself to be another ocean creature altogether.

Essexella fossils date back to the Carboniferous period, when northern parts of Illinois hovered just above the equator. A local river delta fed into the sea, creating a network of brackish wetlands home to sea scorpions, centipedes and early amphibians. Many of these creatures were buried by mudslides, which protected their remains from scavengers and decay. In the 19th century, coal miners began excavating an area, known as Mazon Creek, for fuel, and the fossils turned up in their spoil heaps.

Collectors have been finding the remains of these critters in the Mazon Creek fossil beds for more than a century. Most of the fossils are entombed in ironstone nodules. Cracking these concretions reveals the imprints of soft-bodied animals that resemble bulge-eyed aliens. In the 1950s, a local collector named Francis Tully discovered the imprint of a torpedo-shaped creature with a nozzlelike mouth. The taxonomic identity of the “Tully monster” has perplexed researchers ever since.

Essexella was similarly perplexing. Nondescript fossils turned up by the thousands at Mazon Creek, and they were often sold at local flea markets, or even discarded.

Scientists published the first detailed scientific description of the blobs in 1979. Essexella fossils are composed of two structures — a textured, barrel-shaped region and a smooth bulb. Researchers posited that the textured area represented a skirtlike curtain that wrapped around jellyfish tentacles. The rounded region was the jellyfish bell.

But as time passed, this description struck many researchers as odd.

“We were really shoehorning it to fit the jellyfish model,” Dr. Plotnick said.

No living jellyfish have curtains around their tentacles. Such a curtain would make swimming and feeding cumbersome. The uniform shape of the blob fossils also perplexed Dr. Plotnick. “If it was a jellyfish that fell on the seafloor, it would just splatter out in all directions like an old string mop on the floor,” he said.

Dr. Plotnick tested some other hypotheses to explain the blobs — such as gelatinous, barrel-shaped critters called salps or colonial congregations of tiny creatures known as siphonophores — but each new identity failed to explain Essexella’s anomalous anatomy.

In late 2016, Dr. Plotnick and a colleague, James Hagadorn, a geologist at the Denver Museum of Nature and Science, investigated the motherlode of blobs. They were at the Field Museum in Chicago, a repository for Mazon Creek fossils that has the world’s largest Essexella collection. Most had been donated by amateur collectors who were too intrigued to leave the fossils in the scrap heap.

The scientists sifted through drawer after drawer of the splotchy specimens. They lined up several fossils to photograph and compare side by side on a table. One of the blobs caught Dr. Plotnick’s eye. As he rotated the fossil upside down, he was struck by the clarity that the change of perspective offered.

“It looked like the bottom of an anemone,” Dr. Plotnick said. He added, “That was one of only a few times I’ve actually had the classic eureka moment.”

Artist’s impressions of the anatomy of Essexella as an anemone.

Marjorie Leggitt

As Dr. Plotnick brushed up on sea anemone anatomy, the ambiguous blobs came into focus. “All the things that bothered us about this being a jellyfish now makes sense,” he said.

Instead of being a jellyfish’s bell, the rounded region of the Essexella was an anemone’s burrowing base. The textured barrel was not a tentacle-enclosing curtain but the body of the anemone. Some specimens are preserved so well that the scientists could see the muscles that the anemone used to bend and contract.

Dr. Plotnick, Dr. Hagadorn and their team redescribed Essexella as an ancient anemone last year in the journal Papers in Palaeontology. Because of their soft bodies, ancient anemone species are mostly known from only a handful of poorly preserved fossils. With thousands of relatively well-preserved Essexella specimens, this once puzzling species is now the best-known anemone in the fossil record. Dr. Plotnick posits that these animals once lined the floor of the Mazon Creek estuary.

This isn’t the only time that paleontologists have flipped the scientific script to clarify the identity of a bizarre fossil. Reconstructing any ancient animal is tricky. After millions of years in the ground, fossils have been warped and weathered, crushed and scattered and stamped flat onto slabs of stone.

Sometimes, a fossil’s preservation alone is enough to disorient researchers. For decades, paleontologists were stumped by why armor-clad dinosaurs called Ankylosaurs were almost always fossilized upside down. In 2018, a team posited that the heavily armored animals often went belly up because of bloating as their carcasses floated out to sea.

And then there are the evolutionary oddballs that are difficult to decipher no matter the orientation of their fossils. In 1869, the paleontologist Edward Drinker Cope mistakenly placed the skull of an Elasmosaurus, a marine reptile, at the end of the creature’s tail instead of its elongated neck. Othniel Charles Marsh, another paleontologist, seized on Cope’s error, igniting a rivalry that would fester into the so-called Bone War.

Researchers couldn’t make heads or tails of Hallucigenia when it was found in rock.

The Natural History Museum / Alamy

The head was the tail and the tail was the head on the wormy creature.

De Agostini via Getty Images

Even weirder was Hallucigenia. For decades, researchers could not make heads or tails of the creature, a worm covered in tentacles and stiltlike spines. Then they realized that its head was really its tail, and vice versa. “That was fun and not a mere detail,” said Jean-Bernard Caron, who is a paleontologist at the Royal Ontario Museum and a co-author of a study in 2015 that determined a bulb on one end of the Hallucigenia was the creature’s head. Better-preserved fossils of a related animal in China also revealed that Hallucigenia, like Essexella, was originally reconstructed upside down.

“Clearly Hallucigenia has seen many flips,” Dr. Caron said.

While Dr. Caron’s work helped straighten out Hallucigenia, a recent paper upends his 2012 description of Pikaia, an enigmatic wormlike creature from the Burgess Shale in Canada that was purported to be an early forerunner to vertebrates. The new study suggests that a mysterious tubelike organ that researchers thought ran along Pikaia’s back (and may have been an early nerve cord) is actually the animal’s gut cavity, running along its belly.

“The animal is now on its head!” Dr. Caron said. Yet another fossilized creature got a new story when it turned over.

Science

How to protect yourself from the smoke caused by L.A. wildfires

Published

16 hours ago

January 9, 2025

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How to protect yourself from the smoke caused by L.A. wildfires

You don’t have to live close to a wildfire to be affected by its smoke. With severe winds fanning the fires in and around Pacific Palisades, the Pasadena foothills and Simi Valley, huge swaths of the Southland are contending with dangerous air quality.

Wildfire smoke can irritate your eyes, nose, throat and lungs. The soot may contain all kinds of dangerous pollutants, including some that may cause cancer. The tiniest particles in smoke can travel deep into your lungs or even enter your bloodstream.

Conditions like these aren’t good for anyone, but they’re particularly bad for people in vulnerable groups, including children, those with asthma or other respiratory conditions, people with heart disease and those who are pregnant.

Here’s what you should know to keep yourself safe.

Stay indoors

Minimize your exposure to unhealthy air by staying inside and keeping your doors and windows shut.

If you have a central heating and air conditioning system, you can keep your indoor air clean by turning it on and keeping it running. Make sure the fresh-air intake is closed so that you’re not drawing in outdoor air.

Keep your pets inside

They shouldn’t breathe the unhealthy air either.

Check your air filters

Clean filters work better than dirty ones, and high-efficiency filters work better than regular ones. The California Air Resources Board and the South Coast Air Quality Management District recommend filters with a MERV rating of 13 or higher.

You might consider using portable high-efficiency air cleaner in a room where you spend the most time. The U.S. Environmental Protection Agency has information about them here, and CARB has a list of certified cleaning devices here.

Don’t pollute your indoor air

That means no burning candles or incense. If your power is out and you need to see in the dark, you’re much better off with a flashlight or headlamp.

If you’re cold, bundle up. This is not the time to start a cozy fire in the fireplace. Don’t use a gas stove or wood-fired appliances, since these will make your indoor air quality worse, not better, the AQMD says.

The CDC also advises against vacuuming, since it can stir up dust and release fine particles into the air.

Take care when cleaning up

You don’t want your skin to come into contact with wildfire ash. That means you should wear long sleeves, pants, gloves, socks and shoes. The AQMD even wants you to wear goggles.

If you’re sweeping up ash outdoors, get a hose and mist it with water first. That will keep it from flying up in the air as you move it around. Once the ash is wet, sweep it up gently with a broom or mop. Bag it up in a plastic bag and throw it away.

It’s a good idea to wash your vehicles and outdoor toys if they’re covered in ash. Try not to send ashy water into storm drains. Direct the dirty water into ground areas instead, the AQMD advises.

Those with lung or heart problems should avoid clean-up activities.

Discard spoiled food…

If you lost power for a significant length of time, the food in your refrigerator or freezer may be spoiled.

Food kept in a fridge should stay safe for up to four hours if you’ve kept the door closed. If you’ve been without power for longer than that, you’ll need to toss all perishable items, including meat, poultry, fish, eggs, milk and cut fruits and vegetables. Anything with “an unusual smell, color, or texture” should be thrown out as well, according to the U.S. Centers for Disease and Control Prevention.

Refrigerated medicines should be OK unless the power was out for more than a day. Check the label to make sure.

…even if it was in the freezer

Your freezer may be in better shape, especially if it’s well-stocked. Items in a full freezer may be safe for up to 48 hours if it’s been kept shut, and a half-full freezer may be OK for up to 24 hours. (The frozen items help keep each other cold, so the more the better.)

If items have remained below 40 degrees Fahrenheit (4 degrees Celsius) or you can still see ice crystals in them, they may be OK to use or refreeze, according to the federal government’s food safety website.

Ice cream and frozen yogurt should be thrown out if the power goes out for any amount of time. Meat, poultry, seafood, eggs, milk and most other dairy products need to go if they were exposed to temperatures above 40 degrees F for two hours or longer. The same goes for frozen meals, casseroles, soups, stews and cakes, pies and pastries with custard or cheese fillings.

Fruit and fruit juices that have started to thaw can be refrozen unless they’ve started to get moldy, slimy or smell like yeast. Vegetables and vegetable juices should be discarded if they’ve been above 40 degrees F for six hours or more, even if they look and smell fine.

Breakfast items like waffles and bagels can be refrozen, as can breads, rolls, muffins and other baked goods without custard fillings.

Consider alternative shelter

If you’ve done everything you can but your eyes are still watering, you can’t stop coughing, or you just don’t feel well, seek alternative shelter where the air quality is better.

Hold off on vigorous exercise

Doing anything that would cause you to breathe in more deeply is a bad idea right now.

Mask up outdoors

If you need to be outside for an extended time, be sure to wear a high-quality mask. A surgical mask or cloth mask won’t cut it — health authorities agree that you should reach for an N95 or P-100 respirator with a tight seal.

Are young children at greater risk of wildfire smoke?

Very young children are especially vulnerable to the effects of wildfire smoke because their lungs are still rapidly developing. And because they breathe much faster than adults, they are taking in more toxic particulate matter relative to their tiny bodies, which can trigger inflammation, coughing and wheezing.

Any kind of air pollution can be dangerous to young children, but wildfire smoke is about 10 times as toxic for children compared to air pollution from burning fossil fuels, said Dr. Lisa Patel, clinical associate professor of pediatrics at Stanford Children’s Health. Young children with preexisting respiratory problems like asthma are at even greater risk.

Patel advises parents to keep their young children indoors as much as possible, create a safe room in their home with an air purifier, and try to avoid using gas stoves to avoid polluting the indoor air.

Children over the age of 2 should also wear a well-fitting KN95 mask if they will be outdoors for a long period of time. Infants and toddlers younger than that don’t need to mask up because it can be a suffocation risk, Patel said.

What are the risks for pregnant people?

Pregnant people should also take extra precautions around wildfire smoke, which can cross the placenta and affect a developing fetus. Studies have found that exposure to wildfire smoke during pregnancy can increase the risk of premature birth and low birth weight. Researchers have also linked the toxic chemicals in smoke with maternal health complications including hypertension and preeclampsia.

What about other high-risk populations?

Certain chronic diseases including asthma, chronic obstructive pulmonary disease or other respiratory conditions can also make you particularly vulnerable to wildfire smoke. People with heart disease, diabetes and chronic kidney disease should take extra care to breathe clean air, the CDC says. The tiny particles in wildfire smoke can aggravate existing health problems, and may make heart attacks or strokes more likely, CARB warns.

Get ready for the next emergency

Living in Southern California means another wildfire is coming sooner or later. To prepare for the bad air, you can:

Stock up on disposable respirators, like N95 or P-100s.
Have clean filters ready for your A/C system and change them out when things get smoky.
Know how to check the air quality where you live and work. The AQMD has an interactive map that’s updated hourly. Just type in an address and it will zoom in on the location. You can also sign up to get air quality alerts by email or on your smartphone.
Know where your fire extinguisher is and keep it handy.
If you have a heart or lung condition, keep at least five days’ worth of medication on hand.

Times staff writer Karen Garcia contributed to this report.

Science

Punk and Emo Fossils Are a Hot Topic in Paleontology

Published

23 hours ago

January 8, 2025

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Punk and Emo Fossils Are a Hot Topic in Paleontology

Mark Sutton, an Imperial College London paleontologist, is not a punk.

“I’m more of a folk and country person,” he said.

But when Dr. Sutton pieced together 3-D renderings of a tiny fossil mollusk, he was struck by the spikes that covered its wormlike body. “This is like a classic punk hairstyle, the way it’s sticking up,” he thought. He called the fossil “Punk.” Then he found a similar fossil with downward-tipped spines reminiscent of long, side-swept “emo” bangs. He nicknamed that specimen after the emotional alt-rock genre.

On Wednesday, Dr. Sutton and his colleagues published a paper in the journal Nature formally naming the creatures as the species Punk ferox and Emo vorticaudum. True to their names, these worm-mollusks are behind something of an upset (if not quite “anarchy in the U.K.”) over scientists’ understanding of the origins of one of the biggest groups of animals on Earth.

In terms of sheer number of species, mollusks are second only to arthropods (the group that contains insects, spiders and crustaceans). The better-known half of the mollusk family tree, conchiferans, contains animals like snails, clams and octopuses. “The other half is this weird and wacky group of spiny things,” Dr. Sutton said. Some animals in this branch, the aculiferans, resemble armored marine slugs, while others are “obscure, weird molluscan worms,” he said.

Punk and Emo, the forerunners of today’s worm-mollusks, lived on the dark seafloor amid gardens of sponges, nearly 200 million years before the first dinosaurs emerged on land. Today, their ancient seafloor is a fossil site at the border between England and Wales.

The site is littered with rounded rocky nodules that “look a bit like potatoes,” Dr. Sutton said. “And then you crack them open, and some of them have got these fossils inside. But the thing is, they don’t really look like much at first.”

While the nodules can preserve an entire animal’s body in 3-D, the cross-section that becomes visible when a nodule is cracked open can be difficult to interpret “because you’re not seeing the full anatomy,” Dr. Sutton said.

Paleontologists can use CT scans to see parts of fossils still hidden in rock, essentially taking thousands of X-rays of the fossil and then stitching those X-ray slices together into one digital 3-D image. But in these nodules, the fossilized creatures and the rock surrounding them are too similar in density to be easily differentiated by X-rays. Instead, Dr. Sutton essentially recreated this process of slicing and imaging by hand.

“We grind away a slice at a time, take a photo, repeat at 20-micron intervals or so, and basically destroy but digitize the fossil as we go,” Dr. Sutton said. At the end of the process, the original fossil nodule is “a sad-looking pile of dust,” but the thousands of images, when painstakingly digitally combined, provide a remarkable picture of the fossil animal.

Punk and Emo’s Hot Topic-worthy spikes set them apart from other fossils from the aculiferan branch of the mollusk family. “We don’t know much about aculiferans, and it’s unusual to find out we’ve suddenly got two,” Dr. Sutton said.

Stewart Edie, the curator of fossil bivalves at the Smithsonian National Museum of Natural History, said that Punk and Emo’s bizarre appearances shook up a long-held understanding of how mollusks evolved. Traditionally, scientists thought that the group of mollusks containing snails, clams and cephalopods “saw all of the evolutionary action,” said Dr. Edie, who was not involved with the new discovery. “And the other major group, the aculiferans, were considerably less adventurous.” But Punk and Emo “buck that trend,” he said.

The new alt-rock aculiferans reveal the hidden diversity of their group in the distant past and raise questions about why their descendants make up such a small part of the mollusk class today. “This is really giving us an almost unprecedented window into the sorts of things that were actually around when mollusks were getting going,” Dr. Sutton said. “It’s just this little weird, unexpected, really clear view of what was going on in the early history of one of the most important groups of animals.”

Science

FDA sets limits for lead in many baby foods as California disclosure law takes effect

Published

1 day ago

January 8, 2025

Press Room

FDA sets limits for lead in many baby foods as California disclosure law takes effect

The U.S. Food and Drug Administration this week set maximum levels for lead in baby foods such as jarred fruits and vegetables, yogurts and dry cereal, part of an effort to cut young kids’ exposure to the toxic metal that causes developmental and neurological problems.

The agency issued final guidance that it estimated could reduce lead exposure from processed baby foods by about 20% to 30%. The limits are voluntary, not mandatory, for food manufacturers, but they allow the FDA to take enforcement action if foods exceed the levels.

It’s part of the FDA’s ongoing effort to “reduce dietary exposure to contaminants, including lead, in foods to as low as possible over time, while maintaining access to nutritious foods,” the agency said in a statement.

Consumer advocates, who have long sought limits on lead in children’s foods, welcomed the guidance first proposed two years ago, but said it didn’t go far enough.

“FDA’s actions today are a step forward and will help protect children,” said Thomas Galligan, a scientist with the Center for Science in the Public Interest. “However, the agency took too long to act and ignored important public input that could have strengthened these standards.”

The new limits on lead for children younger than 2 don’t cover grain-based snacks such as puffs and teething biscuits, which some research has shown contain higher levels of lead. And they don’t limit other metals such as cadmium that have been detected in baby foods.

The FDA’s announcement comes just one week after a new California law took effect that requires baby food makers selling products in California to provide a QR code on their packaging to take consumers to monthly test results for the presence in their product of four heavy metals: lead, mercury, arsenic and cadmium.

The change, required under a law passed by the California Legislature in 2023, will affect consumers nationwide. Because companies are unlikely to create separate packaging for the California market, QR codes are likely to appear on products sold across the country, and consumers everywhere will be able to view the heavy metal concentrations.

Although companies are required to start printing new packaging and publishing test results of products manufactured beginning in January, it may take time for the products to hit grocery shelves.

The law was inspired by a 2021 congressional investigation that found dangerously high levels of heavy metals in packaged foods marketed for babies and toddlers. Baby foods and their ingredients had up to 91 times the arsenic level, up to 177 times the lead level, up to 69 times the cadmium level, and up to five times the mercury level that the U.S. allows to be present in bottled or drinking water, the investigation found.

There’s no safe level of lead exposure for children, according to the U.S. Centers for Disease Control and Prevention. The metal causes “well-documented health effects,” including brain and nervous system damage and slowed growth and development. However, lead occurs naturally in some foods and comes from pollutants in air, water and soil, which can make it impossible to eliminate entirely.

The FDA guidance sets a lead limit of 10 parts per billion for fruits, most vegetables, grain and meat mixtures, yogurts, custards and puddings and single-ingredient meats. It sets a limit of 20 parts per billion for single-ingredient root vegetables and for dry infant cereals. The guidance covers packaged processed foods sold in jars, pouches, tubs or boxes.

Jaclyn Bowen, executive director of the Clean Label Project, an organization that certifies baby foods as having low levels of toxic substances, said consumers can use the new FDA guidance in tandem with the new California law: The FDA, she said, has provided parents a “hard and fast number” to consider a benchmark when looking at the new monthly test results.

But Brian Ronholm, director of food policy for Consumer Reports, called the FDA limits “virtually meaningless because they’re based more on industry feasibility and not on what would best protect public health.” A product with a lead level of 10 parts per billion is “still too high for baby food. What we’ve heard from a lot of these manufacturers is they are testing well below that number.”

The new FDA guidance comes more than a year after lead-tainted pouches of apple cinnamon puree sickened more than 560 children in the U.S. between October 2023 and April 2024, according to the CDC.

The levels of lead detected in those products were more than 2,000 times higher than the FDA’s maximum. Officials stressed that the agency doesn’t need guidance to take action on foods that violate the law.

Aleccia writes for the Associated Press. Gold reports for The Times’ early childhood education initiative, focusing on the learning and development of California children from birth to age 5. For more information about the initiative and its philanthropic funders, go to latimes.com/earlyed.