290 Million Year Old Creature Could Sprout New Limbs

If an ancient amphibian lost a limb or a tail, it could simply sprout a new one, according to researchers who found fossil evidence of limb regeneration dating back 290 million years.

The finding shows that some Carboniferous and Permian period animals had regenerative abilities a full 80 million years before salamanders, one of the few modern-day animal groups that can fully regenerate their limbs and tail, existed in the fossil record.

The fact that other tetrapods — a group comprised of four-legged vertebrates, including amphibians, reptiles, mammals and birds — had regenerative abilities suggests there are multiple ways to regrow limbs, said study lead researcher Nadia Fröbisch, a paleontologist at the Natural History Museum in Berlin. [Slithery, Slimy: Images of Legless Amphibians]

“Regenerative medicine is an active and very large research field,” Fröbisch told Live Science. Most regenerative medicine is focused on the molecular mechanisms used by modern salamanders, but “we don’t only have to look for things specific to salamanders, but also mechanisms present in all tetrapods,” she said.

Fröbisch has studied limb regeneration in salamanders for years. She’s not alone — at least 100 years ago, researchers noted that salamander limbs develop differently than those of all other tetrapods, and wondered

Say Aaaah Zoo’s Aardvark Gets 2 Teeth Pulled

Getting a tooth pulled is never fun, but it’s especially irksome if you’re an aardvark. Ali, an aardvark at the Cincinnati Zoo, recently learned this lesson firsthand after two infected teeth landed her in the dentist’s chair.

Aardvarks, the only extant species in the order Tubulidentata, are unusual animals — and they have unusual teeth, said Jack Easley, a Kentucky-based veterinarian who specializes in dentistry. Easley was one of several veterinarians who helped extract Ali the aardvark’s two problematic teeth last month at the Cincinnati Zoo.

Unlike most other mammals, aardvarks don’t have enamel in their teeth. (Enamel is the hard, visible part of the tooth that covers up the more sensitive tissues beneath it.) These soft teeth typically serve aardvarks well, because in their native African habitat, the animals only eat easy-to-chew insects like termitesand ants, Easley told Live Science. [Photos: World’s Cutest Baby Wild Animals]But in zoos, aardvarks don’t always eat soft insects, which may not be readily available. Instead, they eat a special, pelleted feed or some other manufactured food, said Easley, who noted that, sometimes, this diet can lead to dental disease. Ali, who is 11 years old, is also middle-age for an aardvark, which may have contributed

Iguana Relative Shows How Lizards Spread Worldwide

An 80-million-year-old lizard discovered in southern Brazil has provided a surprising clue about how these reptiles evolved, and where they once lived, according to a new study.

Until now, researchers had found acrodontans only in the Old World, including Africa and Asia. (This is a type of lizard is called an iguanian that has teeth fused to the top of its jaws, a group that includes chameleons and bearded dragons.) But the newfound fossil, a partial lower jaw of a new species of acrodontan, shows that they lived in the New World much earlier than thought.

The fossil suggests that acrodontans managed to distribute themselves worldwide before the ancient supercontinent Pangaea broke up about 200 million years ago, the researchers said. [Image Gallery: 25 Amazing Ancient Beasts]

“This fossil is an 80-million-year-old specimen of an acrodontan in the New World,” study co-author Michael Caldwell, a biological sciences professor at the University of Alberta in Canada, said in a statement. “It’s a missing link in the sense of the paleobiogeography and possibly the origins of the group, so it’s

The Science of Adorable What It Takes to Win CuteOff

Science Twitter has gone full squee. Biologists are tweeting pictures of their adorable research subjects in a #CuteOff, and the results are downright nom-able.

Baby elephants? Adorbs. Pert-nosed pikas? Too cute. Hummingbird nestlings? Heart-stopping. Meanwhile, #TeamHerpetology is making a strong showing with shots of baby sea turtles that fit in the palm of a hand, and #TeamEntomology is showing how sweet bugs can be.

“I don’t generally think of fish as cute, but there were some alarmingly cute fish,” said Anne Hilborn, a doctoral student and cheetah researcher at Virginia Tech who helped launch the hashtag.

While the #CuteOff may open eyes to wildlife conservation, it’s also an opportunity to look at what really makes people squee. What are the essential ingredients of cute? Based on the types of animals posted — and previous scientific research on adorableness — here are seven features that could help an animal win a cuteness contest. (This #CuteOff emerged on Twitter following a perhaps, ahem, more salacious animal contest, the #JunkOff.)

1. Big Eyes

Big eyes, full heart, can’t lose. It’s pretty clear that a wide pair of peepers pushes an animal high in the cuteness ratings. Whether it’s a puffer fish or a pygmy possum, many of the

Why Animal Genitals Are Important to Science

Did you know that male black widow spiders have corkscrew-shaped genitals? Or that barnacle penises are up to eight times the length of barnacle bodies? Or that echidnas have frankly horrifying four-headed dangly bits?

If you’ve been following scientists on Twitter in the past week or so, you probably do. That’s because biologists have gone wild posting junk shots of their research subjects, from meerkats to cheetahs to some truly bizarre ants. The #JunkOff hashtag took off last week, and not entirely for sophomoric reasons: Animal genitalia are actually a major window into how evolution works.

“It all goes back to the basis of animal behavior and evolution,” said Anne Hilborn, a doctoral student at Virginia Tech and cheetah researcher who launched #JunkOff and helped start the warmer-and-fuzzier follow-up hashtag, #CuteOff.

Wild junk

As #JunkOff illustrates, the world of genitals is … diverse. And maybe a little scary. But really, let’s focus on the diversity. [The 9 Weirdest Animal Penises]

Alligators, for example, have enormous, permanently erect penises made of connective tissue called collagen. Instead of inflating with blood like most mammalian penises, the alligator penis pops out of the cloaca (the alligator all-purpose genital and waste opening) with the help of rubber-bandlike tendons and

The Cute and Complicated Science of Raising Twin Pandas

The little panda was cold, low energy and having trouble breathing before its heart stopped beating. But the zoo baby left an indelible mark on its caretakers and admirers before it died, just days after being born to mother Mei Xiang, along with its brother. During its short life, the twin rode atop a lacrosse stick, snuggled with its mother and fed from a bottle, the last of which may have led to its demise.

The final necropsy results aren’t complete, but the butter-stick-size panda likely died when fluid got into its lungs and caused inflammation, a condition called aspiration pneumonia. Veterinarians are unsure whether the cub got the condition during a bottle-feeding blunder or from formula it regurgitated, said Dr. Donald Neiffer, the chief veterinarian at Smithsonian’s National Zoo.

“Whether or not the baby aspirated some of that [regurgitated] material or whether he aspirated material earlier in the day, we don’t know, and we will never know,” Neiffer told Live Science. [See Photos of Mei Xiang’s New Twin Panda Cubs]

Express delivery

The pink and fuzzy cubs are part of a delicate plan, orchestrated on an international level, to preserve the giant panda species and, one day, introduce captive-bred pandas back into the

A Mass Die off of the Endangered Saiga Antelope

Why owning a pet makes you happier and more likely to live longer

Owning a lively pet may sometimes prove exasperating, but it appears all the effort is worth it.

Pet owners are healthier, have greater self-esteem and are less lonely than those who don’t have animals at home, according to a study.

Not only that, but they are also more conscientious, extroverted and less fearful, researchers at the American Psychological Association said

Man’s best friend: Owning a pet brings with it many benefits including improved health, greater self-esteem and less loneliness, according to scientists

They believe that pets serve as important sources of social and emotional support for the average person, and not just individuals facing significant health challenges.

Lead researcher, Allen R McConnell, of Miami University in Ohio, said: ‘We observed evidence that pet owners fared better, both in terms of well-being outcomes and individual differences, than non-owners on several dimensions.

‘Specifically, pet owners had greater self-esteem, were more physically fit, tended to be less lonely, were more conscientious, were more extraverted, tended to be less fearful and tended to be less preoccupied than non-owners.’

Pet owners are just as close to key people in their lives as to their animals, the study found.

This indicates no evidence that relationships with pets come at the expense of

New Species of Ancient River Dolphin Actually Lived in the Ocean

The fossilized remains of a new species of ancient river dolphin that lived at least 5.8 million years ago have been found in Panama, and the discovery could shed light on the evolutionary history of these freshwater mammals.

Researchers found half a skull, a lower jaw with an almost complete set of conical teeth, a right shoulder blade and two small bones from a flipper. The fossils are estimated to be between 5.8 million and 6.1 million years old, making them from the late Miocene epoch, researchers said in a new study.

The ancient river dolphin, named Isthminia panamensis, was calculated to be more than 9 feet (2.7 meters) long, according to the study. [Deep Divers: A Gallery of Dolphins]

The ancient mammal was discovered on the Caribbean coast of Panama, at the same site where other marine animal fossils have been found, which suggests that I. panamensiswas also a saltwater species, the researchers said.

I. panamensis is the only fossil of a river dolphin known from the Caribbean, the researchers said in the study.

“We discovered this new fossil in marine rocks, and many of the features of its skull and jaws point to it having been a marine inhabitant, like modern oceanic dolphins,”

Bizarre Human Size Sea Scorpion Found in Ancient Meteorite Crater

About 460 million years ago, a sea scorpion about the size of an adult human swam around in the prehistoric waters that covered modern-day Iowa, likely dining on bivalves and squishy eel-like creatures, a new study finds.

The ancient sea scorpions are eurypterids, a type of arthropod that is closely related to modern arachnids and horseshoe crabs. The findings — which include at least 20 specimens — are the oldest eurypterid fossils on record by about 9 million years, said study lead researcher James Lamsdell, a postdoctoral associate of paleontology at Yale University.

The findings are also the largest known eurypterids from the Ordovician period, which began approximately 488 million years ago and ended 443.7 million years ago. The sea creatures measured up to 5.6 feet (1.7 meters) long. [See Images of the Ancient Sea Scorpion]

Researchers dubbed the newfound species Pentecopterus decorahensis, named for Greek warships (penteconter) and the Greek word for wings (pterus) because the sea scorpion was likely a top predator that sped through the water, the researchers said. The species name also honors the Iowa city of Decorah, where the fossils were uncovered.

“The best way to describe this animal is bizarre,” Lamsdell told Live Science. “For a long time,