Massive, meat-eating predatory dinosaur unearthed



(CNN) -- It lived about 100 million years ago, weighed four tons and likely was at the very top of its prehistoric food chain.

Researchers from Chicago's Field Museum, the North Carolina Museum of Natural Sciences and North Carolina State University announced Friday the discovery of Siats meekerorum, a dinosaur that stretched more than 30 feet long, in eastern Utah.

Given its size and other characteristics, they believe this creature ruled its ecosystem in the middle of the Cretaceous, a period known as the last in the so-called "Age of Dinosaurs."

It's not known if Siats meekerorum existed alongside Tyrannosaurus rex; fossils found from the same patch of Utah's Cedar Mountain Formation shows it did share the land with tyrannosaurs. But relatively speaking, these tyrannosaurs were much smaller (and below the 7 or so tons of later T. Rexes) and definitely down on the predatory food chain.

"At least 98 million years ago, we know that (tyrannosaurs) were small and somebody else was top dog in the neighborhood," said Peter Makovicky, The Field Museum's dinosaur curator.

"(Siats meekerorum) is a large dinosaur," he adds. "And we have no evidence -- nor do the teams that worked in this area prior to us -- of anything bigger."

Its size and appearance alone are reason enough to excite paleontologists. But there are a few other facts that make this find noteworthy, said Makovicky.

One is that Siats meekerorum helps to fill in a roughly 30-million-year gap in the geologic record in North America, a period for which relatively little is known about dinosaurs on the continent. Another: Its closest carchardontosaurian (the family it hails from) kin hailed from elsewhere in the world, suggesting there was more movement and dispersion of dinosaurs at a time the continents had largely already drifted apart than had been thought.
"Until 10 years ago, we thought this was a time period when North American dinosaurs were isolated," Makovicky said. "The evidence is growing that was not actually the case. Dinosaurs were quite good at spreading around the world."

Desert heat of 110 degrees Fahrenheit -- so hot that Makovicky's dog burned his paws -- is bad enough. But for a paleontologist, working in this oven all summer without any big finds? That's definitely a lot worse.

But with a few days in the 2008 field season, Lindsay Zanno from the North Carolina Museum of Natural Sciences spotting something she and her colleagues, including Makovicky, found curious.

The group returned the next year, opening up a bigger area, but still had more work to do once the season ended. Finally, with the help of a jackhammer, they finished unearthing their discovery in 2010, according to Makovicky.

He said, initially, these experts would have speculated the new creature was related to T. rex or Ankylosaurus, both of which roamed what is now North America.

The more they dug, literally and figuratively, the paleontologists realized the species belonged to the carchardontosaurian family, with relatives like the giant Giganotosaurus, a carnivore that dates to the Late Cretaceous period and has been found in Argentina.

The name for the new dinosaur, Siats meekerorum, refers to a cannibalistic monster in mythology of Utes, a Native American people who lived where it was found.

"This dinosaur was a colossal predator second only to the great T. rex and perhaps Acrocanthosaurus in the North American fossil record," said Zanno, the lead author of the study in Nature Communications announcing the discovery, in a press release.


And it hasn't been an isolated breakthrough. Makovicky notes that, since Siats meekerorum, their crews found two other dinosaur species nearby from the same period that likewise are related to others from different continents. Zanno expects more such fresh insights in the years to come.

"Siats is just the tip of the iceberg," she said. "Our teams are unearthing a lost dinosaurian ecosystem right here in the badlands of North America."

Oldest human DNA found in Spain



(CNN) -- There were no genetic tests 400,000 years ago, so our ancient relatives didn't know as much about themselves as we know about them now.

Scientists have reconstructed a nearly complete mitochondrial genome of an ancient human relative, whose remains were found in Sima de los Huesos ("pit of bones") in northern Spain. It is the oldest DNA to be recovered from an early humanlike species, authors of a study wrote in the journal Nature.

The ancient species that has revealed some of its genetic secrets, via bone fragments from a femur, is probably not directly linked to your family tree though.

"It's quite clear that this is not a direct ancestor of people today," said Svante Paabo, a biologist at the Max Planck Institute for Evolutionary Anthropology and senior author of the study.

Instead, he said, this representative of an early humanlike species, called Homo heidelbergensis, could be an ancestor of both Neanderthals and another group called the De nisovans.

The genetic relationship to Denisovans, discovered through this DNA research, is surprising because the Homo heidelbergensis remains found in the cave have many Neanderthal-like features. The only remnants of Denisovans come from Siberia -- a long way from Spain.

"It's sort of an open question really what this means, and I think further research into the nuclear genome of these hominins will address that," Paabo said.

How they did it

Paabo and colleagues used a new method for sequencing ancient, degraded genetic material to put together the 400,000-year-old specimen's mitochondrial genome. It is the oldest DNA ever found outside permafrost conditions -- in other words, it was not permanently frozen.
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Mitochondria are structures in cells that convert food energy into usable forms. DNA stored in the mitochondria is passed to children through the maternal line only (i.e., only moms can pass it on), so it's only a small snapshot of inherited genes.

Genetic material in the cell's nucleus comes from both parents and gives a fuller picture of genetic heritage.

To study genetics of our ancient predecessors, researchers have an easier time studying mitochondrial DNA because there are hundreds of times more copies of it in each cell.

"It's a much bigger chance to find some fragments of this preserved," Paabo said.

A skeleton of a Homo heidelbergensis representative from a cave site in Spain.

A skeleton of a Homo heidelbergensis representative from a cave site in Spain.

The method that researchers used involves separating the two strands of the DNA double helix. They then make a "library" from each of the two strands. If part of one strand is damaged, its analogue on the other strand -- which is made of complementary genetic partners -- may be intact.

"That is sort of the big trick involved," Paabo said.
After sequencing the mitochondrial DNA, researchers then compared the result with genetic information about Neanderthals and Denisovans.

Since nuclear DNA encompasses more information about a person's inheritance, a nuclear genome sequence from Homo heidelbergensis may reveal even more clearly how it is connected to other ancient humanlike species, he said.

But retrieving the nuclear DNA sequence will be challenging, study authors wrote. Just to get the mitochondrial DNA sequence, it took about two grams of bone -- less than 0.1 ounce -- even though hundreds of copies of this DNA are in every cell.

Still, Paabo said, the sequencing technique his group used "opens a possibility to now do this at many other sites, and really begin to understand earlier human evolution."
Relationship to other species

Researchers thought initially the mitochondrial DNA of the Homo heidelbergensis specimen would share a common ancestor with Neanderthals. Neanderthals lived in Europe beginning as much as 300,000 years ago, Paabo said. (Homo sapiens, our species, first appeared in Africa between 100,000 and 200,000 years ago.)

Instead, researchers discovered through the DNA that this specimen is closer to the Denisovans, a group related to the Neanderthals.

A likely explanation is that in Eastern Eurasia this species gave rise to Denisovans, and in Western Eurasia they were the ancestors of Neanderthals, Paabo said. But more research needs to be done to verify that theory.

Little is known about the Denisovans. Although some of their remains were found in southern Siberia, their genetic signature is only found today on islands in the Pacific.

Paabo was also the senior author on a 2012 study in the journal Science analyzing the Denisovan genome. That research suggested that human ancestors and the Denisovans'
ancestors must have branched off from one another as much as 700,000 years ago -- although that number is vague. Still, it seems that the Denisovans must have mated with indigenous people in Papua New Guinea and Australia, Paabo said.

About 3% to 5% of the DNA of people from Melanesia (islands in the southwest Pacific Ocean), Australia and New Guinea as well as aboriginal people from the Philippines comes from the Denisovans.

On the other hand, everyone who lives outside Africa today probably has some Neanderthal DNA in them, Paabo said in 2012.

The bottom line, Paabo said, is that the relationships between these early human relatives -- Homo heidelbergensis, Neanderthals and Denisovans -- are not clear-cut.

"It's going to be a more complex history that one will eventually clarify with the help of DNA," he said.

Elizabeth Landau is on Twitter at @lizlandau.

If humans came from monkeys then why are there still monkeys?

I think it's because of different lines of evolution, we are not descendants of the ones alive today.



Pan are chimpanzees.

Then how do you explain that crazy documentary that came out a few years ago.

I can't remember exactly what it was called, it was like....Ape Planet or something.

HOW DOES YOUR SCIENCE EXPLAIN THAT HUH?

@Iridium he was being sarcastic :lol:

If humans came from monkeys then why are there still monkeys?

'Biggest dinosaur ever' discovered



Fossilised bones of a dinosaur believed to be the largest creature ever to walk the Earth have been unearthed in Argentina, palaeontologists say.

Based on its huge thigh bones, it was 40m (130ft) long and 20m (65ft) tall.

Weighing in at 77 tonnes, it was as heavy as 14 African elephants, and seven tonnes heavier than the previous record holder, Argentinosaurus.

Scientists believe it is a new species of titanosaur - an enormous herbivore dating from the Late Cretaceous period.

A local farm worker first stumbled on the remains in the desert near La Flecha, about 250km (135 miles) west of Trelew, Patagonia.

The fossils were then excavated by a team of palaeontologists from the Museum of Palaeontology Egidio Feruglio, led by Dr Jose Luis Carballido and Dr Diego Pol.

They unearthed the partial skeletons of seven individuals - about 150 bones in total - all in "remarkable condition".



A film crew from the BBC Natural History Unit was there to capture the moment the scientists realised exactly how big their discovery was.

By measuring the length and circumference of the largest femur (thigh bone), they calculated the animal weighed 77 tonnes.

"Given the size of these bones, which surpass any of the previously known giant animals, the new dinosaur is the largest animal known that walked on Earth," the researchers told BBC News.

"Its length, from its head to the tip of its tail, was 40m.

"Standing with its neck up, it was about 20m high - equal to a seven-storey building."



This giant herbivore lived in the forests of Patagonia between 95 and 100 million years ago, based on the age of the rocks in which its bones were found.

But despite its magnitude, it does not yet have a name.

"It will be named describing its magnificence and in honour to both the region and the farm owners who alerted us about the discovery," the researchers said.

Measuring
There have been many previous contenders for the title "world's biggest dinosaur".

The most recent pretender to the throne was Argentinosaurus, a similar type of sauropod, also discovered in Patagonia.

Originally thought to weigh in at 100 tonnes, it was later revised down to about 70 tonnes - just under the 77 tonnes that this new sauropod is thought to have weighed.

The picture is muddied by the various complicated methods for estimating size and weight, based on skeletons that are usually incomplete.

Argentinosaurus was estimated from only a few bones. But the researchers here had dozens to work with, making them more confident that they really have found "the big one".

Dr Paul Barrett, a dinosaur expert from London's Natural History Museum, agreed the new species is "a genuinely big critter. But there are a number of similarly sized big sauropod thigh bones out there," he cautioned.

"Without knowing more about this current find it's difficult to be sure. One problem with assessing the weight of both Argentinosaurus and this new discovery is that they're both based on very fragmentary specimens - no complete skeleton is known, which means the animal's proportions and overall shape are conjectural.

"Moreover, several different methods exist for calculating dinosaur weight (some based on overall volume, some on various limb bone measurements) and these don't always agree with each other, with large measures of uncertainty.

"So it's interesting to hear another really huge sauropod has been discovered, but ideally we'd need much more material of these supersized animals to determine just how big they really got."