Thursday, July 30, 2015

When is a jackal not a jackal? When it's really a 'golden wolf'

A golden jackal is seen in Serengeti National Park, Tanzania in this undated handout picture
A golden jackal (Canis anthus) is seen in Serengeti National Park, Tanzania in this undated handout picture. …
By Will Dunham
WASHINGTON (Reuters) - They look alike, act alike and long have been considered to be the same species. But, in the case of the golden jackals found across parts of Africa, the Middle East, Asia and Europe, it turns out that appearances can be deceiving.
Scientists said on Thursday a comprehensive genetic analysis found that these populations are made up of two entirely distinct species, with those in Africa different from the others.
The scientific name for the golden jackal is Canis aureus. The researchers proposed renaming those in Africa Canis anthus, or the African golden wolf.
"Our results showed that African and Eurasian golden jackals were distinct across all the genetic markers we tested, including data from whole genomes, suggesting these are independently evolving lineages," said Klaus-Peter Koepfli, a conservation and evolutionary geneticist at the Smithsonian Conservation Biology Institute in Washington.
Koepfli said the genetic data indicated the two lineages are not even closely related, with the African population more closely related to gray wolves and coyotes.
The finding raises the number of living species in the mammalian family called Canidae, which includes dogs, wolves, foxes, coyotes and jackals, to 36 from 35.
The African golden wolf is found in north and east Africa, with perhaps some in the Middle East, while the Eurasian golden jackal is found from southern Europe to the Middle East and across southern Asia all the way to the edge of southeast Asia in Vietnam, the researchers said.
"We find no evidence of the Eurasian golden jackal occurring in continental Africa," Koepfli said.
The two species are quite similar in body size, wolf-like build, head shape, teeth and fur color. They thrive across a variety of habitats, from dry savannas in Africa to tropical forests in southeast Asia. They are omnivorous, eating a wide variety of food from small mammals to fruits.
The researchers determined that the African golden jackal lineage split from the lineage including gray wolves and coyotes about 1.3 million years ago while the Eurasian golden jackal lineage split about 600,000 years earlier.
"One of the main takeaways of our study is that even among well-known and widespread species such as golden jackals, there is the potential to discover hidden biodiversity, and that such discoveries are made even more possible by using data sampled from whole genomes," Koepfli said.
The research was published in the journal Current Biology.
(Reporting by Will Dunham; Editing by Sandra Maler)

Friday, July 24, 2015

Pterodactyls Are Not Dinosaurs. So What The Hell Are They?

Esther Inglis-Arkell

Filed to: explainer 7/24/15 11:11am


Pterodactyls lived at the same time as the dinosaurs—but somehow, they’re not actually dinosaurs. They were flying creatures, and paleontologists keep telling us that dinosaurs are birds. But still, we’re supposed to call pterodactyls “pterosaurs.” This feels like a trick—why aren’t pterodactyls dinosaurs?

The name “pterodactyl” is an unfortunate artifact. It was the name given by naturalist and “father of paleontology” Georges Cuvier, to a fossil unearthed in 1801. The flying reptile got its name for its long “finger,” which stretched out to form a wing. It was soon joined by more fossils of winged fingers. Some had teeth and some didn’t. Some were the size of giraffes and some could rest on a person’s hand. They were shaped differently, and clearly ate different diets. The dactyl name just didn’t describe any group of animals any more, and so in 1834 these creatures got the more general name of “pterosaurs.”

This name linked pterosaurs with dinosaurs in the popular imagination—which wasn’t a big deal, because for quite some time paleontologists had no real working definition for dinosaurs. They had scientific names for the different fossils they had discovered, but for them the definition of a “dinosaur” was no different from a bright ten-year-old’s idea of a dinosaur. A dinosaur was defined by popular imagination, not physiology or descent.

In the 1970s, the entire discipline of paleontology took a look at the groups they had placed their fossils in, and found those groups wanting. After re-examining the details of different fossils, they finally came with a new order of things. The wide base group of that order came to be known as Archosauria. You can see crocodiles, the result of one branch of that group, staring up at you from ponds everywhere from Australia to the Florida Everglades.

Another branch from that group is called Avemetatarsalia. Anyone who has had a foot injury knows that metatarsals are located in the foot. The ankle joint of a member of Avemetatarsalia is slightly different from other members of Archosauria. A section of bone that would have been part of an early crocodile’s leg is part of an early member of the group Avemetatarsalia’s foot. This makes the foot work in a slightly different way—a way that can be exploited to get up one one’s back legs and use one’s front arms to grasp, to walk, or to fly. There are other distinguishing characteristics, including elongated metatarsals, a longer neck, and differently-constructed legs, but it’s the ankle that’s the give-away.

What did the members of the Avemetatarsalia do with their snazzy new ankles? Some became Scleromochlus taylori. Scleromochlus taylori would, if shown to most of us laypeople, be immediately identified as a dinosaur—albeit a very slender and elongated one. According to people in the know, however, it has a relatively primitive ankle structure.

That ankle structure was shared by every animal in the group Pterosauria. In fact, Scleromochlus and the Pterosauria sit together on this stubby branch of the evolutionary tree. The animal pictured above and pterosaurs are each other’s closest relatives. To be fair, the pterosaurs didn’t have much use for their ankles. New evidence shows that they were more resourceful in flight than people gave them credit for. They were able to control their body temperature with a fine covering of hair-like fuzz. Their wings were not simple membranes to help them glide, but actual fliers. And they even managed to vault themselves into the air.

But they were on a separate branch of the classification tree from the the members of Dinosaurmorpha—which still weren’t dinosaurs. And they weren’t among the group of animals that branched out from Dinosaurmorpha to become Dinosauriformes—still not dinosaurs. It took yet another branch to get to Dinosauria. Dinosauria had all kinds of limb improvements, from a crest on the humerus to a tibia with a “transversely expanded subrectangular distal end.” It’s no wonder that they probably spent the time between 220 million years ago and 200 million years ago wiping out most of the Dinosaurimorphs. Dinosaurs really did rule the Earth.

Which makes it admirable that pterosaurs hung in perfectly fine until 65 million years ago. They only went extinct when the actual dinosaurs did. So what is the difference between pterosaurs and dinosaurs? The complicated answer is a lot of slight but specific changes to the leg bones. A more general way to look at it though is thinking of a dinosaur as yourself and a pterosaur as your grandmother’s sister. She’s a couple of generations back, and you’re not really her descendant, but you’re both in the same family, and come from a common ancestor.

But she can fly, so she’s cooler.
Top Image: Matt Van Rooijen. Second Image: Daderot. Scleromochlus Image: Jaime A. Headden

Thursday, July 16, 2015

Jurassic Park star was fluffy with wings

An artist's impression released on July 15, 2015 by Ministry of Land and Resources of China shows a reconstruction of the new short-armed and winged feathered dinosaur Zhenyuanlong suni from the Early Cretaceous (ca. 125 million years ago) of China
An artist's impression released on July 15, 2015 by Ministry of Land and Resources of China shows a reconstruction of the new short-armed and winged feathered dinosaur Zhenyuanlong suni from the Early Cretaceous (ca. 125 million years ago) of China (AFP Photo/Chuang Zhao)
Paris (AFP) - Depicted by movie-makers as mean, green, man-eating lizards covered in scales, velociraptors probably looked more like large, toothy turkeys, a study said Thursday.
Close study of a newly-discovered cousin dubbed Zhenyuanlong suni, has revealed that velociraptors likely had large wings and feathery coats, according to research published in the journal Scientific Reports.
"The real velociraptor was not a green, scaly monster like in Jurassic Park," study co-author Steve Brusatte of the University of Edinburgh told AFP.
"The real velociraptor looked like Zhenyuanlong: a fluffy feathered killer."
Brusatte and a team made a fossil reconstruction of Zhenyuanlong, one of the velociraptor's closest relatives, which lived in China's northeastern Liaoning province some 125 million years ago.
It is the largest dinosaur with wings discovered to date.
Zhenyuanlong was about two metres (6.6 feet) long from snout to tail, weighed about 20 kilos (44 pounds), and was a meat-eater.
"Zhenyuanlong is a dinosaur that looks just like a bird," Brusatte told AFP by email -- apart from sharp claws on its wings and a mouth full of teeth.
The Chinese fossil is so well preserved that one can clearly see different kinds of feathers, including hair-like plumes on the body and big quill pen feathers on the arms. Zhenyuanlong would have had "dense feathers" on its wings and tail, according to the team's analysis.
"So it is a fairly large dinosaur with short arms bit it still has wings that look just like those of living birds," Brusatte said.
"That raises a really big mystery: why would such an animal have wings?"
It was probably not for flying: Zhenyuanlong was too big and its arms too short to allow it to take to the air.
The team speculated the wings may have been used for display or for protecting its eggs in the nest.
"And maybe that means that wings didn't even initially evolve for flight, but for another function!" Brusatte said.
"A few years ago, I think most paleontologists would have said that big feathers and wings evolved for flight. But now we don't know anymore."
Scientists had previously observed quill attachment points, or knobs, on the arms velociraptor fossils, but no actual feathers -- meaning they did not know what type or size of plumes it would have had, or for what purpose.
"We are lucky with Zhenyuanlong. It is found in an area where volcanoes buried dinosaurs, preserving fine details of their feathers," Brusatte said.
"So Zhenyuanlong tells us what the feathers of velociraptor probably would have looked like.... They would have had feathers like Zhenyuanlong and even big wings on the arms," he said.
"They would also have been much smaller than their reconstructed movie counterparts.
"A real velociraptor was a little smaller than Zhenyuanlong," Brusatte added.
"It was only about the size of a poodle dog!"
Paleontologists believe the first birds appeared 150 million years ago and were descendants of small feathered dinosaurs.

Tuesday, July 7, 2015

Children's Mysterious Paralysis Tied to New Virus

Children's Mysterious Paralysis Tied to New Virus
A new study suggests that a new strain of a poliolike virus may be responsible for some of the mysterious cases of paralysis in children over the past few years. (Photo: Getty Images) 
Mysterious cases of paralysis in U.S. children over the last year have researchers searching for the cause of the illness. Now, a new study suggests that a new strain of a poliolike virus may be responsible for some of the cases.
So far, more than 100 children in 34 states have suddenly developed muscle weakness or paralysis in their arms or legs, a condition known as acute flaccid myelitis, according to the Centers for Disease Control and Prevention. Previously, researchers linked a virus called enterovirus D68 (EV-D68), which can cause respiratory illness similar to the common cold, with some of these cases.
But only about 20 percent of children with paralysis tested positive for EV-D68, and even in these cases, it wasn’t clear if EV-D68 was the cause of the child’s condition. 
In the new study, researchers say that one case of paralysis, in a 6-year-old girl, is linked with another strain of enterovirus, called enterovirus C105. This virus belongs to the same species (enterovirus C) as the polio virus.
Although the new study doesn’t definitely prove that enterovirus C105 was the cause of the girl’s paralysis, it suggests that there are other viruses besides EV-D68 that are contributing to the outbreak of acute flaccid myelitis.
The study should make researchers aware that “there’s another virus out there that has this association” with paralysis, said study co-author Dr. Ronald Turner, a professor of pediatrics at the University of Virginia School of Medicine. “We probably shouldn’t be quite so fast to jump to enterovirus D68 as the [only] cause of these cases,” Turner told Live Science.
The 6-year-old girl was previously healthy, but she caught a cold from members in her family, and developed a mild fever. Her fever and cold symptoms soon went away, but she was left with persistent arm pain. Then her parents noticed that the girl’s shoulder appeared to droop, and she had difficulty using her right hand, the researchers said.
At the hospital, the girl was diagnosed with acute flaccid myelitis, and a sample from her respiratory tract tested positive for enterovirus C105. This virus was only recently discovered, and the new study is the first report of enterovirus C105 in the United States, the researchers said. The girl tested negative for EV-D68.
Some tests can miss enterovirus C105, because of variation in the virus’s genetic sequence, Turner said. This virus may have gone unrecognized in the current outbreak until now because it is relatively new, and can be hard to detect, he said.
“The presence of this virus strain in North America may contribute to the incidence of flaccid paralysis and may also pose a diagnostic challenge in clinical laboratories,” the researchers said in their study, which will be published in the October issue of the journal Emerging Infectious Diseases.
The researchers noted that enterovirus D68, and now enterovirus C105, have been found in the respiratory tract of children with acute flaccid myelitis, but so far, these viruses have not been found in the spinal fluid of these patients. That’s important because a virus in the respiratory tract would not necessarily cause paralysis.
“You can have a virus in your respiratory tract that’s not doing anything to your nervous system,” Turner said.
In order to more definitively link these cases of paralysis with enterovirus, researchers would need to find the virus in the spinal fluid, he said. But so far, tests have not found the virus there.

Sunday, July 5, 2015

This Texas redhead centipede is freaking the Internet out

The centipede's fangs are actually a modified pair of legs, able to pierce the skin and deliver a painful toxin.
By Brooks Hays   |   Updated July 4, 2015 at 4:43 PM
A giant Texas redhead centipede. Photo by Texas Parks and Wildlife/Facebook
AUSTIN, Texas, July 4 (UPI) -- Even centipedes are bigger in Texas -- bigger and a lot more terrifying. In an apparent bid to freak out the Internet, Texas Parks and Wildlife shared a photo on its Facebook page of a massive Texas redhead centipede found in the state's Hill Country. The bid was successful.
Scolopendra heros is a centipede species found south of the border in Mexico, as well as in the states of south-central and southwestern United States -- ranging as far east as Arkansas and Missouri, and as far west as Arizona and New Mexico.
The massive centipede, commonly called a Texas or giant redhead, preys upon lizards and toads. They've been observed to sometimes catch and eat rodents and snakes.
Boasting between 21 and 23 pairs of legs, the centipede typically measures 6.5 inches in length, but can stretch up to 8 inches. The redhead doesn't always have a red head; being aposematically colored, the body and head can take on a variety of red and black patterns.
According the Texas Parks and Wildlife magazine, there's a story that a Civil War soldier died after being bitten on the chest by a Texas redhead while sleeping. The story is a tall tale, but the centipede does possess poisonous fangs.
Its fangs are actually a modified pair of legs, able to pierce the skin and deliver a painful toxin. In fact, all of the centipede legs are capable (to some degree) of "biting" and delivering toxin.
As frightening as they sound and appear, the centipede's bite is typically accompanied by only momentary pain and swelling. Occasionally, nausea and headaches follows -- and more rarely necrosis and cardiac arrest.
"While caution is certainly warranted when dealing with the giant redheaded centipede," the magazine explains, "downright terror is probably an overreaction."