Giant tortoises, new research


This video is about giant tortoises and turtles.

From the BBC:

The truth about giant tortoises

They’re big but tortoises used to be much bigger, and while they may be slow on their feet their minds may be surprisingly quick

Henry Nicholls

Reputation: Giant tortoises live on islands. They can be aged by studying growth rings on their shells, which is how we know they are the longest lived vertebrate on record. Charles Darwin found they moved a whole lot faster than he’d imagined.

Reality: Giant tortoises are a recent evolutionary innovation and used to be everywhere, not just on islands. It’s impossible to age them accurately unless you know when they hatched. They are actually pretty slow. Darwin was probably chasing them.

The largest tortoises in the world are to be found on the Seychelles in the Indian Ocean and in the Galápagos in the Pacific. But this truth has given rise to the false belief – often found in textbooks – that their large size is a product of island life. It almost certainly isn’t.

This much is evident from a cursory inspection of the fossil record. A typical Galápagos tortoise has a carapace around 100 cm long. If this is the benchmark for “giant”, it is clear that giant tortoises were not restricted to small islands. They were everywhere.

In the southern USA and Central America, for instance, there was a monster of a tortoise known as the southeastern giant tortoise (Hesperotestudo crassiscutata) that only went extinct around 12,000 years ago.

In Queensland, Australia there used to be a beast that goes by the name of Owen’s giant horned ninja turtle (Ninjemys oweni). Before you ask, yes, it was named after the ninja turtles of teenage mutant fame.

Then there was the real mother of all giants, the Siwaliks giant tortoise (Megalochelys atlas), which was tramping around what is now the Punjab in India until a few million years ago. It was around twice the size of a Galápagos tortoise.

In addition, a 1999 genetic analysis of Galápagos tortoises suggests their ancestors were probably pretty large before they left mainland South America several million years ago.

In fact, it’s been argued that being big was a necessary pre-adaption for the successful colonization of remote oceanic islands. If it finds itself in the water, a giant tortoise will bob along tolerably well, its long neck ensuring it doesn’t take on too much water.

If there used to be so many giant tortoises, where are they all now? A recent study by the International Union for Conservation of Nature indicates that giant tortoises have suffered a far higher incidence of extinction than more modestly sized tortoises and turtles.

“These slow moving and non-threatening animals required minimal effort to find,” wrote Anders Rhodin, director of the Chelonian Research Foundation and his colleagues.

Worse, giant tortoises can survive without food or water for long periods. That meant they could be stored – alive – to provide fresh meat many months down the line.

“Tortoises were, essentially, the earliest pre-industrial version of ‘canned food’,” they suggest. Early hominins opened their shells with stone-tool “can-openers”.

It is only because humans came late to the Seychelles and the Galápagos that we can still marvel at these creatures today.

In these isolated spots, giant tortoises have become reptilian representatives, their extreme longevity casting them as a living link to a lost world. But how long do they live, really?

It is often said that you can age a tortoise by counting growth rings on its shell. Unfortunately, this is only reliable for the first year or two and is useless for aging an animal that is fully grown – which for giant tortoises is at the age of around 20.

The only reliable method of aging a tortoise is to record its year of birth. In a few instances where this has been done for giant tortoises, it is clear they can live for 150 years or more.

Giant tortoises are not known for their speed. When in the Galápagos in 1835, Charles Darwin found that they moved faster than he’d imagined.

“One large one, I found by pacing, walked at the rate of 60 yards in 10 minutes, or 360 in the hour,” he wrote in his Zoology Notes. “At this pace, the animal would go four miles [6.4 km] in the day & have a short time to rest.”

More recently, researchers have been using tracking devices to record movements of Galápagos tortoises in more detail. It turns out they are not nearly so lively, most of the time making small movements around a relatively small patch.

“Our tortoises don’t usually move more than absolute max of 2 km per day,” says Stephen Blake, coordinator of the Galápagos Tortoise Movement Ecology Programme. “Darwin was probably chasing them.”

They might be slow, but they are also probably smarter than most people imagine.

Research on the South American red-footed tortoise (a not-too-distant relative of the giant tortoises in the Galápagos) shows they use landmarks to create cognitive maps of their surroundings. They can also follow the gaze of another tortoise and learn from the behaviour of others. It seems likely that giant tortoises are capable of similar cognitive feats.

3.3-million-year-old stone tools discovery in Kenya


This video says about itself:

3.3-Million-Year-Old Stone Tools Found in Kenya

30 April 2015

Archaeologists find stone tools used by early human ancestors in Kenya that predate the oldest known tools found in Ethiopia by some 700,000 years.

From daily The Guardian in Britain:

Stone tool discovery pushes back dawn of culture by 700,000 years

Finding overturns idea that tool-making ability was unique to our own ancestors and is hailed as a “new beginning to the known archaeological record”

Hannah Devlin, science correspondent

Wednesday 20 May 2015 18.00 BST

The oldest known stone tools, dating to long before the emergence of modern humans, have been discovered in Africa.

The roughly-hewn stones, which are around 3.3 million years old, have been hailed by scientists as a “new beginning to the known archaeological record” and push back the dawn of culture by 700,000 years.

The discovery overturns the mainstream view that the ability to make stone tools was unique to our own ancestors and that it was one of a handful of traits that made early humans so special.

The new artefacts, found in Kenya’s Turkana basin, suggest that a variety [of] ancient apes were making similar advances in parallel across the African continent.

“It just rewrites the book on a lot of things that we thought were true,” said Chris Lepre, a geologist at the Lamont-Doherty Earth Observatory and Rutgers University, who precisely dated the tools.

The Homo genus, from which modern humans descend, only emerged around 2.5 million years ago, when forests gave way to open grassland environments in Africa. Until now, it was widely assumed that environmental changes around this time triggered the shift towards a bipedal hunter-gatherer life style.

Jason Lewis, of Stony Brook University in New York and a co-author, said: “The idea was that our lineage alone took the cognitive leap of hitting stones together to strike off sharp flakes and that this was the foundation of our evolutionary success. This discovery challenges the idea that the main characters that make us human, such as making stone tools, eating more meat, maybe using language, all evolved at once in a punctuated way, near the origins of the genus Homo.”

The question of what, or whom, might have made the tools remains a mystery, but fossils from around the same period found at the site provide some clues.

The skull of a 3.3-million-year-old hominin, Kenyanthropus platytops [sic; K. platyops] , was found in 1999 about a kilometre from the tool site and a skull fragment and tooth from the same species were found just a few hundred metres away.

Other species from the same era include Australopithecus afarensis, which the famous Lucy fossil belongs to.

Professor Fred Spoor, a palaeontologist at University College London and part of the team that discovered K. platytops [sic; platyops], said the tools were “a very important find”. “Until now the thinking’s been that if you want to be part of this special club ‘Homo’, you need to be a tool-maker,” he said. “The period before three million years ago was seen as a rather boring period of evolution, but now we know there was stuff happening.”

Until now, hominins such as Australopithecus, from the earlier time period have been caricatured as “upright, bipedal chimpanzees that were just grazing the landscape with not much else going on,” he added.

To the untrained eye, the tools look unremarkable – barely distinguishable from ordinary rocks. But to scientists familiar with early humans, the hallmarks of tool-making were obvious. “I could immediately see the scars and features characteristic of a knapped stone,” said Sonia Harmand, of Stony Brook, who made the discovery.

Professor Spoor and others who have examined the collection of tools have been impressed by the quality of the evidence.

“This is a momentous and well-researched discovery,” said paleoanthropologist Bernard Wood of George Washington University, who was not involved in the study. “I have seen some of these artefacts in the flesh, and I am convinced they were fashioned deliberately.”

The collection of several dozen tools appears to have been made by two different techniques. In one case, a core stone was held on an anvil and hit from above with a hammer stone to chip off sharp flakes, which the scientists believe could have been used to slice meat and plants. Other stones appear to have been held in two hands and struck against the anvil, again producing slices of stone.

Although the end results appear primitive, they demonstrate a degree of mental sophistication that is unexpected for such early hominins. Modern chimpanzees use natural stones as “tools” to crack nuts, for instance, but they stop short of actively fashioning their own tools.

The researchers relied on a layer of volcanic ash below the tools, which matched ash elsewhere that had been dated to 3.3 million years ago, to set a “floor” on the site’s age. The date was then refined by analysing magnetic minerals at the site, which contain a record of the Earth’s periodically switching magnetic field.

The findings are published today in the journal Nature.

See also here.

Amber discovery on Texel island beach


Amber, found on Texel beach by photographer Sytske Dijksen

Translated from Ecomare museum on Texel island in the Netherlands:

Ecomare on Thursday, April 30th, 2015

It is the dream of every beach walker: to find amber. Photographer Sytske Dijksen recently found dozens of pieces of amber on the southernmost point of the Hors peninsula on Texel. Amber is a precious gemstone. It is fossilized and petrified resin. There are a few other “stones” very similar to amber; both originated from resin. But those are not fossil and petrified. Most of the bits of ‘amber’ found in the Netherlands turn out to be not real. In this case, they are!

Real fossil

Amber is old. The pieces of amber that you find in the Netherlands come from the Baltic region and date back to the Eocene epoch, 35 million years ago. Then there were vast coniferous forests. The pine species delivering amber of the highest quality which people prefer to find, Pinus succinifera, is extinct now. The most spectacular amber finds also include insects, spiders or plant residues.

Dinosaur with feathers and bat-like wings discovered


This video says about itself:

A new dinosaur: Flying without feathers

29 April 2015

Birds evolved from dinosaurs – but it wasn’t a smooth transition. Plenty of creatures tried different ways to get into the air – like this newly discovered dinosaur species, Yi qi, unearthed in China. This pigeon-sized creature had elongated fingers that held a membrane wing, more like a bat than a bird. In this Nature Video, we look at what makes this fossil so special, and consider what this dinosaur may have looked like.

From daily The Guardian in Britain:

Is it a bird? Is it a bat? Meet Yi qi, the dinosaur that is sort of both

Incredible new find from China has both feathers and bat-like wings

Dr Dave Hone

Wednesday 29 April 2015 18.01 BST

Researchers today announced the discovery of a stunning new dinosaur fossil: a glider with wings similar to both birds and bats. It has been named Yi qi (meaning ‘strange wing’) and is a small feathered dinosaur from the Middle Jurassic age fossil beds of China that have yielded a host of important fossils in recent years. Yi qi, like so many other small dinosaurs, is preserved with a full coating of feathers and was a close relative of the lineage that ultimately gave rise to birds.

However, what sets this animal apart from numerous other dinosaurian gliders and proto-birds is the composition of its wings. In addition to some unusual feathers that are positioned on the long arms and fingers, there is a truly gigantic bone on each wrist that extends backwards, and between this bone and the fingers is preserved a membrane-like soft tissue that would have given the animal something of a wing, like that of bats.

Yi qi is not a direct ancestor of birds, and more particularly has nothing to do with the origins of the mammalian bats, but its wings are an excellent example of convergent evolution. At various times a great many animals have evolved a similar arrangement of a large bone in the wrist or hand and a supporting membrane, most obviously in numerous gliding mammal lineages. In addition to the bats that are capable of active powered flight, various passive gliders like flying squirrels, sugar gliders and the so-called “flying lemurs” have all independently evolved some extension that that helps to support a membranous wing. At some level then, this is a quite common feature, but it is a real shock to see it in such a dinosaur.

Professor Xu Xing, lead author of the study from the Institute of Vertebrate Paleontology and Paleoanthropology, Beijing said “It definitely evolved a wing that is unique in the context of the transition from dinosaurs to birds.”

There are a number of feathered dinosaurs close to the origins of birds that are thought to have been some form of glider. All were small and light and had extensive feathers that would have formed the flight surface and allowed them to move effectively through the air. Yi qi is from a very odd group of small dinosaurs called scansoriopterygids, who are known from only two other specimens and little is known about their biology or lifestyle, so there is not much to go on. However, it is clearly remarkable that such an animal that had numerous other relatives with large feathers on their arms and would apparently “experiment” with different forms of flight at various times (not least ultimately producing birds) would take such a dramatically different route towards gliding, even if it was one commonly explored by other [sic] mammals.

The evolutionary implications are therefore quite incredible. There have already been suggestions that perhaps powered flight evolved multiple times in the dinosaurs and early birds, with perhaps several different groups making the final jump from gliding to a more active form of movement in the air. Given how few and far between the scansoriopterygids are as fossils, this implies that they never really got going as a group – certainly they are much more restricted in both time and space than their near relatives, so at first approximation the bat-bird combination of Yi qi did not lead to a major new radiation of dinosaurs.

However, quite how the animal may have flown is most unclear. The incomplete preservation of the wings and the uncertain position of the long wrist bone means that it could have had a very broad wing or a narrow one, and the flattened nature of the skeleton makes it hard to tell if this animal might have had the muscles and joints needed for powered flight. Professor Xu notes that “We don’t know if Yi qi was flapping, or gliding, or both”, but it does seem clear that the small size of the animal and large surface area of the wings and feathers would have permitted some form of aerial locomotion.

Dr Mike Habib of the University of Southern California, who was not involved in the study, said “All told, this is an unexpected, exciting specimen that changes our views on the evolution of flight in dinosaurs. It appears that multiple types of wing surfaces evolved within the relatives of birds, making the origins of avian flight potentially more complicated than previously thought.” That alone makes the origins of birds, already an area of intense study, a little more complicated and rather intriguing. The pathway to both birds and powered flight from small feathered dinosaurs, though with a few bumps and oddities on the way shows a relatively consistent progression but Yi qi adds a new twist with one evolutionary branch taking a dramatically different route into the air.

Xu et al., 2015. A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings. Nature. DOI: 10.1038

Vegetarian Tyrannosaurus rex relative discovery in Chile


A reconstruction of the skeleton and external appearance of Chilesaurus. Paleontologists have labelled it “a truly odd mix”. Illustration: Gabriel Lío

From daily The Guardian in Britain:

‘Bizarre’ Jurassic dinosaur discovered in remarkable new find

Chilesaurus diegosuarezi was related to Tyrannosaurus rex, but was vegetarian and has other curious features

Ian Sample, science editor

Monday 27 April 2015 16.25 BST

Fossil hunters in Chile have unearthed the remains of a bizarre Jurassic dinosaur that combined a curious mixture of features from different prehistoric animals.

The evolutionary muddle of a beast grew to the size of a small horse and was the most abundant animal to be found 145 million years ago, in what is now the Aysén region of Patagonia.

The discovery ranks as one of the most remarkable dinosaur finds of the past 20 years, and promises to cause plenty of headaches for paleontologists hoping to place the animal in the dinosaur family tree.

“I don’t know how the evolution of dinosaurs produced this kind of animal, what kind of ecological pressures must have been at work,” said Fernando Novas at the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires.

“What’s surprising is that in this locality the most bizarre dinosaur is not the exception, but the rule. It is the most abundant animal we find,” he added.

The first fossilised bones of the beast were discovered in 2004 when a Chilean couple, who are geologists, were studying rocks in the Andes to understand how the mountain range formed. The couple’s son, Diego, was playing nearby when he found a fossilised bone that turned out to belong to the new species.

The discovery prompted the geologists, Manuel Suarez and Rita de la Cruz, to team up with Novas and other scientists and return to the site, called Black Hill, in a breathtaking rocky expanse near General Carrera Lake in southern Chile.

On returning to the site, the researchers found bones from at least a dozen of the strange animals, including four nearly complete and well-preserved skeletons. The skeletons showed that the weird mix of head, neck, shoulder, rib, pelvis, leg and tail bones all belonged to the same creature.

Named Chilesaurus diegosuarezi after 7-year-old Diego, the animal belongs to the theropod group of dinosaurs, which includes the carnivorous tyrannosaurs and velociraptors. But unlike its meat-eating cousins, Chilesaurus had switched diets and become a vegetarian. Meat eaters tend to have sharp teeth and large heads supported by thick necks. Chilesaurus had a horny beak, flatter teeth for chomping plants, a small head and slender neck. “It’s a theropod that turned vegetarian,” said Novas. Details are published in the journal Nature.

Other anatomical peculiarities have surprised paleontologists. Its forelimbs were stocky, like an allosaurus, and instead of sharp claws, it sported two stumpy fingers. Most of the Chilesaurus remains belonged to juveniles, no larger than turkeys, but the team found bones from adults too that suggest the animals reached 3 metres from snout to tail when fully grown.

The remains of the animals were found alongside bones of small prehistoric crocodiles and huge herbivorous cousins of diplodocus. The researchers hope to return to the site next year to uncover more bones, including those of the predators that must have stalked the land long before the Andes had formed.

The curious form of Chilesaurus is an extreme example of mosaic convergent evolution, where different parts of an animal adapt to the environment along the same path taken by other creatures.

Paul Barrett, a dinosaur researcher at the Natural History Museum in London said Chilesaurus ranks as one of the most interesting dinosaur discoveries of the past 20 years.

“It has an unbelievably weird mixture of anatomical features. If you found isolated bones from this one animal in different places you’d probably conclude that the bones came from completely different dinosaur groups, rather than representing one unusual species,” he said.

“Some of the bones look like they belong to an early theropod, others like they belong to a group of weird plant-eating theropods called therizinosauroids and yet others look like they belong to a completely different dinosaur group, the prosauropods. A truly odd mix.”

“It shows that dinosaurs were experimenting with a wide range of body types and that some unexpected features like a vegetarian diet turned up independently again and again in the ‘predatory’ theropod dinosaurs.”

“Its relationships to other dinosaurs are really tricky to pin down because of this mix of features and it wouldn’t surprise me if its position in the dinosaur evolutionary tree changes regularly as more people see the material,” he said.

See also here.

Dinosaurs, humans, sun and earth, medieval religious dogmas in Spain


This video says about itself:

Dinosaurs, and Creationism Debunked

1 March 2015

To believe that non-avian dinosaurs exist today or have ever existed with mankind is to show the highest level of ignorance in history, archaeology, and paleontology. This is my debunking of a creationist video that says dinosaurs once existed with man and that there is evidence for this in history.

From daily The Independent in Britain today:

One in three Spaniards thinks humans lived at the same time as dinosaurs

Today in worrying news, 30 per cent of people in Spain think humans lived at the same time as dinosaurs.

A government-backed study also showed 25 per cent of respondents think the Sun orbits the Earth.

One positive to take from the Social Perception of Science study, from Spain’s Foundation for Science and Technology, is that at least scientific knowledge is improving in the country – in 2006 the proportion of people believing the previous two incorrect assertions was 50 per cent for dinosaurs and 40 per cent for the Sun.

Overall, nine years ago people answered 58 per cent of questions correctly, while now the ratio is 70 per cent.

This video says about itself:

Testing Geocentrism

15 November 2012

… a series on geocentrism, these videos take a wry look at the subject and how it stacks up against basic observations. This part [1] looks at whether the geocentrist explanation of the seasons holds any merit, why Polaris doesn’t move and how basic observations of the inner and outer planets hold up to the ideas of the geocentrist. A simple introduction is given to relevant concepts, providing topic pointers for the viewer who wants to find out more for themselves.

Subtitles: English
Guidance: Contains some mild language within a comedy context.

* I noticed after completing this video that the introduction should have said “Over two thousand years after Aristarchus” not “Nearly one thousand”.

Hundreds of dinosaur footprints discovered in Canada


This video says about itself:

Dinosaur Discovery GalleryTumbler Ridge, British Columbia

21 April 2015

The gallery contains displays primarily focused on interpreting regional vertebrate palaeontology including material from B.C.’s two dinosaur excavations. There are also displays on dinosaur and other vertebrate tracks and traces which make up the vast majority of the terrestrial vertebrate record of western Canada. One of British Columbia’s best-kept secrets is the massive fossil record of Triassic marine fish and reptiles from this region. Our volunteers and scientists have collaborated to bring together an impressive and rapidly growing collection of specimens for ongoing scientific research and public interpretation here in the gallery.

Our recently expanded Dinosaur Discovery Gallery contains several new and enhanced palaeontology exhibits including a full-scale re-creation of a 100 million-year-old dinosaur track environment. An interactive theatre provides several presentation options for visitors to view and learn about the pre-history of the Peace Region of British Columbia.

From the Canadian Press:

B.C. dinosaur path tracks heyday of prehistoric beasts

Discovered dinosaur path 115 million years old

Sunday, April 26, 2015 1:00 am

Dirk Meissner

VICTORIA – A type of dinosaur Autobahn, with a riot of ancient footprints that are likely more than 100 million years old, has been discovered in northeastern British Columbia.

Hundreds of prints from extinct carnivores and herbivores are pressed into the flat, rocky surface spanning an area the size of three Canadian football fields, indicating the site was a major dinosaur thoroughfare.

Many of the three-toed prints at the site — located near Williston Lake about 1,500 kilometres northeast of Vancouver — closely resemble the Toronto Raptors logo.

“From what I saw there is at least a score or more of trackways, so 20-plus trackways of different animals,” said paleontologist Rich McCrea.

“We’re looking at a few hundred foot prints that were exposed when I visited the site. If it keeps up that density and we are able to peel back a bit of the surface and expand it by another 1,000 square metres we’re likely to find there are thousands of foot prints.”

McCrea is the curator of the Peace Region Paleontology Research Centre in Tumbler Ridge, B.C. He believes the dinosaur path has major potential as a world-class scientific and tourism site, but said he’s concerned the B.C. government’s approach to protecting and promoting dinosaur zones is somewhat prehistoric.

“It would be one of the top sites, unquestionably,” said McCrea, who’s part of a local crowdfunding campaign to raise $190,000 to research and promote the dinosaur track site. “It already looks like it’s going to be one of the biggest sites in Canada. That also means one of the biggest sites in the world.”

He said his visits to the secret site indicate the area was a major travel zone for the Allosaurus, a Jurassic Park look-alike, 8.5-metre-long, two-legged predator with a huge head and rows of teeth.

McCrea said the area is also ripe with tracks made by the Anklosaurus [sic; Ankylosaurus], a four-legged, nine-metre-long herbivore, that weighed almost 6,000 kilograms and was known for its distinctive armour-plated head and long, club-like tail.

He estimated those tracks are between 115 million and 117 million years old.

“This was still in the dinosaurs’ heyday,” said McCrea. “It’s kind of like the middle age of dinosaurs.”

He said he wants the area protected by the B.C. government, and he’s part of a pitch to create a Peace Country dinosaur tourist zone that rivals Alberta’s Royal Tyrrell Museum at Drumheller. McCrea envisions dinosaur tours to Tumbler Ridge, Williston Lake and the Philip J. Currie Dinosaur Museum in nearby Wembley, Alta.

Last fall, Tumbler Ridge was designated as a UNESCO global geopark that recognizes geological heritage. The community converted a school into a dinosaur museum and repository for the dinosaurs fossils discovered in the area.

McCrea said he wants to see a tourist building overlooking the dinosaur trackway area at Williston Lake. A similar concept at China’s Zigong Dinosaur Museum attracts seven million people a year, he said.

Tumbler Ridge Liberal MLA Mike Bernier said he’s been trying to convince cabinet ministers that the area is an important asset and needs heritage and fossil protection policies.

“People go crazy when they see dinosaur bones and fossils. There’s something about it: the old Jurassic Park movie coming to life in your riding,” he said.

Bernier said he’s reviewing heritage protection laws from across North America and plans to submit a proposal to government this year.

B.C. Forests, Lands and Natural Resource Operations Minister Steve Thomson, whose ministry covers fossil protection, said he’s seen the Tumbler Ridge dinosaur site and has met with Bernier on strengthening the province’s fossil management.

Five years ago the government protected the world-renowned McAbee fossil beds near Cache Creek in B.C.’s Interior from professional fossil hunters and others who were mining the area for cat litter.

“We are looking at what legislative adjustments might be needed to be put in place,” said Thomson.

McCrea said Alberta and others have protected and profit from their fossil heritage, while B.C. remains behind the times.

“We’re missing out on all the opportunities, not just tourism and education, but also, how about just pride that the province itself is the custodian of all its natural resources,” he said.