Ancient Toothless Pterosaurs Once Dominated the World's Skies

Ancient Toothless Pterosaurs Once Dominated the World's Skies - Giant toothless pterosaurs with wingspans stretching 39 feet (12 meters) across ruled the skies 60 million years ago, and new research suggests that these ancient flying creatures once had a worldwide presence, and likely played an important role in the Late Cretaceous ecosystem.

Despite their formidable size, the pterosaurs in the Azhdarchidae family had no teeth. The new research suggests they replaced their toothed relatives as the dominant species when high levels of carbon dioxide killed off important microscopic marine creatures, leading to a mass extinction about 90 million years ago.

An artist's illustration of the Azhdarchid pterosaur species Quetzalcoatlus northropi 

"This shift in dominance from toothed to toothless pterodactyloids apparently reflects some fundamental changes in Cretaceous ecosystems, which we still poorly understand," Alexander Averianov, from the Russian Academy of Sciences, wrote in a new study of this type of pterosaur. 

Fossil records show that pterosaurs were likely the first airborne vertebrates and they took to the skies around 220 million years ago. Some were so large they likely had to get a running start before taking off and had a hard time landing, according to research presented at the 2012 Geological Society of America meeting. The name Azhdarchidae comes from the Persian word "aždarha," which means dragon.These toothless creatures lived during the Late Cretaceous Period, about 70 million years ago.

Scientists know little about pterosaurs, since their fossil record is largely incomplete. Pterosaur bones are more fragile than other dinosaur bones and there are few that have survived. Most Azhdarchidae pterosaur fossils are preserved in soft sediment deposits called Konservat-Lagerstätten. These kinds of fossils are rare for the Late Cretaceous, so paleontologists have a hard time piecing together the pterosaur lineage.

"Azhdarchidae currently represents a real nightmare for pterosaur taxonomists," Averianov wrote in the paper.

Fossil evidence suggests that after toothless 'dragon' pterosaurs replaced their toothed relatives, they became one of the dominant creatures in the Late Cretaceous period.

In a 2008 review of Azhdarchidae, scientists examined 32 bones, but Averianov examined 54 known Azhdarchidae fossils: 51 bones and three fossilized tracks. The giant birds likely lived in a variety of environments, but after closely examining the sediments in which the fossils were discovered, Averianov discovered that most of the toothless pterosaurs probably lived near lakes and rivers and along coastlines.

About 13 percent of the pterosaur fossils were found in lake sediments, 17 percent from river sediments, 17 percent from coastal plains, 18 percent from estuaries and 35 percent from marine sediments.

Most Azhdarchidae species are only defined based on a few fragmented bones. The more complete skeletons scientists have discovered are not very well preserved. This lack of fossils led researchers to create an "inflated" number of pterosaur species, according to Averianov. After reviewing the taxonomy, Averianov found that paleontologists created separate species of Azhdarchidae based on sparse fossil evidence and may have misclassified some of the bone fragments.

In an effort to learn more about the evolution of pterosaurs, scientists created an online database of fossils called PteroTerra,which maps out the distribution of these ancient creatures using Google Earth. ( livescience.com )

The new taxonomy research was published Aug. 11 in the journal ZooKeys.

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Fossils show huge penguin once roamed New Zealand

Fossils show huge penguin once roamed New Zealand - Fossilised remains of one of the largest penguins ever, an “elegant” giant standing 1.3 metres tall, have been found in New Zealand, scientists said on Tuesday.

The penguin lived 27-24 million years ago, when New Zealand was mostly underwater and consisted of isolated, rocky outcrops that offered protection from predators and plentiful food supplies, researchers said.

The first traces of the penguin, dubbed Kairuku – Maori for diver who returns with food – was found embedded in a cliff at Waimate in the South Island by University of Otago paleontologist professor Ewen Fordyce in 1977.

 

Over the years, Fordyce discovered more complete remains and invited University of North Carolina specialist Dan Ksepka to help reconstruct the lost giant in 2009.

They determined the bird was much larger than the biggest modern penguin, the Emperor, which grows up to 1.0-metres, and weighed in at 60 kilograms, twice as much as the Emperor.

“Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet,” Ksepka said.

Fordyce said the bird’s large size was an adaption that allowed it to swim further and dive deeper than its modern-day counterparts.

He was unsure why it became extinct, suggesting climate change or increased predation from dolphins and seals as possible reasons for its demise.

The findings were published in the latest edition of the Journal of Vertebrate Paleontology.

In 2010 scientists reported finding a fossilised specimen from 36 million years ago estimated to have been 1.5 metres tall. ( dawn.com )

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Scientists reconstruct extinct giant penguin

Scientists reconstruct extinct giant penguin - It has taken 26 million years, but scientists say getting the first glimpse at what a long-extinct giant penguin looked like was worth the wait.

Experts from New Zealand and the United States have reconstructed the fossil skeleton of one of the giant sea birds for the first time, revealing long wings, a slender build and a spear-like bill that have them describing it as one elegant bird.

In research published this week in the Journal of Vertebrate Paleontology, the scientists say the bird they have dubbed Kairuku _ Maori for “diver who returns with food” _ stood about 4 feet 2 inches (1.3 meters) tall and had a body shape unique from any previously known penguin, living or extinct. Kairuku lived in the Oligocene period, about 26 million years ago.

 

The first Kairuku bones were discovered 35 years ago in New Zealand by Ewan Fordyce, a professor of geology at New Zealand’s University of Otago. He recently teamed up with Dan Ksepka, a research assistant professor at North Carolina State University, to reconstruct a skeleton from multiple sets of fossils, using a king penguin as a model.

“It’s pretty exciting,” Fordyce told The Associated Press. “We’ve got enough from three key specimens to get a pretty reliable construction of its body size.”

Fordyce said the bird’s elongated bill may have been useful in catching swift prey and its large body size likely helped it swim longer distances and dive deeper than modern-day penguins.

The bird is about a foot (30 centimeters) taller than the largest modern-day penguin, the emperor. It would have weighed about 132 pounds (60 kilograms), 50 per cent more than an emperor.

When Kairuku was alive, most of modern-day New Zealand was submerged beneath the ocean. The scientists believe the remaining isolated, rocky land masses helped keep the penguins safe from potential predators and provided them with plentiful supplies of food.

Fordyce said there are several reasons why the giant penguins might have become extinct: It could have been from climate change, the arrival of new predators, or increased competition for food from seals and other creatures. ( dawn.com )

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Is this the oldest lifeform on earth? The 34,000-year-old bacteria that's still alive

Is this the oldest lifeform on earth? The 34,000-year-old bacteria that's still alive - A scientist has discovered 34,000-year-old bacteria buried underneath a Californian desert.

The discovery was made after researchers dug up salt crystals below Death Valley in Eastern California for climate research.

Ancient microbes were found trapped inside tiny, fluid-filled chambers within the crystals.

Ancient microbes: Scientists have discovered 34,000-year-old bacteria inside ancient salt crystals (File Photo)

'It was actually a very big surprise to me,' said Brian Schubert, who made the discovery.

'They're alive, but they're not using any energy to swim around, they're not reproducing,' he told OurAmazingPlanet. 'They're not doing anything at all except maintaining themselves.'

Schubert, who is now an assistant researcher at the University of Hawaii, said the bacteria was shrunken and small, and suspended in a type of hibernation state.

The reason for the microbes' astounding life span appears to be due to the fact that they were trapped alongside the algae of a group called Dunaliella.

Significant discovery: The crystals were found below the desert of Death Valley National Park in Eastern California (pictured)

'The most exciting part to me was when we were able to identify the Dunaliella cells in there, because there were hints that could be a food source,' he added.

Tim Lowenstein, a professor in the geology department at Binghamton University says that new research indicates this process can occur in modern saline lake.

'It's permanently sealed inside the salt, like little time capsules,' said Lowenstein.

The new findings, along with details of Schubert’s work, are published in the January 2011 edition of GSA Today, the publication of the Geological Society of America. ( dailymail.co.uk )

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