Pluto may harbour alien life, says UK Physicist

Pluto may contain a subsurface ocean warm enough to host life, according to a UK Physicist Brian Cox who also said that humans could be the only complex life in our galaxy. Cox believes the tell-tale ooze of glaciers on Pluto's surface hints at the possibility of a subterranean sea warm enough to host organic chemistry.

"The New Horizons probe showed you that there may well be a subsurface ocean on Pluto, which means - if our understanding of life on Earth is even standing of life on life on Earth is even slightly correct - that you could have living things there" Cox said. The New Horizons spacecraft performed a flyboy of Pluto in July. The spacecraft captured detailed images and other data of Pluto and also of its moons: Charon, Styx, Nix, Kerberos and Hydra.

It is unlikely, however, that New Horizons would be able to tell for certain whether warm water exists beneath the dwarf planet. Cox said that the most immediate prospect for finding evidence of life was on the moons of other planets closer to home.

Oldest Leukemia Case in 7000-year-old skeleton

Scientists have discovered what may be the oldest known case of leukemia in an approximately 7,000 year old skeleton of a woman from a Neolithic graveyard in Germany.

Researchers used high resolution computer tomography to detect indications of the blood cancer in the skeleton of woman who died between 30 and 40 years of age.

Except alveolar inflammation and dental caries, the individual G61 from the Neolithic graveyard of Stuttgart-Muhlhausen was was not affected  by other diseases, according to Dr Heike Scherf of the Senckenberg Center for Human Evolution and Paleoenvironment at the University of Tubingen.

Dr. Heike Scherf and her colleagues foind indications of leukemia on the skeleton of the woman, who was between 30 and 40 years of age at the time of death .

49,000 years ago South Africans used Milk-based Painting

While the use of ochre by early humans dates to at least 250,000 years ago in Europe and Africa,  this sis the first time a paint containing ochre and milk has ever been found in association with early humans in South Africa, said Poala Villa a curator at the University of Colorado Museum of Natural history and lead study author. The milk likely was obtained by killing lactating members of the bovid family such as buffalo, eland, kudu and impala, she said.

The powdered paint mixture was found on the edge of a small stone flake in a layer of Sibudu Cave, a rock shelter in northern KwaZulu-Natal, Africa, that was occupied by anatomically modern humans in the Middle Stone Age from roughly  77,000 years ago to about 38,000 years ago. Said Villa. While ochre powder production and its use are documented in a number of Middle Stine Age South African sites, there has been no evidence of the use of milk as a chemical binding agent until this discovery.

Cattle were not domesticated in South Africa until 1,000 to 2,000 years ago and Wild South African Bovids are known to separate from the herd when giving birth and usually attempt to hide their young, a behavior that may have made them easy prey for experienced Middle Stone Age hunters. 

Source: University of Colorado

Archaeologists Uncover Entrance Gates, Fortification of Ancient City

The fortifications and entrance of the biblical city of Gath of the Philistines - home of Goliath and the largest city in the land during the 10th -9th century BCE, about the time of the 'Untied Kingdom' of Israel and King Aheb of Israel - has been found by investigators. The excavations are being conducted in the Tel Zafit National Park, located in the Judean Foothills, about halfway between Jerusalem and Ashkelon in Central Israel. 

The city gate of Philistines Gath is referred to in the Bible (in I Samuel 21) in the story's of David's escape from King Saul to Achish, King of Gath.

Source : Bar-Ilan University

Most Big Animals Tried Grass but Many Switched Diet or Extinct

As grasses grew more common in Africa, most major mammal group tried grazing on them at times during the past four million years, but some of the animals went extinct or switched back to browsing on trees and shrubs.

Mass Extinction can Wiped Out Any Species

There have been five mass extinction events in the Earth's history, including climate change caused by volcanoes and an asteroid hit that wiped out the dinosaurs. In general, geographically widespread animals are less likely to become extinct than animals with smaller geographic ranges, offering insurance against regional environmental catastrophes. 

However, a study published in the Nature has found this insurance is rendered useless during global mass extinction events and  that widely distributed animals are just as likely to suffer extinction as those that are less widespread. 

The researchers explored the fossil record of terrestrial vertebrate (including dinosaurs) from the Triassic and Jurassic periods (252 - 145 million years ago).

Source: University of Leeds

Widest Distribution of Mammoth during the Last Ice Age

Ice Age paleontologist recorded the maximum geographical distribution of the woolly mammoth during the last Ice Age and published the most accurate global map in this regard. A total distribution area of 33,301,000 square kilometers and may thus be called the most successful large mammals of this era. The study determined that the distribution was limited by a number of climate driven as well as climate-independent factors.

Woolly Mammoth Tusk

Source : Science Daily

Genome Analysis lighted up the Arrivals and Spreading of first Americans

An international team of researchers compared the genomes of 31 living Native Americans, Siberians and people from Oceania with 23 Native Americans genome to establish a timeline for the arrival and spread of Amerindian populations. They concluded that the first Americans arrived after about 23,000 years ago and diverged around 13,000 years ago into two populations. They found no admixture of Polynesian or European genes, but did find some East Asian gene flow.

Source: University of California

Early Dogs drove to Extinction by the Cats

The dogs family originated in North America 40 Million of years ago and reached a maximum diversity around 22 million of years ago, when more than 30 species inhabited the continent. Today only 9 species of them lived in North America. They progressively increased in body size and species and specialized into becoming large predator. Some of them exceeded 30 kg and were among the largest carnivore on the North American continent. Although there are several large carnivores today face a higher extinction risk than smaller species, the author of the study found no evidence of a similar pattern in ancient canid species.

In the ancient times in the North America the canid species and the felid species fights for the same food just what we see in the Africa today where lions, leopards, Hyenas, wild dogs and other carnivores. New researches revealed that the ancient felids have strong negative impacts on the survivals of the ancient dogs but the opposite is not true. 

This also proved that the ancient felid species are much more efficient hunters than the ancient dogs.

Source: University of Gothenberg

Sky Diving Spiders found in S America

Scientists have discovered a type of nocturnal hunting spider in South America, that is able steer while falling. The spider, from the genus Selenops, is the only arachnid that is able to do this. They manoeuvre by spreading their legs in order to use lift and drag to steer themselves towards the tree when they fall. If they fall upside down, they are able to right themselves in midair.

World Without Humans

Researchers have provided the first estimate of how the mammal diversity world map would look like if modern man had never existed. Then most of northern Europe would probably now be home to not only wolves, Eurasian elk and bears, but also animals such as elephants and rhinoceroses.

Researches have based their estimates on the distribution of each species according to its ecology, bio-geography and the current natural environmental template. "Northern Europe is far from the only place in which humans have reduced the diversity of mammals", said Jens-Christian Svenning, from the Department if Bioscience, Aarhus University in Denmark. The current world map of mammal diversity shows that Africa is the only place with a high diversity of large mammals.

However, the world map shows far greater distribution of high large-mammal diversity across most of the world,with particularly high levels in North and South America.

"Most safaris today take place in Africa, but under natural circumstances, as many or even more large animals would no doubt have existed in other places such as Texas and region around northern Argentina-Southern Brazil", said lead author Soren Faurby.

World Without Us 

We are Responsible for the Extinction of the Mega Fauna

Scientists claimed their research settles a prolonged debate over mankind or  climate change was the dominate cause of the demise of massive creatures in the time of the saber-tooth, the woolly mammoth, the Woolly Rhinos and the giant armadillo.

Woolly Mammoth

Early human were the dominate cause of the extinction of a variety of species of giant beasts. 

Source: University of Exeter 

Marks on 3.4 Million Years Old Bones not Due to Trampling

Marks on two 3.4 million years old animal bone found at the site of Dikika, Ethiopia were not caused  by trampling, an extensive statistical analysis confirms.

The results of the study developed by new methods of fieldworks and analysis for researchers exploring the origins of tool making and meat eating in our ancestors


Source: Emory Health Sciences

Evidence of mass murder during Stone Age Found

Archaeologists have discovered evidence of a brutal mass murder that took place outside Frankfurt Some 7,000 years ago during the Stone Age. The massacre also includes what could be one of the earliest evidence of torture.

Archaeologists dug up 26 bodies in the mass grave and said the horror of their deaths marked them out.

Stone Age People

The legs of the victims seems to have been broken - either just before or after death, 

"Many have injuries, skull fractures caused by typical weapons from the time", said Christian Meyers, who was a PhD student at the University of Mainz when he conducted the research.

The injuries are often on the left of the skull, indicating that they were facing the attacker when they were hit with an adze.

Ancient Reptiles Attacked with Giant Fangs

According to the researchers the Giant ancient Prehistorical mammal like reptiles that grazed across the globe in the Permian Period may have possessed many of the fighting tactics seen in mordern herbivores, including head butting and attacks with the giant fangs. A number of these extinct beasts also possessed complex molar like teeth on the roof of their mouth.

About 250 to 300 million years ago, right before the Age of Dinosaurs the most successful vertebrates on land were the ancestors of mammals - also known as the primitive therapsids that are sometimes called mammal-like reptiles. These ancient creatures includes anomodonts,

Few states in US require HPV vaccine

An examination of state vaccination requirements for adolescents finds that the human papillomavirus (HPV) vaccine is currently required in only two states, many fewer than another vaccine associated with sexual transmission (hepatitis B) and another primarily recommended for adolescents (meningococcal conjugate), according to a new study

Lightening can Warp Rocks at Their Core

When a high energy lightening strike bombards a rock, it can heat the rock more than 3,000 degree Fahrenheit which can be twice as hot as lava and deforms not only the appearance of the rock, also the chemical bond that holds it together.

When this happens, the lightening zapped rock becomes covered in natural glasses called fulgurites. In the new study, the researchers took a microscopic look at the quartz fulgurites and found a thin layer of warped quartz crystal underneath the glassy quartz, induced by the high pressure of the strike. This warped layer consists of distinct, parallel and remarkably straight lines and can only be seen with intense magnification. This features control the fundamental structure of the rocks.

Abusive men put female partners at greater sexual risk

Men who were physically and sexually abusive to women were more likely than non-abusive men to engage in behaviors that exposed them and their partners to sexual transmission infections.

Sexting and internet safety climb top 10 list of health concerns for children

With more kids online and using cell phones at increasingly young ages, two issues have quickly climbing higher on the public's list of major health concerns for children across the U.S. sexting and internet safety.

Source: Science Daily

After KT extinction Age of Modern Fishes rises

According to two paleontologist, working in the National Academy of Science have determined that the world's most numerous and diverse vertebrate - ray finned fishes - began their ecological dominance of the oceans 66 million years ago, aided by the KT mass extinction event that killed of the Dinosaurs.

An assortment of Early Cenozoic ichthyoliths.

Entire Genomes of Wooly Mammoth Mapped

A international team of researcher has sequenced the nearly complete genome of two Siberian wooly mammoths. It revealed most complete picture of wooly mammoth to date.It includes the new information about the species' evolutionary history and the conditions that led to its mass extinction at the end of the Ice Age.

Trunk of a baby mammoth

Source: Science Daily

13 year study suggests Bushmeat grows with Economy

Comprehensive results of 13 years of one of the longest continuously running studies of commercial hunting activity have been published. The researchers recorded more than 197,000 animal carcasses for sale and analyzed market patterns in relation to political, economic and legal factors in the country of Equatorial Guinea in Central Africa.

Red Colobus

Source: Science Daily

Parasitized spider makes bed for its natural enemy, wasp larva

An ichneumonid parasitic wasp seizes control of the parasitized spider and exploits its 'resting web' building behavior as seen before moulting, scientists have discovered. Researchers examining the threads’ force, found that the web produced through parasitic manipulation is more robust than the resting web. Given that the wasp induces a behavior inherent in the spider, revealing the molecular mechanism of the web manipulation is likely to contribute to the practical application of spider silk.

Source: Science Daily

Why it's hard to make a Bunny Mad

Rabbits have long been considered immune to prior disease, but recently scientists have shown that under certain circumstances they can get transmissible spongiform  encephalopathy (the scientific name of the fatal brain disease causes by prion). Two studies suggests what makes rabbits hard to infect with prions and how they resistance can be overcome.

Head of Brazilian frogs are venomous wepeons

It's no surprise that some frogs secrete poison from glands in their skin. But researchers have discovered the first two species of frog, both living in Brazil, that are actually venomous. Not only do the frogs produce potent toxins, but they also have a mechanism to deliver those harmful secretions into another animal using bony spines on their heads.

Brazilian Frogs

Source: Science Daily

Sun's activity controls Greenland Temperature

According to a new study the Sun's activity could be affecting a key ocean circulation mechanism that plays an important role in regulating Greenland's climate according to a new study. The phenomenon could be responsible for cool temperatures the island experienced in the late 20th century and potentially lead to increased melting of the Greenland ice sheet in the coming decades;

According to the climate scientist Takuro Kobashi, around starting 2025, temperature of the Greenland will be much higher than it was previously anticipated and the ice sheet could melt faster than projected. 

New Dinosaur found from Triassic-Jurassic Period

A new herbivorous dinosaur species, Sefapanosaurus zastronensis, has been found in the the Elliot formation of South Africa.

This report published on 23rd June 2015, in the zoological Journal of the Linnean Society.

This Dinosaur is a herbivore form the southern regions of Gondwanaland some 200 million years ago in the late Triassic or Early Jurassic.  

Jurassic Saw the Fastest Evolution of Mammals

A report of a research published in Current Biology says that the fastest mammal evolution occurs in the Jurassic period.

Early mammals lived alongside dinosaurs during the Mesozoic Era (252 - 66 Million years ago). They were thought to be exclusively small, nocturnal and insect-eaters but fossils discoveries of the past decades, especially from China and South America, shows that they developed diverse adaptation for feeding and locomotion, including gliding, digging and swimming. 

To find the how rapidly the evolution happens they did a large-scaled analysis of the skeleton and dental changes of the Mesozoic mammals. By calculating, the researchers found the evolution reaches its peak at the Jurassic period (200-145 million years ago).

The team comprised researchers from Oxford University and Macquarie University. Dr. Roger Close of Oxford University is the lead author of this report.  

2014 is the warmest year on record

A report compiled by the NOAA's center for weather and climate at the National centers for environmental information is based on contributions from 413 scientists form 58 countries of the world. It provided the detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instruments located on land, water, ice and in space.

The Key highlight on the report include:

• Greenhouse Gases continued to climb: Carbon Di Oxide, Methane and Nitrous Oxide continued to rise during 2014 period. Atmospheric CO2 concentration increases by 1.9 ppm in 2014, reaching a global average of 397.2 ppm for the year.
• Record temperatures observed near the earth's surface: Four independent global datasets showed that 2014 was the warmest year on record. The warmth was widespread across land areas. Europe was the warmest continent on record in this year 2014. 20 countries Europe crossed their previous records. Africa's almost every country crossed above average temperate throughout 2014. Australia saw third warmest year on record. Mexico saw their first warmest year on record. Argentina and Uruguay saw their second warmest. Eastern North America was the only major region to experience below-average annual temperature.
• Tropical Pacific Ocean moves towards El-Nino Southern Oscillation conditions: The El Nino Southern Oscillation was in a nutral state in 2014 , although it was on the cool side in thee beginning of the year and approached warm El Nino conditions by the end of the year. The pattern played a major role in several regional climate outcomes.
• Sea surface temperatures were record high: The global averaged sea surface temperature was the highest on record. The warmth was particularly notable in the North Pacific Ocean.
• Global Upper ocean heat content was record high: Globally, the upper ocean heat content reached a record high for the year, reflecting the continuing accumulation of thermal energy in the upper layer of the oceans. Oceans absorb over 90% of earth's excess heat from greenhouse gas forcing.
• Global sea level was record high: Global average sea level rose to a record high in 2014. This keeps pace with the 3.2+/- 0.4 mm per year trend in sea level growth observed over past two decades.
• The Arctic continued to warm: The arctic experience its warmest year in record. Arctic snow melt occurred 20-30 days earlier than the 1998-2010 average.
• The antarctic shows highly variable temperature pattern: Some regions are cooler than normal and some are warmer than normal. Resulting a near-average condition as a whole. This 2014 is the third consecutive year of record maximum sea ice extent.
• Tropical cyclone above average overall: There are 91 cyclones in 2014 which is well above the average of 82 storms 

10 Extinct Animal That Returned

We often heard that Some species is extincted from the earth but  it is very seldom that we hear that some extinct species returned from extinction. Yes, it may sounds like the Jurassic Park movie but this type of things sometimes happened naturally. It will be more precise if we say sometimes we make mistakes and miss to count or find them. 

Here is the list of 13 species that once thought to be extinct but still alive in earth

COELACANTH

Coelacanth is a ancient world fish which was believed to be extinct in the Cretaceous Period about 65 plus million years ago. In 1938, one person miraculously discovered this fish in the East coast of South Africa near the mouth of Chalumna River. This species is lies among the oldest living jawed fish known to exists. The live about 100 years and swim about 90 to 100 meters below the surface of the water.

BERMUDA PETREL

It is believed to be extinct since 1620's. It remained extinct for 330 years. then in 1951, 18 nesting pairs were found in a very remote rocky islets in Castles Harbor. The are still battling extinction with only about 250 individuals.

CHACOAN PECCARY

In 1930 we only describe them by fossil records. But in 1975 researchers discovered one living species. To they there are 3000 known animals of this species. They resembles the pigs but they cannot be domesticated. It is found in the Chaco regions of Paraguay. 

LORD HOWE ISLAND STICK INSECT

Sometimes it referred to a land lobster or a walking sausages. It believed to be extinct in 1930. But in 2001 with only 30 individuals this Lord Howe Island  Stick Insect was found on the small Islet of Ball's Pyramid, the world's tallest and most isolated sea stack

MONITO DEL MONTE

It remains extinct for 11 million years until it had been discovered in the thicket of Chilean bamboo in the southern Andes. This creature more closely related with their Australian Marsupials than the South American Marsupials which lived 55 million years ago.

LA PALMA GIANT LIZARD

This creature extinct for 500 years until it is rediscovered in 2007 in the La Palma region of the Canary Island. In the IUCN red list still lists it as the Extinct species.

TAHAHE

This flightless birds believed to be extinct but in 1948 this species rediscovered near Lake Anua. This bird is still endangered with only 250 individuals.

CUBAN SOLENODON

This strange looking creature is very rare and only 34 individuals ever found. It is discovered in 1861 but from 1890 to 1974 no individuals were found. So, it is believed to be extinct. In 2003 one individual found and given a name Alejendrito.

CALEDONIAN CRESTED  GECKO

It is described first in 1866 and then after no individuals found. So it was put in the Extinct species lists but in 1994 it is again came into existence.

HOLLAND MOUSE

It was first discovered in 1843. then it was vanished from the earth at least for a century. In 1967 it was rediscovered at Ku-ring-gai National Park in Sydney. After a lot of conservation effort it is still fighting for existence. One of its remote population was wiped out in a wildfire in 1983. Though the healthier population still roaming the earth in Tasmania and New South Wales.

Megalonychidae

Temporal Range:  35 Mya - 0 Mya

OVERVIEW

                      Megalonychidae is a group of sloth that includes the extinct ground sloth and the living two toed sloth. Megalonychidae first appeared in the early Oligocene, about 35 million years ago, in Southern Argentina (Patagonia), and as far as the Antilles by the early Miocene. Megalonychids first reached North America by island hopping, about 9 million years ago. prior to the formation of the Isthmus of Panama.
                        Megalonychid ground sloths went extinct in North and South America around the end of the Pleistocene and in the Antilles apparently by about 5000 BP, living two-toed sloths of genus Choloepus as the only surviving member of the family.

EVOLUTION

                        Megalonyx means giant claws. Megalonyx is widespread North American genus that lived past in the close of the last Ice Glaciation. Remains of Megalonyx have been found as far north as Alaska to the Yukon. Ongoing excavations at Tarkio Valley in southwest Iowa may reveal something of the familial life of Megalonyx. An adult was found in direct association with two juveniles of different ages, suggesting that adults cared for young of different generations.
                          The earliest known North American megalonychid, Pliometanastes protistus, lived in Florida and the southern U.S. about 9 million years ago, and is believed to have been the predecessor of Megalonyx. Several species of Megalonyx have been named; actually most of the good specimen described as different species. A broader perspective on the group, accounting for age, sex, individual and geographic differences, indicates that only three species are valid (M. leptostomus, M. wheatleyi, and M. jeffersonii) in the late Pliocene and Pleistocene of North America. Although work by McDonald lists five species.

South Kashmir is in Flood Alert

Flood alert has been declared for Anantnag and Pulwama district of South Kashmir as river Jhelum was flowing close to danger mark at Sangam.

According to PTI, the Chief Engineer,

Irrigation and Flood Control Department, Javed Jaffer said,

 

"Flood alert has been declared for Anatnag and Pulwama districts as river Jhelum is flowing at 22 feet at Sangam, one feet below the danger mark,".

People living in and around flood prone areas in these districts have been advised to shift to safer areas.

The water level in Jhelum and its tributaries rose sharply following heavy rainfall since early on Wednesday.
The weatherman has forecast more rains over the next 48 hours in Kashmir.

Heatwave in Pakistan's Sindh killed 224 people

Some 224 people are now believed to have died during a heatwave in Pakistan's southern Sindh province.

Health officials say most of the deaths have been in the largest city, Karachi, which has experienced temperatures as high as 45C (113F) in recent days. 

The city has seen power cuts caused by an increased demand for electricity because of the extreme weather.

Many of the victims are elderly people who have been suffering from fever, dehydration and gastric problems. 

Hundreds of patients suffering from the effects of the heatwave are being treated at government hospitals, provincial health secretary Saeed Mangnejo said.

 

Local media report that more than 150 bodies have been taken since Saturday to the Edhi morgue in Sohrab Goth, which usually receives about 20 bodies a day.

The demand for electricity for air conditioning has coincided with increased power needs over Ramadan, when Muslims fast during daylight hours.

Hot weather is not unusual during summer months in Pakistan, but prolonged power outages seem to have made matters worse, the BBC's Shahzeb Jillani reports.

Sporadic angry protests have taken place in parts of the city, with some people blaming the government and the city's main power utility, K-Electric, for failing to avoid deaths, our correspondent says.

Source: BBC News

Crocodiles rocked pre-Amazonian Peru: Seven crocodile species found in single 13-million-year-old bone bed

 

Thirteen million years ago, as many as seven different species of crocodiles hunted in the swampy waters of what is now northeastern Peru, new research shows. This hyperdiverse assemblage, revealed through more than a decade of work in Amazon bone beds, contains the largest number of crocodile species co-existing in one place at any time in Earth's history, likely due to an abundant food source that forms only a small part of modern crocodile diets: mollusks like clams and snails. The work, published today in the journal Proceedings of the Royal Society B, helps fill in gaps in understanding the history of the Amazon's remarkably rich biodiversity.

"The modern Amazon River basin contains the world's richest biota, but the origins of this extraordinary diversity are really poorly understood," said John Flynn, Frick Curator of Fossil Mammals at the American Museum of Natural History and an author on the paper. "Because it's a vast rain forest today, our exposure to rocks--and therefore, also to the fossils those rocks may preserve--is extremely limited. So anytime you get a special window like these fossilized "mega-wetland" deposits, with so many new and peculiar species, it can provide novel insights into ancient ecosystems. And what we've found isn't necessarily what you would expect."

Before the Amazon basin had its river, which formed about 10.5 million years ago, it contained a massive wetland system, filled with lakes, embayments, swamps, and rivers that drained northward toward the Caribbean, instead of today's pattern of eastward river flow to the Atlantic Ocean. Knowing the kind of life that existed at that time is crucial to understanding the history and origins of modern Amazonian biodiversity. But although invertebrates like mollusks and crustaceans are abundant in Amazonian fossil deposits, evidence of vertebrates other than fish have been very rare.

Since 2002, Flynn has been co-leading prospecting and excavating expeditions with colleagues at fossil outcrops of the Pebas Formation in northeastern Peru. These outcrops have preserved life from the Miocene, including the seven species of crocodiles discussed in Proceedings B. Three of the species are entirely new to science, the strangest of which is Gnatusuchus pebasensis, a short-faced caiman with globular teeth that is thought to have used its snout to "shovel" mud bottoms, digging for clams and other mollusks. The new work suggests that the rise of Gnatusuchus and other "durophagous," or shell-crunching, crocodiles is correlated with a peak in mollusk diversity and numbers, which disappeared when the mega-wetlands transformed into the modern Amazon River drainage system.

"When we analyzed Gnatusuchus bones and realized that it was probably a head-burrowing and shoveling caiman preying on mollusks living in muddy river and swamp bottoms, we knew it was a milestone for understanding proto-Amazonian wetland feeding dynamics," said Rodolfo Salas-Gismondi, lead author of the paper and a graduate student at the University of Montpellier, in France, as well as researcher and chief of the paleontology department at the National University of San Marcos' Museum of Natural History in Lima, Peru.

Besides the blunt-snouted crocodiles like Gnatusuchus, the researchers also recovered the first unambiguous fossil representative of the living smooth-fronted caiman Paleosuchus, which has a longer and higher snout shape suitable for catching a variety of prey, like fish and other active swimming vertebrates.

"We uncovered this special moment in time when the ancient mega-wetland ecosystem reached its peak in size and complexity, just before its demise and the start of the modern Amazon River system," Salas-Gismondi said. "At this moment, most known caiman groups co-existed: ancient lineages bearing unusual blunt snouts and globular teeth along with those more generalized feeders representing the beginning of what was to come."

The new research suggests that with the inception of the Amazon River System, mollusk populations declined and durophagous crocodile species went extinct as caimans with a broader palate diversified into the generalist feeders that dominate modern Amazonian ecosystems. Today, six species of caimans live in the whole Amazon basin, although only three ever co-exist in the same area and they rarely share the same habitats. This is in large contrast to their ancient relatives, the seven diverse species that lived together in the same place and time.

This story is taken from Science Daily

Underground ants can't take the heat

Underground species of army ants are much less tolerant of high temperatures than their aboveground relatives -- and that difference in thermal tolerance could mean that many climate change models lack a key element of how animal physiology could affect responses to changing environments. 

According to a new study from Drexel University, underground species of army ants are much less tolerant of high temperatures than their aboveground relatives--and that difference in thermal tolerance could mean that many climate change models lack a key element of how animal physiology could affect responses to changing environments.

At face value, this is not surprising, noted Sean O'Donnell, PhD, a professor in Drexel's College of Arts and Sciences and senior author of the study published in the Journal of Animal Ecology. Ants that live above ground are exposed to higher temperatures than subterranean ants, so they should be expected to tolerate hotter conditions--but the relationship between microhabitat and heat tolerance simply hadn't been tested before. No one knew whether the subterranean ant species might have been capable of handling high temperatures, even if they prefer cooler ones.

Current models of climate change are built on predictions that animal species may shift their geographic ranges to new latitudes or elevations when the temperature rises. But these models typically use temperature averages taken at a macro resolution--commonly measured 1 meter above ground, and encompassing areas of a square kilometer or more--and they don't generally take into account that different species have varied levels of heat tolerance.

"A few inches of soil can make a big difference in temperature," said Kaitlin Baudier, a doctoral student in O'Donnell's lab and lead author of the study.

 

To look at whether factors like microhabitat preference--living above ground vs. below ground--affected an animal's thermal range, Baudier, O'Donnell and colleagues looked at nine closely related species of army ants that lived in the same general area in Costa Rica's tropical forests. They sampled ants from each of the species and experimentally tested their maximum heat tolerance in the lab.

They found that the best predictor of heat tolerance was how active the ant species was in above-ground environments. Above-ground army ants were most tolerant of higher temperatures, while species that lived mostly below-ground had much lower tolerance to heat, and species that used a combination of above- and below-ground environments had intermediate levels of tolerance.

Body size and habitat type also interacted, so that in comparisons of same-size individuals from different species, the species that are active above-ground were more heat tolerant--another indicator that habitat use signals the species' tolerance to heat. Within each species, smaller ants were more sensitive to rising temperatures than the larger ants of the same type.

"The takeaway message is that an animal's adaptation to its microhabitat is relevant to its thermal physiology," said Baudier.

"This shows us that the ways these species respond to a changing climate will be different depending on habitat type, and it's important to know that microhabitat could be an indicator of heat tolerance," O'Donnell said.

This story is taken from Science Daily

Vagrant bachelors could save rare bird

A study has revealed the importance of single males in small, threatened populations. Results from a study of endangered New Zealand hihi birds shows that bachelor males who don't hold breeding territories, known as 'floaters,' could help maintain genetic diversity and decrease the likelihood of inbreeding by sneakily fathering chicks. 

These underestimated individuals are vital to the long-term survival of small populations, such as in the hihi, a rare bird found only in New Zealand. There are thought to be only 2,000 individuals left in the wild, making them extremely vulnerable to natural disasters or disease, of which a single severe incident could wipe out the whole species.

While floaters have much lower breeding success rates than coupled males, in hihis they are able coerce females, which are already coupled up, into mating. This has been shown to have a small but significant impact on population size by increasing the number of breeding birds, as well as influencing the sex ratio. These factors are important in maintaining genetic diversity and decreasing levels of inbreeding.

Dr Patricia Brekke, researcher at ZSL and the lead author of the study, said: "Conservation management often discounts individuals that are thought to be unable to produce offspring, thinking that they have no effect on populations. We have shown that in hihi, floaters are able to reproduce and pass on their genes from one generation to the next, which helps with long-term survival of this endangered bird.

 

"Despite being difficult to study, as they have no fixed abode, we should pay more attention to these bachelor males as they can potentially have a big effect on genetic diversity and therefore the survival of species with very few individuals remaining. Not taking floating individuals into account can undermine our conservation efforts."

The hihi is one of the world's most evolutionarily unique birds, classed as the only member of its own family, and were lost from New Zealand's North Island by around 1895 because of introduced predators such as rats, habitat loss due to farming and disease. They are the only bird species in the world to mate face-to-face like humans.

Floating behaviour has been observed in a variety of animals including fish, mammals and insects. Floating can be a successful breeding strategy as bachelor males avoid investing their energy into defending territory and looking after chicks, instead spending time searching for mates. In hihi birds, floaters tend to be either younger males (around a year old) that are inexperienced at holding a territory or older males (over five years) who lack the energy to defend territory. Their 'homelessness' makes them difficult to study as they travel between different areas looking for food and potential mates.

Conservation efforts to save the species began in the 1980s and involves reintroducing birds to different islands and mainland reserves. ZSL has so far been involved in establishing three reintroduced populations, but these are all small (less than 150 birds each) and so hihi remain in a precarious situation.

This story is taken from Science Daily

Tiger-spray DNA shown as valuable conservation tool

Scientists have demonstrated a new technique to non-invasively survey tigers using their scent sprays, which are detected much more frequently in the wild than scat--the 'breadcrumb' that researchers have traditionally used to track the endangered animals. The findings show that DNA taken from tiger spray is just as good or even better than scat in identifying individual tigers and their gender, and have the potential to increase the power of conservation surveys and management. 

"Genetic monitoring of tiger source populations is a conservation priority," said Anthony Caragiulo, a postdoctoral researcher in the American Museum of Natural History's Sackler Institute for Comparative Genomics. "The utility of this new method is really impactful because it will let us dramatically build upon the number of tigers that can be surveyed and, consequently, increase our understanding of these elusive animals--hopefully before they are gone."

Despite intense conservation efforts, there are fewer than 3,200 tigers (Panthera tigris) in the wild, living in less than seven percent of their historical range. When a population is confined to small islands of wilderness, as are tigers, there is a higher risk of inbreeding and loss of genetic diversity, leaving the species with weaker young. To combat this, the Museum has been working with the global wild-cat conservation organization Panthera to establish "genetic corridors" that allow tigers to seek new territory for prey and new populations for breeding. "Tracking" individual cats using genetic markers lets researchers map movement within and between populations.

Genetic tracking has traditionally relied on extracting DNA from scat collected in the wild. But in humid, tropical landscapes--like those in Sumatra, where a number of tigers live--scat often degrades before researchers can find it. Scent sprays left by tigers on trees and overhanging leaves degrade less quickly, and can be detected by researchers between two and eight times as frequently as scat. So, to boost the effectiveness of genetic monitoring of tigers in warm regions, the research team questioned whether DNA could be extracted from sprays.

The researchers collected spray samples from three captive tigers in Ontario with cotton swabs that were then stored in tubes of buffer to help preserve the DNA. Tiger spray is a combination of anal gland secretions--said, surprisingly, to have a floral scent like citrus--and urine, which contains DNA in the form of cells from the urethra. The researchers were able to amplify microsatellite loci, which are noncoding DNA sequences with unique numbers of repeated nucleotides providing enough information to "fingerprint" individual tigers, and portions of the sex chromosome to determine whether they are male or female.

"We recently spent weeks looking for tiger scat in the field with very little luck," said Rob Pickles, monitoring specialist for Panthera. "Although this new spray technique wouldn't replace scat studies entirely, we now know that we can use both methods in conjunction to drastically increase our monitoring abilities."

The next step for the researchers is to test the technique in the field, where it also could be used to monitor other scent-spraying animals, like lions.

This Story is taken from Science Daily