Posts Tagged ‘paleontology’
Abnormal Neanderthal bone (above) compared with normal Neanderthal specimen (below)
A Neanderthal living 120,000 years ago had a cancer that is common today, according to a fossil study.
A fossilised Neanderthal rib found in a shallow cave at Krapina, Croatia, shows signs of a bone tumour…The discovery is the oldest evidence yet of a tumour in the human fossil record, say US scientists.
The research, published in the journal PLOS One, gives clues to the complex history of cancer in humans.
Until now, the earliest known bone cancers have been identified in ancient Egyptian remains from about 1,000-4,000 years ago.
“It’s the oldest tumour found in the human fossil record,” Dr David Frayer, the University of Kansas anthropologist who led the US team, told BBC News.
“It shows that living in a relatively unpolluted environment doesn’t necessarily protect you against cancer, even if you were a Neanderthal living 120,000 years ago.”
The fossil was uncovered from an important archaeological site that has yielded almost 900 ancient human bones, along with stone tools…The tumour was diagnosed by a medical radiologist from X-rays and CT scans.
Although efforts to extract ancient DNA from the Neanderthal fossil have proved unsuccessful, the researchers hope other fossils may shed light on cancer in prehistoric humans.
Commenting on the study, Kat Arney, science information manager at Cancer Research UK, said: “Some people think that cancer is only a modern disease, but there’s evidence from fossils, bones and mummies that it’s actually many thousands of years old.
Opens up a whole new range of scary possibilities – but, I’m not even up to an educated guess on this narrow topic. So, I’ll shut up.
In 2008, a fossil hunter named Frank Hadfield went for a walk among the hoodoos of Drumheller, Alberta. Up on one of these chunky sandstone minarets studding the southern Albertan badlands, Hadfield spied what appeared to be the remains of a small carnivorous dinosaur. He made a few calls and soon his colleague Francois Therrien, a paleontologist at the nearby Royal Tyrrell Museum of Paleontology, to come have a look…
While they were working on the outcropping, a chunk of it split off the main block. Examining it, Therrien saw it was laced with black streaks. The streaks looked familiar. Like all modern paleontologists, Therrien was acquainted with the spectacular feathered-dinosaur fossils of the Liaoning beds in China, where the idea that dinosaurs are the ancestors of birds got its biggest boost, thanks to the preservation of feathers–both the thread-like ones known as “dinofuzz” and the more familiar shafted kind–in the silky mud of an ancient lake bottom. “If we were in China,” he cracked, “we’d call those feathers.”
Interest piqued, the scientists changed the way they’d usually prepare the fossil, cleaning it to the level of its skin, rather than down to the bone, to see whether more of the curious features could be found. The work was not in vain. The 2008 specimen, along with another found in 2009, have just been announced in this week’s issue of Science as the first feathered dinosaurs to be found in the Americas. The finds may suggest new places to look for feathered dinosaurs, since these were found in stone previously thought to be too coarse for the preservation of feathers. And they may also, along with a newly re-examined specimen found in 1995, provide insight into what role feathers played for animals that did not use them for flight…
The search for more feathery fossils has already begun. “I’ve been out this summer looking for more, and the museum is probably looking as well. I’m sure lots of people will be looking once this paper comes out,” Zelenitsky says. “And I think people will start looking through their collections, and start preparing fossils that haven’t been prepared.”
At least now we know that you can find feathered dinosaurs anywhere, Therrien says. And he emphasizes that people will have to be careful: “If it hadn’t been for that lucky break, I’m convinced that we would have never found those feathers. We would have just prepared through them.” In this case, preparing through them would have meant losing them–and losing a discovery too.
Another unintended consequence – though motivated by curiosity about what might be found by varying the technique.
East Gallery of the Denisova Cave
A 30,000-year-old finger bone found in a cave in southern Siberia came from a young girl who was neither an early modern human nor a Neanderthal, but belonged to a previously unknown group of human relatives who may have lived throughout much of Asia during the late Pleistocene epoch. Although the fossil evidence consists of just a bone fragment and one tooth, DNA extracted from the bone has yielded a draft genome sequence, enabling scientists to reach some startling conclusions about this extinct branch of the human family tree, called “Denisovans” after the cave where the fossils were found…
By comparing the Denisovan genome sequence with the genomes of Neanderthals and modern humans, the researchers determined that the Denisovans were a sister group to the Neanderthals, descended from the same ancestral population that had separated earlier from the ancestors of present-day humans. The study also found surprising evidence of Denisovan gene sequences in modern-day Melanesians, suggesting that there was interbreeding between Denisovans and the ancestors of Melanesians, just as Neanderthals appear to have interbred with the ancestors of all modern-day non-Africans.
“The story now gets a bit more complicated,” said Richard Green, an assistant professor of biomolecular engineering in the Baskin School of Engineering at UC Santa Cruz. “Instead of the clean story we used to have of modern humans migrating out of Africa and replacing Neanderthals, we now see these very intertwined story lines with more players and more interactions than we knew of before.”
The Denisovans appear to have been quite different both genetically and morphologically from Neanderthals and modern humans. The tooth found in the same cave as the finger bone shows a morphology that is distinct from Neanderthals and modern humans and resembles much older human ancestors, such as Homo habilis and Homo erectus. DNA analysis showed that the tooth and the finger bone came from different individuals in the same population.
It is not clear why fossil evidence had not already revealed the existence of this group of ancient human relatives. But Green noted that the finger bone was originally thought to be from an early modern human, and the tooth resembles those of other ancient human ancestors. “It could be that other samples are misclassified,” he said. “But now, by analyzing DNA, we can say more definitively what they are. It’s getting easier technically to do this, and it’s a great new way to extract information from fossil remains.”
Fascinating work. Think about this sort of research as a career or at least an avocation. Do your species some good with your spare time.
When Nicholas Longrich discovered a new dinosaur species with a heart-shaped frill on its head, he wanted to come up with a name just as flamboyant as the dinosaur’s appearance. Over a few beers with fellow paleontologists one night, he blurted out the first thing that came to mind: Mojoceratops.
“It was just a joke, but then everyone stopped and looked at each other and said, ‘Wait — that actually sounds cool,’ ” said Longrich, a postdoctoral associate at Yale University. “I tried to come up with serious names after that, but Mojoceratops just sort of stuck.”
With the publication of Longrich’s paper describing his find in the Journal of Paleontology…the name is now official…
It was only after coming up with the unusual name that Longrich looked into its etymology. Surprisingly, he found that it was a perfect fit for the species, which sported a flamboyant, heart-shaped frill on its head.
“I discovered that ‘mojo’ is an early 20th-century African-American term meaning a magic charm or talisman, often used to attract members of the opposite sex,” he said. “This dinosaur probably used its frill to attract mates, so the name made sense.” The full name is Mojoceratops perifania, with “perifania” meaning pride in Greek. (The other part of the name mojoceratops follows the convention of other related species, with “ceras” being Greek for horn and “ops” being Greek for face.)
While all ceratopsids have frills on the tops of their skulls, “Mojoceratops is the most ostentatious,” Longrich said, adding that their frill is also the most heart-shaped of all the related species.
Haven’t been in New Haven in decades; but, I wonder which bar he was drinking in.
You have beaucoup choices. You can hangout near the campus and be surrounded by Yalies. Or wander out into the old neighborhoods like Wooster Street and have some dynamite pizza along with your beer.
Paleontologists watching nutball video – trying to keep a straight face
Tamaki Sato was confused by the dinosaur exhibit. The placards described the various dinosaurs as originating from different geological periods — the stegosaurus from the Upper Jurassic, the heterodontosaurus from the Lower Jurassic, the velociraptor from the Upper Cretaceous — yet in each case, the date of demise was the same: around 2348 B.C.
“I was just curious why,” said Dr. Sato, a professor of geology from Tokyo Gakugei University in Japan…
But here in the Creation Museum in northern Kentucky, Earth and the universe are just over 6,000 years old, created in six days by God. The museum preaches, “Same facts, different conclusions” and is unequivocal in viewing paleontological and geological data in light of a literal reading of the Bible…
The worlds of academic paleontology and creationism rarely collide, but the former paid a visit to the latter last Wednesday. The University of Cincinnati was hosting the North American Paleontological Convention, where scientists presented their latest research at the frontiers of the ancient past. In a break from the lectures, about 70 of the attendees boarded school buses for a field trip to the Creation Museum, on the other side of the Ohio River.
“I’m very curious and fascinated,” Stefan Bengtson, a professor of paleozoology at the Swedish Museum of Natural History, said before the visit, “because we have little of that kind of thing in Sweden…”
“I’m speechless,” said Derek E.G. Briggs, director of the Peabody Museum of Natural History at Yale, who walked around with crossed arms and a grimace. “It’s rather scary…”
“I think they should rename the museum — not the Creation Museum, but the Confusion Museum,” said Lisa E. Park, a professor of paleontology at the University of Akron.
“Unfortunately, they do it knowingly,” Dr. Park said. “I was dismayed. As a Christian, I was dismayed.”
Dr. Bengtson noted that to explain how the few species aboard the ark could have diversified to the multitude of animals alive today in only a few thousand years, the museum said simply, “God provided organisms with special tools to change rapidly.”
“Thus in one sentence they admit that evolution is real,” Dr. Bengtson said, “and that they have to invoke magic to explain how it works.”
Makes an interesting read for a short while. I’m not certain I’d want to waste part of a free day – wandering through the bowels of ignorance.
The oldest-known tracks of a creature apparently using legs have been discovered in rock dated to 570 million years ago in what was once a shallow sea in Nevada.
The aquatic creature left its “footprints” as two parallel rows of small dots, each about 2 millimeters in diameter. Scientists said today that the animal must have stepped lightly onto the soft marine sediment, because its legs only pressed shallow pinpoints into that long-ago sea bed.
The tracks were made during what is called the Ediacaran period, which preceded the Cambrian period, the time when most major groups of animals first evolved. Scientists had once thought only microbes and simple multicellular animals that existed prior to the Cambrian, but that notion is changing, said Ohio State University Professor Loren Babcock.
“We keep talking about the possibility of more complex animals in the Ediacaran — soft corals, some arthropods, and flatworms — but the evidence has not been totally convincing,” Babcock said. “But if you find evidence, like we did, of an animal with legs — an animal walking around — then that makes the possibility much more likely.”
Little can be gleaned about what sort of creature it was, but Babcock “reasonably certain — not 100 percent” that it was an arthropod, such as one resembling a centipede or millipede, or by a leg-bearing worm. It might have been about one as wide as a pencil and may have had multiple, spindly legs.
Another one of the several disciplines I wish I got into when I was a kid.