Category Archives: Fossil

How English-style drizzle killed the Ice Age’s giants

Alan Cooper, University of Adelaide; Matthew Wooller, University of Alaska Fairbanks, and Tim Rabanus-Wallace, University of Adelaide

Wet weather at the end of the last ice age appears to have helped drive the ecosystems of large grazing animals, such as mammoths and giant sloths, extinct across vast swathes of Eurasia and the Americas, according to our new research. The Conversation

The study, published in Nature Ecology and Evolution today, shows that landscapes in many regions became suddenly wetter between 11,000 and 15,000 years ago, turning grasslands into peat bogs and forest, and ushering in the demise of many megafaunal species.

By examining the bone chemistry of megafauna fossils from Eurasia, North America and South America over the time leading up to the extinction, we found that all three continents experienced the same dramatic increase in moisture. This would have rapidly altered the grassland ecosystems that once covered a third of the globe.

The period after the world thawed from the most recent ice age is already very well studied, thanks largely to the tonnes of animal bones preserved in permafrost. The period is a goldmine for researchers – literally, given that many fossils were first found during gold prospecting operations.

Our work at the Australian Centre for Ancient DNA usually concerns genetic material from long-dead organisms. As a result, we have accrued a vast collection of bones from around the world during this period.

But we made our latest discovery by shifting our attention away from DNA and towards the nitrogen atoms preserved the fossils’ bone collagen.

Lead Author Tim Rabanus-Wallace hunts for megafaunal fossils in the Canadian permafrost in 2015.
Julien Soubrier

Chemical signatures

Nitrogen has two stable isotopes (atoms with the same number of protons but differing number of neutrons), called nitrogen-14 and nitrogen-15. Changes in environmental conditions can alter the ratio of these two isotopes in the soil. That, in turn, is reflected in the tissues of growing plants, and ultimately in the bones of the animals that eat those plants. In arid conditions, processes like evaporation preferentially remove the lighter nitrogen-14 from the soil. This contributes to a useful correlation seen in many grassland mammals: less nitrogen-14 in the bones means more moisture in the environment.

We studied 511 accurately dated bones, from species including bison, horses and llamas, and found that a pronounced spike in moisture occurred between 11,000 and 15,000 years ago, affecting grasslands in Europe, Siberia, North America, and South America.

Alan Cooper inspects ice age bones from the Yukon Palaeontology Program’s collection, Canada, 2015.
Julien Soubrier

At the time of this moisture spike, dramatic changes were occurring on the landscapes. Giant, continent-sized ice sheets were collapsing and retreating, leaving lakes and rivers in their wake. Sea levels were rising, and altered wind and water currents were bringing rains to once-dry continental interiors.

The study shows that a peak in moisture occurred between the time of the ice sheets melting, and the invasion of new vegetation types such as peatlands (data shown from Canada and northern United States).

As a result, forests and peatlands were forming where grass, which specialises in dry environments, once dominated. Grasses are also specially adapted to tolerate grazing – in fact, they depend upon grazers to distribute nutrients and clear dead litter from the ground each season. Forest plants, on the other hand, produce toxic compounds specifically to deter herbivores. For decades, researchers have discussed the idea that the invading forests drove the grassland communities into collapse.

Our new study provides the crime scene’s smoking gun. Not only was moisture affecting the grassland mammals during the forest invasion and the subsequent extinctions, but this was happening right around the globe.

Extinction rethink

This discovery prompts a rethink on some of the key mysteries in the extinction event, such as the curious case of Africa. Many of Africa’s megafauna — elephants, wildebeest, hippopotamus, and so on — escaped the extinction events, and unlike their counterparts on other continents have survived to this day.

It has been argued that this is because African megafauna evolved alongside humans, and were naturally wary of human hunters. However, this argument cannot explain the pronounced phase of extinctions in Europe. Neanderthals have existed there for at least 200,000 years, while anatomically modern humans arrive around 43,000 years ago.

We suggest instead that the moisture-driven extinction hypothesis provides a much better explanation. Africa’s position astride the Equator means that its central forested monsoon belt has always been surrounded by continuous stretches of grassland, which graded into the deserts of the north and south. It was the persistence of these grasslands that allowed the local megafauna to survive relatively intact.

Our study may also offers insights into the question of how the current climate change might affect today’s ecosystems.

Understanding how climate changes affected ecosystems in the past is imperative to making informed predictions about how climate changes may influence ecosystems in the future. The consequences of human-induced global warming are often depicted using images of droughts and famines. But our discovery is a reminder that all rapid environmental changes — wet as well as dry — can cause dramatic changes in biological communities and ecosystems.

In this case, warming expressed itself not through parched drought but through centuries of persistent English drizzle, with rain, slush and grey skies. It seems like a rather unpleasant way to go.

Alan Cooper, Director, Australian Centre for Ancient DNA, University of Adelaide; Matthew Wooller, Professor, University of Alaska Fairbanks, and Tim Rabanus-Wallace, PhD candidate, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Hot weather and CO2 made the tropics a no-go zone for early plant-eating dinosaurs

One of the missing links in our understanding of the Triassic Period – between 252 and 201m years ago – is why there were so few dinosaurs in the tropics. Our research suggests that volatile, hot dry weather and high carbon dioxide levels are to blame. The research can even tell us something about the challenges we humans face from climate change.

The first dinosaurs emerged just over 230m years ago, during the Late Triassic Period. This was one of the most dynamic intervals in the Earth’s history, with large-scale climatic changes. The planet was also coping with the recovery from one mass extinction and the onset of another. At the same time, many of the animal groups that dominate today’s terrestrial ecosystems – including frogs, salamanders, turtles, lizards, and mammals – were emerging.

One of the major unresolved questions of dinosaurs’ rise to dominance is why large-bodied herbivorous dinosaurs were missing from the tropics, despite the fact that they lived in higher latitudes. Small, carnivorous dinosaurs, however, populated the entire planet – including in the tropics.

Of crushing importance

To tackle the issue, our international team investigated sedimentary rocks from a number of places around the Upper Triassic Chinle Formation in New Mexico, including the fabled “Ghost Ranch”, whose multicoloured cliffs inspired artist Georgia O’Keeffe’s landscapes. However, they also preserved North America’s most extensive fossil evidence of the rise of dinosaurs and their competitors.

At the time that these sediments were deposited by rivers and streams, the areas were very close to the equator at about 12°N latitude (northern New Mexico is at 36°N today). This is the same as the current latitude of the southernmost tip of India.

Chinle Badlands
via wikimedia

By excavating unweathered rock in the field and then crushing samples in the lab we could separate the isotopes of carbon from fossilised organic matter in rocks using mass spectrometry. The isotopic ratios suggest that major rapid changes in ecosystem productivity and atmospheric CO2 levels took place during the Triassic Period.

These rocks also preserve abundant fossil charcoal. Based on the amount of light reflected from fossil charcoal under a microscope, we could see that wildfires must have swept the landscape at the time. These would have continually changed the vegetation available for large plant-eating dinosaurs.

By extracting fossil pollen and spores from the sediments and by excavating and identifying vertebrate body fossils, we could also identify the plants and animals living in the area. Our data show that plant groups varied in abundance in connection with climate swings, and that the only dinosaurs present were rare, meat-eating theropods. As such, we conclude that large plant-eating dinosaurs were absent because there were not enough predictable food and water resources for them to thrive.

Our study suggests that the climatic effects of elevated CO2, which were four to six times that of modern levels, drastically reshaped the environment and had profound consequences on the composition of ecosystems on land.

The discovery is not only important for understanding our past. Rapid climate swings and extremes of drought and intense heat driven by increasing atmospheric CO2 levels have as much ability to alter the vegetation supporting modern human populations as they did for the large plant-eating dinosaurs in the Triassic.

These data therefore suggest there are potentially profound challenges to human sustainability in the future if we experience the high CO2 conditions predicted to develop in the coming 100-200 years.

The Conversation

Jessica H. Whiteside is Lecturer in Ocean and Earth Science at University of Southampton.

This article was originally published on The Conversation.
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Found: preserved dinosaur cells – but sadly scientists still can’t build Jurassic World

The science behind the Jurassic Park films always seemed far-fetched, even before the latest instalment, Jurassic World, introduced the idea of genetically engineered super-dinosaurs.

For one thing, finding mosquitoes that had drunk the blood of dinosaurs and then been preserved in amber for hundreds of millions of years is incredibly unlikely. But there’s another more important reason: organic molecules such as proteins and DNA degrade fast after a creature’s death. They are almost never found preserved in bones older than a few thousand years. This has been the dogma for many years.

The idea of molecular-level preservation within fossils has always been controversial. No DNA has ever been extracted, for example, from a dinosaur bone precisely because this complex molecule degrades away over relatively short periods of geological time.

But other kinds of molecular and cellular preservation have been reported in fossils, including blood cells, skin cells and the original cellular components of feathers and muscles. The preservation of these kinds of cells and molecules has always been assumed to be extremely rare, only likely at sites of exceptional preservation.

In the case of dinosaur feathers and skin cellular preservation, sites like the Jehol Biota fossil deposit of western China (where rocks are around 120m years old), have proved important because animals are preserved in incredible detail in a fine-grained laminated sediment.

A new study by Sergio Bertazzo and colleagues, most based at Imperial College in London, looks set to change this perception. It suggests preservation of organic remains might be much more common that has always been assumed.

Just your average dinosaur bone.
Laurent Mekul

Bertazzo’s team studied a series of Canadian dinosaur bones, all about 80m years old, using state-of-the-art analytical techniques to examine the surfaces and internal composition of the fossils at very small scales. Intriguingly, not all of the team’s dinosaur bones were exceptionally preserved. They were just ordinary chunks of bone, the kind very often collected by palaeontologists from Mesozoic-era (the period when dinosaurs lived) sites around the world.

The researchers analysed the fossils at the nanoscale, using an electron microscope to reveal details smaller than can be seen with light, and a mass spectrometer to analyse their chemical composition. The study identified clear structures in the fossils that were consistent with the preservation of original bone collagen, the protein component of all vertebrate bones.

3D reconstruction of one of the fossils

The structures seen in the Canadian bones might not be pretty, but this is a hugely important piece of work that changes our perception of how and why soft tissue are preserved in fossil bones.

Unfortunately, it doesn’t make a Jurassic Park-style theme park any more feasible because the DNA in the cells had still degraded. But at least we have more information about cell shapes and the preservation of proteins that make up bones.

The potential to identify cellular structures and their organic components also means further studies on extinct animals, long thought largely impossible, might indeed be doable using the techniques highlighted in this paper if more cells are found.

Not pretty
Sergio Bertazzo

One clear area that could use these results would be the hugely debated field of dinosaur physiology. Were dinosaurs really warm-blooded with a faster metabolism like living birds, or were they more reptilian in their biology?

We might not (yet) be able to bring dinosaurs back to life, but we are moving towards understanding much more about their fossil preservation and biology than ever thought possible.

This article was changed after publication to correct an error introduced during the editing process

Now read this: How I dissected a T.rex (it took chainsaws, feathers and lots of latex)

The Conversation

Gareth Dyke is Palaeontologist at University of Southampton.

This article was originally published on The Conversation.
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How I dissected a T. rex (it took chainsaws, feathers and lots of latex)

I dissected a Tyrannosaurus rex in front of television cameras.

That may be the most surreal sentence I’ve ever written. So let me explain. I’m part of a team that built a life-sized model of Tyrannosaurus rex and then cut it up. The spectacle is a bloody, gory two-hour television special called T.rex Autopsy. The premise may seem absurd. But this is a whole new way of communicating science to the public, and it has been one of the highlights of my career.

I’m a paleontologist who has been studying dinosaurs for more than a decade. I’ve dug up T.rex fossils in the western United States, travelled the world studying tyrannosaur bones in museums, and described some of T.rex’s closest cousins. It’s a pretty cool job, but it comes with something of a peculiar annoyance. Sometimes I get strange people ringing me up with their pet theories on how dinosaurs evolved from space aliens, or emailing me long screeds about how dinosaurs never existed.

I got an email like that last August from a television producer in London. At first it seemed like a joke: they wanted to autopsy a T.rex corpse in front of the cameras. Just another ambitious but insane young producer, I thought, wanting to make his mark in a television landscape where shows on Bigfoot and mermaids are now standard fare on networks that used to be dedicated to science programming.

But I agreed to hear him out, and very quickly my opinion changed. They wanted to dissect a T.rex alright, but by building the most scientifically accurate model possible, then using the pageantry of an autopsy to reveal how this most famous of dinosaurs actually functioned as a living, breathing, feeding, moving, growing animal.

They needed a T.rex expert to consult on the build of the model. I signed up immediately, along with several of my esteemed colleagues, and was later asked to expand my role and appear on-screen as one of the dissectors. That was how I found myself in the famous Pinewood Studios near London last April, next to where they were filming the new Bond movie, chopping up a 43-foot T.rex with chainsaws, dripping with synthetic blood. Not a normal day at the office for an academic scientist who spends most of his time writing grants, advising students, and lecturing.

I’m incredibly proud of the end result. We’ll probably be criticised by some internet cynics who feel we’re trying to hoodwink the public into thinking this is a real tyrannosaur, or who disparage the whole idea of doing a dinosaur autopsy as too over-the-top. But that would be missing the point.

We took the utmost care to make sure our tyrannosaur was completely in line with what we know from fossils. Everything we couldn’t reconstruct from real fossils was informed speculation based on careful comparisons with living crocodiles, which are close cousins of dinosaurs, and birds, which are their descendants. And having four real scientists (a vet and three paleontologists) conducting the autopsy, without a script, made it even more authentic.

When I first walked into the autopsy room and saw the dinosaur, I was blown away.
Yes I had consulted on the build, but the producers had deliberately prevented me from seeing the final model so I would be surprised. It was so realistic – pretty much how I think a real T.rex would have looked – but made of latex, silicone, plastic, corn syrup, and various other goodies. What the artists made in four-and-a-half months and 10,000+ man hours is surely the most accurate and life-like dinosaur of all time.

Inside rex

We go from head-to-tail on the dinosaur, cutting it up, talking about how each bit helps us understand T.rex as a living animal; what it ate, how fast it moved, what injuries it suffered, what its metabolism was like and how quickly it grew, how it reproduced.

So what exactly did we learn? If you thought dinosaurs were dim-witted, overgrown reptiles, think again. T.rex had a huge brain, its eyesight was keen, it had feathers and it grew really fast. It was essentially a huge fluffy bird from hell.

Some of my favourite moments were spent inside the belly of the beast, as we removed the super-sized internal organs. We don’t know much about dinosaur hearts and lungs and stomachs, because these soft parts don’t easily fossilise. But they can leave signatures on the bones, and we can use birds and crocodiles for plausible speculation. That’s how we designed the size, shape, and position of the guts in our model.

The organs were remarkably life-like, and I say this as somebody who has dissected a lot of animals. In particular, the suitcase-sized heart really looked and felt like it had just been cut from a real T.rex cadaver. The heart had four chambers inside, just like a bird, a sign of high metabolism and consistent with evidence from bones that T.rex was a dynamic, fast-growing animal.

Everything was designed to be as life-like as possible

The lungs had balloon-like extensions called air-sacs. These store air during the breathing cycle to make the lungs extra efficient, also just like birds. We know about these from the traces the air-sacs have left on T.rex bones. The stomach was also incredibly bird-like, with two chambers. This isn’t total speculation either: there is one spectacularly preserved tyrannosaur fossil with stomach contents that helped us in our design.

It’s easy to think of T.rex as a monster, a villain in movies, a terror in our nightmares. But it was a real living breathing animal, a great lost wonder of the world. If our programme gives people a sense of what this creature was really like, it will have been well worth the hard work.

T.rex Autopsy is on the National Geographic Channel.

The Conversation

Stephen Brusatte is Chancellor’s Fellow in Vertebrate Palaeontology at University of Edinburgh.

This article was originally published on The Conversation.
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Found: our 3m-year-old forebear who lived alongside ‘Lucy’

They call it Australopithecus deyiremeda. The name comes from a language spoken in the Afar region of Ethiopia and means “close relative”. This is a brand new and previously unsuspected species – discovered in Ethiopia – that lived at the same time as one of our potential ancestors: “Lucy” (A. afarensis).

There are few things more exciting to a palaeontologist than the discovery of a new species. Work will now begin to try to figure out exactly how this hominin relates to our own species. The discovery was made from a number of fossils, dating back to 3.5m-3.3m years ago. They comprise part of an upper jaw bone with some of the teeth as well as most of a lower jaw bone with a few of its teeth. There are also a couple of other fragments of jaws and teeth.

Walking or crawling?

The fossils raise many questions that are hard to answer. For instance we can’t know whether the hominin actually walked upright, as there are no bones apart from the skull bones available. The researchers, who report their findings in the journal Nature, have previously found fragments of a foot bone in the same area which dated to 3.4m years ago. The owner of this foot may not yet have completely left the trees.

As there are specimens of Lucy’s species A. afarensis not far away, it is likely that the two were contemporary. We know that Lucy and her kind were bipeds as we have their foot bones. There is also an amazingly preserved footprint trail in Laetoli, Tanzania.

Lucy stood tall at 1.1m.
Matt Celeskey/Flickr, CC BY-SA

The foot of A deyiremeda – if that earlier discovery of a partial foot does turn out to belong to this species – is quite different from Lucy’s.

There are other Australopiths around at the same time too. In Chad there is the enigmatic A. bahrelghazali, only a little older. In South Africa, there’s the Littlefoot skeleton from Sterkfontein, recently re-dated to 3.7m years ago. Some palaeoanthropologists want to interpret Littlefoot as a new species of Australopith A. prometheus, but others are reluctant to identify it as a new species yet.

But the case the discoverers of A. deyiremeda have put forward supports their fossils being a new species. There are numerous differences in the jaws and teeth between these remains and those of other species of Australopith. Further south in Kenya there is another hominin around at the same time, not only a different species, but one belonging to a wholly different genus – Kenyanthropus platyops. However A. deyiremeda is not like this either.

A palaeontologist’s puzzle

Exactly where A. deyiremeda fits in among our ancestors is, however, hard to know. We are Homo sapiens sapiens. Our genus, Homo, is the family we belong to along with our extinct cousins like Homo neanderthalensis and possible ancestors like Homo erectus. Our species is sapiens, meaning wise, and we add another sapiens on to our name to distinguish ourselves from the very earliest members of our species. But here is the thing: we are the only species in our genus – and, from an evolutionary perspective, that is not a healthy sign.

Up until today, genus Australopithecus had six, maybe seven species in it depending on who you believe. Now that is an astonishingly successful genus as far as evolution goes. The oldest yet found is A. anamensis, which is more than 4m years old. The youngest is A. sediba which is about 1.9m years old. That’s a life span of nearly two million years between these species. The reason so many species can emerge is because natural selection experiments with different adaptations and different ecological niches.

Upper jaw of A. deyiremeda
Yohannes Haile-Selassie

The newly discovered A. deyiremeda comes from the earlier phase in Australopith evolution. Exactly how it relates to our own species is hard to know. However, many of the features of its jaws and teeth are seen in later hominins, particularly a group of flat-faced ape men called Paranthropus. These are not on our evolutionary line. The researchers also describe some similarities between A. deyiremeda and early Homo, but in the paper they also point out some important differences between the new discoveries and the earliest known member of our own genus, currently dated to 2.8m years old. So for the moment this is an open question.

But there is a last twist to the tale here. For a long time we believed that members of our own genus were the only tool makers in the hominin record. Now we know that’s not true. Recent reports have established the oldest yet discovered stone tools date to 3.3m years ago, that’s half a million years older than the earliest member of genus Homo.

Tool making may even go back a little bit further. There are contested cut marks from stone tools on bones dated at 3.4m years ago at Dikika in Ethiopia. Guess which species are around at that time in East Africa? You guessed it: A. afarensis, K. platyops and A. deyiremeda. Up until today it was K. platyops that was the favoured candidate for this early tool maker, but today’s announcement of A. deyiremeda puts a new player in the game.

The Conversation

John McNabb is Senior Lecturer in Palaeolithic Archaeology at University of Southampton.

This article was originally published on The Conversation.
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How fish fossils can help us build better submarines

The ocean, which covers the vast majority of the world’s surface, holds many secrets. For more than a year a multinational team has tried to find the missing Malaysia Airlines flight MH370 on the bottom of it – without success. But it turns out fish fossils could help us explore it.

Understanding the development of sound navigation in fish has the potential to improve remotely operated underwater vehicles, such as the equipment used in the search for MH370.

A new field of research is developing that aims to convert our knowledge of the evolution of extinct species into modern innovations. Such research, which I would like to dub “palaeobiomimicry” – creating artificial structures that mimic a biological system that can be seen in fossils – is still at an embryonic stage, but I believe it has the potential to provide advances in everything from civil engineering to high-tech clothing. Put simply, the fossil record is a valuable source of innovation.

The power of natural selection

Palaeobiomimicry has huge potential. All animals rely on their senses to interact with the world around them. Many artificial systems, such as aircraft, submarines and most recently driverless cars, also require systems that allow them to detect their environment. However, such systems may not necessarily operate to the best of their abilities in a rapidly changing environment because they cannot adapt to the world about them.

Senses of an organism differ from engineered objects in that they function within the constraints of natural selection pressure. But by just studying living organisms you only get a snapshot of this optimisation. What is needed is a long period of time in order to see how a particular part of a body has evolved and how the optimisation has changed. Only the fossil record can provide that.

An image of the skull (grey) and internal nervous system (yellow) in the nose region of a 380 million year old lungfish from Caithness, Scotland. The images are created using micro-CT scanning which reveals in great detail the fish’s ‘sonar’ (blue tubes).

Like a submarine, fish possess a system for feeling pressure waves in water produced by predators and prey, or to avoid obstacles. In a submarine this is an arrangement of hydrophones – sensors that convert changes in water pressure into an electrical signal. Together, this is called a sonar system. Instead of hydrophones, fish have an elaborate pattern of tubes and grooves that house many movement-sensitive hair cells, called the lateral line.

As the delicate hair cells do not fossilise, one may look towards how the function and shape of these tubes change over time. The ideal time to investigate this phenomenon is the period that fish evolved into the first land vertebrates – the Devonian Period. We have a good grasp of what these organisms were adapting to during this period of evolution – from fish sensing pressure in water to land vertebrates sensing pressure in air.

Technological advances

Modern palaeontology has been greatly advanced by the introduction of three-dimensional X-ray scanning techniques, similar to CAT-scanning used in hospitals. With computer-driven analyses to calculate how fluid flows through the varying shapes of sensory tubes and grooves in fossil and living fish, it will be possible to discover how sensitivity changes with differently shaped tubes. This information could then be used to create the first working adaptive artificial sonar system based on the new concept of palaeobiomimicry.

A fish’s sonar is contained in the outer parts of its head and body. Adapting such a system in technology could pave the way for dramatically reducing the amount of space taken up by conventional sonar systems. It could also aid development of an apparatus that changes function with the environment, just as fish use different parts of their sonar system for different purposes.

New understandings of how sonar evolved in fish could be used in remotely operated underwater vehicles for search purposes – such as the equipment used in the search for flight MH370. It could also be used for maintaining underwater installations, in submarines for research and defence, and in aquatic surveying research equipment.

Senses in fossil fish are but one example. My current favourite example is research that is currently in progress at the University of Leeds on how fossil shark scales help reduce drag in water).

There is a lot of stake. Duncan Wingham, the chief executive of the UK’s Natural Environment Research Council, recently warned that palaeontology will struggle to receive funding in the near future, on the grounds that it does not deliver a direct impact and benefit to society.

With funding for research continuing to be tight, it is up to palaeontologists to step up to the challenge and find new ways to contribute to society.

The Conversation

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Big bang theory: how did dinosaurs have sex?

Dinosaurs were the largest animals to ever walk Earth, and they ruled the planet for more than 160 million years. The long-necked Argentinosaurus, with back vertebrae almost two metres high, possibly grew to 30 metres long and weighed up to 80 tonnes. So did the earth really shake for them when they mated?

The real question here though is: how did they really mate and what evidence do we have to reconstruct their sex lives?

The internet offers vague speculation. One website claims they probably didn’t have penises so must have used cloacal kissing, juxtaposing their massive bottoms together for the interchange of seminal fluid to the female, as do most frogs and many birds.

I disagree with this view, as evidence from living animals, close relatives of dinosaurs, implies they must have mated using copulation, and that the male must have had very large and flexible penises.

Ainvar Photography

We now know with confidence that the meat-eating theropods, such as Tyrannosaurus and kin, were the group that gave rise to the first birds about 160 million years ago.

This is established from a large number of exquisite fossils showing various feathered dinosaurs and early dinosaur-like birds from sites in northern China.

Crocodiles and their kin evolved from the last common ancestor of the dinosaur-bird group, so crocs can’t be regarded as “descendents of the dinosaurs” as some crocodile park ads would have us believe.

All male crocodiles have a penis and most primitive living birds also possess one, so it follows that dinosaurs must also have had a penis. The majority of living birds though have secondarily lost the penis. For them a mating is a simple, quick cloacal kiss where sperm is rapidly passed to the female.

Once all the fancy dancing and singing is done, the sexual act can be over in a second or less in some birds, such as dunnocks, shown in the video below:

Doing it dunnock style.

So how did the dinosaurs do it? Biomechanics experts such as Professor McNeill Alexander of The University of Leeds claim that the weight of the male would have rested on the females hips to mount from behind as elephants do, but the resulting stresses would have been massive.

Professor Roger Seymour from the University of Adelaide studied giraffes mating (see video below) and proved that the male’s blood pressure is roughly twice that of other mammals. Their hearts need be proportionately 75% larger due to the physiological constraints of the long neck and highly perched head.

A high-pressure situation.

Bearing this in mind, he suggested that, for long-necked dinosaurs, they could only have mated in a particular way. A dinosaur with, say, a ten-metre-long neck would have seven times the normal mammalian blood pressure. So rear mounting is not a big problem if one keeps the neck horizontal.

Just imagine a 70-tonne giant sauropod fainting after loss of blood pressure to the head at the time of orgasm while mounting its mate. Yes, the earth would have most certainly shaken for them.

New clues

Recent molecular studies of the major bird groups find that the ostriches and other primitive flightless birds are indeed the most ancient members of the living birds, with ducks and geese and some other waterbirds also very old lineages.

All these primitive living birds possess a penis, with ducks having the most bizarre types – a regular sized Argentine lake Duck has a corkscrew-shaped organ with a brush on the tip that measures up to 42 cm long.

Muscovy ducks can also explosively evert their penises in 0.3 second to 20 cm long – roughly the same speed as driving at 70kph – as can be seen in the video below:

Duck and cover.

So, it’s quite likely their distantly extinct ancestors, the meat-eating theropod dinosaurs also mated using an eversible penis, most likely a terrifyingly large one.

For an animal the size of Tyrannosaurus (14 metres long) to mate effectively the male organ would need be in the order of at least two metres long, and maybe a lot more if it happened to be cork-screw shaped like a duck’s.

It’s not unlikely that one day palaeontologists will find a fossilised dinosaur penis. Extraordinary soft-tissue preservation in fossils are coming to light each year along with new fossil sites being discovered.

Greater detail can be resolved in fossils using new technologies, such as micro-CT and synchrotron tomography. Recently, 380 million-year-old fossil fishes from Australia were found to have complete sets of muscles preserved.

A small dinosaur fossil found in the spring of 1981 in central Italy, named Scipionyx, revealed excellent soft tissue preservation, with clear impressions of the intestines, liver and some muscles. Such fossils offer hope.

I truly believe the day will surely come, probably when we least expect it, when a remarkable new dinosaur fossil pops up solving the age old mystery of how dinosaurs really did do the deed.

The Conversation

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Archaeologists Change Direction in Kenya, Find World’s Oldest Known Tools

Archaeologists surveying the Kenyan Rift Valley area quite accidentally discovered what are perhaps the oldest known stone tools in the world. They date back about 3.3 million years ago, which would make them at least 700,000 years older than what were formerly the oldest stone tools – discovered in the Ethiopian region of Hadar. So old are the most recent discoveries, that in fact they are precursors of even the earliest fossilized skulls we have of our own genus, Homo, by about half a million years. This is the exciting part. Although we’d like to think that Homo was the first to craft tools – it was actually the work of a more primitive and distant ancestor that we share.

The ancient tools might never have been discovered were it not for a happy accident. Sonia Harmand from Stony Brook University and her team were on their way to a previously uncovered fossil site at the western shore of Lake Turkana on one particular morning in July of 2011. However, the group made a wrong turn and ended up near what was then an uncharted formation of rock. The researchers quickly decided that it was an ideal enough place to harbor artifacts, decided to survey it and by the afternoon, they discovered what they were looking for. The site has been named Lomekwi 3, and giving a closer look, they managed to uncover dozens of stone age tools— including the leftover flakes from cut minerals, as well as cores and even anvils, which were discovered both at the surface, as well as below the ground. Harmand first described her team’s findings on April 14 when giving a lecture during the annual meeting of the Paleoanthropology Society in San Francisco.

“The cores and flakes we recovered are clearly knapped and are not the result of accidental or natural rock fracture,” Harmand said. “The Lomekwi 3 knappers were able to deliver sufficient intentional force to detach repeatedly series of adjacent and superposed flakes and then to continue knapping by rotating the cores.” The team was able determined the age of the tools using a relative dating technique, analyzing the area in which they had been found, between what were two layers of volcanic ash as well as a magnetic reversal of the known ages – due to the nature of continental drift and the Earth’s rotation, magnetic fields change polarity over time, and knowing these periods can help determine the age of the materials.

Another surprising feature of the Lomekwi 3 tools is that they are unusually large – much larger than the stone tools that were excavated in Ethiopia that had previously set the record for the oldest known tools, and they are in fact even larger than the rocks typically used by chimpanzees to crack apart nuts and shells, pointing to a unique transitional period in hominid technology. As described by Harmand, these preliminary observations could indicate that the Lomekwi toolmakers deliberately sought out the biggest, heaviest blocks made out of very hard raw material from local sources despite the availability of smaller blocks. They then applied a number of knapping techniques in order to remove some of the sharper edged flakes away from the core of the rocks. While the chimps, who we share a common ancestor with (and several primate species long deceased,) have been known to go on hunts, the exact purpose of the Lomekwi tools is still unclear. Chimps have been known to use spear-like objects, but the size and weight of the tools suggest another purpose.

Animal bones of the same period have been recovered from the site, perhaps conjuring up images of the ape in 2001: Space Odyssey, who realized he could use bleached tapir bones as a weapon. However, they contain no markings to indicate human activity. Evidence from another site, however, dating to the time of the tools does suggest that hominins (the group in which we, H. sapiens and our extinct relatives all fall into) were already butchering animals for food.

Back in 2010, researchers working at the dig site of Dikika, also in Ethiopia, (where the remains of Australopithecus afarensis, the three-million year-old species to which Lucy belonged, had once been uncovered), made the announcement that they had unearthed 3.4 million-year-old animal bones which showed distinctive marks, knife scrapings from where the hominins had sliced away morsels of meat from the bone with their stone tools. The claim didn’t go without a rather heated debate. Some skeptics refuted the discovery with the suggestion that any alleged cut marks were actually due to these bones being cut and trampled by the feet of passing animals. Other researchers countered that the distinct cut marks may actually have been due to the bites of crocodiles scavenging food. Although the latest discovery of tools at the Lomewki site does not necessarily prove nor disprove that hominins were responsible for making marks on the Dikika remains, it certainly is sufficient evidence to maintain that hominins close enough to be contemporaries of the Dikika nomads did in fact create implements that capable of leaving distinct cut marks.

The identity of these Lomekwi knappers remains unknown. If the manufacture of stone tools is exclusive to the Homo genus, then the evidence suggests that they may have evolved significantly earlier than what the fossil record currently suggests. A more likely scenario, however, which Harmand endorses, is that either the Australopithecus or another hominin, Kenyanthropus (which has been found nearby)— both of which have been known to have existed some 3.3 million years ago were responsible for the Lomekwi tools. Whether in fact the Kenyanthropus is actually of a distinct hominin lineage or just another type of Australopithecus still remains a point of contention, however.

Up until this point, the earliest known stone tools were considered to be derived out of the so-called Oldowan toolmaking tradition. The 20th century paleontologist Louis Leakey coined this term when he described some of the first primitive tools discovered at the Olduvai Gorge back in the 1930s. However, Harmand says that these newly discovered tools are actually different in comparison to the early Oldowan discoveries that they deserve a new name: the Lomekwian tradition.

James Sullivan
James Sullivan is the assistant editor of Brain World Magazine and a contributor to Truth Is Cool and OMNI Reboot. He can usually be found on TVTropes or RationalWiki when not exploiting life and science stories for another blog article.

New species of prehistoric bird lived 1.8 million years ago

3.5 million years ago, when our ancestors were just beginning to walk upright, the real rulers of the Earth were carnivorous birds with hooked beaks who stood up to ten feet tall as they stalked their prey in the grasslands, apex hunters who were even able to compete with the fearsome saber tooth cats in a time when low sea levels and frozen land bridges were not uncommon. Paleontologists in South America recently uncovered a new species of these large avian predators, known as “terror birds,” an almost complete skeleton, which is already revealing a great deal about how they hunted.

The fossil was first discovered on the beaches of Mar del Plata back in 2010, a city located at the eastern coast of Argentina, not far from the country’s fossil rich region of Patagonia, where many intriguing species of Cretaceous dinosaurs have been found in recent years. Over 90 percent of the creatures bones remain intact, according to the lead researcher on the study, Federico Degrange, who serves as an assistant researcher of vertebrate paleontology at the Centro de Investigaciones en Ciencias de la Tierra and the Universidad Nacional de Córdoba of Argentina.

The scientists have given this particular species of terror bird a new name: Llallawavis scagliai, merging classical Latin with the Quechua dialect spoken in the central Andes. “Llallawa” is the Quechua word for “magnificent,” while “avis” is Latin for bird. The name is in honor of the Argentine naturalist Galileo Juan Scaglia (1915-1989), who was the former director of Mar del Plata’s science museum. Scaglia’s own grandson discovered the bird fossil, and the findings were documented this week in the Journal of Vertebrate Paleontology.

Due to its exceptional preservation, the fossil has been an invaluable resource for studying the terror bird’s anatomy in depth, allowing for a fairly accurate reconstruction of the animal. The specimen marks the first time a fossilized terror bird with a complete trachea and complete palate (the roof of its mouth). It’s a bit smaller than most species in the terror bird family, and was also among the last to roam the Earth. Even more intriguing are the intricate bones of the animal’s ears, complete with its eye sockets, brain box and skull, which allow scientists to understand a great deal about the flightless bird’s sensory capabilities.

A look at the inner ear structure of L. scagliai would suggest that the terror bird was capable of picking up low-frequency sounds, meaning it was capable of listening for only the footsteps of its prey hitting the ground with a low rumble before striking. It may have also used noises of low frequency to communicate with other members of the flock, as the bird was a known pack hunter – sending messages in pitches that only they could hear.

“That actually tells us quite a bit about what the animals do, simply because low-frequency sounds tend to propagate across the environment with little change in volume,” said Lawrence Witmer, a professor of anatomy
 from Ohio University
, who has collaborated before with Degrange, but did not participate involved in the new study.

“Low-frequency sounds are great for long-[distance] communication, or if you’re a predator, for sensing the movements of prey animals,” Witmer said in an interview with Live Science.

This ability gives L. scagliai some famous company. Other animals that are capable of hearing low-frequency sounds include the greatest prehistoric hunter of all time – Tyrannosaurus rex, as well as modern day elephants and rhinos, and even crocodiles, which are distantly related to modern birds – an ancestry dating back some 230 million years.

Another surprising feature the researchers took notice of was the bird’s skull, which they found to be surprisingly more rigid than the skulls of other birds. This, however, may actually have worked to the bird’s advantage, according to the scientists, because a rigid skull would have enabled the terror bird to crush the jugular vein of its prey with a large beak, likely the way in which it brought down prey.

“Terror birds didn’t have a strong bite force, but they were capable of killing prey just by striking up and down with the beak,” Degrange said.

The near-complete skeleton also indicates that the terror birds were of a much more diverse variety during the Late Pliocene epoch than what experts had once thought. The birds enjoyed a considerably long period on this planet. They emerged in the Cenozoic, with the oldest fossils dating back between 52 million and 50 million years ago. The latest species are estimated to have died out 1.8 years ago, although some scientists maintain that there may have been terror bird populations that only became extinct as recently as 17,000 years ago – coinciding with the arrival of the first humans in South America. Evidence for this is rather sparse as of now, according to Degrange, although large predatory flightless birds did have populations on islands in the tropics until about 400 years ago, such as the moa. The only one that survives today is the cassowary, found primarily in Papua New Guinea, and has been known to attack people.

While it’s an exciting time for the researchers, classification is only the initial stages. In the years ahead, they hope to further study in depth the terror bird’s eye bones, brain case and skull over the next several years, hoping that they will come to a deeper understanding of how the bird saw and other capabilities that allowed it to hunt so successfully through the grasslands of the Pleistocene.

James Sullivan
James Sullivan is the assistant editor of Brain World Magazine and a contributor to Truth Is Cool and OMNI Reboot. He can usually be found on TVTropes or RationalWiki when not exploiting life and science stories for another blog article.

Why Brontosaurus is no longer a dirty word for dinosaur hunters

A team of palaeontologists is claiming to have “resurrected” Brontosaurus, the famous long-necked, pot-belled dinosaur. No, they haven’t conducted some mad DNA cloning experiment. They have built a big new family tree of long-necked dinosaurs and argue that Brontosaurus is distinctive enough to be classified separately from its closest relatives.

Confused? I don’t blame you. Brontosaurus is of course an iconic dinosaur. If you could only name a few dinosaurs, you would probably come up with Tyrannosaurus, Triceratops and Brontosaurus. Ever since 1903, however, you would have been mistaken with the last one. That was the year that palaeontologists determined that Brontosaurus was nearly identical to another dinosaur called Apatosaurus and was not the appropriate name to use.

Needless to say, this never filtered down to pop culture. You have never needed to look far to see Brontosaurus name-dropped in films, books, postage stamps and wherever else. We scientists would sometimes secretly scoff at friends and family who used the name – a sure sign of those uninitiated to our fossil fraternity. But now it looks as though pop culture had it right all along. After all these years, Brontosaurus may now cease to be a dirty word among palaeontologists.

The argument that Brontosaurus is different from Apatosarus is being put forward by a team led by young palaeontologist Emanuel Tschopp from Universidade Nova de Lisboa in Portugal, published on April 7 in the open-access journal PeerJ. Their paper is nearly 300 pages long, with vast tables of measurements and photos of fossils.

Dinosaur fever

The story dates back to the 1870s, a golden era of dinosaur discovery. As big money transformed New York and other eastern American cities, museums and wealthy individuals sent teams of explorers to the American west to bring back the trendy status symbol of the day: huge dinosaurs.

Dinosaur daddy: OC Marsh

Many bones found their way to a Yale palaeontologist named OC Marsh, who was locked in a bitter battle with his Philadelphia rival ED Cope. In their unquenchable desire to one-up the other, these men described some great fossils but also made a lot of mistakes by rushing new discoveries into print.

You can imagine Marsh’s excitement when he was shipped crates of giant bones from Wyoming and Colorado. They belonged to 150m year-old animals, which were some of the biggest ever found. In 1877 Marsh named the first of these long-necked behemoths Apatosaurus, then named the second Brontosaurus two years later. Both generated enormous fame in the press – especially Brontosaurus, whose name means “thunder lizard” and is a thing of linguistic beauty.

Bronto on display at Yale
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But in 1903 a palaeontologist named Elmer Riggs reviewed Marsh’s work. He determined that Marsh had been overzealous: Apatosaurus and Brontosaurus had nearly identical skeletons, with only a handful of tiny differences. To Riggs these two dinosaurs were the same creature – and because Apatosaurus had been named first it was the name that had to stick, following the rules scientists have respected for generations. Brontosaurus might have been a beautiful name, but it was an invalid one.

Welcome back Bronto

Over the next century, scientists forgot about the Brontosaurus name (scoffing aside). It left the palaeontological lexicon in the same way as so many archaic words are dropped from the Oxford English Dictionary every year.

In the meantime, palaeontology became a discipline in which a new species of dinosaur is being found every week. Hundreds or even thousands of dinosaurs have come to light since Riggs sunk Brontosaurus. Dr Tschopp examined hundreds of dinosaurs in museums across the world and built a huge database that records how they differ in age, size and anatomical features.

From this they built a family tree that showed Apatosaurus and Brontosaurus as closely related, but not identical. They also applied various statistical analyses to the database and family tree to demonstrate that the skeletons of Apatosaurus and Brontosaurus were more different from each other than many other types of long-necked dinosaurs that have long been classified separately.

The final word?

So does this mean the case is closed and Brontosaurus thunders back to its throne? Maybe, or maybe not. I am curious to see how my fellow palaeontologists react to the paper. I suspect some will agree with Tschopp’s team, while others will continue to maintain that Brontosaurus and Apatosaurus are just too similar to be considered different. To be honest, I am on the fence myself.

You say Bronto, I say Apato

There may be no firm resolution to this debate, which is frustrating. But this is because naming things is more art than science. There is no machine or experiment that can tell you whether two things are different enough to be called different. Even modern biologists struggle mightily to define species of modern animals – and we can observe those and study their DNA. Nomenclature will always be open to debate, value judgements and passionate arguments.

But that’s OK. It doesn’t really matter what we call Brontosaurus. Regardless of its name, it was a monstrous creature which thrived hundreds of millions of years ago and was larger than almost anything else that ever lived on land. This dinosaur by any other name, or any name indeed, would still be just as fascinating.

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