Tyrannosaur family various species, video


This video says about itself:

Tyrannosaur family species comparison

13 August 2018

Welcome to the second round of the new dinosaur comparison videos. In this comparison video, we shall compare the different Tyrannosaurus family species or also known as Tyrannosaurids.

These dinosaurs have a strong jaw and are among the largest terrestrial predators to have existed in the world.

Tyrannosaurus rex, T-rex, is one of the largest land predators to have ever existed while Tarbosaurus is also on the top ten list along with others like Albertosaurus, Gorgosaurus, Daspletosaurus, Zhuchengtyrannus, Qianzhousaurus etc.

There are 11 tyrannosaurids that have been confirmed from fossils and these tyrannosaurus species differ in size and comparison so much that the smallest of them weighs less than one tonne and the largest weighs more than 10 tonnes.

The smallest tyrannosaurid measures only 5-6 meters in length while the largest measures more than 12-13 meters in length. These tyrannosaurus species all have one thing in common, the noticeable strong and rounded skull.

In this video of the Tyrannosaurus family species comparison, we shall take a more detailed look at the 11 tyrannosaurids, their size, where and when they existed.

So enjoy this video on Tyrannosaurus family species comparison.

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Megalodon sharks, film fiction and reality


This video is called The Meg, Official Trailer #1 (2018). Jason Statham, Ruby Rose: Megalodon Shark Movie HD.

By Carolyn Gramling, 12:41pm, August 10, 2018:

What ‘The Meg’ gets wrong — and right — about megalodon sharks

A paleobiologist helps Science News separate fact from fiction in the film

OK, so what if a giant prehistoric shark, thought to be extinct for about 2.5 million years, is actually still lurking in the depths of the ocean? That’s the premise of the new flick The Meg, which opens August 10 and pits massive Carcharocles megalodon against a grizzled and fearless deep-sea rescue diver, played by Jason Statham, and a handful of resourceful scientists.

The protagonists discover the sharks in a deep oceanic trench about 300 kilometers off the coast of China — a trench, the film suggests, that extends down more than 11,000 meters below the ocean surface. (That depth makes it even deeper than the Mariana Trench’s Challenger Deep, the actual deepest known point in the ocean). Hydrothermal vents down in the trench supposedly keep those dark waters warm enough to support an ecosystem teeming with life. And — spoiler alert!—   of course, the scientists’ investigation inadvertently helps megalodons escape from the depths. The giant living fossils head to the surface, where they terrorize shark fishermen and beachgoers a la Jaws.

But could a population of megalodons actually have survived down there? To explore what is and isn’t possible and what we still don’t know about sharks, Science News went to the movies with paleobiologist Meghan Balk of the Smithsonian’s National Museum of Natural History in Washington, D.C., who studies the ancient predators.

Did megalodons ever actually get as big as they are in the movie? Extremely unlikely

The megalodon sharks of The Meg reach sizes of about 20 to 25 meters long, the film says — massive although just a tad smaller than the longest known blue whales. But estimates based on the size of fossil teeth suggest that even the largest known C. megalodon was much smaller, at up to 18 meters — “and that was the absolute largest”, Balk says. On average, C. megalodon tended to be around 10 meters long, she says, which still made them much bigger than the average great white shark, at around 5 to 6 meters long.

Would a megalodon otherwise look like the film version? Yes and no

The movie’s sharks aren’t entirely inaccurate representations, Balk says. These megalodons correctly have six gills — between five and seven is accurate for sharks in general, she says. And the shape of the dorsal fin is, appropriately, modeled after the great white shark, the closest modern relative to the ancient sharks. Also, a male meg in the film even has “claspers”, appendages under the abdomen used to hold a female during mating. “When I looked at it, I was like, oh, they did a pretty good job. They didn’t just create a random shark”, Balk says.

On the other hand, it’s actually a bit odd that the movie’s megalodons wouldn’t have evolved some significant anatomical differences from their prehistoric brethren, Balk says. “Like the eye getting bigger” to see better or becoming blind after a few million or so years living in the darkness of the deep sea, she says. Or you might even expect dwarfism, in which populations restricted by geographic isolation, such as being stuck within a trench, shrink in size.

Would such huge sharks have had enough to eat down there? Extremely unlikely

In general, “there’s just not enough energy in the deep sea” to sustain giant sharks, Balk says. Life does bloom at hydrothermal vents, although the deepest known hydrothermal vents are only about 5,000 meters deep. But even if there were vents in the deepest trenches, it’s not clear there would be enough big species living down there to sustain not just one, but a whole population of massive sharks. In the film, the vent field is populated with many smaller species known to cluster around hydrothermal vents, including shrimps, snails and tube worms. Viewers also see one giant squid, but there would have had to be a whole lot more food of that size. C. megalodon — like modern great whites — ate many different things, from orcas to squid. And the humongous megalodon sharks in the movie “would have eaten a lot of squid”, Balk says, laughing.

Could sharks live at such depths? Unlikely

How deep sharks can live in the ocean is actually still a big unknown (SN Online: 5/7/18). “Quantifying the depth that sharks go to is a big endeavor right now”, Balk says. Few sharks are known to inhabit the abyssal regions of the ocean below about 4,000 meters — let alone the depths of oceanic trenches lying below 6,000 meters. Aside from the scarcity of food, temperature is another limitation to deep-sea living.

Sharks that do inhabit deeper parts of the ocean, such as goblin sharks and the Greenland shark (SN 9/17/16, p. 13), tend to have low metabolic rates. That means they move much more slowly than the energetic predators of the movie, Balk says. C. megalodon, although it lived around the globe, tended to prefer warmer, shallower waters and used coastal regions as nursing grounds.

So, could megalodons have survived to modern times without humans knowing about it? Extremely unlikely

Sharks shed a lot of teeth throughout their lives, and those teeth are the main fossil evidence of the life and times of prehistoric sharks (SN Online: 8/2/18). Fossilized C. megalodon teeth found in sediments around the world suggest that the creatures lived between about 14 million and 2.6 million years ago — or perhaps up until 1.5 million years ago at the latest, Balk says. It’s not clear why they went extinct. But there are a handful of hypotheses: competition for food with other creatures like orcas; ocean circulation changes about 3 million years ago when the Isthmus of Panama formed (SN: 9/17/16, p. 12); nearshore nursery sites vanished; or possibly a loss of prey sources stemming from a marine mammal extinction about 2.6 million years ago.

Bottom line: The sheer abundance of shed teeth — as many as 20,000 per shark in its lifetime  — is one of the strongest arguments against megalodon surviving into modern times, Balk says. “That’s one of the reasons why we know megalodon’s definitely extinct. We would have found a tooth.”

“The Meg”, Warner Bros.’ big-budget shark flick, took $44.5 million at the domestic box office on its opening weekend — jumping into the No. 1 spot.

Homo erectus, extinct by laziness?


This 2016 video is called HD Documentary: Becoming Human, Episode 2, Birth of Humanity (Homo Erectus).

From Australian National University:

Laziness helped lead to extinction of Homo erectus

August 10, 2018

New archaeological research from The Australian National University (ANU) has found that Homo erectus, an extinct species of primitive humans, went extinct in part because they were ‘lazy’.

An archaeological excavation of ancient human populations in the Arabian Peninsula during the Early Stone Age, found that Homo erectus used ‘least-effort strategies’ for tool making and collecting resources.

This ‘laziness’ paired with an inability to adapt to a changing climate likely played a role in the species going extinct, according to lead researcher Dr Ceri Shipton of the ANU School of Culture, History and Language.

“They really don’t seem to have been pushing themselves”, Dr Shipton said.

“I don’t get the sense they were explorers looking over the horizon. They didn’t have that same sense of wonder that we have.”

Dr Shipton said this was evident in the way the species made their stone tools and collected resources.

“To make their stone tools they would use whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used”, he said.

“At the site we looked at there was a big rocky outcrop of quality stone just a short distance away up a small hill.

“But rather than walk up the hill they would just use whatever bits had rolled down and were lying at the bottom.

“When we looked at the rocky outcrop there were no signs of any activity, no artefacts and no quarrying of the stone.

“They knew it was there, but because they had enough adequate resources they seem to have thought, ‘why bother?’.”

This is in contrast to the stone tool makers of later periods, including early Homo sapiens and Neanderthals, who were climbing mountains to find good quality stone and transporting it over long distances.

Dr Shipton said a failure to progress technologically, as their environment dried out into a desert, also contributed to the population’s demise.

“Not only were they lazy, but they were also very conservative”, Dr Shipton said.

“The sediment samples showed the environment around them was changing, but they were doing the exact same things with their tools.

“There was no progression at all, and their tools are never very far from these now dry river beds. I think in the end the environment just got too dry for them.”

The excavation and survey work was undertaken in 2014 at the site of Saffaqah near Dawadmi in central Saudi Arabia.

Coral reefs since the age of dinosaurs


This May 2018 video says about itself:

The Coral Reef: 10 Hours of Relaxing Oceanscapes | BBC Earth

Sit back, relax and enjoy the colourful world of coral reefs as we take you on a journey through some of the most vibrant parts of our blue planet with this 10 hour loop.

From Penn State university in the USA:

Diverse symbionts of reef corals have endured since ‘age of dinosaurs

August 9, 2018

Coral-algal partnerships have endured numerous climate change events in their long history, and at least some are likely to survive modern-day global warming as well, suggests an international team of scientists.

The team’s conclusion is based on the finding that the relationship between corals and the mutualistic micro-algae that enable them to build reefs is considerably older and more diverse than previously assumed.

“Past estimates placed the initiation of these symbiotic relationships at 50 to 65 million years ago“, said Todd LaJeunesse, associate professor of biology, Penn State. “Our research indicates that modern corals and their algal partners have been entwined with each other for much longer — since the time of the dinosaurs, approximately 160 million years ago. During their long existence, they have faced severe episodes of environmental change, but have managed to bounce back after each one.”

According to LaJeunesse, the micro-algae, commonly called zooxanthellae — of the dinoflagellate family Symbiodiniaceae — live inside the cells of corals, allowing them to acquire energy from sunlight and to build the massive, economically valuable reef formations upon which countless marine organisms rely for habitat.

“The fossil record shows that today’s reef-building corals exploded in diversity around 160 million years ago,” said LaJeunesse. “Finding that the origin of the algal symbionts corresponds to major increases in the abundance and diversity of reef-building corals implies that the partnership with Symbiodiniaceae was one of the major reasons for the success of modern corals.”

The team used genetic evidence — including DNA sequences, phylogenetic analyses and genome comparisons — to calculate the micro-algae’s approximate age of origin. They also used classical morphological techniques in which they compared visual characteristics of these symbionts using light and electron microscopy, along with computer modeling and other methods, to discover that in addition to being older, the algae family is far more diverse than previously perceived. The results appear online today (Aug. 9) in Current Biology.

“Presently, numerous algal lineages, called clades, are lumped into just one genus”, said John Parkinson, postdoctoral researcher, Oregon State University. “Using genetic techniques, we provide evidence that the family actually comprises at least 15 genera, including hundreds and possibly thousands of species worldwide.”

This is important, he explained, because some micro-algal symbionts have characteristics that make them more resilient to changes in the environment than other symbionts.

“The updated naming scheme offers a clear framework to identify different symbionts”, said Parkinson. “Accurate taxonomy (the identification and naming of species) is a critical step in any biological research. This is especially true for studies attempting to understand how the partnership between reef corals and their micro-algae, which are needed for survival and growth, may adapt to climate change. For example, when many corals are exposed to high temperatures they lose their symbiotic algae and die. Others are far more tolerant of heat, and some of this resilience is based on the species of algae they have.”

Parkinson noted that the team has been working for close to a decade to modernize coral symbiont taxonomy in order to improve communication among scientists and advance future research on reef corals.

“Until now, studies on the physiology and ecology of these algae attempted to compare apples to apples”, said Parkinson. “Considering how different some of them are, we now recognize that often we were comparing apples to oranges. These changes will help researchers to think more accurately about the comparisons they are making in experiments.”

Dinosaur age birds, video


This 7 August 2018 video says about itself:

When Birds Had Teeth

Experts are still arguing over whether Archaeopteryx was a true bird, or a paravian dinosaur, or some other kind of dino. But regardless of what side you’re on, how did this fascinating, bird-like animal relate to today’s birds? It turns out its teeth were a clue that this story goes all the way back to what we now call the non-avian dinosaurs.

Thanks to Ceri Thomas for the excellent Longipteryx reconstruction.

Silurian fossil worm discovery


This 30 January 2017 video says about itself:

500-million year-old species offers insights into the lives of ancient legged worms

A new species of lobopodian, a worm-like animal with soft legs from the Cambrian period (541 to 485 million years ago), has been described for the first time from fossils found in the Burgess Shale in the Canadian Rocky Mountains. Details of the new species, called Ovatiovermis cribratus, are being published in the open access journal BMC Evolutionary Biology this week.

Read more here.

From the University of Oxford in England:

New species of rare ancient ‘worm’ discovered in fossil hotspot

August 8, 2018

Scientists have discovered a new species of lobopodian, an ancient relative of modern-day velvet worms, in 430 million-years-old Silurian rocks in Herefordshire, UK.

The team, comprising researchers from the universities of Oxford, Yale, Leicester and Manchester, and Imperial College London, has been able to three-dimensionally reconstruct the exceptionally well-preserved fossil using digital technology.

The research is reported in the Royal Society journal Open Science.

First author Derek Siveter, Professor Emeritus of Earth Sciences at Oxford University and Honorary Research Associate at Oxford University Museum of Natural History, said: ‘Lobopodians are extremely rare in the fossil record, except in the Cambrian Period. Worm-like creatures with legs, they are an ancestral marine relative of modern-day velvet worms, or onychophorans — predators that live in vegetation, mainly in southern latitudes.

‘This new lobopodian, which we have named Thanahita distos, was discovered during fieldwork in an area of Silurian rocks in Herefordshire. It is the first lobopodian to be formally described from rocks of Silurian age worldwide; exceptionally, it is fully three-dimensionally preserved, and it represents one of only eight known three-dimensionally preserved lobopodian or onychophoran fossil specimens.

‘We have been able to digitally reconstruct the creature using a technique called physical-optical tomography. This involves taking images of the fossil at a fraction of a millimetre apart, then “stitching” together the images to form a “virtual fossil” that can be investigated on screen.’

Professor Siveter and colleagues have been carrying out fieldwork in Herefordshire since the mid-1990s. The sedimentary deposit in which it was discovered has since become known as the Herefordshire Lagerstätte, the term Lagerstätte indicating that it contains exceptionally preserved fossilised remains of soft-bodied animals. The fossils were deposited 430 million years ago within a marine basin that extended across what is now central England into Wales, and they are preserved in nodules in a soft, cream-colored volcanic ash mixed with marine sediment.

Professor Siveter said: ‘Thanahita distos and the other animals that became fossilised here likely lived 100 to 200 meters down, possibly below the depth to which much light penetrates. We deduce this because we found no vestiges of photosynthetic algae, which are common in contemporaneous rocks laid down at shallower points on the seafloor to the east.

‘Some special circumstances allowed for their remarkable preservation. The first was the immediate precipitation of clay minerals around the dead organisms, which decayed over time, leaving empty spaces behind. The mineral calcite — a form of calcium carbonate — then filled these natural moulds, replicating the shape of the animals. Almost at the same time, hard concretions began to form, being cemented by calcite. Thanks to the early hardening of these Silurian time capsules in this way, the fossils were not squashed as the ash layer slowly compacted.’

He added: ‘Some lobopodians lie in a position on the tree of life which foreshadows that of the terrestrial velvet worms, while others are precursors of the arthropods: the “king crabs”, spiders, crustaceans and related forms. Since its discovery, the Herefordshire Lagerstätte has yielded a diversity of arthropods that have contributed much to our understanding of the palaeobiology and early history of this very important invertebrate group. The lobopodian Thanahita distos belongs to an extended, panarthropod grouping.

‘Further, morphological analysis places it within a lobopodian group that typifies an earlier period of geological time in the Cambrian — about 520 to 510 million years ago — thus indicating the survival of this group over some 100 million years.’

New extinct mammals atlas


The blue color shows the range of brown bears today. The red color shows where you would also find brown bears today, had they not been driven away by human activity. Credit: Soeren Faurby, University of Gothenburg

The blue color on this map shows the range of brown bears today. The red color shows where you would also find brown bears today, had they not been driven away by human activity.

From Aarhus University in Denmark:

For the first time, scientists are putting extinct mammals on the map

August 8, 2018

Summary: Researchers have produced the most comprehensive family tree and atlas of mammals to date, connecting all living and recently extinct mammal species (nearly 6,000 in total) and overturning many previous ideas about global patterns of biodiversity. The atlas shows where species occur today as well as where they would occur, if they had not been driven away or extinct.

Researchers from Aarhus University and University of Gothenburg have produced the most comprehensive family tree and atlas of mammals to date, connecting all living and recently extinct mammal species — nearly 6,000 in total — and overturning many previous ideas about global patterns of biodiversity.

While others have tried to map the ranges of all mammals or figure out their family tree, previous studies always left out one crucial group of mammals: species driven to extinction by humans.

“This is the first time we’ve been able to comprehensively include extinct species like the Tasmanian tiger or the woolly mammoth as well as account for human-induced regional range losses among extant species in such a large database, and it’s really changing our beliefs about what is ‘natural’ or not”, said biologist Søren Faurby of the University of Gothenburg in Sweden, who co-led the assembly of the database and the study, which was recently published in the scientific magasine Ecology.

Scientist often use maps of mammal species ranges to investigate patterns of biodiversity or to predict how climate change will affect species. But these maps are incomplete because they don’t show species’ natural ranges, only where they occur today. Many species have had their ranges drastically reduced by humans, for instance, through overhunting and habitat destruction.

Brown bears may be emblematic of Alaska or Russia today but their range used to stretch all the way from Mexico to Northern Africa before widespread hunting by humans. If we want to predict how a warming climate will affect these bears, we can’t leave out these natural areas of their range”, said Faurby.

Tasmanian tigers and mammoths back on the map

It is also important to include species that have been totally exterminated.

“If we are studying global patterns of biodiversity, we really need to start considering species like the Tasmanian tiger that was hunted to extinction less than 100 years ago, a mere eye blink in geological time”, said paleontologist and co-leader Matt Davis of Aarhus University in Denmark.

We associate large mammals like elephants and lions with Africa today, but for most of the last 30 million years, big animals roamed all over the Earth. It was only relatively recently that humans drove many of these large mammals extinct, leaving a world depauperate of giants.

“Even a species like the woolly mammoth, that we think of as prehistoric, lived up to the time the Great Pyramid was being built“, Davis said.

Old maps and new algorithms

Assembling a database that included every species of mammal was no easy task. It took the research team, headquartered at Aarhus University, months just to stitch together existing datasets and fill in missing holes in the data.

They then poured over old maps and checked museum records to see where species natural ranges might be without the interference of modern humans.

Adding extinct species to the mammal family tree and making modern ranges for them was even harder. The scientists combined DNA evidence and data from fossil dig sites around the world with a powerful new computer algorithm to predict where extinct species fit in with mammals that are alive today.

New baselines for restoration

“This comprehensive database has already provided much needed evidence to inform restoration baselines and to provide re-assessments of several hotly debated ideas in biology, but this is just the beginning” said Jens-Christian Svenning, professor at Aarhus University and leader of the Aarhus team.

He expects that other researchers, conservationists, and educators will also find the easy to use and publicly available database valuable.

“We are already using the database to quantify and map human-induced biodiversity deficits and assess restoration potential across the globe.