Tag Archives: paleontology

The Earth’s oldest fossil?

The uncertainty of science: Geologists this week announced the discovery of what they think is the Earth’s oldest fossil, approximately 3.7 billion years old.

While the press as usual is going gaga over this announcement, it should be noted that many others in the field have expressed significant doubts.

But the discovery involves some of the most physically tortured rocks on Earth, which have been squeezed and heated over billions of years as crustal plates shifted. The pressure and heat recrystallizes the rocks, erasing much of the fine-scale detail that researchers normally use to identify fossilized stromatolites — so the work is already triggering heated debate. “I’ve got 14 queries and problems that need addressing before I’ll believe it,” says Roger Buick, a geobiologist at the University of Washington in Seattle.

It wasn’t just an asteroid that killed the dinosaurs

Scientists have now obtained enough solid data to confirm that the large extinction of the dinosaurs 65 million years ago was caused not just by the Yucatan asteroid impact but also by the gigantic volcanic event in India called the Deccan Traps.

The researchers said the asteroid strike occurred 66.04 million years ago, plus or minus about 30,000 years. They said eruptions in a region called the Deccan Traps were already underway at a lower intensity but dramatically accelerated after the asteroid strike as if the powerful impact triggered it. The dating method they used found this acceleration began within 50,000 years of the impact, but it could have been in the mere days, months or years afterward. “Within measurement error, they’re simultaneous,” said volcanologist Loÿc Vanderkluysen of Philadelphia’s Drexel University. “The two processes in tandem caused the extinctions,” added Paul Renne, director of the Berkeley Geochronology Center and a University of California, Berkeley geologist, who led the study in the journal Science.

Though many planetary scientists have discounted the Deccan Traps for decades, paleontologists have tended to favor it as a major factor in the extinction. This new study suggests that both were involved, which was the theory held by most of the more reasonable scientists in both fields. While many liked to push one or the other theory in the press, the better scientists considered both a possible factor and have been working to determine this possibility.

New human species found?

The uncertainty of science: Scientists in South Africa think they have found fossils of a new human species.

In the end, the work of more than 60 researchers yielded a picture of “a relatively tall, skinny hominid with long legs, humanlike feet, with a core and shoulder that is primitive,” Berger says. Some body parts have come into sharper focus than others. In an analysis of the remarkably complete hands, paleoanthropologist Tracy Kivell of the University of Kent in the United Kingdom found that bones in the wrist were shaped like those in modern humans, suggesting that the palm at the base of the thumb was quite stiff. That would allow forces to dissipate over a larger area of the hand than in more primitive humans—a trait associated with tool use. At the same time, H. naledi had a weird thumb and long, curving fingers, as if it still spent a lot of time climbing.

The story of the discovery is interesting in that the fossils were found in a cave in a room that is very difficult to access, so difficult that the scientists themselves have never seen the site. Instead, they have sent very small cavers inside to do the fossil gathering.

There are many caveats to this story. The 15 skeletons appear different than humans, but to then create a whole human species from this single location is a bit risky.

I think the biggest mystery about this find involves its location. How the heck did these 15 individuals get trapped in this room at the back of a cave that requires you to squeeze down a vertical 100-foot chute only about 8 inches wide to enter?

Did some dinosaur soft tissues survive fossilization?

The uncertainty of science: New research strongly suggests that within dinosaur fossils are found many preserved soft tissues from when the creature was still living.

As early as the 1970s, researchers captured images of what looked like cellular structures inside dinosaur fossils. But did the structures contain actual tissue? Proteins commonly decay hundreds to thousands of years after an organism dies, but in rare cases they have been known to survive up to 3 million years. In a series of studies beginning a decade ago, a team led by North Carolina State University paleontologist Mary Schweitzer reported that they had extracted what appeared to be collagen, the most abundant protein in bone, from a 68-million-year-old T. rex fossil. They sequenced fragments of the protein and concluded that it closely matched that of birds, dinosaurs’ living descendants (see here and here). But other teams haven’t been able to replicate the work, and others suggested that the collagen could be contamination.

The new study, led by materials scientist Sergio Bertazzo and paleontologist Susannah Maidment, both of Imperial College London, has a different strategy for hunting down ancient proteins. Bertazzo, an expert on how living bones incorporate minerals, uses a tool called a focused ion beam to slice through samples, leaving pristine surfaces that are ideal for high-resolution imaging studies. He teamed up with Maidment to apply the technique to eight chunks of dinosaur toe, rib, hip, leg, and claw.

What they found shocked them. Imaging the fresh-cut surfaces with scanning and transmission electron microscopes, “we didn’t see bone crystallites” as expected, Maidment says. “What we saw instead was soft tissue. It was completely unexpected. My initial response was these results are not real.” [emphasis mine]

It must be noted that the new research depends on many uncertainties that still need to be replicated or confirmed.

Russian hunters find frozen carcass of extinct whoolly rhino

In September Russian hunters accidentally discovered the frozen remains of an adolescent whoolly rhinoceros.

Larger than modern-day rhinos and more suited to extreme cold and harsh environments, the woolly rhino first appeared about 3.6 million years ago. Weighing up to an estimated 4,000 pounds and equipped with 24-inch-long horns, these intimidating creatures co-existed with early humans and were often hunted. Yet for all their strength, the woolly rhino became extinct over 10,000 years ago. Unlike the woolly mammoth, little is known about this species since few specimens have ever been retrieved. Those that have were often mummified to a point where study was impossible, and up until now, no calf has ever been found.

RT reported that experts at the Yakutsk academy will attempt to extract DNA from the calf’s remains and try to come up with a more accurate date on when the creature died. Nicknamed “Sasha,” researchers say the calf died at least 10,000 years ago and may have been 18 months old when it perished.

Brontosaurus returns!

The uncertainty of science: The popular but unofficial and rejected dinosaur name “Brontosaurus” has been resurrected by paleontologists.

A new study has found that the bones that had been assigned to Apatosaurus, the term that paleontologists in the 1970s chose over the more popular term Brontosaurus, actually appear to come from two distinct but different species, and they have chosen the more popular term for one of these species.

Brontosaurus was always easy to pronounce, which has probably contributed to its popularity as a general term for dinosaurs. When it was officially rejected in the 1970s there were a lot of unhappy fans of paleontology. I suspect the modern generation of scientists, children in the 1970s, had a warm spot in their heart for the term and have thus found a way to bring it back.

New data says volcanoes, not asteroids, killed dinosaurs

The uncertainty of science: A careful updating of the geological timeline has strengthened the link between the dinosaur extinction 66 million years ago and a major volcanic event at that time.

A primeval volcanic range in western India known as the Deccan Traps, which were once three times larger than France, began its main phase of eruptions roughly 250,000 years before the Cretaceous-Paleogene, or K-Pg, extinction event, the researchers report in the journal Science. For the next 750,000 years, the volcanoes unleashed more than 1.1 million cubic kilometers (264,000 cubic miles) of lava. The main phase of eruptions comprised about 80-90 percent of the total volume of the Deccan Traps’ lava flow and followed a substantially weaker first phase that began about 1 million years earlier.

The results support the idea that the Deccan Traps played a role in the K-Pg extinction, and challenge the dominant theory that a meteorite impact near present-day Chicxulub, Mexico, was the sole cause of the extinction. The researchers suggest that the Deccan Traps eruptions and the Chicxulub impact need to be considered together when studying and modeling the K-Pg extinction event.

The general public might not know it, but the only ones in the field of dinosaur research that have said the asteroid was the sole cause of the extinction have been planetary scientists.

Newly discovered dinosaur tracks

A cluster of dinosaur tracks discovered recently in Alaska has revealed to paleontologists a wealth of new information about their behavior.

The thousands of impressions, created on a 180-meter-long portion of near-coastal flood plain, today pepper a steep mountainside. Most of the tracks, made somewhere between 69 million and 72 million years ago, were left by hadrosaurs, commonly known as duck-billed dinosaurs (the crested creatures in this artist’s representation).

The consistent and excellent preservation of tracks suggests all the footprints were created within a short time period. Varying in width from 8 to 64 centimeters, the footprints cluster within four distinct size ranges, which researchers suggest represent specific age groups within a multigenerational herd. About 84% of the tracks were made by adult and near-adult hadrosaurs and 13% by young presumed to be less than 1 year old. A mere 3% of the tracks represent juvenile hadrosaurs, a rarity that strongly suggests the young of this species experienced a rapid growth spurt and therefore spent only a short time at this vulnerable size, the researchers report online this week in Geology.

Scientists have found 800,000 year old footprints of a family on Britain’s eastern coast.

Scientists have found 800,000 year old footprints of a family on Britain’s eastern coast.

The prints could be as old as one million years, and are significant in that they show that humans had spread from Africa with remarkable quickness once the species took hold.

Were the dinosaurs covered by feathers or scales? Scientists disagree.

Were the dinosaurs covered by feathers or scales? Two scientists find that most had scales.

Palaeontologists Paul Barrett of the Natural History Museum in London and David Evans of the Royal Ontario Museum in Toronto created a database of all known impressions of dinosaur skin tissues. They then identified those that had feathers or feather-like structures, and considered relationships in the dinosaurian family tree.

The results, which Barrett revealed at the Society of Vertebrate Palaeontology’s annual meeting in Los Angeles in late October, indicate that although some ornithischians, such as Psittacosaurus and Tianyulong, had quills or filaments in their skin, the overwhelming majority had scales or armour. Among sauropods, scales were also the norm.

The uncertainty of science: Don’t bet any money on this result. The number of dinosaur fossils actually known is relatively tiny — making the overall database tiny as well — and further discoveries could change everything.

A non-paleontologist documents significant errors in the work of several noted paleontologists.

Dinosaurgate: A non-paleontologist documents significant errors in the work of several noted paleontologists.

About two and half years ago, Dr. Myhrvold came across a 2009 paper by Dr. Erickson as he was trying to answer the question, “Why were dinosaurs big?” He said data in two of the graphs, one plotting the length of the thigh bone versus age, the other mass versus age, conflicted with each other. “I instantly knew that this couldn’t be correct,” Dr. Myhrvold said.

Dr. Myhrvold said he contacted Dr. Erickson, asking for the original data. While Dr. Erickson answered some questions, he said the data was on a computer he had gotten rid of and later that he did not have time to answer more questions, Dr. Myhrvold said.

Dr. Myhrvold was able to obtain some of the data from other researchers and thought he could do a better statistical analysis. Last year, he submitted a paper with his calculations — a fairly esoteric scientific disagreement about how best to extract reasonable generalizations from a limited number of fossils.

Dr. Erickson was one of the reviewers and argued strongly against publication. While praising Dr. Myhrvold’s accomplishments and saying the calculations appeared to be numerically correct, Dr. Erickson said the paper would not advance scientific understanding.

“In fact it will hurt our field by producing inherently flawed growth curves, misrepresenting the work of others, and stands to drive a wedge between labs that are currently cordial with one another,” he wrote. [emphasis mine]

Shades of Phil Jones of Climategate fame, who when asked for his original climate data first stalled, then stonewalled, then admitted that the data had been “lost.” Similarly, like the Climategate scientists who tried to squelch the work and careers of anyone who challenged them, the paleontologist being accused here attempted to prevent the accusation from been published.

A recently discovered 1.8 million year old skull suggests that the multiple human species theorized by paleontologists were actually just one.

The uncertainty of science: A recently discovered 1.8 million year old skull suggests that the multiple human species theorized by paleontologists were actually just one. More details here.

It is one of five early human skulls — four of which have jaws — found so far at the site, about 100 kilometers (62 miles) from the capital Tbilisi, along with stone tools that hint at butchery and the bones of big, saber-toothed cats. Lead researcher David Lordkipanidze, director of the Georgian National Museum, described the group as “the richest and most complete collection of indisputable early Homo remains from any one site.”

The skulls vary so much in appearance that under other circumstances, they might have been considered different species, said co-author Christoph Zollikofer of the University of Zurich. “Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species,” he said. The researchers compared the variation in characteristics of the skulls and found that while their jaw, brow and skull shapes were distinct, their traits were all within the range of what could be expected among members of the same species.

I have always thought that paleontologists were too quick to name each new major find as a new species. Among all species there is always a wide variety of features. One person is tall. Another has a big forehead or head. This discovery reinforces this idea. The five skulls were all found in the same place, from the same group. Yet they were very different from each other.

Scientists have found a fossil of a mosquito with traces of blood in its engorged abdomen.

Scientists have found a fossil of a mosquito with traces of blood in its engorged abdomen.

Although scientists have found fossils of suspected blood-sucking insects, the creatures’ feeding habits have mostly been inferred from their anatomy or the presence of blood-borne parasites in their guts. But Greenwalt’s fossilized mosquito contains molecules that provide strong evidence of blood-feeding among ancient insects back to 46 million years ago. It is a fortunate find. “The abdomen of a blood-engorged mosquito is like a balloon ready to burst. It is very fragile,” says Greenwalt. “The chances that it wouldn’t have disintegrated prior to fossilization were infinitesimally small.”

Some news reports have implied that the scientists had found actual blood 46 million years old. This is not the case. They found “large traces of iron and the organic molecule porphyrin — both constituents of haemoglobin, the oxygen-carrying pigment found in vertebrate blood. These molecules were either rare or absent in the abdomen of a fossilized male mosquito (which does not drink blood) of the same age, found at the same location.” Still, even though this isn’t actual blood, the evidence is good and so the result is quite cool.

Archeologists are disputing the age of a jawbone found in a cave in England.

The uncertainty of science: Archeologists are disputing the age of a jawbone found in a cave in England.

Both sides of the debate agree that there is a lot riding on the outcome. “What is at stake is the entire [prehistory] of Neandertals and early modern humans in Europe,” Pettitt says. Apart from the Kents Cavern fossil and some 43,000- to 45,000-year-old teeth from Italy whose status as modern human or Neandertal is currently also debated, the oldest undisputed human fossils in Europe are about only 40,000 years old and come from a site in Romania. If modern humans really made it all the way to northwest Europe by 41,500 years ago or even earlier, it would mean that they entered Europe much earlier than once thought and also spread across the continent very rapidly. It would also increase the overlap between modern humans and the Neandertals, who already lived in Europe, and who went extinct sometime between 40,000 and 35,000 years ago. What’s more, such an overlap could make it more likely that Neandertals, who made sophisticated ornaments and tools in their last years, copied these techniques from modern humans rather than inventing them on their own.

Evidence from a cave in Australia suggests that humans were doing deep sea fishing more than 40,000 years ago

New evidence from a cave in Australia suggests that humans were doing deep sea fishing — with the sophisticated maritime skills such ocean-going requires — far earlier than previously believed, as much as 42,000 years ago.

More evidence dinosaurs were warm-blooded

A new study has found new evidence that dinosaurs were warm-blooded and active, unlike modern reptiles. Even more surprising,

“The dinosaurs appeared to be even more active than the mammals. We certainly didn’t expect to see that. These results provide additional weight to theories that dinosaurs were warm-blooded and highly active creatures, rather than cold-blooded and sluggish.”

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