Archive for the ‘paleontology’ Category

Is this a fossilized lair of the dreaded bobbit worm?

January 24th, 2021
The head of a gruesome yet colorful worm projects from the seafloor.

Enlarge (credit: Getty Images)

Not to toot my own horn, but I know a thing or two about bizarre animals. And I can tell you without a hint of doubt that the bobbit worm is by far the most bizarre. Growing to 10 feet long, the worm digs a burrow in the seafloor, leaving only its bear trap of a mouth sticking out. When a fish approaches, the bobbit worm shoots out of its burrow with astonishing speed, snapping its jaws around its prey. With violent tugs, the worm then drags the victim down into its lair, where it eats the fish alive. (Oh, there's video.)

Now scientists say they've found evidence that an ancestor of the bobbit worm may have been menacing fish 20 million years ago. Writing today in the journal Scientific Reports, the researchers argue that hundreds of fossilized worm burrows, found in what is now Taiwan, show telltale signs of struggle. They haven't found the worms themselves, mind you, as boneless critters like worms (known as invertebrates, because they lack spinal columns) very rarely fossilize. Instead, they discovered trace fossils, geological features that hint at the behavior of ancient animals, in sandstone that was once a seafloor.

"This is, we believe, the first time that we've actually found a trace fossil that shows how invertebrates like worms were feeding on vertebrates," says National Taiwan University sedimentologist Ludvig Löwemark, co-author of the new paper. "Because, typically, what we find in the sedimentary record is animals that are moving through the sediment." Invertebrates, for instance, might dig tunnels through the sea bottom and pump water through their burrows, filtering out particles. "But this is a record of a much more active behavior," he continues. "The worms were actually hiding in the sediment, jumping out, catching their prey, and then dragging this prey down into the sediment."

Read 12 remaining paragraphs | Comments

Posted in bobbit worm, fossils, paleontology, science | Comments (0)

Dire wolves aren’t wolves at all—they form a distinct lineage with jackals

January 13th, 2021
Two canid skeletons facing each other.

Enlarge (credit: Wikimedia commons)

Dire wolves had a burst of newfound fame with their appearance in Game of Thrones, where they were portrayed as a far larger version of more mundane wolves. Here in the real world, only the largest populations of present-day wolves get as large as the dire wolf, which weighed nearly 70 kilograms. These animals once shared North America—and likely prey—with predators like the smilodon, a saber-toothed cat. Prior to the arrival of humans, dire wolves were far more common than regular wolves, as indicated by the remains found in the La Brea tar seeps, where they outnumber gray wolves by a factor of about 100.

Like the smilodon and many other large North American mammals, the dire wolf vanished during a period of climate change and the arrival of humans to the continent, even as gray wolves and coyotes survived. And with their departure, they left behind a bit of a mystery: what were they?

A new study uses ancient DNA from dire wolf skeletons to determine that they weren't actually wolves and had been genetically isolated from them for millions of years.

Read 10 remaining paragraphs | Comments

Posted in dire wolves, Dogs, evolution, Genetics, Genomics, paleontology, science, wolves | Comments (0)

Yukon gold miner unearths a mummified Ice Age wolf pup

December 22nd, 2020
Color photo of wolf mummy puppy laying on a pillow

Enlarge / The puppy's remains are dried out but mostly intact thanks to being buried in permafrost. (credit: Government of Yukon)

This Ice Age wolf puppy doesn’t look much like a fearsome predator, what with her tiny puppy teeth and soft little ears. According to her DNA, however, the mummified puppy, named Zhùr, came from a population that's among the ancestors of all modern wolves. Canada’s permafrost freeze-dried her remains shortly after her death around 57,000 years ago.

“She’s the most complete wolf mummy that’s ever been found. She’s basically 100 percent intact—all that’s missing are her eyes,” said Des Moines University paleontologist Julie Meachen.

Puppy surprise

In July 2016, miner Neil Loveless of Favron Enterprises was searching for gold in Alaska’s famed Klondike gold fields. He was water-blasting the frozen mud along the banks of Last Chance Creek. It’s a process called “hydraulic thawing,” meant to thaw and soften the frozen permafrost so miners can search for gold in the streambed deposits, an approach called placer mining. But Loveless found something far stranger and even more interesting than Klondike gold: a frozen, mummified wolf puppy.

Read 20 remaining paragraphs | Comments

Posted in ancient DNA, gold mining, klondike, mummies, paleontology, Permafrost, pleistocene, science, wolves, Yukon | Comments (0)

Forgotten trove of fossil feathers belonged to tiny polar dinosaurs

January 15th, 2020
Image of a rock with a feather fossil that preserves many fine branches.

Enlarge / One of the spectacular feather fossils that has been sitting in a museum's sample collection for decades. (credit: Melbourne Museum)

Researchers have described ten fossil feathers from the polar regions of the former continent Gondwana for the first time. The collection, documented in a recent paper in Gondwana Research, contains a highly diverse array of feathers collected from the 118 million-year-old Koonwarra Fossil Bed in Victoria, Australia. 

The paper describes what is potentially the earliest evidence of a flight feather, and the first-ever non-avian dinosaur feathers found within the Antarctic Circle. It also documents dark coloration and insulating branching structures on some of the feathers, providing valuable insight into how polar dinosaurs might have stayed warm during long, dark winters. 

The fossils were initially discovered in the 1960s, but most of the technologies and knowledge used to understand the feathers described in this study didn’t yet exist at that point. Since then, they were tucked away in a drawer in the Melbourne Museum for decades, until lead author Martin Kundrát happened across an old paper in 2012 that described one of the feathers. 

Read 17 remaining paragraphs | Comments

Posted in dinosaurs, feathers, fossils, paleontology, Staff | Comments (0)

Fossil bonanza paints detailed picture of mammals after dinosaur extinction

October 25th, 2019
Dr. Tyler Lyson, Curator of Vertebrate Paleontology for the Denver Museum of Nature & Science, holds open a split concretion and reveals the cross section of a vertebrate skull inside.

Enlarge / Dr. Tyler Lyson, Curator of Vertebrate Paleontology for the Denver Museum of Nature & Science, holds open a split concretion and reveals the cross section of a vertebrate skull inside. (credit: HHMI Tangled Bank Studios)

Paleontologists in Denver have uncovered a treasure trove of fossils that give a thrilling new insight into the rise of the mammals after the extinction of the dinosaurs.

The discovery, detailed in a paper published this week in Science, has yielded a colossal amount of data showing how tiny mammal species grew and diversified dramatically after the extinction. The finding throws a spotlight on a previously unknown part of our own history: the very early days of a period that eventually produced all current mammal species on Earth.

The mystery of the first million years

There's still a ton that nobody understands about what happened after the extinction 66 million years ago. Researchers have been piecing together evidence about the event itself, which wiped out around three-quarters of all species on Earth and ended the era of the dinosaurs. "The time afterward has been shrouded in mystery," said paleobotanist Ian Miller, one of the lead researchers in the team that found the fossils, in a Q&A published by the Denver Museum of Nature and Science.

Read 13 remaining paragraphs | Comments

Posted in dinosaurs, Earth science, paleontology, science | Comments (0)

Before life exploded in the Cambrian, there were worms

September 4th, 2019
Illustration of a segmented worm leaving traces.

Enlarge (credit: Dr. Zhe Chen/Nanjing Institute of Geology and Paleontology)

The Cambrian is rightly famous for being the period when animal life first exploded into a dizzying diversity of forms, including some body plans that remain with us today. But the first animals in the fossil record predate the Cambrian by tens of millions of years. Entire ecosystems of creatures appeared over about 50 million years near the end of the Ediacaran Period and then vanished at the start of the Cambrian.

But the Ediacaran animals were rather strange, with body plans that don't even have the same starting materials as the more familiar Cambrian forms do. And most of them weren't mobile, instead simply attaching themselves to surfaces and staying there. There were, however, limited indications that the ancestors of Cambrian animals had already evolved in the Ediacaran. Traces left in sediments indicated that something was moving through them, and one odd disk-like creature appeared to have had a bilateral body plan. But the tracks weren't left by anything disk shaped, raising questions about what else might have been moving around in the Ediacaran.

Those questions have been at least partially resolved with today's announcement of Yilingia spiciformis, an Ediacaran worm that wouldn't look entirely out of place in today's oceans. Yilingia was segmented, it created tracks, and it even appears to have been able to burrow into sediments. And it managed to do all that without any prominent structures at its head.

Read 7 remaining paragraphs | Comments

Posted in Biology, Cambrian, ediacaran, evolution, paleontology, science | Comments (0)

Fossilized teeth of Ice Age predators yield clues to why certain species survived

August 6th, 2019

Paleontologist Larisa DeSantis studies ancient predators trapped in the La Brea Tar Pits. Courtesy Vanderbilt University.

Visitors to the La Brea Tar Pits in Los Angeles are accustomed to seeing recreated scenes of, say, extinct saber-tooth cats taking down a horse or bison in an open field. But according to the most detailed study yet of Ice Age predators by paleontologists at Vanderbilt University, this would have been an extremely rare occurrence. They describe a different ecological scenario in their latest paper in Current Biology—one in which saber-toothed cats preferred to hunt under the cover of a forest, while dire wolves preferred to track their prey in open environments. And their findings may offer valuable hints about why some ancient predator species went extinct (dire wolves and saber-toothed cats), while others survived (coyotes).

The so-called Pleistocene Epoch dates from 2.5 million years ago to roughly 10,000 years ago, a time period that includes dramatic shifts in climate and the evolution of humans into the ecological mix. The La Brea Tar Pits is one of the best repositories for preserving the remains of now-extinct ancient species from this era. For tens of thousands of years, animals would become mired in the tar, gradually getting sucked down into the pit before dying of asphyxiation.  Over time, their remains became fossilized as the lighter fractions of the petroleum evaporated, leaving the bones trapped in a more solid substance until archaeologists uncovered them thousands of years later. And there are far more carnivore and predator specimens in the pit than herbivores, perhaps because they were drawn to the pits when herbivores became mired in the tar, and became mired themselves.

The first recorded sighting of the La Brea Tar Pits is in 1769, when the Spanish governor of Baja California headed an excursion down what is now Wilshire Boulevard in midtown Los Angeles. The expedition observed large marshes of a pitch-like substance, bubbling and boiling.  The George C. Page Museum of La Brea Discoveries now stands adjacent to the pits, where scientists continue to excavate new fossilized remains from the tar to this day, aided by volunteers during the summer keen to hunt for fossilized treasure.

Read 9 remaining paragraphs | Comments

Posted in Extinction, La Brea tar pits, paleontology, science | Comments (0)

Scientists name new fossil species after Millennium Falcon from Star Wars

August 3rd, 2019

A new species from the Burgess Shale has been discovered by paleontologists from the Royal Ontario Museum.

Paleontologists excavating a site in the Canadian Rockies known as the Burgess Shale have discovered the fossilized remains of a heretofore-unknown species of arthropod with a distinctive horseshoe-shaped upper shell. They whimsically named the species Cambroraster falcatus after the Millennium Falcon starship piloted by Han Solo in the Star Wars franchise. The discovery, reported in a new paper in the journal Proceedings of the Royal Society B, sheds light on the diversity of the earliest relatives of insects, crabs, and spiders.

Discovered in 1909 by paleontologist Charles Walcott and dating back to the mid-Cambrian era some 508 million years ago, the Burgess Shale has since become one of the richest troves of preserved fossils from that period. The late Stephen Jay Gould immortalized its importance in his bestselling 1989 book, Wonderful Life, in which he argued (somewhat controversially) that the sheer diversity of the Burgess Shale fossils was evidence for several unique evolutionary lineages that became extinct, rather that continuing down to today's modern phyla. The Burgess Shale was declared a World Heritage Site in 1980.

In 2013, scientists discovered yet another piece of the Burgess Shale in Kootenay National Park and excavated the fossilized remains of some 50 new species in just 15 days. That's the area where a team of paleontologists affiliated with the Royal Ontario Museum discovered this latest arthropod.

Read 4 remaining paragraphs | Comments

Posted in Burgess shale, fossils, Millennium Falcon, paleontology, science, Star Wars | Comments (0)

Physics indicates some of Earth’s earliest animals helped each other feed

June 21st, 2019
Image of bright lines representing fluid flow.

Enlarge / The result of a fluid mechanics simulation with multiple Erniettas. (credit: Dave Mazierski)

What drove the evolution of the earliest animal life? In modern animals, it's easy to infer a lot about an organism's lifestyle based on its anatomy. Even back in the Cambrian, with its large collection of bizarre looking creatures, these inferences are possible. Anomalocaris may have had a freakish, disk-shaped mouth, but it clearly was a mouth.

Go back to Earth's earliest animals in the Ediacaran, however, and things get much, much harder. There's only one species known so far that appears to have the right body plan to act as a predator of sorts. Beyond that, it's all a collection of soft-looking fronds and segments that are difficult to ascribe any obvious function to. Faced with a lot of questions without obvious answers, biologists turned to an unlikely source of help: physicists and engineers who understand fluid mechanics.

All of these creatures lived in an aquatic environment, so tracing how fluid flows across them can provide some hints as to how food might have arrived. Now, the same sort of research indicates that a strange cup-shaped species grew in communities because it improved the feeding of some of the community members.

Read 15 remaining paragraphs | Comments

Posted in Biology, ediacaran, evolution, fluid mechanics, fossils, paleontology, Physics, science | Comments (0)

Billion-year-old fossils may be early fungus

May 22nd, 2019
Image of a ball on a stalk.

Enlarge (credit: Loron, et. al.)

When did the first complex multicellular life arise? Most people, being a bit self-centered, would point to the Ediacaran and Cambrian, when the first animal life appeared and then diversified. Yet studies of DNA suggest that fungi may have originated far earlier than animals.

When it comes to a fossil record, however, things are rather sparse. No unambiguous evidence of a fungus appears in fossils until after the Cambrian was over. A few things from earlier may have looked fungus-like, but the evidence was limited to their appearance. It could be that fungi branched off at the time suggested by the DNA but didn't evolve complex, multicellular structures until later. Alternatively, the fossils could be right, and there's something off about the DNA data. Or, finally, it could be that we simply haven't found old enough fossils yet.

A new paper out in today's Nature argues strongly for the last option. In it, a small team of researchers describe fossils of what appear to be fungi that could be up to a billion years old. And the researchers back up the appearance with a chemical analysis.

Read 12 remaining paragraphs | Comments

Posted in Biology, evolution, fossils, fungus, paleontology, science | Comments (0)