Category: Dinosaur and Prehistoric Animal News Stories

New Species of Ancient Dolphin Hiding in a Museum Collection

Arktocara yakataga – May Hold Key to Freshwater Dolphin Evolution

Back in the early fifties, when geologist Donald J. Miller (United States Geological Survey), was mapping the area of Alaska that would eventually become Yakutat City, he came across an ancient skull of a whale. The snout had been broken off and lost but the preserved cranium led to the conclusion that the cranial material and associated teeth belonged to an ancient dolphin.  The fossils were despatched to the Smithsonian’s National Museum of Natural History, where they remained until a newly published study revealed their significance.

A New Species of Prehistoric Dolphin

The fossils represent a new species of prehistoric dolphin, an animal that lived around twenty-five million years ago and it represents the most northerly specimen of this type of toothed whale ever found.  The genus name translates from the Latin as “Face of the North” a reference to the high latitude location of the fossil discovery and the fact that the skull has been designated the holotype.

A Line Drawing (A) and a View of the Fossil Skull (B)

Arktocara skull.

A dorsal view of the skull of Arktocara (right) and associated line drawing (left)

Picture Credit: James Di Loreto, Smithsonian Institute

Published in the academic journal “PeerJ”, palaeontologists Nicholas Pyenson and Alexandra Boersma describe the fossils and place it within the toothed-whale group, specifically the Platanistoidea.  Ironically, the only extant members of this group are confined to freshwater river systems, but the fossil record indicates that these types of dolphins evolved in marine environments.  The scientists hope that this new fossil discovery, a specimen that had languished in the Smithsonian fossil collection for more than half a Century, will help to shed light on the phylogeny of the Platanistoidea as well as assisting in the research to determine how these particular toothed whales evolved.

Alex Boersma, currently based at the California State University, commented:

“It’s a lovely skull, which is probably the first thing I noticed about it”.

The Skull and Other Fossil Elements

Arktocara Fossil Material

The fossil Arktocara yakataga (resting on an 1875 ethnographic map of Alaska) belonged to a dolphin that swam in subarctic marine waters around 25 million years ago.

Picture Credit: James Di Loreto, Smithsonian Institute

The researchers are confident that more strange Cetacean skulls may be awaiting discovery in northern latitudes and Alex is sure that this specimen “could answer questions about how this once cosmopolitan group dating back over twenty million years dwindled down to just a few freshwater species.”

The Poul Creek Formation

The fossil comes from the Poul Creek Formation, but the exact location remains unknown, however, the scientists estimate that the fossil dates from between 29 and 24 million years ago, an important period in the history of whale evolution as the two main groups the toothed-whales “Odontoceti” and the baleen whales “Mysticeti” were diversifying and radiating into a number of new genera.

Measuring a little under two and a half metres in length, Arktocara yakataga was about the size of a modern Common Bottlenose Dolphin (Tursiops truncatus).  Although the scientists cannot be absolutely certain where the animal died, after all, bones can be transported considerable distances prior to burial and fossilisation, it seems reasonable to assume that this mammal did live in a marine environment.  The research team stress that many other types of important fossil may be lingering within the collections of museums, their significance having not yet been realised due to incorrect labelling or inaccurate classification.

An Illustration of Arktocara yakataga

Arktocara illustrated.

An illustration of Arktocara.

Picture Credit: Linocut print art by Alexandra Boersma

To read a recently published article about the origin of high frequency hearing in whales: How High Frequency Hearing in Whales May Have Evolved

How the Marsupial Lion Got To Grips With Its Prey

Unique Elbows of Thylacoleo Hints at Hunting Strategy

The fearsome Thylacoleo (Thylacoleo carnifex), commonly referred to as the “Marsupial Lion” may have had a unique hunting strategy.  The anatomy of the limbs indicate that this native of Australia up until around 46,000 years or so ago, had very robust front legs, but it was not a fast runner.  It was probably an ambush specialist, but how did this 100 kilogramme mammal despatch its prey?  After all, it did not have the teeth typical of a carnivore.  For example, Thylacoleo lacked canines in the lower jaw and although they were present in the upper jaw, they were extremely small (a feature no doubt noted by Richard Owen, later Sir Richard Owen, who named and described this genus back in 1859).

The Fearsome Thylacoleo – but How Did it Hunt and Kill?

The fearsome Thylacoleo (Marsupial Lion)

Capable of climbing trees and with strong forelimbs for despatching prey.

Picture Credit: Peter Trusler/Australian Post

In a new paper, published in the academic journal “Paleobiology”, scientists from the University of Málaga (Spain), in collaboration with colleagues from Bristol University conclude that Thylacoleo used its big but blunt incisors to grab prey before carrying out the “coup de grâce” with a swipes from its powerful paws which possessed a formidable set of claws including a super-sized claw on its first digit, (the equivalent digit in our species being the thumb).

Comparing Elbows

How was this conclusion made?  It’s relatively simple really, the scientists studied the fossilised elbows of Thylacoleo and compared them to a number of living mammals (placental as well as marsupial).  It turns out that this pouched predator had a unique elbow joint amongst carnivorous mammals.

One of the authors of the newly published paper, Christine Janis (Marie Curie Research Fellow at the University of Bristol, currently on a leave of absence from a professorship at Brown University, United States), explained that this study indicates that there is a strong association between the anatomy of the humerus where it articulates with the ulna and radius (the elbow) and the way in which animals move about.

The Fossilised Remains of a Marsupial Lion

Marsupial Lion (Thylacoleo) remains.

The fossilised bones of a Marsupial Lion (Australia).

Specialised runners like canids (dogs) have an elbow joint indicating movement restricted to a back and forwards motion, helping to stabilise their bodies on the ground, great for running, whilst mammals that are confident climbers, monkeys for example, have an elbow joint that allows for rotation of the hand.  Felidae (cats), have an elbow joint of intermediate shape, as they use their forelimbs to wrestle prey and many types of cat are adroit when it comes to climbing.

In contrast, the unique elbow joint of Thylacoleo permitted extensive rotation of the hand but it also possessed features not seen in extant mammals that permitted the elbow to stabilise the limb when the animal was on the ground.  The “Marsupial Lion” has long been thought to have been at home in the trees, an animal capable of an arboreal existence, although ironically a number of the most complete and best preserved Thylacoleo fossils have been found in limestone caves in the Nullabor Plain region of Australia (Nullabor loosely translates as “no trees”).

Christine Janis stated:

“If Thylacoleo had hunted like a lion using its forelimbs to manipulate its prey, then its elbow joint should have been lion-like.  But, surprisingly, it had a unique elbow-joint among living predatory mammals , one that suggested a great deal of rotational capacity of the hand, like an arboreal mammal, but also features not seen in living climbers, that would have stabilised the limb on the ground (suggesting that it was not simply a climber).”

Christine and her colleagues group Thylacoleo with living animals that have an extreme amount of forelimb manoeuvrability, animals such as primates, sloths and anteaters.  The analysis showed that it had a greater degree of manoeuvrability than any living, meat-eating placental mammal and the team concludes that Thylacoleo was mainly terrestrial but with some climbing abilities and the forelimbs were used to overpower prey.

The African lion (Panthera leo) does not possess such flexible forelimbs and when the unique elbow joint is considered in conjunction with that over sized first digit claw, the researchers hypothesise that the “Marsupial Lion” used its claws to kill.  The big, but blunt incisors in the jaws were probably used to clamp down on prey and then with the large and retractable claw on the semi-opposable thumb (the dew claw), Thylacoleo could have slashed at its victims.

The First Human Inhabitants of Australia Knew All About the Marsupial Lion

However, it hunted, Thylacoleo was one creature that you would not want to have encountered in the outback.   The first Australians, the ancestors of the today’s aboriginal people, would have known Thylacoleo and probably they were wise enough to give it a wide berth.

The scientific paper: “Ecomorphological determinations in the absence of living analogues: the predatory behaviour of the marsupial lion (Thylacoleo carnifex) as revealed by elbow joint morphology”

To read an earlier article which examined the link between scratches made on cave walls and the climbing abilities of the Marsupial Lion: Don’t Climb a Tree to Avoid a Thylacoleo!

Getting Excited About Paleo-Creatures

A Short Video of the Paleo-Creatures Replicas

Team members at Everything Dinosaur are getting very excited at the imminent arrival of the first of the Paleo-Creatures prehistoric animal models.  Stocks of Xenacanthus, Tullimonstrum (Tully’s monster) and Atopodentatus (A. unicus) et al,  will soon be filling our warehouse shelves and we can’t wait for the shipment to arrive.  Everything Dinosaur announced recently that they would be stocking the Paleo-Creatures line of high quality, polyurethane resin replicas.

The Paleo-Creatures range of hand-crafted, scale model prehistoric animals has been created by talented Spanish artist and designer Jesús Toledo.  He very kindly sent Everything Dinosaur a link to a short video showing the models that we had ordered laid out ready for packing before they were despatched to our warehouse.  In this short video (one minute forty-five seconds), viewers get the chance to see up close for themselves just how gorgeous these models are.  Check out the video in this link: Paleo-Creatures Video

Video Credit: Jesús Toledo (Jetoar’s Collectables)

A Row of Torvosaurus Models from Paleo-Creatures

Paleo-Creatures Torvosaurus

A row of Paleo-Creatures Torvosaurus.

Picture Credit: Jesús Toledo (Jetoar’s Collectables)

 The picture above is from the short video that was sent to Everything Dinosaur.  The video shows some of the models lined up ready for packing prior to their despatch to our warehouse.   The model in the middle is the beautiful Paleo-Creatures Torvosaurus replica.  What a fantastic dinosaur model this is!  Just behind Torvosaurus some Paleo-Creatures Tullimonstrum (T. gregarium) can be seen.  Lining up in front of the fearsome Torvosaurus are some Kosmoceratops models, perhaps being just in front of a hungry Torvosaurus, especially a model with an articulated lower jaw, is quite a dangerous place for a horned dinosaur model to be.

Aegirocassis and Koolasuchus Replicas (Paleo-Creatures)

Paleo-Creatures models.

The Aegirocassis replicas (foreground), Koolasuchus models (background).

Picture Credit: Jesús Toledo (Jetoar’s Collectables)

The splendid Aegirocassis (anomalocaridids, also referred to as anomalocarids) are lined up ready to be packed, these are wonderful models of the giant Ordovician filter-feeder.  In the background, some of the Koolasuchus replicas are awaiting their turn to be packed.  They too, are very beautiful and highly detailed, hand-crafted models.

To read a press release announcing that Everything Dinosaur would be stocking the Paleo-Creatures model range: Paleo-Creatures Coming to Everything Dinosaur

A Close Up of the Paleo-Creatures Concavenator

The Paleo-Creatures Concavenator.

A close up view of the Paleo-Creatures Concavenator.

Picture Credit: Jesús Toledo (Jetoar’s Collectables)

The fine detailing on these models can really be made out, both in these still pictures and from the video that was kindly sent in to us.

Eotyrannus (E. lengi) Model from Paleo-Creatures

Paleo-Creatures Eotyrannus model.

The Paleo-Creatures Eotyrannus ready for shipping.

Picture Credit: Jesús Toledo (Jetoar’s Collectables)

Orthacanthus was a Cannibal

Teeth in Coprolites Indicate Cannibalism in Orthacanthus

A study of the coprolites of a prehistoric, freshwater shark suggest that this fish indulged in cannibalism when times were hard.  The shark in question, an Orthacanthus (identified from the typical spiral shape of the fossil poo), probably ate members of its own species when other food resources became scarce.

During the Late Carboniferous, much of the northern hemisphere was covered by swamps and ancient forests.  Amphibians and primitive reptiles dominated the land, but in the water, the fish reigned supreme and one group of fishes, that have survived through to today, the sharks, were particularly diverse and numerous.

Sharks not only dominated marine environments but they were also present in large numbers in brackish conditions and freshwater.  One group of sharks, the Xenacanthiforms were very common in freshwater environments and Orthacanthus was a member of this group.  Fossil coprolites found in the Minto Coalfield of New Brunswick, Canada, reveal a dark secret.  The 300 million-year-old shark poo is packed with the fossilised remains of juvenile members of its own genus.  This is evidence of cannibalism, specifically fillial cannibalism – when adults of one species deliberately hunt and consume young of their own species, even their immediate offspring.

An Illustration of the Prehistoric Freshwater Shark Orthacanthus

The prehistoric freshwater shark Orthacanthus

An illustration of the prehistoric freshwater shark Orthacanthus, scientists have found evidence of cannibalism.

Picture Credit: Alain Beneteau

Orthacanthus – A Freshwater Prehistoric Shark

A number of species of Orthacanthus shark have been described.  These sharks, that possessed a long spine just in front of their sinewy dorsal fin, evolved in the Devonian.  Orthacanthus fossils (especially teeth) are quite common in Carboniferous rocks located in North America and Europe.  Orthacanthus teeth fossils have been found in Cumbria (UK), close to the small port of Whitehaven, a part of the coast we at Everything Dinosaur, know quite well.  The sediments in that part of Cumbria represent a coastal environment and amongst the carbonised remains of ancient plants, occasionally the distinctive tricuspid (three pointed) teeth of Orthacanthus can be found.

PhD student Aodhán Ó Gogáin (School of Natural Sciences, Trinity College Dublin, Ireland), one of the co-authors of the study that has been recently published in the journal of the Palaeontology Association “Palaeontology”, stated:

“Orthacanthus was a three-metre-long Xenacanth shark with a dorsal spine, an eel-like body, and tricuspid teeth.  There is already evidence from fossilised stomach contents that ancient sharks like Orthacanthus preyed on amphibians and other fish, but this is the first evidence that these sharks also ate the young of their own species.”

A Typical Shark Coprolite (note the spiralling)

A spiral shaped shark coprolite.

Shark coprolite indicates cannibalism in Orthacanthus.

Picture Credit: Journal Palaeontology

Corkscrew Coprolite

Fossil shark poo (coprolite) is not rare, it can be found in quite plentiful quantities in some bedding planes.  Shark coprolite comes in all shapes and sizes, but it often has a distinctive spiral pattern on it, an impression of the intestinal tract in which it was formed and of the rectum in which it was passed through.  It is this spiral pattern that has permitted the scientists to identify the coprolite down to genus level in this instance.

Another co-author of the report, Dr Howard Falcon-Lang, of the Royal Holloway University of London commented:

“We don’t know why Orthacanthus resorted to eating its own young.  However, the Carboniferous Period was a time when marine fishes were starting to colonise freshwater swamps in large numbers.  It’s possible that Orthacanthus used inland waterways as protected nurseries to rear its babies, but then consumed them as food when other resources became scarce.”

Fillial cannibalism has been observed in a number of extant shark species, including the Bull Shark (Carcharhinus leucas).  The researchers suggest that Orthacanthus may have filled a similar environmental niche as modern Bull Sharks.  Both types of shark are able to migrate backwards and forwards between salt and freshwater and in the case of Orthacanthus, this unusual adaptation for a fish may have helped it play an important role in the colonisation of inland freshwater environments.

A Polished Section of a Orthacanthus Coprolite with Juvenile Teeth Fragments Highlighted

A polished section of Orthacanthus coprolite reveals evidence of cannibalism.

A cross section of Orthacanthus coprolite with the fossilised teeth of a juvenile Orthacanthus indicated in the box.

Picture Credit: Journal Palaeontology

In the picture above a cross section of a Orthacanthus coprolite shows tricuspid teeth of a juvenile preserved within the fossil poo (black box).

The scientific paper: “Fish and Tetrapod Communities Across a Marine to Brackish Salinity Gradient in the Pennsylvanian (early Moscovian) Minto Formation of New Brunswick, Canada, and their Palaeoecological and Palaeogeographical Implications”.

Chinese Fossil Primates Unravel Evolutionary Puzzle

Ancient Asian Primates Decimated by Climate Change

The lineage of primates that led to the monkeys, the apes and eventually the hominins (that’s us), originated in Asia.  Palaeoanthropologists and palaeontologists tend to agree on this as the known fossil record suggests a Far Eastern evolutionary heritage for our distant ancestors.  However, there is a conundrum, if the anthropoids (those flat-faced monkeys that led to the apes and ourselves), evolved in Asia, then why didn’t this evolutionary line continue and lead to higher apes and hominins from Asia?

The fossil record indicates that the earliest anthropoid fossils date from 45 million years ago (Asian fossil discoveries).  In African strata some seven or eight million years younger, the first fossils of African anthropoids are found.  We can conclude from this fossil evidence that the anthropoids first evolved in Asia, only making their way to Africa around 38 million years ago, with the hominins evolving something like 33 million years later, but only in Africa, so what caused the Asian anthropoids to stall?

Thanks to some remarkable fossil finds from China, scientists have solved this primate puzzle, it seems that dramatic climate change some 34 million years ago, nearly wiped out Asian primates, decimated populations and rendered much of that continent as “no go” areas for our distant cousins.

Ancient Teeth and Bones Provide an Important Breakthrough in Our Understanding of Primate Evolution

Fossil jaws and teeth of ancient Chinese primates.

Different types of ancient primate from southern China identified from their fossilised jaws and teeth.

Picture Credit: Chinese Academy of Sciences

The picture above shows the different types of fossil teeth and jawbone used by the scientists to identify new species of Asian Oligocene primates.

In a study published in the journal “Science”, researchers from the University of Kansas in collaboration with colleagues from the Chinese Academy of Sciences, report on the identification of six new species of primates from a site in southern China.  Described as a “mother lode”, these extremely rare and precious fossils shed light on how some Asian primates survived the global cooling event that marked the end of the Eocene Epoch.

Eocene to Oligocene Transition (EOT)

The end of the Eocene Epoch is marked by a significant extinction event.  It may not have been as devastating as the end Cretaceous extinction that led to the demise of something like 70% of all large terrestrial animals, but nonetheless, there was a considerable amount of faunal turnover with many long-established genera (such as the early whales), becoming extinct.  Some 34 million years ago, the Earth cooled dramatically.  Global temperatures fell from an average of around 21 degrees Celsius to around 16 degrees Celsius.  Scientists remain uncertain as to the cause of the cooling, although there was considerable tectonic plate activity, volcanism and a number of extraterrestrial impacts during the Late Eocene.  Some studies have indicated a fall in atmospheric carbon dioxide at this time.  This “greenhouse gas”, so feared today, because of its affect on global warming, may have been reduced in the atmosphere to such an extent that the Earth entered a phase of dramatic cooling.  It is at this time that Antarctica began to change into the frozen wasteland we know today.

As the Earth grew colder so the tropical forests shrank and the available habitat for Asian primates was greatly reduced, the six newly described species were part of an ecosystem that clung on in southern China, an area where a tropical climate still persisted.

Commenting on the significance of this decade long study, co-author of the scientific paper, K. Christopher Beard, (senior curator at the University of Kansas Biodiversity Institute) stated:

“Primates like it warm and wet, so they faced hard times around the world — to the extent that they went extinct in North America and Europe.  Of course, primates somehow survived in Africa and southern Asia, because we’re still around to talk about it.”

The Key to Understanding the Evolution of Primates

As anthropoid primates first appeared in Asia, these new fossil discoveries help scientists to understand the fate of primates on that continent, which is fundamental to understanding early primate and ultimately ape evolution.

Senior curator Beard added:

“This has always been an enigma.  We had a lot of evidence previously that the earliest anthropoids originated in Asia.  At some point, later in the Eocene, these Asian anthropoids got to Africa and started to diversify there.  At some point, the geographic focal point of anthropoid evolution — monkeys, apes and humans — shifted from Asia to Africa.  But we never understood when and why.  Now, we know.  The Eocene-Oligocene climate crisis virtually wiped out Asian anthropoids, so the only place they could evolve to become later monkeys, apes and humans was Africa.”

Working with colleagues from the Chinese Academy of Sciences (Institute of Vertebrate Palaeontology and Palaeoanthropology), specifically Xijun Ni, Qiang Li and Lüzhou Li, the researchers were able to shift through the 34 million-year-old sediments to find teeth and jaw fragments that enabled them to erect six new species.  The fossils were recovered from the upper part of the Caijiachong Formation, Yuezhou Basin, Yunnan Province, through a combination of careful site mapping and scree washing.  It seems that whilst much of Asia became inhospitable for primates, this part of China retained tropical forest so a number of species ended up being crowded into a limited space.

A List of the Six New Species of Primate Named

  1. Yunnanadapis folivorus (pronounced You-nan-ah-dap-is) a member of the Strepsirrhini (lemurs).  In the fossil teeth photograph above Y. folivorus is A.
  2. Yunnanadapis imperator (pronounced You-nan-ah-dap-is) a member of the Strepsirrhini (lemurs).  In the fossil teeth photograph above Y.  imperator is B.
  3. Laomaki yunnanensis (pronounced Lay-oh-ma-key) a lemur-like primate (Strepsirrhini).  In the photograph of the fossil teeth above L. yunnanensis is C.
  4. Gatanthropus micros (pronounced Gat-anthro-pos) another lemur-like primate.  In the fossil teeth picture above G. micros is D.
  5. Oligotarsius rarus (pronounced Olee-go-tar-see-us) the only member of the Tarsiidae (Tarsiers) described from this location.  O. rarus is represented by E in the fossil teeth picture above.
  6. Bahinia banyueae (pronounced Ba-hin-nee-ah), the only anthropoid identified, superficially similar to today’s marmosets, represented by F in the fossil teeth photograph above.

Differences in Oligocene Primate Faunas

The team’s research suggests that the Eocene-Oligocene transition (EOT) led to completely different primate faunas in Asia compared to Africa and the Near East.  In Africa, the anthropoid primates radiated, diversified and became dominant.  However, in Asia, it was the lemur-like primates the Strepsirrhini that seem to have dominated.  The EOT acted as an evolutionary filter dramatically altering the evolution of primates around the world.

The EOT Acted as an Evolutionary Filter Changing Primate Evolution

Global cooling changed primate evolution.

Changing Primate Faunas due to Eocene to Oligocene transition.

Picture Credit: Chinese Academy of Sciences

The EOT changed the evolutionary history of the primates, acting as a filter.  When the composition of early Oligocene primate faunas of Asia and Afro-Arabia are compared, we see that in Asia it was the lemur-like primates (Strepsirrhini) that rose to dominance, whereas in Afro-Arabia, the lemurs became much rarer and it was the anthropoid apes that diversified and became prominent.

The Rare Oligotarsius

Tarsier fossils are incredibly rare in the fossil record, and very little is known about the evolution of the Tarsiidae, the trivial name of O. rarus recognises this.  The teeth of Oligotarsius are very similar to modern tarsiers found today in Indonesia and the Philippines.  This suggests that extant tarsiers are little changed from their ancient ancestors.

Tarsiers – A “Living Fossil”

An extant tarsier.

A photograph of a modern tarsier, described as a “living fossil”.

Picture Credit: University of Kansas/Andrew Cunningham

Dr. Beard explained:

“If you look back at the fossil record, we know that tarsiers once lived on mainland Asia, as far north as central China.  The fossil teeth described in this paper are nearly identical to those of modern tarsiers.  Research shows that modern tarsiers are pretty much living fossils, those things have been doing what they do ever since time immemorial, as far as we can tell.”

A Vulnerability of All Primates?

This new study underscores a vulnerability of perhaps, all primates, that is how they cope when there is dramatic climate change.  The global cooling of the EOT altered primate evolution and transformed the primate faunal mixes of both Asia and Africa.  The EOT is an opposite climate effect to what we are experiencing today.  Thirty-four million years ago the world cooled, today people are very concerned about global warming, the key point is this, whether the climate warms or grows cold, primates seem to be more sensitive to a changing world than other mammals.  This could mean very bad news for our own species.

Food for Thought

It is a sobering thought, but what if the Eocene-Oligocene cooling had not taken place?  Asian anthropoids would have continued to evolve and diversify, potentially with far-reaching consequences for all primates, including hominins and our own species.  Homo sapiens (that’s us), evolved in Africa some 220,000 years ago, however, had this ancient cooling not occurred, the outcome in terms of anthropoid and ultimately human evolution could have been very different.

For an article on potentially the oldest primate: The Oldest Primate To Date?

To read about Miocene Tarsiers from Thailand: Miocene Tarsier Fossils from Thailand

“Meg” The Megalodon Movie

Prehistoric Shark Thriller Movie to Feature Megalodon

It may be more than forty years since “Jaws” hit our cinemas screens, but sharks still fascinate and terrify, although statistically you are more likely to be killed by a cow than by a shark.  Sharks may have a reputation for being cold-blooded, merciless killers but in reality, there are on average, about half a dozen or so reported fatalities each year from shark attacks.  Cows tend to be more dangerous.  Cows with young can be very protective and have been known to charge and trample unwary people who venture too close.  According to the Health and Safety Executive (HSE) some seventy-four people have been fatally attacked by cows in the UK since the year 2000.  Globally, cows present a much greater risk than any shark.  Within the shark group (Elasmobranchii), there are around 480 extant species, but only three of these, the Bull shark, Tiger and Great White, represent a significant threat to beach goers.  However, expect a spike in the number of people claiming to have Selachophobia (a morbid fear of sharks), as filming of a new shark-inspired movie gets into full swing.

C. Megalodon to Feature in a New Horror Film

Based on the series of “Meg” novels by the talented American science-fiction writer Steve Alten, filming is getting underway on the Warner Bros production and a tentative release date of March 2nd 2018 has been proposed.  This is a full three months before Universal Pictures intend to release their Jurassic World sequel, which currently has the working title “Jurassic World II – Ancient Futures”.

Jason Statham (Transporter, The Expendables, Snatch) has been confirmed as the lead actor, he has been joined on the cast list by Jessica McNamee.  Statham plays formal U.S. Navy diver Jonas Taylor who is given the chance to redeem his reputation by leading a rescue mission to save a team of Chinese scientists who have encountered a Megalodon (giant prehistoric shark) in a deep ocean trench.

The Front Cover of the Book “Meg” by Steve Alten

"Meg" front cover image.

Exciting and thrilling adventure story based on Megalodon.

Directed by Jon Turtletaub (National Treasure: Book of Secrets), the film is likely to be a watery gore-fest, although we at Everything Dinosaur doubt whether this feature will have quite the impact of Steven Spielberg’s 1975 film about a killing spree from a Great White.

Of course it’s all hokum, the likelihood of a giant, apex predator shark lurking in the deepest recesses of the ocean is extremely remote.  There are undoubtedly a vast number of marine organisms new to science awaiting discovery.  After all, we know more about the surface of the moon than we do about the deep sea, but there is simply not enough food in the Hadalpelagic Zone (that part of the ocean that comprises the deepest trenches and underwater canyons), to sustain such a large fish, even a single sixty foot long specimen.  Still when did science ever get in the way of a good movie script?

The Huge Jaws of a Megalodon Shark (C. megalodon)

Megalodon jaws.

Reconstructed jaws of a Megalodon shark (human gives scale).

Picture Credit: Rex Features

Safari Ltd produced an excellent replica of the giant prehistoric shark C. megalodonWild Safari Dinos Megalodon Shark Model

The Wild Safari Dinos Megalodon Shark Model

The Wild Safari Dinosaurs Megalodon shark model.

Rows and rows of teeth inside the mouth.

Picture Credit: Everything Dinosaur

It looks like Megalodon (C. megalodon) is going to join that ever-growing list of prehistoric creatures that have featured in movies.

World’s First Mass Extinction Engineered by Animals

Ediacaran Faunal Out Competed by Newly Evolved Animals

A remote fossil site in Namibia has helped strengthen the theory that the fauna of the Ediacaran was unable to survive the radical “re-engineering of marine ecosystems” that resulted with the evolution of more advanced biological organisms.  Newly evolved metazoans (animals that have three types of tissue layer in the embryo and are multi-cellular), altered the marine environment so much that most of the older, largely immobile, species that had dominated the Ediacaran geological period died out.

A Late Precambrian (Ediacaran) Marine Environment

Ediacaran marine life.

Life in the Ediacaran.

Picture Credit: John Sibbick

The Ediacaran geological period is defined as the last geological period of the Proterozoic (early life), it lasted from around 635 million years ago to 542 million years ago and this geological period saw the emergence of a diverse variety of soft-bodied multi-cellular creatures, most of which have no living descendants today.  The ecosystems that existed were very simple with short food chains, multi-cellular life was bizarre with many organisms shaped like discs, tubes or fronds.

Towards the end the Ediacaran more advanced and crucially mobile organisms began to evolve.  Food chains became more complicated with the evolution of active predation amongst organisms.  These new species were “ecological engineers” who changed the environment in ways that made it more and more difficult for Ediacaran organisms to survive.  That is the conclusion of the research team which studied the Namibian fossil remains.

Assistant Professor Simon Darroch Searching the Namibian Site for Fossils

Fossil hunting (Namibia)

Searching for fossils dating from the Ediacaran (southern Namibia).

Picture Credit: Sarah Tweedt, Smithsonian Institution

Writing in the journal “Palaeogeography, Palaeoclimatology, Palaeoecology”, the scientists, which include Simon Darroch (Assistant Professor of Earth and Environmental Sciences at Vanderbilt University located at Nashville Tennessee), report that they have found one of the best-preserved examples of a mixed community of Ediacaran and metazoan organisms preserved in strata from the Zaris sub-basin of southern Namibia.

The Biota Replacement Model

Palaeontologists had predicted that evidence would be found in the fossil record to indicate ecosystems dominated by Ediacaran organisms being replaced by ecosystems dominated by organisms whose fossil record persist into the Cambrian and beyond.  The Namibian fossils provide the best evidence yet of a close ecological association between these distinct types of life-form.

Assistant Professor Darroch explained:

“Until this, the evidence for an overlapping ecological association between metazoans and soft-bodied Ediacaran organisms was limited.  Here, we describe new fossil localities from southern Namibia that preserve soft-bodied Ediacara biota, enigmatic tubular organisms thought to represent metazoans and vertically oriented metazoan trace fossils.  Although the precise identity of the trace makers remains elusive, the structures bear several striking similarities with a cone-shaped organism called Conichnus that has been found in the Cambrian period.”

Conichnus Trace Fossils from Namibia – Evidence of Biota Replacement

Conichnus trace fossils (Namibia).

Conichnus burrows are trace fossils. The surface bumps represent vertical tubes that were originally occupied by anemone-like animals that may have fed on Ediacaran larvae

Picture Credit: Vanderbilt University/Darroch

Conichnus is an ichnogenus (known only from trace fossils), that may have been some form of anemone that fed on Ediacaran larvae.  The scientists also report that they have found strands of Ediacaran frond-like organisms with animal fossils preserved in place coiled around their holdfasts.  The Namibian fossil material provides a snapshot of a transitional ecosystem prior to the Cambrian explosion which led to the evolution of much more modern looking food chains.

Assistant Professor Darroch stated:

“Both animal burrows – ‘trace fossils’ – and the remains of animals themselves sharing the same communities, lets us speculate about how these two very different groups of organisms interacted.”

Lessons for Today

Although the research team are studying the remains of organisms preserved in rocks that were laid down more than 540 million years ago, the biota replacement model that these fossils seem to confirm has relevance for our planet today.  Some of the fossil strata shows the preserved body fossils of a bizarre metazoan called Shaanxilithes, these fossils are coiled found the anchoring, trace fossil (a holdfast) of a frond-like organism),

Shaanxilithes Fossils (Ediacaran Strata – Namibia)

Signs of Late Ediacaran biota replacement.

Shaanxilithes are odd, annulated and ribbon-like fossils that start showing up near the end of the Ediacaran period. In this fossil they are wrapped around Aspidella holdfasts.

Picture Credit: Vanderbilt University/Darroch

Simon explained:

“There is a powerful analogy between the Earth’s first mass extinction and what is happening today.  The end-Ediacaran extinction shows that the evolution of new behaviours can fundamentally change the entire planet, and today we humans are the most powerful ‘ecosystems engineers’ ever known.”

This research entitled: “A mixed Ediacaran-metazoan assemblage from the Zaris sub-basin, Namibia”, builds on an earlier scientific paper published last year that examined a large number of animal burrows preserved in the Namibia rocks that were interpreted as representing the fossil record of a community under stress.

The Disc-Like Structures Represent the Holdfasts of Ediacaran Organisms

Trace fossils (Aspidella).

The disc-like fossils are the preserved remains of holdfast structures used by the Ediacaran species Aspidella that went extinct about a million years after these individuals died and were preserved.

Picture Credit: Vanderbilt University/Darroch

The picture above shows the preserved remains of several disc-like fossils in the Namibian strata.  These have been interpreted as the holdfast, anchoring structures of the fern-like Aspidella.  Once thought to be an ancestral jellyfish, at the time it was first studied, it was the first Precambrian body fossil to have been formally scientifically described.  These disc shapes are now interpreted as trace fossils, examples of the benthic, immobile fauna of the Ediacaran, that was being replaced by more complex and mobile metazoans.

Stirring up Sediments

Hunting and eating the Ediacaran fauna might not have been the only destructive behaviour of the more complex mobile organisms that represented emerging fauna that would dominate the Cambrian.  The researchers also point out that mobile Cambrian animals would have stirred up nutrients leaving them in suspension above the sea floor, far away from the reach of the benthic Ediacaran life-forms.  In essence, the microbial mats and more complex but ultimately, confined to the sea floor Ediacaran fauna, would have found that nutrients that once always fell to the seabed were now suspended in a new marine ecosystem, effectively placing these nutrients out of reach.

The Origin of High Frequency Hearing In Whales

Ancient “Echo Hunter” Provides Insight into Whale Evolution

Scientists from the College of Osteopathic Medicine, New York Institute of Technology (New York), in collaboration with colleagues from a number of other institutions including the Museum of Natural History (Paris), have published a paper on a newly described species of toothed whale, one that suggests that echolocation abilities started early in the Cetaceans.

Writing in the journal “Current Biology” the researchers report that they have found evidence of ultrasonic hearing and the use of echolocation as a probable navigation aid in the beautifully preserved inner ear of a 27 million-year-old toothed whale.

An Illustration of Echovenator (E. sandersi) A Newly Described Genus of Toothed Whale

Echovenator sandersi.

A small, early toothed whale (Echovenator sandersi).

Picture Credit: A. Gennari

Known from a skull, jaws and an atlas bone (bone from the neck), which are believed to represent a single individual, Echovenator sandersi had features in its inner ear that suggest that this marine mammal could hear a greater range of high-pitched sounds when compared to most other mammals.  Believed to be a basal member of the Odontocetes (toothed whales),  this fossil suggests that sophisticated echolocation evolved very early on in this whale lineage.

From a Ditch in South Carolina

The fossil remains were discovered during work on a drainage ditch in Berkeley County, South Carolina fifteen years ago.  The bones and fossil teeth are associated with a basal bed of the Chandler Bridge Formation (Upper Oligocene).  The rocks of this formation were laid down in a marine environment, close to the shore (nearshore marine or possibly an embayment).

Commenting on the conclusions of the research, lead author Morgan Churchill (New York Institute of Technology), stated:

“We can tell a lot about how well this animal fits within whale evolution based on the cranial features and we can use that cranial anatomy to determine whether or not it could echolcate.”

Dr. Churchill, a postdoctoral Fellow at the College of Osteopathic Medicine added:

“The fossil specimen shows several features that we would see in a modern whale with echolocation.”

The Prepared Fossil Skull of the Early Toothed Whale (E. sandersi)

The skull of Echovenator sandersi

The prepared skull of the prehistoric toothed whale Echovenator.

Picture Credit: M. Churchill/Journal of Current Biology

A Well-Travelled Whale

In order to assess the morphology and likely capabilities of the inner ear of this early whale, a number of X-ray scans were taken of the skull fossils.  The skull was carefully X-rayed at the Nikon Metrology X-ray facilities in Tring, (Buckinghamshire, England) and these results were compared to X-ray studies of living and extinct whales skulls undertaken at the University of Texas Austin and the National Museum of Natural History in Paris

By examining Echo Hunter’s inner ear, the researchers found evidence of its ability to receive ultrasonic frequencies.  A soft tissue structure called the basilar membrane, while not present in the fossil itself, was indicated by other parts of the ear to be of a size and thickness consistent with high-frequency hearing.  Another part of the inner ear, a thin, bony structure within the cochlea, provided further evidence of a likely echolocation ability.  Echolocation is the use of vocalisations to navigate and to find prey underwater, other studies have proposed that the ability to produce very high frequency sounds occurred early on in the evolution of the Cetacea, this new research suggests echolocation evolved in basal members of the toothed whale group.

Jonathan Geisler, a co-author of the study and a professor at the New York Institute of Technology commented:

“We had suspicions that they were echolocating but to really get down to a rough estimate of frequency, you really had to look in the inner ear in more detail and that’s where this project comes in.”

Echovenator sandersi

About the size of a small dolphin, Echovenator hunted fish and other small, nektonic creatures close to the shore.  It used its echolocation to help it forage in the murky, sediment-filled coastal waters.  The genus name is Latin which means “echo hunter”, the species name honours Albert Sanders, a former curator of The Charleston Museum, in recognition of his contribution to the scientific study of Cenozoic whales.  Mark D. Uhen, a professor at George Mason University, who in 2008 erected a new family of ancient whales, the Xenorophidae, the oldest and most primitive of the toothed whales, the whale family to which Echovenator has been ascribed, explained that previous research had suggested that the earliest toothed whales could echolocate, but that the new paper provided a clearer picture.

The Evolution of High Frequency Hearing and Echolocation in Whales

The evolution of echolocation and ultrasonic hearing in whales.

Plotting the evolution of ultrasonic hearing and echolocation in early whales.

Picture Credit: College of Charleston

Dr. Uhen, who was not involved in this study, said that the development of high-frequency hearing in whales was a nice illustration of natural selection.

Professor Uhen commented:

“I think the way evolution mostly works is that animals adopt a behaviour, and then natural selection changes generation after generation so that they get better and better and better at that behaviour.  Whales started feeding in the water so their feeding apparatus and their ears changed early.”

Heard the one about the origins of echolocation?: The Origins of Echolocation in Dolphins (related article)

To read an article about a potential terrestrial ancestor of whales: Deer-like Fossil Confuses Early Cetacean Evolution

To read an article about a huge, Pliocene toothed whale that swam in the waters around Australia: Giant Aussie Whale a Terror of the Pliocene Seas

First Case of Septic Arthritis Diagnosed in a Dinosaur

Hadrosaur Had Septic Arthritis

Scientists writing in the Royal Society Open Science journal have identified the first diagnosed case of septic arthritis in a dinosaur.  The unfortunate animal was a type of duck-billed dinosaur that roamed New Jersey (USA), some seventy million years ago.  Identifying disease and injuries preserved in the fossil record (pathologies) permits scientists to gain valuable insights into the lives of long extinct creatures.  The indeterminate duck-billed dinosaur may have suffered for many years with a debilitating injury.

A Typical Hadrosaurid Hadrosaur

Gryposaurus - Hadrosaur Model available from Everything Dinosaur.

Duck-billed Dinosaur model

Picture Credit: Everything Dinosaur

Severely Damaged Elbow

The fossilised lower arm bones (ulna and radius) of a plant-eating, duck-billed dinosaur were excavated from sediments that form a component of the Upper Cretaceous exposures of the Navesink Formation (New Jersey).  Both bones show malformation and deformed bone-growth, the result of some form of pathology.  However, it was only when the team subjected the diseased part of the bones to an examination by a non-invasive technique, X-ray microtomography, could the research team, that included palaeopathologist Jennifer Anné, (University of Manchester), make a diagnosis.

The Diseased Ulna of the Indeterminate Hadrosaurid

The diseased ulna of a hadrosaurid.

The pathology of a Hadrosaur ulna showing a large amount of reactive bone growth.

Picture Credit: Royal Society Open Science

The photograph above shows the pathological ulna from an indeterminate species of duck-billed dinosaur.  A substantial amount of bone re-growth can be seen on the end of the bone, the portion that is in articulation with the surface of the radius (PRU).  The researchers describe the diseased bone as having a “cauliflower-like” appearance.  The olecranon process that forms the elbow joint is very misshapen and damaged with large, prominent lesions (circled red).  The red box in the diagram shows the portion of the ulna that was subjected to X-ray microtomography.

The research team conclude that this dinosaur would have been in pain and as a facultative biped it would have found movement difficult.  However, bone re-growth suggests that this dinosaur lived for some time with this injury.

New Jersey and Dinosaurs

Although dinosaur fossils from the eastern coast of the United States are much rarer than those from the western USA, New Jersey is regarded by many scientists as the birthplace of American palaeontology.  The very first, scientifically described dinosaur discovery took place close to the town of Haddonfield in New Jersey.  The bones of a large animal were excavated from a quarry and the eminent American scientist Dr. Joseph Leidy (University of Pennsylvania), was given the task of studying them.  He defined them as belonging to a member of the Order Dinosauria and erected the genus Hadrosaurus (H. foulkii).

A statue of “Haddy” the Hadrosaur can be seen in Haddonfield, commemorating the discovery of “America’s first dinosaur.”

To read more about “Haddy” the Hadrosaur: A Hidden Gem (Dinosaur Statue)

Septic Arthritis

Having analysed the bones, the most likely explanation for the damaged bone is a form of osteoarthritis, a condition affecting movable joints by deterioration of articular cartilage, bone spur formation and this leads to considerable bone re-growth and remodelling.  Such conditions are usually localised in extant reptiles, whereas in humans, these conditions can spread throughout the body.  It is worth noting that osteoarthritis in extant birds and reptiles is usually associated with other, contributory factors such as trauma, disease or infection.  Based on the images generated by the X-ray scans, the researchers began to eliminate the possible causes such as osteomyelitis (the bone itself is infected) and finally concluded that the pathology probably represents septic arthritis (infected cartilage affecting the surrounding bone tissue).

What Caused the Injury?

If the septic arthritis was brought on by an injury then this begs the question, what caused the injury in the first place?  Sadly, the seventy million-year-old dinosaur arm bones don’t provide any clues.

Jennifer Anné commented:

“It could have started out that it did have arthritis.  It could have gotten a cut, or broken that joint, and then had an infection.  It’s a hard-knock life for any wild animal.”

X-ray Microtomography Scans (Longitudinal and Transverse Scans) Showing Disease Presence in the Ulna

Probably septic arthritis in a dinosaur.

Signs of injury and disease in the bones of a dinosaur.

Picture Credit: Royal Society Open Science

The picture above shows the scans of the hadrosaurid ulna in various views (a-d).  The area scanned is shown on the picture on the white background in the lower left portion of the image.  Locations for the transverse sections (a-d) are indicated by red lines on the longitudinal section.  Reactive bone growth can be identified and is circled in pictures c and d.  Abnormal bony projections at the attachment sites for ligaments (enthesiophytes) can be seen in a and c (indicated by red arrows).  These abnormal bony growths are a sign of stress.  Dead bone (necrosis) can be seen along the proximal articulation surface and is highlighted by a red circle in picture b.  Scale bar for all images ten mm.

Dr. Anné stated that the use of non destructive and non-invasive techniques such as X-ray microtomography is having a big effect on palaeopathology.

She added:

“As a result, how we’re approaching diagnosing is changing, it’s letting us look at more individuals, so we have a higher chance of finding things.”

Thirsty Woolly Mammoths of St. Paul Island

St. Paul’s and Wrangel Island Woolly Mammoth Populations

This week has seen the publication of research undertaken by an international team of scientists led by academics from the University of Pennsylvania, that explains the demise of one of the last populations of Woolly Mammoths to have lived on Earth.  Mammoths (Mammuthus primigenius) survived on the remote Alaskan island of St. Paul until around 5,600 years ago (+/- 100 years or so), whilst their mainland cousins were extinct by about 10,500 years ago.  Writing in the “Proceedings of the National Academy of Sciences” (United States), the researchers conclude that a warming climate which led to rising sea levels caused the amount of freshwater available to fall dramatically, in essence the Woolly Mammoths died of thirst.

Study Suggests Some of the Last of the Woolly Mammoths were Unable to Quench Their Thirst

Mammoths died of thirst on St. Paul Island.

Lack of freshwater is suspected to have led to the demise of the Woolly Mammoth population on St. Paul Island.

Picture Credit: Everything Dinosaur

The Island of St. Paul in Relation to Wrangel Island

Readers of this blog will probably know that the very last population of Woolly Mammoths to have existed, survived on Wrangel Island until about 4,300 years ago (although an extinction date of as recently as about 1,700 B.C. has been proposed).  Both St. Paul Island and Wrangel are remote locations deep within the Arctic circle, however, there are considerable differences between these two islands and whilst scientists such as Professor Russell Graham (University of Pennsylvania) and lead author of the St. Paul Island study, propose that a lack of drinking water led to the St. Paul’s Island Mammoth population dying out, debate remains as to the probable cause of the Wrangel Island extinction.  In both cases the presence of humans impacting on the population of Mammoths can be ruled out, these hairy elephants were long gone before the first humans visited these isolated, desolate places (once sea levels rose).

The Location of St. Paul Island in Relation to Wrangel Island

The location of the last of the Woolly Mammoths (St. Paul Island and Wrangel Island).

The dark grey areas represent today’s landmass, the light grey areas show the extent of the Bering Land Bridge (Beringia).

Picture Credit: PNAS with additional annotation by Everything Dinosaur

The picture above shows the approximate position of the Bering Land Bridge (Beringia) in light grey compared to the landmasses of Siberia and Alaska today (dark grey).  At its maximum during the Quaternary glacial intervals, the land joining Asia to North America would have been over six hundred miles wide, over the last 20,000 years rising sea levels led to the eventual loss of a land link between the continents of North America and Asia.

St. Paul Island was part of the southern portion of Beringia. Today, it is located in the Bering Sea.  In contrast, the much larger Wrangel Island is found in what was the northern portion of Beringia and it is located today in the Arctic Ocean.  Wrangel Island is over seventy times bigger than St. Paul Island, in the past both these islands were considerably bigger but with a warming climate in the latter stages of the Pleistocene and into the Holocene Epoch, sea levels rose and St. Paul Island in particular began to shrink.  The island is presently, around forty square miles in size, the researchers used a variety of techniques to plot the ingress of sea water and the decline of freshwater on the island over the last fifteen thousand years.

The Reduction of St. Paul Island from the Late Pleistocene to the Present Day

St. Paul Island 15,000 years ago to the present day.

The shrinking of St. Paul Island over the last fifteen thousand years.

Picture Credit: PNAS

The picture above shows a palaeogeographical map compiled by the research team that plots the reduction in the size of St. Paul Island over the last 15,000 years or so.  The red dot in the centre of the island (present size is outlined in brown), represents Lake Hill, a small, freshwater lake from which a series of sediment cores were extracted so that the scientists could trace the history of the location and how changes in climate affected the fauna and flora of the island.

The sediment cores (taken in 2013), built on data generated from core samples taken back in the 1960’s and they have provided a number of independent indicators to suggest that the Mammoth population survived until around 5,600 years ago.  The flora of St. Paul Island remained relatively unchanged, however, the scientists were able to deduce that St. Paul Island shrank rapidly due to rising sea levels until about 9,000 years ago.  It continued to shrink, albeit more slowly until around 6,000 years ago but declining freshwater sources and a generally drier climate with reduced precipitation from around 7,850 years ago to the time of the Mammoth’s extinction was probably the cause of the demise of this elephant population.

Independent Indicators of Mammoth Extinction

  • Analysis of sedimentary ancient DNA (sedaDNA) to provide an understanding of the ancient flora of the environment and how a drying climate and rising sea levels impacted upon it.
  • The level of fungal spores that are associated with animal dung (coprophilous fungal spore types).  Three types of fungal spore were studied, this fungi would have thrived on Mammoth dung, the sudden elimination of the fungal spores from the core samples indicate a mega fauna extinction.
  • Micro fossils such as those of water fleas (indicating freshwater) and pollen grains along with diatoms (different types of algae some of which are associated with sea water).
  • Magnetic susceptibility, in arbitrary units (AU) of Lake Hill sediments from the cores, this data looks at the differences between different types of sediment and from this an understanding of changes in the palaeoenvironment over time can be mapped.
  • Radiocarbon dating, isotope degradation analysis and analysis of protein remnants from St. Paul Island Mammoth remains.

Given the variety of information sources, the “best fit” for the Mammoth extinction is approximately 5,600 years ago (+/- 100 years).

The Mammoths Contributed to Their Own Downfall

As sources of freshwater dwindled, so the Mammoths would have congregated around the remaining waterholes.  More intensive, localised Woolly Mammoth activity would have accelerated the fall in water levels.  Vegetation would have been consumed therefore exposing sediments that would have been washed into the lakes and ponds thus degrading the water quality, reducing water levels further and exacerbating the already acute water shortage.

A spokesperson from Everything Dinosaur commented:

“Extant Indian elephants can consume as much as two hundred litres a day, sometimes more if it is a lactating female.  We suspect Mammoths too, had a high demand for drinking water.  A concentration of mega fauna around remaining sources of drinking water on St. Paul Island would have probably accelerated the extinction.  It is also likely, that with large animals having to survive on an ever diminishing landmass, the elephant population was already probably under considerable environmental stress.”

Lead author of the PNAS paper, Professor Russell Graham explained a likely extinction scenario:

“They [the Mammoths] were milling around, which would destroy the vegetation, we see this with modern elephants.  This allows for the erosion of sediments to go into the lake, which is creating less and less fresh water.  The Mammoths were contributing to their own demise.”

The scientific paper: “Timing and causes of mid-Holocene Mammoth extinction on St. Paul Island, Alaska”.

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