Category: Animal News Stories

Hiding in Plain Sight the “Higgs Bison”

Cave Paintings Reveal Surprising Clues to Bovid Evolution

The cave paintings left by our ancestors can be very evocative.  The often elaborate and highly stylised frescoes represent life in the very distant past, a life so far removed from today.  However, the paintings, in most cases, a record of the animals that shared the environment with these hunter/gatherers, hide hidden clues regarding prehistoric animals that modern-day researchers are only just beginning to appreciate.

A report published in the journal “Nature Communications” by scientists from the University of Adelaide, documents the study of DNA recovered from fossil bones in order to map how climate change affects large animals.  A surprise awaited the scientists, they have discovered a previously unknown species of bison, only to find out that this bovine was already recorded on the walls of caves across Europe, such as in the Niaux Cave (south-western France).  These cave paintings are dated to around 17,000 years ago (Late Upper Palaeolithic).

Cave Paintings Thought to Be Stylised and Symbolic May Reflect Anatomical Accuracy

A Woolly Rhino depicted in a cave painting.

Cave art depicts a Woolly Rhinoceros

Picture Credit: BBC/inocybe

In 1999, the Australian-based research team commenced the study of DNA extracted from bison bones excavated from a number of sites located in the northern hemisphere, where the Steppe bison (Bison priscus) roamed.  The objective of the study was to assess the impact of changing global climate upon animal populations and in North America the fossil record for bison reflected the impact of a changing world.  Bison numbers crashed around the Last Glacial Maximum (between 18,000 and 21,000 years ago.)  Such data supports the idea that climate change played a significant role in the extinction of “megafauna”.

The scientists then expanded the boundaries of their research by examining data from South America, this also revealed that rapid warming events were a significant factor in large animal extinctions, often with species being further pushed towards extinction by the effect on animal populations by human hunters.

A Puzzle from Europe

When the focus of the research was directed at the fossil record and climate data from Europe, a rather puzzling picture emerged.  By studying mitochondrial DNA (which is inherited exclusively through the maternal line), recovered from fossilised remains, the team realised that the genetic signatures they were finding did not match those expected if the fossils had come from the Steppe bison (Bison priscus).  This was something of a puzzle as palaeontologists had thought that the Steppe bison was the only species to have been present in Europe before 10,000 years ago.

The researchers realised that there were looking at the genes of something novel, an unknown species distantly related to modern cattle and to the exceptionally rare European bison (Bison bonasus), also called the Wisent.  The European bison is Europe’s largest, native, extant terrestrial mammal.  Once widespread, this bovine is now found in a few, remote and protected forests, particularly the Białowieża Forest between Belarus and Poland.  In a story, somewhat similar to the more famous Przewalski’s horse, the last wild Wisent was shot in 1927, but the species clung on thanks to a handful of animals kept in protected reserves.  Modern herds are descended from just a dozen individuals, including one bull from the Caucasus.

The European Bison Also Known as the Wisent (Bison bonasus)

The Wisent (European bison).

The European bison.

Picture Credit: Rafał Kowalczyk

To read about the conservation of Przewalski’s horse: Przewalski’s Horse – A Conservation Success Story

The Elusive “Higgs Bison”

That famous Australian dry sense of humour came to the fore, when the DNA from the fossil bones proved to be neither Steppe bison or modern European bison, the team thought they had a new species but they could not be certain.  The elusive animal was nick-named “Higgs bison”, after all, the team had found evidence of something new, but they were not quite sure what this animal looked like, a parallel with physicists and their search for the Higgs boson particle.

In order to unravel this “Higgs bison” puzzle, the University of Adelaide research team set out to confirm their mitochondrial DNA results by obtaining nuclear DNA from the sixty-four European bison bones involved in the study.  Although, much harder to retrieve, nuclear DNA records all aspects of ancestry, not just the maternal line.  The small amount of nuclear DNA retrieved from the samples demonstrated that the “Higgs bison” was a hybrid, a cross between a female wild cow (extinct Aurochs) and a male Steppe bison.  The team dated this hybridisation event to more than 120,000 years ago.  This ancestry was the same for the Wisent and even though the mitochondrial DNA was different, a consequence of the recent near extinction event for the European bison, the “Higgs bison” was revealed as the ancestor of the Wisent.

Pressure on bovine populations as a result of rapid fluctuations in climate could have triggered the hybridisation process.

Male offspring of the Aurochs/Steppe bison cross were sterile, a common outcome for mammal hybrids.  As a result, several generations of females back-crossed with Steppe bison males (maybe even the same bull), resulting in a genetic ancestry of about 10 percent Aurochs and 90 percent Steppe bison.

Hybridisation Between Female Aurochs and Male Steppe Bison Leads to a New Species

The Evolution of the European bison.

Wisent evolution.

Picture Credit: Nature Communications

Genetics and cave art reveal the assymmetric hybridisation between female Aurochs and male Steppe bison. Male hybrid offspring are sterile, and female offspring backbred with Steppe bison for several generations, possibly the same bull.

Looking for More Evidence – the North Sea and Cave Paintings

Having reached this conclusion, the Australian team then set about finding other sources of evidence to support the idea of a newly discovered species of prehistoric bison, resulting from the cross breeding between wild cattle and Bison priscus.  Two strands of supporting evidence were identified, both from surprising sources.

  1. Scientists from Holland reported that amongst the many numerous Steppe bison and Aurochs bones dredged up by fisherman from the North Sea (for much of the Pleistocene Epoch sea levels were much lower and Scotland was joined to Denmark by a wide and extensive plain), bones of a less common, smaller bovine had been found.
  2. French cave art researchers had identified two distinct forms of bison depicted in the artwork of our ancestors, one type resembled the hump-backed, massive Steppe bison, whilst the other depiction was of a more evenly shaped animal with reduced horns, much like a modern-day Wisent.

Depicted in Prehistoric Cave Art – the Newly Discovered Species of Bison

A Wisent (European bison) depicted in Cave Art

820 examples of bison depicted in European cave art are known, two distinct forms have been identified, representing two different species.

Picture: D. Viat/Tourismeoccitanie

Radiocarbon dating of the artworks showed that the wedge-shaped form was drawn when Steppe bison were present on the landscape (around 18,000 years ago), while the small-horned version was drawn when the newly discovered species dominated Europe (after 17,000 years ago).  Each species appears to have dominated Europe for long periods of time, alternating in response to major climate changes.  Thanks to the accurate artwork of Stone Age people, scientists have a good understanding of what this new species of bison looked like.  It had been hiding in plain sight all along.

This study has thrown up a number of surprises.  Apparently, mammals can form new species by hybridisation, even if only rarely.  It also shows that despite the huge bison fossil record the depictions of these ancient creatures made many thousands of years ago, still have a lot to tell us about life in the past.

Everything acknowledges the help and support of “The Lead South Australia” in the compilation of this article.

The scientific paper: Soubrier, J. et al. Early cave art and ancient DNA record the origin of European bison. Nat. Commun. 7, 13158 doi: 10.1038/ncomms13158 (2016).

Spiny Plants, Ungulates and the Savannah Habitat

The Evolution of Spiny Plants Holds Key to the Establishment of the Savannah

The continent of Africa contains a wide diversity of habitats, dominating the south, central part of Africa are the grasslands, the extensive savannahs that are home to a great diversity of iconic animals.  A team of international scientists writing in the academic journal “The Proceedings of the National Academy of Sciences United States”, have mapped the origins of the African savannah and concluded that the emergence of this ecosystem is, at least in part, down to the grazing habits of antelopes and their kin.

Ancient Bovids Influenced Habitat Formation in Africa

Rusingoryx illustrated

Honking to communicate in the hot savannah.

Picture Credit: Todd Marshall

The picture above shows an illustration of Rusingoryx atopocranion a wildebeest from the Pleistocene Epoch.  Grazing bovids and antelopes may have had a remarkable impact on the evolution of plant communities.

In a study that plotted flora/faunal relationships on a continental scale, the researchers identified which mammal browsers are most closely associated with spiny communities of trees.  The team were able to show that over the last sixteen million years or so, plants from unrelated taxa developed spiny defences against being eaten a total of fifty-five times.  This pattern of convergent evolution suggests that the arrival and diversification of bovids in Africa changed the rules for persisting in woody communities.  Contrary to current understanding, this new data indicates that browsers predate fire by millions of years as agents driving the origin of the African savannah.

The study was conducted in an unorthodox manner.  The researchers, which included biologists from McGill University (Montreal, Quebec, Canada), started by observing fauna and flora relationships in Africa today and then working backwards in time to the middle of the Miocene Epoch.

An Arms Race Between Plants and Animals

Many browsers like gazelles, delicately pick leaves off branches full of wicked-looking spines that are several centimetres long.  The scientists were able to uncover what happened in the past by mapping the distribution and evolution of the spiny plants on which gazelles and their relatives like to feed today.

A Gerenuk Antelope Browsing

A Gerenuk Antelope Browsing

A Gerenuk Browsing on Trees.

Picture Credit: Everything Dinosaur

Research team member, Jonathan Davies, (McGill University) commented:

“It’s been difficult to get a picture of how savannah ecosystems evolved because the conditions needed to preserve animal and plant fossils are very different from one another.  By working with the African Centre for DNA Bar-coding at the University of Johannesburg, we were able to sequence and compare DNA from nearly two thousand trees, and show that African plants only developed spines about fifteen million years ago. That was about the same time that a new type of mammal, antelope and their relatives, spread across the continent following the collision between the continental plates of Africa and Eurasia.”

Prior to this collision, the African continent had been dominated by the large, now extinct, ancestors of browsing elephants and hyrax.  These large herbivores would have bull-dozed trees and trampled vegetation, so spines were an ineffective defence against them according to the lead author of the study, Tristan Charles-Dominique (University of Cape Town).  However, antelopes and their relatives that arrived in Africa after the continental plate collision were highly efficient browsers, often using their delicate lips and prehensile tongue to remove leaves from branches.  It is likely that plants developed spines to defend themselves against these new plant “predators”.

Evolving a Spiny Defence Against Browsers

The study suggests a remarkable “arms race” between the trees and plant-eaters.  The arrival of new and efficient herbivores on the continent of Africa led to the evolution of more and more elaborate defences, including longer and longer spines.  One of the implications of this research is that the loss of large mammals like antelopes today, through human activities such as the bush meat trade, may have a substantial impact on the African landscape, with present day open savannahs being converted into thicket or brush.  Extensive forests may also make a comeback.

The Paper:  “Spiny Plants, Mammal Browsers and the Origin of the African Savannahs”.

Everything Dinosaur acknowledges the support of McGill University in the compilation of this article.

Remembering the Thylacine – Threatened Species Day

Remembering the Thylacine

On this day, eighty years ago, the last known Thylacine died at Beaumaris Zoo in Hobart.  It was on the 7th of September 1936, that staff at the Tasmanian zoo discovered “Benjamin”, as the animal was believed to have been named, dead.  Sadly, just two months earlier, the species Thylacinus cynocephalus had been granted protected status, after more than a hundred years of persecution.  Today, we live in what is regarded as more enlightened times, and September 7th in Australia is “National Threatened Species Day”, a day dedicated to honouring those people who work to protect Australia’s unique wildlife.  It is also a day for reflecting on how our own species has led to the demise of other species.  For example, the Thylacine was thought to attack and kill sheep and other domesticated animals and so it was hunted with bounties being paid for each “Tasmanian Tiger” killed.

The Last Known Thylacine circa 1935

A photograph of a Thylacine.

A picture of “Benjamin” the last known Thylacine to live in captivity.

Picture Credit: David Fleay

The Sad Tale of Benjamin – The Last Known Thylacine

Benjamin is believed to have been captured in the Florentine Valley area (south central Tasmania) in 1933 and brought to Beaumaris Zoo (Hobart).  Although once thought to be female, a more recent analysis confirmed that Benjamin was indeed, in all probability a male.  An inability to determine gender reflects the relative neglect the animal suffered in the zoo.  Indeed, the fact that the animal was even nick-named Benjamin has been challenged by a number of academics and authors.  The Tasmanian winter of 1936 was particularly severe and it seems that the last known Thylacine in captivity probably died of exposure after having been locked out of its sheltered sleeping quarters.  And so, the last Thylacine was dead.  Ironically, Beaumaris Zoo, for years dogged by financial difficulties, was to close shortly afterwards.  It was shut down by the Hobart City Council in the last week of November 1937.

In 1996, on the sixtieth anniversary of the death of the only Thylacine to have been given official protection, “National Threatened Species Day” was declared.  A time to reflect on the demise of the Thylacine and how similar fates await other species of flora and fauna unique to Australia unless action is taken to reverse their decline.

The CollectA Female Thylacine Model

Everything Dinosaur is proud to have added the beautiful CollectA female Thylacine model to its range of CollectA models.  The Thylacine, (Thylacinus cynocephalus), was the largest carnivorous marsupial to have lived in Australia in modern times and the last member of a once much more diverse group of marsupials.  The “Tasmanian Tiger” may be thought to be extinct, but is it?

The CollectA Thylacine Model

The CollectA Thylacine replica.

The CollectA Thylacine model.

Picture Credit: Everything Dinosaur

To purchase the CollectA “Tasmanian Tiger” model: The CollectA Thylacine Model

Is the Thylacine Extinct?

The main island that makes up the State of Tasmania is a fraction under 25,000 square miles in size, that’s around three times the size of Wales or about the size of the State of West Virginia in the USA.  There have been a number of reported sightings of “Tigers” both in Tasmania and on the Australian mainland.  Evidence for the existence of Thylacines is a little threadbare to say the least.  Blurred and very indistinct photographs, casts of footprints and some poor quality film footage, but nonetheless, there are a number of people, including academics who fervently believe that the Thylacine, although extremely endangered and very vulnerable, is still holding on.  Every now and then a new eyewitness account is published.

Let’s hope that the Thylacine still exists and that one day soon, September 7th will have even greater significance to the people of Australia.

The Gradual Decline of the Dinosaurs – Earth Day Thoughts

The Gradual Decline of the Dinosaurs – Earth Day Thoughts

Today, the 46th commemoration of Earth Day, some 171 nations signed and ratified the historic Paris Agreement on climate change.  In essence, the Agreement sets out that the global increase in temperature will be limited to no more than around two degrees Celsius as countries work together to cut greenhouse gas emissions, widely believed to be responsible for a rapidly warming Earth. Some fifteen nations had already signed this international accord prior to today, mainly small island states in the Pacific, but with the addition of the 171 signatories, this is a record number for a new treaty.

Commenting on the importance of this Agreement, United Nations Secretary-General Ban Ki-moon stated:

“Paris will shape the lives of all future generations in a profound way – it is their future that is at stake.”

UN Secretary-General Ban Ki-moon Addresses Delegates in New York

Ban Ki-moon address the conference in New York

Ban Ki-moon address the conference in New York

Picture Credit: Getty Images

The Two Degree Limit

The Paris Agreement sets out a global action plan to put the world on track to avoid dangerous climate change by limiting global warming to well below 2°C.  Although, the implementation of the agreement will not be easy and several countries, including a number from Africa and central Asia have not signed, if the Earth continues to warm, then our own species could well be threatened.

UN Secretary-General Ban Ki-moon explained that as the planet experienced record highs in average annual temperatures:

“We are in a race against time.  I urge all countries to join the agreement at the national level.  Today we are signing a new covenant for the future.”

Yesterday, Everything Dinosaur reported on some new research conducted by scientists at Reading and Bristol Universities that looked at the extinction of the dinosaurs.  A statistical study (Bayesian analysis), revealed that the Dinosauria had been in gradual decline for some fifty million years before finally becoming extinct. To read an article on this research: Fifty Million Year Decline of the Dinosauria

Extinction of the Dinosaurs Will the Human Race Go the Same Way Due to Global Climate Change?

Unless there is a proactive plan to tackle global climate change a mass extinction event cannot be ruled out.

Unless there is a proactive plan to tackle global climate change a mass extinction event cannot be ruled out.

Picture Credit: Mark Garlick/Science Photo Library

A spokesperson from Everything Dinosaur commented:

“There is already quite a strong body of evidence indicating that our planet is experiencing a mass extinction event.  Many key species are endangered or threatened and as we are top of the food chain it is in all our interests to try to limit greenhouse gas emissions so that a global climate catastrophe can be avoided.”

One of the authors of the research into the decline of the dinosaurs, that we reported upon yesterday, Dr. Sakamoto, pointed out that the research into the demise of the Dinosauria might have a significance with regards to what we are experiencing today.

He stated:

“Our study strongly indicates that if a group of animals is experiencing a fast pace of extinction more so than they can replace, then they are prone to annihilation once a major catastrophe occurs.  This has huge implications for our current and future biodiversity, given the unprecedented speed at which species are going extinct owing to the ongoing human-caused climate change.”

If the UN General-Secretary calls this a “race against time”, then this is one race that the human race cannot afford to lose.

Extinct Bird of New Caledonia Mystery Solved

Giant Bird Mystery Solved But Heaps of Problems

Scientists including researchers from Flinders University (South Australia), have solved the mystery of an extinct flightless bird that once roamed the island archipelago of New Caledonia.  For the first time, the post cranial skeleton has been reconstructed using fossils from a number of cave sites, however, the strange heaps found on the island may not have been nesting mounds created by this large bird, the mounds remain a mystery.

The bird named Sylviornis neocaledoniae, was about the size of a Dodo, but with much longer legs and a longer neck, large individuals may have reached 80 centimetres tall and weighed as much as 34 kgs.  It survived on these isolated islands until very recently, there is evidence to suggest that these birds were around 2,500 years ago.  The arrival of humans in New Caledonia led to the extinction of Sylviornis, but a mystery remained.  Large earth mounds were believed to be nesting sites excavated by these flightless birds but an analysis of foot bones reveals that this extinct New Caledonian resident was not a member of the Megapodiidae (incubator birds), if it did not build these mounds than what or who did?

Scientists have Reconstructed the Skeleton of Sylviornis neocaledoniae

Scale bar = 50 cm, a skeletal reconstruction of the giant, flightless bird from New Caledonia Sylviornis.

Scale bar = 50 cm, a skeletal reconstruction of the giant, flightless bird from New Caledonia Sylviornis neocaledoniae.

Picture Credit: PLOS One

Known bones are shaded white in the illustration above, bones not associated with known remains are shaded grey.  Previously, only the skull had been reconstructed, this robust bird probably fed on small animals including invertebrates.

The islands of New Caledonia in the south-west Pacific lie some 750 miles to the east of the coast of Queensland.  Dinosaur enthusiasts might remember that New Caledonia was the location chosen to shoot episode three of the ground-breaking BBC television series “Walking with Dinosaurs” that first aired back in 1999.  The exotic fauna of these tropical islands contains a number of unique trees and plants, that are descended from species that once existed on the super-continent Gondwana.  The isolation of the islands permitted several types of ancient flora to survive, for example the New Caledonia Pine (Araucaria columnaris) is descended from ancient trees once grazed by dinosaurs.  The islands became Oxfordshire in the Late Jurassic some 149 million years ago, for the purposes of episode three of the television series – “The Cruel Sea”.

The research, published in the on line journal PLOS One suggests that S. neocaledoniae is not closely related to megapodes, birds such as the Australian Brush Turkey (Alectura lathami) or the Malleefowl (Leipoa ocellata), it had feet more like a chicken than the feet of birds that construct large mounds of earth and vegetation which they then lay eggs in, relying on the mound to incubate the eggs.

Comparison of Foot Bones S. neocaledoniae (left) with a Malleefowl (Leipoa ocellata)

Sylviornis foot bones (left) compared to the extant, mould building Malleefowl of Australia (right).

Sylviornis foot bones (left) compared to the extant, mould building Malleefowl of Australia (right).

Picture Credit: PLOS One

The two black bars are scale bars, each one equates to ten centimetres.  The foot of Sylviornis may have been much bigger than the extant Malleefowl, but the toes are proportionally much smaller, the claws less sharp and indeed, the pedal unguals (bones that make up the digits) are also proportionally smaller than that found in the Malleefowl.  The scientists conclude that these feet were not adapted to creating nesting mounds and that S. neocaledoniae probably incubated its eggs by sitting on the nest in the same way as Ostriches and Emus.

Commenting on the study, one of the authors of the scientific paper, Miyess Mitri (Flinders University) stated:

“I was privileged to study this amazing bird, whose large legs and tiny wings made it look like a turkey on steroids.  The tell-tale muscle scars showed that the muscles for the toes were weak and the claws were just like those of chickens — nothing like the mini-spades of mound-builders.”

A phylogenetic analysis using characteristics observed from more than 600 bones studied, suggests that the closest relative of Sylviornis neocaledoniae was Megavitiornis altirostris, colloquially known as the Noble Megapode, that was once resident on the island of Fiji some 850 miles east of New Caledonia.  Sadly, the flightless Megavitiornis seems to have suffered the same fate as Sylviornis, it too became extinct once humans settled on Fiji.  It is likely that both birds, believed to be from the same bird family as the chicken, were hunted to extinction because they tasted good and being flightless they would have been relatively easy to catch.

As for those strange heaps of earth, the research team suggest that they could have been caused by a phenomenon of natural erosion.

We Have Frog Spawn

Frog Spawn Spotted in the Pond

More than a week later than 2015 and a day later than what we recorded in 2013 but we have got the first batch of frog spawn in our office pond.  We noted increased frog activity about a week ago and in the warm weather yesterday afternoon we spotted a mating pair and suspected that the eggs would be laid in the night.  Sure enough, when the pond was examined this morning we noticed our first batch of frog spawn for the 2016 season.

A Close up of the Frog Spawn in the Office Pond

Frog spawn in the office pond (spring 2016).

Frog spawn in the office pond (spring 2016).

Picture Credit: Everything Dinosaur

The picture above shows a batch of frog spawn, the first of the season in our office pond.  A large Ramshorn snail is close by but this herbivore will pose no threat to the newly laid eggs.  The frog species is the Common Frog (Rana temporaria), these amphibians are no longer common, their numbers have declined dramatically in recent years and garden ponds are an important habitat for them.  Most gardeners welcome these unobtrusive creatures as they consume lots of garden pests such as slugs and beetles.

We suspect it will not be long before our second batch of frog spawn is laid.  We have noticed another breeding pair in the pond this afternoon.  It is likely that we will have a second batch of spawn in the morning.  Interestingly, the spawn has been laid in one of the deeper parts of the pond.  The office pond is only about two feet deep (sixty centimetres) and it has been cleaned out with a lot of the weed having been removed recently, however, in folklore, frogs laying their spawn deep means that we are in for a particularly dry spring.  We doubt the weather forecasting abilities of the frogs ourselves but we shall have to wait and see.

Mystery Tadpole in the Pond

A single large tadpole has been observed in the office pond.  This animal overwintered in the pond and has yet to develop legs.  We were surprised to see this tadpole, we were not aware that some tadpoles did not undergo metamorphosis in the summer months after hatching in the spring.  Some research led us to the website of the Freshwater Habitats Trust: Freshwater Habitats Trust – The Common Frog and in their highly informative article, it is stated that the overwintering phenomenon has been recognised but the reasons for adopting this strategy are not fully understood.  The web page did state that these tadpoles are in some way ahead of the game come the following spring and the decision about whether to follow this strategy appears to be made quite early on in the year.  We are not aware whether individual tadpoles are genetically predisposed to develop over two years or whether all Common Frog tadpoles could potentially do this.

Reference is made to an academic paper on this subject, namely: Larval over-wintering: plasticity in the timing of life-history events in the common frog P. T. Walsh, J. R. Downie, P. Monaghan, Journal of Zoology Volume 276, Issue 4, pages 394–401, December 2008.

The Wildebeest and Lambeosaurine Connection?

Ancient Beast “Honked Like a Hadrosaur”

Convergent evolution throws up strange bedfellows from time to time.  Scientists studying an ancient bone bed have uncovered extensive fossil material from an ancient wildebeest that shows that this hoofed mammal had a raised nasal dome, reminiscent of a hollow crested duck-billed dinosaur.  Researchers have suggested that the bizarre anatomical structures helped these herd animals communicate more effectively.  It’s a question of what evolution did for the likes of Corythosaurus some 75 million years ago has been repeated in a Pleistocene bovine from around 75,000 years ago.

A Trumpeting Wildebeest – Rusingoryx atopocranion

Honking to communicate in the hot savannah.

Honking to communicate in the hot savannah.

Picture Credit: Todd Marshall

The ancient ungulate (hoofed mammal), was poorly known until a bone bed containing the remains of at least twenty-four individuals was discovered on Kenya’s Rusinga Island.  The fossilised remains, which includes juveniles as well as adult animals, has enabled scientists to piece together a much more comprehensive picture of the anatomy of this grazing mammal, part of a diverse African bovine fauna that flourished on the hot, dry savannah of southern Africa during the Pleistocene Epoch.

Stone tool marks on the bones indicate that these animals were butchered and it has been suggested that Middle Stone Age people had driven the animals into a river and ambushed them, or perhaps, a tribe benefited from a chance discovery of a group of these creatures who had recently drowned in a flood event.

Hollowed-out Headgear

The wildebeest is known as Rusingoryx atopocranion, but until now it had only been known from partial remains, including incomplete skulls.  The Rusinga excavation, supported by the National Geographic Society’s Committee for Research and Exploration has uncovered a total of six skulls, most of them complete.  Thanks to these fossils, scientists have a much better idea of what these animals actually looked like.

Commenting on the new evidence, lead author of the study, Haley O’Brien (Ohio University) stated:

“The first time I saw them my jaw completely dropped”.

Previous studies based on much less complete fossil material had speculated that Rusingoryx possessed a proboscis, but the new skulls discount this idea.  Instead, they reveal that R. atopocranion had a high nasal dome in front of its eyes, a sort of “cow with a Roman nose”.  The raised naris was hollow, encasing a winding, circuitous nasal passage.

The Skull of Rusingoryx (R. atopocranion)

The dome shaped skull (raised nasal bones).

The dome shaped skull (raised nasal bones).

Picture Credit: Haley O’Brien

PhD student Haley explained:

“There aren’t any living animals with a nasal apparatus like this, but there are some fossil ones.  Outside and in, the nose of Rusingoryx resembles the hollow crests of the “duck-billed” dinosaurs, animals like Corythosaurus and Lambeosaurus, which lived about 75 million years earlier.  Both groups essentially push the nasal part of their airway into the crest and they’re using similar suites of bones to form the crest itself.”

The Skull of the Mexican Lambeosaurine Velafrons (Velafrons coahuilensis)

Raised nasals - an example of convergent evolution.

Raised nasals – an example of convergent evolution.

Picture Credit: Paul Fraughton/Salt Lake Tribune

Commenting on the similarities between Rusingoryx and Late Cretaceous duck-billed dinosaurs, palaeontologist David Evans (Royal Ontario Museum, Toronto), stated that he was “blown away” by the skulls of Rusingoryx, he added:

“The resemblance between Rusingoryx and some hollow-crested dinosaurs in the form of the nasal structures is truly striking.”

Convergent Evolution

The dome shaped nasal area of Rusingoryx is an example of convergent evolution, whereby unrelated organisms evolve independently similar features, such as the streamlined bodies and tail flukes of dolphins and ichthyosaurs.  These are adaptations to similar habitats or ecological niches.

However, faced (no pun intended), with this strange-faced wildebeest, the big question is what sort of function did these domed noses have?

A number of ideas have been put forward:

  • The expanded naris played a role in cooling or warming incoming air

The large nose of Rusingoryx may certainly have been able to undertake this function and all mammals have some ability to do this, thanks to scroll-like bones called turbinates that increase the surface area of the nose.  As Rusingoryx lived in a very hot, dry environment this theory is plausible, but the dome’s internal anatomy did not support this conclusion.

  • The raised domes were used in ritual combat

A number of bovines use their skulls as battering rams to settle disputes and as defensive weapons.  However, the skull bones of Rusingoryx are very thin, much thinner than those of extant Artiodactyls (even-toed hoofed mammals) that indulge in such behaviour.

  • The nasal area acted as a resonating chamber for sound

Social, hoofed, herd-dwelling herbivores tend to be quite vocal.  They have ways to modulate their vocal tracts to increase the variety and range of sounds that they can make.  The skull anatomy suggests that the big dome-faced wildebeest used this structure to vocalise.

Student O’Brien explained:

“We calculated a frequency of between 250 and 750 hertz, which is not only pretty low, it also overlaps with the sonic frequencies of a vuvuzela.  Rusingoryx could very likely make a low trumpeting sound but there’s a good chance it could also vocalise in stealth mode.”

Being able to communicate at a low frequency making it difficult for some predators to hear, has a distinct evolutionary advantage, human hunters for example would have had difficulty picking up these sounds.  In addition, a herd of these animals would have been capable of making a lot of noise, much like a stadium full of South African football fans waving their vuvuzelas.

If Crocodiles and Some Birds Sleep with One Eye Open – Could Dinosaurs?

Unihemispheric Sleep and the Dinosauria

A new study from scientists from the Max Planck Institute for Ornithology (Seesiesen, Germany), and La Trobe University (Melbourne, Australia) suggests that juvenile Saltwater crocodiles might sleep with one eye open.  This could be an indication of a phenomenon observed in aquatic mammals, some birds and reptiles, that of unihemispheric sleep.  Unihemispheric sleep occurs when only half the brain slumbers whilst the other half remains alert.  This ability may have evolved in unrelated groups of animals independently, a case of convergent evolution, whereby similar characteristics evolve in unrelated animals as a result of having to adapt to similar environments or conditions.  Alternatively, this ability could have evolved long ago, in the shared, common ancestor of modern birds, mammals and crocodiles.

Crocodiles May be Capable of Unihemispheric Sleep

It might be more alert than you think!

It might be more alert than you think!

Picture Credit: The Press Association

Dinosaurs Sleeping with One Eye Open?

This newly published information, reported in the Journal of Experimental Biology, involved the study of the responses of young Saltwater crocodiles (Crocodylus porosus).   The team filmed the reptiles and recorded their reactions to certain potential threats, such as the presence of another crocodile or a human.  It was noted that the crocodiles usually slept with both eyes closed.  However, in the early part of the day, it was observed that the crocodiles opened one eye briefly during periods of sleep.  When isolated crocodiles had a second crocodile introduced into their tank, the crocodile kept their open eye on the intruder.  The researchers state that this is consistent with a “vigilance function” – staying aware of danger.  When a person entered the crocodile’s enclosure, whilst the crocodiles appeared to slumber, they actually took a lot of notice, keeping their vigilant eye focused on the potential threat for several minutes at a time.

A number of vertebrates have this ability to keep one eye open and connected to the conscious half of the brain.  The closed eye is connected to the other half of the brain that has shut down and is resting.  This behaviour may have evolved to help animals avoid predators.  In addition, aquatic mammals like dolphins keep one eye open when sleeping so that they can remain close to their pod.  Perhaps young crocodiles keep one eye open when sleeping to help them stay aware of their siblings as well as looking out for danger.

Commenting on the significance of their research, senior author of the academic paper, Dr. John Lesku (La Trobe University), stated:

“They definitely monitored the human when they were in the room.  But even after the human left the room, the animal still kept its open eye… directed towards the location where the human had been – suggesting that they were keeping an eye out for potential threats.”

Potential Implications for the Dinosauria

With the majority of dinosaurs being ground-dwelling, the implications of this study can be quite profound.  If some birds and now crocodiles sleep with an eye open, then perhaps the dinosaurs did as well.   Birds and crocodiles are the closest living relatives of the Dinosauria.  Could this study provide an insight into the sleeping habits of dinosaurs? Resting on the ground, unable to climb a tree to roost or to hide in a burrow, a sleeping dinosaur may have been very vulnerable to attack.  Living in a social group such as a herd would have offered some protection, after all, some of the herd members could sleep whilst the remainder stayed vigilant but this new study does lead onto the intriguing question as to whether members of the Dinosauria were capable of unihemispheric sleep to.

Did Dinosaurs Sleep with One Eye Open?

Did dinosaurs sleep with one eye open?

Did dinosaurs sleep with one eye open?

The animals used in the study were less than half a metre in length and Everything Dinosaur is not aware of any research of this nature carried out on larger crocodiles, or indeed of any study undertaken to ascertain the sleeping habits of Crocodilians in the wild.  The researchers conclude that crocodiles may sleep with one eye open, but to confirm unihemispheric sleep they need to be able to monitor the brain activity in both brain hemispheres of a sleeping crocodile.  Attaching sensors to the skull of even a half metre long crocodile will present quite a challenge.  In order to confirm the team’s ideas the researchers might have to risk losing a finger to these feisty carnivores.

New Species of Rat Discovered in Sulawesi

The Magical Rodent Infested Forests of Sulawesi – Hyorhinomys stuempkei

The small island of Sulawesi can be found in the central part of the range of islands that form Indonesia.  The fauna of this heavily forested island has fascinated scientists for a very long time.  It is located approximately half-way from Australia and Papua New Guinea to the east and Malaysia/south-east Asia to the west.  The Philippines lie to the north.  Researchers have studied the Sulawesi ecosystem in order to gain an understanding of how organisms have migrated across land bridges that once existed in the past.  Think of Sulawesi and this part of the world as a crossroads, where the fauna of Australasia and the rest of Asia mixes.

The Magnificent and Remote Mountainous Forests of Sulawesi

A magical place with a unique fauna.  The remote forests of Sulawesi.

A magical place with a unique fauna. The remote forests of Sulawesi.

Picture Credit: Dr. Kevin Rowe/Museum Victoria

The great scientist and naturalist Alfred Russel Wallace, who co-authored the 1858 paper on the theory of evolution by natural selection with Charles Darwin, spent many years exploring the jungles and forests.  It was because of his travels in this part of the world that he formulated many of his ideas on the natural world.  Wallace’s in-depth exploration of the Indonesian islands allowed him to develop a theory related to the geographical spread of organisms.  He noted that the world’s animals could be divided up into zoogeographical regions, the Mammalian fauna of Indonesia illustrate this idea nicely.  Sulawesi lines to the east of an imaginary line drawn through the archipelago (the Wallace Line).  Many Asian animal types have their eastern most distribution on Sulawesi and conversely many Australian lineages have their most westerly distribution on Sulawesi.  This has led to evolution of a very unique fauna on the island, most of the human inhabitants (about twenty million) live on the coast, some parts of the island remain relatively unexplored.  The island is also very big, it is the eleventh largest island in the world, and its landmass is roughly equivalent to the size of England, Wales and Northern Island combined.

The Approximate Position of the Wallace Line

Marking the barrier between Asian and Australasian faunas.

Marking the barrier between Asian and Australasian faunas.

Picture Credit: Google Map/Everything Dinosaur

Over the last few years, scientists from Museum Victoria, in collaboration with Indonesian colleagues and researchers from the United States have been trapping rodents in the forests found in the more mountainous and difficult to access parts of the island.  They have recorded a unique and very varied rodent assemblage, including the latest addition, the newly discovered Hyorhinomys stuempkei (hog-nosed rat).

This rat with its proportionately large ears, flat claws and bizarre hog-like nose is so genetically different from other species that it has been assigned its own genus.   A paper on the research team’s study will be published this month in the “Journal of Mammalogy”.

Hyorhinomys stuempkei (hog-nosed rat) of Sulawesi

The Hog-nosed rat - Hyorhinomys stuempkei

The Hog-nosed rat – Hyorhinomys stuempkei

Picture Credit:

H. stuempkei is not the first new rodent species to be discovered by Dr. Kevin Rowe (Museum Victoria) and his colleagues.  Sulawesi seems to be home to a whole host of unique rodents.  For example, Dr. Rowe was involved in the discovery and description of a very curious rat – Paucidentomys vermidax, a rodent like no other known to science.  It is almost toothless and unable to gnaw or chew.  It hunts worms and other soft-bodied creatures on the forest floor.  It’s discovery provided evidence to scientists that, under certain conditions, even highly successful traits such as gnawing teeth, a defining characteristic of the Rodent Order, can be lost.

The Almost Tooth-less, Worm Eating Paucidentomys vermidax

Paucidentomys vermidax - a bizarre newly discovered rodent from Sulawesi.

Paucidentomys vermidax – a bizarre newly discovered rodent from Sulawesi.

Picture Credit: Museum Victoria

In the case of the hog-nosed rat  Hyorhinomys stuempkei, the striking feature of this rodent is its large, pink and very flat nose with forward facing nostrils.  It also lacks a coronoid process on the lower jaw, an attachment site for muscles involved in chewing that is present in almost all other mammals including our own species.   Hyorhinomys stuempkei is very probably entirely carnivorous feeding on invertebrates, possibly bounding or hopping after its prey as its back legs are unusually long.  It has a disproportionately small mouth, but long incisors, which are bright white (strange for a rat as the incisors are usually orange coloured in most other rodents).  Take note of this, could companies with an interest in selling tooth-whitening products be making a bee-line for the remote forests of Indonesia?

Commenting on the new rodent discovery, Dr. Rowe stated:

“The Hog-nosed Rat is exciting for us because it extends the diversity of an already amazing group of rodents that are only found on the island of Sulawesi.  Even though there are only eight species in this endemic group, they exhibit a huge eco-morphological range including small grey rats, a nearly toothless vermivore, an amphibious rat, and now a long-limbed, hog-nosed rat.  There are millions of species on this Earth that are yet to be discovered and described, but I am still amazed that we can walk into a forest and a find a new species of mammal that is so obviously different from any species, or even genus, that has ever been documented by science.”

It’s worth noting that almost all of the mammals native to Sulawesi are endemic to this island and the genus name Hyorhinomys translates from the Greek as hog (hyo), nose (rhino) and rat (mys).

Discovered by an international team comprising Dr. Kevin Rowe (Museum Victoria); Heru Handika (Museum Victoria); Anang Achmadi (Museum Zoologicum Bogoriense); and Dr. Jacob Esselstyn (Louisiana State University Museum of Natural Science) this new discovery is the third new genus described by this international collaboration since 2012.

Carbon Dioxoide Emissions Threaten Ocean Ecosystems

Marine Life Could Be Irreversibly Damaged

Increased carbon dioxide emissions will cause great damage to oceanic ecosystems that cannot be reversed warns an international team of scientists.  In a new paper, published in the academic journal “Science”, researchers, which include Dr. Carol Turley OBE, of the Plymouth Marine Laboratory state that unless CO2 emissions are curbed, the temperature of the oceans will continue to rise, oxygen levels will continue to fall and more seawater acidification will occur.  The scientists paint a very gloomy picture for the Earth’s oceans declaring that CO2 emissions from the burning of fossil fuels was increasing the acidity of the oceans at a faster rate than at any time since the End Permian extinction event some 250 million years ago, that led to the greatest mass extinction known in the fossil record.  Something like 95% of all the life on Earth died out during this extinction event.

The researchers looked at a number of scenarios and models and the scientists stated that the two degree Celsius maximum temperature rise as agreed by governments is not enough to stave of the damaging effects of increased CO2.  In a very pessimistic outlook, the scientists claim that the range of options is decreasing and the cost of coping with the implications will rocket.   The team of twenty-two leading marine scientists report that politicians are not responding as quickly as they should to the approaching crisis.  The oceans of the world are at risk and more must be done to deal with the impact of global climate change.

The World’s Oceans are Under Threat

Increased CO2 emissions could spell disaster for the oceans.

Increased CO2 emissions could spell disaster for the oceans.

Picture Credit: Everything Dinosaur

Nearly 30% of the carbon dioxide produced since 1750 has been absorbed by the ocean.  As CO2 is slightly acidic it is changing the chemistry of the water and making it more acidic.  This is disastrous for those organisms that use calcium or argonite to build shells or to construct colonies.

Dr. Turley stated:

The ocean is at the frontline of climate change with its physics and chemistry being altered at an unprecedented rate so much so that ecosystems and organisms are already changing and will continue to do so as we emit more CO2.  The ocean provides us with food, energy, minerals, drugs and half the oxygen in the atmosphere, and it regulates our climate and weather.  We are asking policy makers to recognise the potential consequences of these dramatic changes and raise the profile of the ocean in international talks where, up to now, it has barely got a mention.”

Recently, Everything Dinosaur reported on the research conducted by scientists at the Universidad Nacional Autónoma de Mexico, the University of California, Stanford University, Princeton University and the University of Florida that concluded that our planet was entering a sixth, global mass extinction phase.

To read more about this research: Study Suggests Sixth Mass Extinction Event in Earth’s History

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