This video shows how that happened.
See also here.
This video shows how that happened.
See also here.
This video is called Rare Gigantic Crocodiles [DOCUMENTARY].
From Wildlife Extra:
Crocodiles are able to climb trees
February 2014: Although mostly seen skulking in water or labouring across the ground they can also climb tree new research show.
Researchers from the University of Tennessee, Knoxville has found that the reptiles can climb trees as far as the crowns. Research assistant professor Vladimir Dinets and his team observed crocodile species on three continents—Australia, Africa and North America—and examined previous studies and anecdotal observations.
They found that four species climbed trees—usually above water—but how far they ventured upward and outward varied by their sizes. The smaller crocodiles were able to climb higher and further than the larger ones. Some species were observed climbing as far as four meters high in a tree and five meters down a branch.
Their research is published in the journal Herpetology Notes and can be found here. “The most frequent observations of tree-basking were in areas where there were few places to bask on the ground, implying that the individuals needed alternatives for regulating their body temperature. Likewise, their wary nature suggests that climbing leads to improved site surveillance of potential threats and prey.”
The data suggests that at least some crocodile species are able to climb trees despite lacking any obvious morphological adaptations to do so.
“These results should be taken into account by paleontologists who look at changes in fossils to shed light on behaviour,” said Dinets. “This is especially true for those studying extinct crocodiles or other Archosaurian taxa.”
From Kyodo news agency in Japan:
Paleontologist finds fossil of gator dating back 20 million years on Oki
by Haruka Nishimoto
Dec 30, 2013
MATSUE, SHIMANE PREF. – Shigenori Kawano, 32, found last summer what was later identified as East Asia’s oldest fossil of a giant alligator, dating from around 20 million years ago, on Oki Island in the Sea of Japan.
In mid-July, the researcher at Shimane Nature Museum of Mount Sanbe found a 30-cm rock on the Shimane Prefecture island’s shore while studying local animal and plant life.
Kawano said that when he saw part of a bone exposed on the surface of the rock, he instantly knew it must be that of a reptile.
“The size was nothing compared with that of a turtle or a soft-shelled turtle,” he said.
After carefully examining the rock, he learned that the bone, which measured 21 by 18 cm, was a fossilized portion of the backbone of an alligator estimated to be up to 7 meters long.
Kawano said, “I spontaneously shouted, ‘I did it!’ “
The previous oldest fossil of a giant alligator was found on the Penghu Islands in Taiwan and is believed to date from about 10 million years ago.
A native of Takeo, Saga Prefecture, Kawano was a second-grader when he started collecting fossils.
Taken by his father, who was a civil engineer, he collected fossils of snails and shark teeth not only in coastal areas and construction sites in Saga Prefecture but also in other parts of northern Kyushu and Shikoku.
Since his mother and younger brother were also fans of archaeology, it has become a sort of “leisure activity for our family,” Kawano said.
When his family went on an excavation trip to a remote island, all of the members got so absorbed in digging that they forgot that the tide was rising and were almost unable to return to the mainland.
Kawano has made remarkable discoveries since he was a junior high school student.
He found a bird bill from about 34 million years ago when he was a sophomore at junior high school and the bill is still a treasure for him.
At Shimane University, which he chose to enter simply because he can go fishing and fossil hunting by bicycle, he studied paleontology for 10 years.
And now, from prehistory to today.
From Wildlife Extra:
New discovery more than doubles known crocodile species
Study reveals how little is still known about crocodiles’ biogeography, proves invaluable to conservationists
December 2013: Research has revealed that there are more than twice as many species of African crocodile, perhaps the continent’s most iconic creature, as previously believed. A recent study by the University of Florida has now found there are at least seven distinct species of African crocodile – long thought of as just three known species.
The UF team’s latest discovery, led by then-doctoral candidate Matthew H. Shirley, is that what had been believed to be a single species of slender-snouted crocodile, is actually two.
The results emphasise how little is known about crocodile biogeography, or how species are distributed geographically over time, in Western and Central Africa, said Jim Austin, a co-author on the paper and Shirley’s doctoral adviser at UF.
In the paper, Shirley and his team describe that West African populations of the slender-snouted crocodile do not share the same genetic or specific physical features as those populations in Central Africa – and they estimate the two populations have been separated from each other geographically for at least 7 million years.
Biologists and conservation agencies need to know the precise taxonomy of animals and plants to avoid allocating precious conservation funding and effort working to protect species that may be more plentiful than believed, or – as in this case – ensuring that those resources can be directed toward species whose numbers are lower than estimated.
This video says about itself:
Male slender-snouted crocodile bellowing to a female. Later, they mated. Notice the very characteristic posture: tail raised, head oblique.
The Wildlife Extra article continues:
Now that researchers know the West African slender-snouted crocodile is not the same species as its Central African cousin, Shirley said, that changes its standing.
“The West African slender-snouted crocodile is actually among the three or four most endangered crocodiles in the world,” said Shirley. “By finally recognising that it is a unique species, we are in a much better position to advance its conservation and ensure its future.”
Crocodile species are often difficult to identify by physical characteristics alone. Most non-scientists can barely tell the difference between an alligator and a crocodile, in fact. The UF team looked at skull characteristics of slender-snouted crocodiles from museum collections and were able to find consistent differences between the species, Austin said.
See also here.
This video is called The BEST of Discovery’s Dinosaurs.
What a Dinosaur Brain May Have Looked Like
November 13, 2013 01:50pm ET
SAN DIEGO — Fossils have painted an often colorful and sometimes feathery picture of what dinosaurs looked like in their heyday, but almost nothing is known about the brains of man’s favorite Jurassic beasts.
“No one has ever found a preserved dinosaur brain,” said Erich Jarvis, a neurobiologist at Duke University in Durham, N.C., who presented the research with a colleague Tuesday (Nov. 12) here at the annual meeting of the Society for Neuroscience.
The only scraps of evidence available are fossilized molds of dinosaur brains, called endocasts — including one of Tyrannosaurus Rex. But endocasts don’t accurately reflect the brain’s internal structure. For that, Jarvis and his colleagues turned to the brains of dinosaurs’ closest living relatives. [Gallery: Stunning Illustrations of Dinosaurs]
Birds evolved from a group of predatory dinosaurs, overwhelming evidence suggests. Until recently, scientists thought bird brains lacked a true cortex, the outer layer found in mammalian brains where complex cognition takes place. Then, in 2004, a new view emerged of the bird brain — one containing a cortex, or pallium, with distinct subregions. Jarvis and his team added to this new picture, showing that certain brain regions were mirror images of each other.
Meanwhile, the brain of the crocodile, which first emerged on Earth before dinosaurs, has remained essentially a black box, Jarvis said. He and his colleagues set out to fill in the gaps in science’s knowledge of the crocodile’s brain.
The researchers took fresh postmortem brains from American alligators (Alligator mississippiensis), which belong to the same group as crocodiles; sliced them like deli meat; and used a radioactive labeling method to measure which genes were active in the animals’ brains. They compared the brains with those of zebra finches (Taeniopygia guttata), as well as turtles and lizards.
The alligator brain proved to be about 85 percent similar to the bird brain, and contained six of seven major regions found in the bird brain. In birds, two of these regions are involved in vocal learning. And like bird brains, the alligator brains had genes that became active in response to sounds from other members of their species.
Based on the structure of bird brains and alligator brains, Jarvis’ team infers that dinosaurs must have sported a similar brain with a cortex and six subdivisions, and with them, the capacity for sophisticated behavior.
“Dinosaurs may be underrated in complexity,” Jarvis said.Editor’s Recommendations
From Wildlife Extra:
Orinoco crocodiles to be tracked by satellite
Four of these reptiles will be released and monitored with satellite transmitters
The Orinoco crocodile can reach seven feet long and is the only crocodile species whose distribution is contained in a single watershed. Although they originally lived throughout the entire area of the Orinoco, it has been endangered by indiscriminate hunting, especially 1930-1950.
“Today there are only two relic populations of these animals in the wild, in Arauca region (At the confluence of the Ele, Lipa and Cravo Rivers) and the Meta region (In the Guayabero, Duda and Losada Rivers),” says the environmental scientist Willington Martinez, of the UN’s Roberto Franco Tropical Biology Station.
The Franco station has been working on plans to protect the species by developing a project to reintroduce Orinoco crocodiles into the wild; the project is being run with the Ministry of Environment and Sustainable Development (MADS). The project plans to release and monitor four Orinoco crocodiles, which have been fitted with satellite transmitters in the department of Meta.
Experts have chosen pre-juvenile specimens that retain their hunting instinct, have been isolated from the public, and are used to capturing live prey. They have undergone blood tests and physical examinations to establish that they are in good health.
The transmitters will be attached externally, and every time one of the animals removes its head from the water, the data will be sent to a satellite. The information can be accessed from a web page (which can be accessed by any user) and even be sent to mobile phones of the experts.
The researchers hope to obtain data that allow them to determine patterns of habitat use and movement.
Read more at the website of the National University of Colombia; also here.
This video is called Underwater Encounter with the Nile Crocodile – Swimming with Crocodiles – Episode 1 – BBC Two.
From New Era (Windhoek):
Namibia: Study Quantifies River Crocs
By Irene !hoaës, 23 April 2013
A recent report on the Nile crocodile (Crocodylus niloticus), the only type of croc species in Namibia, revealed that the main crocodile sub-population occurs in the Caprivi Region with a population estimate of 1 314 crocodiles over 2 metres in size.
However, a significant percentage of this population occurs within international border waters and therefore is technically shared with neighbouring countries. An estimated 28 percent of Caprivi’s hippopotamus population theoretically belongs to neighbouring countries and it would be reasonable to assume a similar percentage for crocodiles, since the two species share a similar habitat.
Thus the estimated population size for northeastern Namibia, excluding the Okavango River population west of the Caprivi Region, is approximately 946 adult crocodiles. A study in 2011 estimated a male to female sex ratio of 1:1.3 in the Okavango Delta panhandle region of northern Botswana, and it would be reasonable to assume similar ratios for Namibia. If these assumptions are correct, there are approximately 529 adult female crocodiles and 417 males.
“It is important to note that this probably represents a conservative estimate,” a 2012 study by the ministry of environment and tourism states. In Namibia the Nile crocodile is protected and approximately 10 percent of the available crocodile habitat falls within or on the borders of protected areas. However in the Caprivi Region, 74.0 percent can be found in protected areas, while 12.0 percent can be found in conservancies and 14.0 percent in undesignated or communal land.
In Namibia, natural populations occur in the major river systems in the north of the country, including the Kunene, Kavango, Kwando, Chobe and Zambezi rivers. West of Caprivi, information on the status of crocodile populations is relatively lacking. Crocodiles occur throughout the course of the Namibian section of the Okavango River, but no systematic population surveys have taken place upstream of the Caprivi section.
The Okavango River supports the highest concentration of humans per kilometre of river frontage in northeastern Namibia, while crocodile densities show a strong negative correlation with human densities on this river, revealed 2004 and 2009 studies. “It is likely that direct and indirect human pressure is a significant conservation threat to the future of crocodiles living outside of protected areas on the Namibian section of the Okavango River,” according to the 2012 study report.
No crocodile surveys have been carried out on the Kunene River, however, data on human/crocodile conflict from conservancy event books and anecdotal accounts suggest the population is significant and stable along the entire Namibian section. The unique characteristics of this aquatic ecosystem and relative geographical isolation suggest there could be important biological and/or ecological differences in this sub-population.
Until such time as detailed population surveys can be carried out on the upper Okavango and Kunene rivers, it would be reasonable (and probably conservative) to assume that these river sections effectively double Namibia’s crocodile population. The Okavango crocodile population is linked to the East Caprivi population via the Selinda Spillway. Notable concentrations occur around the eastern Caprivi floodplains and Muhango National Park on the Okavango River.
In general, densities decline away from protected areas. River fertility and concentrations of fish and other natural prey species are probably the most important determinants of population density in most cases. “This would explain the persistent population along the Zambezi River section and the unexplained density variation between protected and non-protected areas,” states the report.
The Kwando River basin drains Kalahari quartzite soils and thus the river has a very low nutrient content. Crocodiles do not occur in the Orange River, most likely because the water and local climate are too cold. Nile crocodiles are capable of limited oceanic movements thus the prevailing currents and water temperatures make marine sightings in Namibia highly unlikely.
Even crocodiles need their five a day, it seems. At least half of all species of alligator and crocodile supplement their meaty diet with the flesh of fruit: here.
From the BBC:
28 January 2013 Last updated at 02:00 GMT
‘Blood-biting’ predator identified
Prehistoric remains discovered more than a century ago have been identified as a new species of marine super-predator.
Researchers said the 165-million-year-old creature was distantly related to modern-day crocodiles.
The species has been named as Tyrannoneustes lythrodectikos, meaning “blood-biting tyrant swimmer”.
Scientists found that the partial skeleton – including a jawbone and teeth – belonged to a group of crocodiles that were similar to dolphins.
The animal’s pointed, serrated teeth and large gaping jaw meant it would have been suited to feeding on large-bodied prey.
A team of experts led by the University of Edinburgh said it would help scientists better understand how marine reptiles were evolving about 165 million years ago.
Their findings have been published in the Journal of Systematic Palaeontology.
Dr Mark Young of the University of Edinburgh’s School of GeoSciences, said: “It is satisfying to be able to classify a specimen that has been unexamined for more than 100 years, and doubly so to find that this discovery improves our understanding of the evolution of marine reptiles.”
Dr Neil Clark, palaeontology curator at the Hunterian, said little research had been done on the specimen since it was first listed in 1919.
He added: “It is comforting to know that new species can still be found in museums as new research is carried out on old collections.
“It is not just the new species that are important, but an increase in our understanding of how life evolved and the variety of life forms that existed 163 million years ago in the warm Jurassic seas around what is now Britain.”
From Wildlife Extra:
London Zoo animal photography prize winners revealed
Zoological Society of London reveals winning entrants of ZSL Animal Photography Prize 2012
September 2012. Mysterious manatees emerging from the dark waters of a river in Florida and a striking shot of a gharial‘s head reflected in the water as it swims are some of the dramatic images judged by the Zoological Society of London (ZSL) to best depict the magic of the animal kingdom. The pictures are just some of the breathtaking images from the ZSL Animal Photography Prize 2012, which will be on display in a stunning exhibition at ZSL London Zoo.
The competition, the first of its kind run by the Zoological Society of London, launched in April in a bid to inspire amateur and professional photographers to get out and capture the wonders of the natural world.
Photographer Robert Heischman, who captured the winning shot of the reflective gharial in the adult’s Weird and Wonderful category said: “Photographing reflections effectively requires a bunch of factors to come together. You need intense light, still water, a low camera angle, and an interesting subject to make it work. I love gharials for how sharp and angular they are, so when I saw this individual holding his head at such a steep angle, I knew I had an interesting shot on my hands.
ZSL’s project manager for the exhibition Sarah Barron added: “These photographers have managed to capture some truly amazing shots which will challenge peoples’ perception of the animal kingdom.”
Other extraordinary images that will be on display at the Zoo include a curious gorilla getting behind the camera, a close up of an Amur leopard baring its teeth, and a Madagascan giant leaf-tailed gecko showing off its incredible camouflage skills.
Adult and junior photographers submitted entries for the competition’s seven categories including The Human Animal and Birds and the Bees, to be in with the chance of winning part of the £10,000 prize fund.
To find out more about the ZSL Animal Photography Prize and to book tickets to see the exhibition please visit www.zsl.org/photo-prize.
From The Scotsman in Scotland:
Snap! Ancient crocodiles just like killer whales, Scottish scientists discover
By JULIA HORTON
Published on Wednesday 19 September 2012 00:00
SCOTTISH experts have found a link between killer whales and ancient crocodiles which suggests that today’s reptiles don’t deserve their “living fossil” reputation.
Researchers at the University of Edinburgh used fossilised remains from the Natural History Museum in London of two giant crocodylians, Dakosaurus maximus and Plesiosuchus manselii, to reconstruct their huge heads.
To their surprise, they found that the shape and size of the creatures’ teeth and skulls matched those of modern killer whales which now swim in the same British seas inhabited by the reptiles 150 million years ago.
The findings suggest that both species evolved the same hunting and feeding techniques, which challenges the widespread view that crocodiles have hardly changed since prehistoric times.
Dakosaurus had a bullet-shaped snout for suction-feeding and badly worn teeth, like some killer whales today, leading experts to conclude that it swallowed fish whole and also ate tough-skinned sharks.
Meanwhile, the teeth of the Plesiosuchus showed no wear and tear, suggesting that it had adapted like modern-day “type two” killer whales to be even more brutal, possibly devouring other marine reptiles of the time.
Dr Mark Young, lead researcher at the University of Edinburgh’s School of GeoSciences, said: “A lot of people refer to [modern] crocodiles as living fossils, but we have found that ancient marine crocodiles seem to have fed like killer whales do now, which means they were probably as evolved as mammals are today.”
The ancestors of today’s crocodiles were more than four metres long and both belonged to the Metriorhynchidae family. Their front limbs had modified into flippers to adapt to life in the oceans and they had a shark-like tail fin, giving them a very different appearance to crocodiles today.
The findings from the study, published in the scientific journal PLoS ONE, also help to explain how so many ancient reptiles survived for so long – and could help to predict what the impact of global warming might be on killer whales in future.
Dr Young added: “We’ve never really understood how so many different species survived in such close proximity then – we would expect they would out-compete or even eat each other. This seems to show that they were able to survive because they evolved to feed in different ways.
“We are now looking at why they became extinct and whether there are links between what happened to the ancient crocodiles at that time and what could happen to killer whales today as a result of climate change.”
While different types of killer whale exist in other parts of the world, until recently only one type was known to live in the waters around the UK.
In 2010, Scottish scientists in Aberdeen reported finding a second type of the marine mammal in the North Atlantic which, unlike the first, suffered virtually no wear to its teeth even in the oldest adults. Dr Andy Foote from the University of Aberdeen, who carried out the study, concluded that while the first type of killer whale sustains massive damage to its teeth because it sucks up herring and mackerel, the new type has evolved to feed differently, in order to find a new ecological niche.