fossils •

Molar Teeth Could Be The Answer To Human Evolution

February 29, 2016 By Deborah Nielsen Leave a Comment

Teeth fossils are the key to unlocking human evolution.

Yes, it is true – according to this new research, molar teeth could be the answer to human evolution. You may wonder: what can teeth tell us about human evolution? A lot. An Australian study has spotted a common pattern in mammals and humans’ molar teeth, one that could help identify human fossils that are otherwise incomplete.

For years scientists have debated the evolution of our third molars, more commonly known as wisdom teeth. While the molars are often very small or fail to even develop in humans, those of other hominin species in our evolutionary tree were huge. Their chewing surfaces could be two to four times larger than those in an average modern human.

However, many scientists have long tried to explain the profound size change to dietary and cultural shifts considered to be unique to humans. Think cooking, for example.

A new study, published this week in the journal Nature, by a team of researchers led by evolutionary biologist Alistair Evans of Monash University in Australia offers an explanation that make us appear far less special.

Teeth can tell us a lot about the lives of our ancestors, and how they evolved over the last 7 million years.

declared Professor Evans in a recent press release.

Evans and his team came up with their conclusion after analyzing hundreds of fossilized teeth from modern humans and their ancestors alike, as well as those from chimpanzees, gorillas, and other similar apes.

They tried using several methods to gauge tooth size, including CT scans, but eventually discovered that the simplest method was the most accurate – multiplying a tooth’s width and length to create a rectangle representing crown size.

Additionally, the study suggests that the difference in Homo and Australopith tooth size could be indicative of differences in their respective diets.

Evan says that paleontologists have worked for decades to interpret these fossils and look for new ways to extract more information from teeth. Rather than viewing their evolution as the result of human-specific selective pressures, he proposes that the shrinking of wisdom teeth may be explained by basic developmental mechanisms that we share with most mammals.

Moreover, Evan’s research confirms that molars follow the sizes predicted by Professor Grant Townsend what is called ‘the inhibitory cascade’, a rule that shows how the size of one tooth affects the size of the tooth next to it.

Another author on the Nature paper was from the University of Adelaide’s School of Dentistry. The study examined teeth of modern humans, including those in one of the world’s largest collections of dental casts housed at the Adelaide Dental Hospital.

All in all, the findings of the study will be very useful in interpreting new hominin fossil finds, and looking at what the real drivers of human evolution were. As well as shedding new light on our evolutionary past, this simple rule provides clues about how we may evolve into the future.

Image Source: capitalotc.com.

Scientists Unravel 1.1-Million-Year-Old Stegodon Tusk

February 17, 2016 By Rebecca McGhee Leave a Comment

This is how a stegodon looked like.

The pakistani scientists unravel 1.1-million-year-old stegodon tusk in the province of Punjab, potentially shedding new light on the mammal’s evolutionary journey.

It is known that stegodonts are distant cousins of modern elephants. They are thought to have been present on earth from around 11 million years ago until the late Pleistocene period, which lasted until the end of the last Ice Age around 11,700 years ago.

According to the team, the tusk that has been recently unearthed measures eight feet (2.44 metres) in length and is around eight inches (20.3 cm) in diameter, making it the the largest ever discovered in the country. The stegodon tusk was discovered by scientists from the University of the Punjab’s zoology department during an expedition in the Padri district.

This discovery adds to our knowledge about the evolution of the stegodon, particularly in this region.

stated Professor Muhammad Akhtar, lead researcher of the excavation. He also added that the discovery sheds light on what the mammal’s environment was like when it was alive.

So far, the age of the stegodon tusk was determined through a radioactive dating technique that involved uranium and lead, researchers declared. However, the dating of the tusk needs further verification.

An interesting fact about stegodonts is that they were known for their long, nearly straight tusks and low-crowned teeth with peaked ridges. This indicated they were browsers or mixed feeders in a forested environment, in contrast to the high-crowned plated molars of elephants, which allowed them to graze.

On the other hand, stegodons were good swimmers. They were thought to have come from Africa and then quickly spread to Asia, where most fossils of the mammal were found.

Dr. Gerrit Van Den Bergh is a paleontologist at the University of Wollongong in Australia, who has done extensive research on the ancient mammals of several countries, including Pakistan. He noted that stegodons became extinct around the time when modern humans emerged.

The same paleontologist added that around 1.2 million years ago the creatures were still thriving. In what concerns their species, they are mostly Asian, but remains have been found further afield. The expert also informs us that a molar fragment has recently been discovered in Greece.

However, this is not the first time when the excavation-site grabbed headlines for prehistoric fossils. Previously, researchers discovered ancient skulls and teeth of bovid from the Punjabi dig site. After analysis, it was found that the remains belong to subfamily Reduncinae.

Image Source: photobucket.com.

Unique Ancient Fossils Of A ‘Wildebeest’ Unearthed In Kenya

February 5, 2016 By Jason Leathers Leave a Comment

Diagram of a Rusingoryx skull.

The paleontologists are discussing about the unique ancient fossils of a ‘Wildebeest’ unearthed in Kenya. The creature named Rusingoryx has left researchers speechless, as its nasal structure is more like of a dinosaur than that of a mammal.

At first glance, it seems unlikely that a shaggy-maned antelope from the Ice Age could have anything in common with a group a dinosaurs that roamed during the Cretaceous period 145 to 66 million years ago. However, science can be full of surprises.

Rusingoryx atopocranion is the name of the spcies that is related to the modern wildebeest. Below, you can see an image with the wildebeest in its natural habitat:

And here is an artist’s interpretation of Rusingoryx atopocranion:

The experts’ observation is that the newly discovered ‘beast’ shares a bizarre adaptation with a group of hadrosaurs: a hollow, domed ridge of bone along the front of its face called a nasal crest.

This structure was incredibly surprising. To see a hollow nasal crest outside of dinosaurs and in a mammal that lived so recently is very bizarre.

– Ohio University paleontologist Haley O’Brien said.

These fossils of Rusingoryx, about the size of its close cousin the wildebeest, date from about 55,000 to 75,000 years ago. Hadrosaurs with similar nasal structures, Lambeosaurus and Corythosaurus, lived about 75 million years ago.

O’Brien said the structure was an example of ‘convergent evolution‘ in which disparate organisms independently evolve similar features, like the wings of birds, bats and the extinct flying reptiles called pterosaurs, to adapt to similar environments or ecological niches.

About Rusingoryx’s lifestyle, the researchers say that they led a lifestyle similar to hadrosaurs: herbivores both likely traveling in herds. Many scientists think hadrosaurs also used their crests to communicate vocally with one another.

Moreover, the experts say that Rusingoryx’s nasal apparatus may have allowed it to deepen its normal vocal calls into ‘infrasound’ levels other species may not have been able to hear.

In order to come to a conclusion, the researchers examined six adult and juvenile Rusingoryx skulls. The bony crest, laying on the top and front of the skull, was mostly hollow inside. It contained nasal passages that followed the outside of the structure then took an S-shaped pathway down into the soft tissue part of the airway. The nasal passage then sat atop of a pair of large sinuses.

At least 24 Rusingoryx individuals were found at the site. University of Minnesota paleoanthropologist Kirsten Jenkins said butchered bones and stone tools there indicated humans may have caused their deaths. Jenkins said hunters may have driven a herd into the stream for an ambush.

This research was published in the journal Current Biology.

Image Sources: abc.net.au; wikimedia.org; guim.co.uk.

Ancient fossil exposed the Multicellular life existed 600 million years ago

September 25, 2014 By Brian Galloway 1 Comment

Three circular fossils found in China are supposed to be from the world’s initial animals, dating back 600 million years.
A latest research, which is available in the journal Nature, titled Cell differentiation and germ–soma separation in Ediacaran animal embryo-like fossils, discloses that the fossils, identified as Megasphaera, are multicellular organisms from 60 million years before skeletal animals become visible on earth in what is recognized as the Cambrian Explosion.
For researchers, this has challenged numerous ancient theories about the development of multicellular organisms.

“This opens an innovative path for us to discover more secrets about the ancient multicellular fossils and the evolutionary steps that were taken by multicellular organisms that would ultimately go on to control the Earth in a very noticeable way,” said Shuhai Xiao, a professor of Geobiology in the Virginia Tech College of Science.

The research has revealed that the Megasphaera showed indications of cell-to-cell adhesion, differentiation, and planned cell death, which are aspects of difficult multicellular eukaryotes, such as animals and plants.
They are doubtful to be bacteria or single-celled life, as earlier thought, because their difficult multicellular nature doesn’t match that of those forms of life from 600 million years ago.

Fossils comparable to these have been understood as bacteria, single-cell eukaryotes, algae, and transitional forms associated with current animals such as sponges, sea anemones, or bilaterally balanced animals and this paper lets us put aside some of those clarifications.
The three strange fossils were recovered from phosphate rocks in an effort to find out more about how multicellularity arose from single-celled ancestors and the discovery have shed a new light on the development and the details about how and when single-celledorganisms connected with others to make one life form.

Investigate report will now concentrate on wider paleontological search in order to recreating the whole life-cycle of the fossils and this, successively, should inform researchers a bit more about the origins of life on Earth.

Wacky Sphere Fossils Might Be Amongst World’s Primitive Animals

September 25, 2014 By Jason Leathers Leave a Comment

A chain of mystifying spherical fossils originated in Southern China seems to be the leftovers of some of the world’s most primitive animals.

According to the recent study, these notorious fossils are not expected to be bacteria or single celled protists. Their cells are quite complex and differentiated, which were seized in rock from over 600 billion years ago. Though, these spherical fossils might be multi-cellular algae or even the embryos of primitive animals.

Shuhai Xiao (researcher), a geobiologist at Virginia Tech in Blacksburg stated that, “The existent worth of these spherical fossils is that, we are having some clear proofs regarding how the evolution of single-celled organisms to things like animals and plants happened in the past.”

Multi-Cellular and Differentiated

According to the researchers, these spherical fossils, which are named as ‘Megasphaera’, originated in Sothern China in a rock layer known as Doushantuo Formation. Xiao told that, I studied the Megasphaera samples way back in 1998 and concluded that they may be animal embryos.

Every spherical fossil gauges a mere of 0.03 inches. Though, the researchers said that, there are no such animals that might have produced these embryos, leaving the identity of the fossils open to study. Xiao told Live Science that, ancient Megasphaera fossils were hauled out from a grey-rock the Doushantuo Formation. Presently, he and his fellow colleagues have accomplished in hauling more impossible-to-find fossils from the formation of black rocks.

The researchers told that, we have wedged the rock into ultra-thin pieces and found shine light through the fossils to view the formation inside similar to stained glass. With the help of microscopy, the researchers have observed the manifold of cells sliced together in spherical clusters. These cells are dissimilar to one another in the size and shape proposing that they have formed various tissue types with the method called as cell differentiation and apparently have dissimilar cellular functions, Xiao claimed.

He further told that, these fossils are showing the signs of complexity of multi-cellular organisms, which you were not present in bacteria and protists.

Along with the cells, there were clusters consisted of smaller cells as compared to the rest of fossils. As of their snuggled look, the researchers called these clusters as ‘matryoshkas’ later than the word for Russian nesting dolls. They supposed these clusters as reproductive cells.

Animal or Plant Like?

Xiao told that, some of these fossils have peripheral layers which are dissimilar to the interior cells. He further stated that, “These fossils are multi-celled with the cellular differentiation and they too have separate reproductive cells from sterile somatic body cells. This is quite astonishing, as if you see the contemporary multi-cellular organisms, including animals; this seems to be the serious step towards very complex multi-cellular organisms.”

Xiao stated that, these spherical fossils might therefore signify the transition between single-celled life and multi-cellular animals. Though, their composition is quite similar to algal life forms, implication that the fossils can be plant like instead.

Nomad Found Fossils: Helped Solve the Mystery of the Swimming Spinosaurus

September 12, 2014 By Germaine Hicks Leave a Comment

Scientists declared on Thursday, 11th of September that the detection in Moroccan desert cliffs of the new fossil remains of Spinosaurus, a 15-meter long.

The latest incomplete skeleton is of a Spinosaurus not fully grown, about 36 feet long and its forelimbs were huge and strong, with scythe like claws; its hind legs were undersized, with paddle-shaped feet after concluding of this fossil they found that Spinosaurus was the single recognized dinosaur adapted to living almost completely in the water.

New fossils of the gigantic Cretaceous-era predator indicated the facts that this Spinosaurus adjusted to life in the water some 95 million years ago, providing the most convincing evidence to date of a dinosaur capable to live and hunt in an aquatic environment.

Spinosaurus had been interesting anonymous specie for a long time. The oldest fossil of the dinosaur, found in Egypt a century ago and shifted to a German museum, was demolished during World War II, and left just only some drawings for paleontologists to consider and research.

The paleontologists found even more bones and soon they realized that same general feature in aquatic animals such as these bones were very bizarre indeed and the interlocking, a crocodile like teeth, ideal for catching swimming prey; the nostrils in the middle of the snout, high on the head; small hind limbs, the flat paddle like feet and the bendable rudder like tail. The bones were very dense, without the empty modularly cavity, these bones are only found in marine animals.

The animal we are restoring is so weird, it’s unlike any other dinosaur I have ever seen and working on this animal was like studying an alien from outer space that it is going to force dinosaur experts to change many things they thought they knew about dinosaurs,” said Nizar Ibrahim, who led the latest research of Spinosaurus.

They also used past records and figures from the first reported Spinosaurus detection in Egypt more than 100 years ago. Above all these features were created panic in Ibrahim and his colleagues that Spinosaurus is an aquatic species.

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