Fossil Reveals Some Ancient Lizards were Viviparous

120 Million Year Old “Pregnant” Lizard Discovered

Most reptiles lay eggs, however, a number of extant species are viviparous, that is they bring forth live young, retaining the embryos inside the body of the female and not laying eggs that are deposited outside the body.  The ability to produce live young is found in a number of lizards and snakes species today (Order Squamata), scientists were not sure when this ability evolved, but the discovery of a heavily gravid fossilised lizard in China, shows that viviparity had evolved in lizards by the Early Cretaceous.

Garter snakes, harmless snakes of the genus Thamnophis can be found over much of North America including high latitudes.  The twenty or so species of Garter snakes are all relatively small, if we exclude Thamnophis gigas, a species of Garter snake found in California which grows to over a metre long.  All of these snakes produce live young, broods of between 14 and 40 dependent on the particular species.   These snakes prefer semi-aquatic environments and many, resident in the northern part of their range, hibernate to escape the worst of the cold weather.  It is believed that the ability to bring forth live young, evolved as a response to the harsh environments members of the Order Squamata lived in. Such conditions such as the cold springs of North America make the survival of any eggs laid outside the body less likely.

The newly discovered fossil of a pregnant lizard proves that some Squamate reptiles were giving birth to live young, rather than laying eggs, in the Early Cretaceous period, much earlier than previously thought.  The fossil shows a pregnant female filled with the tiny skeletons of more than 15 baby lizards at a stage of development similar to that of late embryos of modern lizards.  The mother lizard, which is 30 centimetres long (excluding her tail), probably died only a few days before giving birth.  The research into this heavily gravid lizard was carried out by scientists at the University College London in co-operation with researchers from the Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences (Beijing).  The paper detailing this study has just been published in the scientific journal “Naturwissenschaften”.

The Slab and Counter Slab Showing the Gravid Lizard Fossil

Picture Credit: University College London

The red circle in this picture indicates the area of the image that has been enlarged to reveal the fossilised embryos of the lizards.

A Close up of the Lizard Fossil Showing the Unborn Babies

The fossil evidence

Picture Credit: University College London

Joint lead-author of the research paper, Professor Susan Evans of the University College London stated:

“Mention live birth and most people think only of furry mammals, but roughly 20% of living lizards and snakes also produce live young rather than laying eggs.  We previously thought that lizards adapted to live birth after mammals, but now it looks like it happened at roughly the same kind of time.  This specimen is the oldest we have seen, which implies physiological adaptations, like adequate blood supply to the embryos and very thin shells, or no shells at all, to allow oxygen supply, evolved very early on.”

The fossil comes from world famous rocks of the Jehol Group of north-eastern China (Liaoning Province) that have produced hundreds of exquisite specimens of fish, amphibians, reptiles (including dinosaurs) birds and mammals, as well as plants and invertebrates.  Indeed, back in 2009, scientists published a paper on a small Theropod dinosaur that proposed that at least one genus of the Dinosauria had a characteristic in common with members of the Squamata – it may have been venomous just like a rear-fanged snake.

To read an article about this: A Venomous Dinosaur from China

The mother lizard is identified as a specimen of Yabeinosaurus, a large, slow-growing, and relatively primitive lizard that is well-represented in the Jehol Biota, although previously nothing was known of its reproductive habits.  Up until now the fossil records only contained examples of marine lizards giving birth to live young (for example, Ichthyosaurs).

A Fossil Showing an Ichthyosaur Giving Birth (Viviparity)

“Ichthyosaurus Mum”

Picture Credit: Natural History Museum

The picture above shows a very famous fossil of a female Ichthyosaur that perished whilst in the process of giving birth.  A young Ichthyosaur can be seen emerging tail first from the mother, and inside the body cavity the remains of other baby Ichthyosaurs can be seen.

To read more about viviparous Ichthyosaurs: The Evidence to Prove that Ichthyosaurs gave Birth to Live Young

The evolution from being oviparous (laying eggs) to giving birth to live young (viviparous) is usually associated with cold, dangerous environments where eggs are unlikely to survive.  The drawback is that the mother is limited in terms of movement and self-defence.  This explains why scientists previously thought that live birth in extinct reptiles was restricted to specialised aquatic groups, as movement in water is much easier for a gravid female.

Professor Evans went onto add:

“We do know that this lizard lived near to water and we think it likely that they could swim even though they primarily lived on land.  This would make sense as a pregnant lizard would be less constrained by carrying offspring, she would be able to escape into water if a hungry dinosaur came along!”

The work was funded by a joint Anglo-Chinese project funded by the Royal Society and the National Natural Science Foundation of China and we at Everything Dinosaur are grateful to the University College London for their help in putting together this article.

It’s a Dogs Life! Evidence of Dog Domestication from 33,000 Years Ago

An Ice Age Gave Dog Domestication the Cold Shoulder

Regarded as “mans best friend” dogs have had an extraordinary relationship with humans and as a result can be regarded as one of the most successful types of mammal on the planet.  A new study suggests that mankind’s close relationship with dogs began as early as 33,000 years ago.  However, an Ice Age that started approximately 26,000 years ago; which resulted in dramatically changing climatic conditions over much of the northern hemisphere interrupted this domestication process.  It was not until the climate became milder and more stable some 7,000 years later did the dog/mankind relationship start up again in earnest.

In a new study published in the online scientific journal PLoS ONE (Public Library of Science) researchers claim that although dogs had started to become domesticated at least 33,000 years ago, these canines did not produce descendants that survived beyond the Ice Age.

It’s a Dogs Life – An Impression of What Some of the First Domesticated Dogs Looked Like

Picture Credit: Leutscher

The theory, based on the analysis of the 33,000-year-old remains of a dog that may have been a partly domesticated, explains why the remains of possible prehistoric dogs date to such early periods, and yet all modern dogs appear to be descended from ancestors that lived at the end of the Ice Age 17,000-14,000 years ago.  How and why creatures such as wolves began to associate with people has been the subject of debate for a long time.  In Darwin’s time it was thought that domesticated dogs originated from a number of wild stocks, however, modern genetics indicates that all dogs today can trace their ancestry back to the wolf.  Wolves and humans have a surprising amount in common, especially when their roles as predators are considered.  For example, humans and wolves hunt in daylight, both are social creatures and use vision as an important sense when attacking prey.  They also preyed on the same types of animal – the mega herbivores as they are known.  It is likely that wolves began to associate with humans getting scraps from kills and slowly but surely the path towards domestication began to be taken.

The 33,000 doggy remains were found in a cave in the Altai Mountains of southern Siberia (Razboinichya cave).  It was found amongst other wild animal bones but was the only dog-like creature found.

Susan Crockford, co-author of the study stated:

“The Razboinichya dog find demonstrates that the right wolf/human conditions suitable for getting domestication started were present at least 33,000 years ago.  However, such conditions would have had to be present continuously [stable climatic conditions] for many wolf generations, for the domestication process to generate a true dog.”

An ongoing Russian study into foxes has been testing how quickly wild animals can become domesticated. The study has been operating for many years, with each generation of fox cubs selected for tameness, with these animals being allowed to breed with other foxes that although show a degree of domestication.  Over many generations of foxes the Russian scientists have been able to produce a fox that behaves in a very similar way to domesticated dogs.

Susan Crockford, a researcher at Pacific Identifications Inc. added:

“It appears that such stable conditions were not present until after the Ice Age, sometime after 19,000 years ago,.  Even after the Ice Age, domestication of wolves could have got started at several different times and places, and still failed because the conditions were not continuous enough for the changes to become permanent.”

The Siberian animal was unearthed some years ago, but was only recently dated to 33,000 years ago by three independent radiocarbon dating facilities.  Crockford and her colleagues conclude that it was a partly domesticated dog because of its mixture of dog and wolf features.  It was about the size and shape of a large male Samoyed dog, so it was smaller than a European wolf,but its teeth were still wolf-sized. The scientists have concluded that it “probably behaved more like a wolf than a dog.”

Its remains were excavated from a cave area containing wild animal bones. Usually fully domesticated dogs, even very early ones, received more careful burials, often being placed in graves with, or next to, their owners.  In fact, a recent discovery may indicate that the fox Vulpes vulpes may have been early man’s best friend.

To read an article about the discovery of a fox buried with humans in a Mesolithic grave: Is the Fox Man’s Best Friend?

Since no other dog-like animals were found at the site, the researchers think this animal was an “incipient” dog in the early stages of domestication.  The scientists hold that domestication can happen naturally, without direct human intervention, when wolves are attracted to settlements and gradually adjust to a human-dependent lifestyle, relying on people for scraps of food and such like.  Certainly, if a wolf-like animal could be domesticated it would have had tremendous benefits for people.  These dogs could have acted as watch dogs, helping to keep people safe from other wild animals, they could have assisted in hunting and, for anyone who has had a dog curl up on their feet, as wolves have a higher body temperature than humans they would have been very good at keeping us warm at night.

The Ice Age, however, changed the abundance and migration patterns of the animals that the people in the Altai Mountains of Siberia hunted for food.  The researchers conclude that with the climate change, people would have been more nomadic and this would have interrupted any domestication of wolves.

Without the conditions that fuel domestication, the dog or dog-like animals gradually died off, the researchers suspect.  Dogs reemerged after the Ice Age, reproducing and becoming the ancestors to today’s modern dogs.  It is unclear when the first pre-Ice Age dogs emerged, but a dog-like skull dating to 36,500 years ago was found at Goyet Cave in Belgium.  It’s possible then that the first dogs appeared in parts of Europe and Asia much earlier than commonly thought.  Many scientists do believe that the wolf was the first animal to be domesticated by mankind, and may partially explain why dogs and humans have such a special relationship, indeed dogs do seem to have developed some unique ways of understanding our moods and communicating with us.  After all, it is now thought that the dog “bark” was adopted by dogs so that they could communicate with humans – wolves don’t bark as a rule.

Other scientists have queried these research results and have suggested that more fossil specimens will be needed to prove conclusively the theory postulated by Susan Crockford and her colleagues.  Without more specimens,  it cannot be ruled out that the Siberian dog, and possibly some of the other pre-Ice Age animals, were different representatives of now-extinct wolves.

Richard Meadow, director of the Zooarchaeology Laboratory at Harvard University’s Peabody Museum, expressed his reservations about the study’s conclusions.

Crockford admits that the paper presents “a new way of thinking about domestication, but it fits the evidence better than the idea that people deliberately created dogs for some specific purpose.”

We await to see what lies lurking in the depths of the caves of the Altai Mountains, perhaps an ancient dog collar or maybe a rubber bone anyone?

Low Tide Reveals Triassic Marine Reptile

Marine Reptile Fossil Exposed at Low Tide

It is an apt location to find the fossilised remains of a 220 million year old marine reptile, in the inter-tidal zone of a rock strewn beach  After all, marine reptiles were very much at home in the sea, although many types did return to the land to lay eggs, to bask in the sun and so forth.  However, for one team of dedicated researchers having to extract what could be the best preserved fossil of a Thalattosaur ever found in North America meant a tricky job with time and tides against them.

Thalattosaurs were a group of diapsid, marine reptiles known from Mid and Upper Triassic aged strata. These animals superficially resembled monitor lizards, but they were not closely related to modern lizards (Order Squamata).  Their fossilised remains have been found all over the world – North America, Europe and China, a number of families have been identified although their taxonomic relationship to other marine reptiles such as the Ichthyosaurs remains uncertain.  Some of Thalattosaurs (the name means “ocean lizards” grew to lengths in excess of 4 metres.  Finding an almost complete fossil skeleton of such a creature is an extremely rare event.

Illustrations of Thalattosaurs (Xinpusaurus and Clarazia)

Picture Credit: David Peters

Scientists believe that the Thalattosaurs evolved from terrestrial reptiles, but adapted to an aquatic life style.  Gradually the skulls become longer and the chests deeper as these creatures evolved.

Working in very difficult conditions, Ken Olson (Museum of the Rockies) realised that he and his colleagues would need some more expert help if fossils of rare marine reptiles were to be recovered from the intertidal zone.  He turned to Patrick Druckenmiller, (Earth Sciences Curator at the University of Alaska Museum of the North), who had recently been involved in a project to excavate Plesiosaur fossils in Norway.  In May of this year, an intriguing vertebrate fossil had been noticed partly exposed out of rock, but to excavate this specimen would be difficult due to the fact that for most of the time the fossil was covered in sea water, the site only being exposed at very low tides.

Tongass National Forest geologist Jim Baichtal immediately sent photographs to University of Alaska Museum of the North Earth Sciences Curator Patrick, who went through the process of eliminating what it could be:

Patrick stated:

“We know the rocks are about 220 million years old.  Based on the age of the rocks and what I could see in the picture, I was 99 percent sure that’s what it was.”

The Exposed Fossil at Low Tide

Picture Credit: P. Druckenmiller

The posterior portion of the fossil can be clearly made out in the picture.

Druckenmiller and his museum colleague, Kevin May, travelled to the site in mid-June to collect the specimen from the semi-exposed outcrop near the small Alaskan town of Kake. The location lies in the intertidal zone, the tide problem meant they needed to excavate during a two-day window and would only have four hours each day, when the tide was at its lowest, (Spring tide) to retrieve the fossil.  If they missed their chance, the outcrop wouldn’t be exposed again until October (the next period of extremely low tides at which the fossil would be exposed again).

The team used rock saws to hack a series of steps down to the layer of rock surrounding the fossil.  On the first day, they were able to complete the excavation just five minutes before the site was submerged.  Druckenmiller spotted more bone penetrating the rock, so the team removed an even larger section on the second day, hoping it would contain the rest of the skeleton.

Druckenmiller added:

“We couldn’t see anything that day, we thought, ‘it’s probably here and the animal is probably this long, so we’ll take out a slab about that big.”

The two slabs of rock, weighing over 200 kilogrammes between them were transported by boat to Thorne Bay, from there, they went onto to the fossil preparation laboratory at the museum.  It will take many months to reveal the rest of the skeleton but the researchers are optimistic that they have recovered an large portion of the fossil, including skull material.

Rock Saws were used to Cut the Fossil Matrix away from the Rest of the Rock Outcrop

Picture Credit: P. Druckenmiller

Patrick went on to state:

“It’s reasonably complete and once we reveal more of the skeleton, we will be able to compare it to other Thalattosaurs to see if it is a new species.”

Even if it is a known species, it will be one of the best specimens ever found in North America and possibly anywhere else in the world.  The Thalattosaur is currently one of Alaska’s most compete fossil vertebrates.

After the specimen has been prepared and formally studied and the results published, the fossil will be available for display at the museum.

Is Archaeopteryx About to Be Knocked off its Perch?

New Archaeopteryx-like Theropod Dinosaur Discovered

Researchers from the Chinese Academy of Sciences have published scientific papers describing the discovery of a new type of Jurassic Theropod dinosaur which they believe is very closely related to the iconic prehistoric animal Archaeopteryx (A. lithographica).  As a result, they are challenging the long held assumption that Archaeopteryx was the “very first bird”.

In 1860, just one year after Charles Darwin published “The Origin of Species”, a single fossilised feather was discovered in the finely grained lithographic limestones at Solnhofen (Bavaria, Southern Germany).  An important cornerstone (no pun intended) of Darwin’s new theory was the gradual evolution of species via natural selection that would lead to new species – the search for what was to become known as “missing links” had begun.  In 1861, a virtually complete skeleton of the creature that had feathers was found in southern Germany, this was to become known as Archaeopteryx an example of a “missing link” between birds and reptiles as the fossil showed characteristics of both orders.  To be more precise, this transitional fossil, one of less than a ten fossils of Archaeopteryx known had a combination of reptilian and bird characters. There were of course the feathers and a breast bone, but this animal also had teeth and a long tail, just like a dinosaur.  Here was a transitional form that linked one major group of animals (birds) to an older, ancestral group (the reptiles) from which it had evolved.  This was evidence of Darwin’s theory – species were not immutable and Darwin had predicted that such transitional fossils would be discovered.

An Archaeopteryx Fossil – the First Bird?

Picture Credit: Stanford University

The picture shows an almost complete and perfectly preserved fossil of the Late Jurassic creature known as Archaeopteryx (A. lithographica).  The feathers (a feature of birds) can clearly be seen along with the long tail (a feature of reptiles).

The Chinese scientists have identified a new species of Archaeopteryx-like Theropod dinosaur from lake deposits formed about 160 million years ago in northeastern China.  According to findings published online in the scientific journal “Nature”, the new dinosaur species Xiaotingia zhengi is a close relative of Archaeopteryx, which is widely accepted as the most primitive bird, known from the fossil record.  However, a phylogenetic analysis incorporating new information from this find suggests that Archaeopteryx is not a bird, which has significant implications for our understanding of bird origins the evolutionary relationship between Aves (birds) and the Reptilia.

Xiaotingia weighed about 800 grams, comparable to Archaeopteryx in size, and is one of the smallest non-avian Theropod (carnivorous) dinosaurs ever identified by scientists.  The fossil shows evidence of conical teeth, as well as long, robust arms that are similar to those of primitive birds.  Its specialised feet have the highly extensible second toe characteristic of the Deinonychosauria, the group of bird-like dinosaurs that includes Velociraptor and Utahraptor.

An Artist’s Illustration of Xiaotingia zhengi

Picture Credit: XING Lida and LIU Yi

Dr.Xu Xing of the Institute of Vertebrate Palaeontology and Palaeoanthropology, Chinese Academy of Sciences, lead author of this paper and one of the world’s most influential dinosaur researchers stated:

“The most exciting result from our research is that both Xiaotingia and Archaeopteryx are primitive Deinonychosaurs rather than birds.  In other words, Archaeopteryx is a kind of Velociraptor ancestor rather than a bird ancestor.”

This research is certainly going to challenge long held views about the significance of Archaeopteryx.

It is now widely accepted that birds are descended from dinosaurs, but scientists are still working hard to reconstruct how the dinosaur-bird transition occurred.  One of the most important jobs is to reconstruct a reliable family tree, based on this research, scientists can find out which dinosaurs evolved into birds and what the most primitive birds were actually like.  Xu’s team has made several significant discoveries related to this fundamental issue in the study of evolution.

The Holotype Specimen of Xiaotingia zhengi

Picture Credit: Dr. Xu Xing

The picture shows the holotype fossil the creature’s head is to the left of the picture.

Dr. Xu explained:

“We named the four-winged dinosaur Anchiornis huxleyi in 2008.  At that time we already noticed some striking similarities between Anchiornis huxleyi and Archaeopteryx, such as the presence of a long bony tail fully covered by large feathers.  Xiaotingia is from the same site as Anchiornis.  Like Anchiornis, it also bears long flight feathers on the feet, a feature that we suspected was also present in Archaeopteryx.  The discovery of Xiaotingia provides further support for a close relationship between these species.”

We at Everything Dinosaur note the reference to Thomas Huxley in the scientific nomenclature.  Thomas Huxley (1825-1895) was an English biologist who supported the ideas of Charles Darwin (he was known as “Darwin’s Bulldog”), he was one of the first scientists to realise the close anatomical links between birds and reptiles.

The researchers noticed that Archaeopteryx, Xiaotingia, and Anchiornis are more similar to other Deinonychosaurs than to birds in having a lightly built skull, in stark contrast to the more robust skull seen in other known primitive birds and also the Oviraptorosaurian dinosaurs.  A comprehensive analysis by the researchers indicates an interesting evolutionary divergence between a primarily herbivorous lineage leading to modern birds and a carnivorous lineage leading to the likes of the fearsome Cretaceous dinosaur Velociraptor.  This new pattern has significant implications for avian origins, and for related issues such as the early evolution of feathers and flight.

Archaeopteryx is perhaps, one of the most famous of all the prehistoric creatures named and described so far. Despite the paucity of fossils there is an extensive and on-going research programme based around this particular creature from the Upper Jurassic strata of Germany.

To read a recent article on Archaeopteryx research: New Fossil Study Shows Chemical Link between Reptiles and Birds

We suspect that the feathers are about to fly once again in the world of palaeontology.

Everything Dinosaur is grateful to the Chinese Academy of Sciences for their press release information in helping to compile this article.

Save the M5 Dinosaur

Owner of T. rex Sculpture Vows to get Dinosaur Up Again

The owner of a giant Tyrannosaurus rex sculpture that used to brighten the journeys of holiday makers as they made the long trip down the west country heading for Devon and Cornwall has vowed to get his dinosaur on its feet again after it was damaged by vandals.

The fearsome beast used to stand overlooking the M5 motorway near to North Newton (Bridgwater, Somerset) but vandals maimed the £7,000 artwork, this is just one of a number of recent cases were artworks, sculptures and other installations have been attacked and vandalised.

Tyrannosaurus rex always tops the annual Everything Dinosaur poll which surveys prehistoric animal trends and attempts to find out which is the most popular of all the dinosaurs with boys and girls.  On hearing about the demise of the twenty foot sculpture, a spokes person for Everything Dinosaur commented:

“It is such a shame.  We know the dinosaur cheered up families as they drove down the motorway, many children used to try to be the first to spot it as they sat in the back of the car.”

Benjamin Slade, the owner of the sculpture said he would “not surrender” and has vowed to prevent at least this T. rex from becoming extinct.  A Facebook campaign has been launched called “Save the M5 dinosaur” in a bid to help restore this iconic feature just off junction 24 of the motorway.

The “Save the M5 Dinosaur” Facebook Group: Save the M5 Dinosaur

Mr Slade, who owns the nearby Maunsel House, said:

“We have got to get a new monster.  I’m going to get one specially made, with sharper teeth.”

Tyrannosaurus rex was one of the last of the dinosaurs to evolve, and one of the largest land carnivores known from the fossil record.  Although the Tyrannosaurids only became the iconic, apex predators towards the end of the Cretaceous with animals such as Gorgosaurus, Daspletosaurus and T. rex itself, this group of dinosaurs originated in the Mid Jurassic and seem to have been geographically very dispersed.  However, it was only in the northern hemisphere that the Tyrannosaurs evolved into the large and fearsome monsters so often seen in movies and on television.

An Illustration of Tyrannosaurus rex Fighting an Ankylosaurus

Picture Credit: Mike Fredericks

Longest Tooth Marks Found in Dinosaur Fossil Bones

Evidence of Dinosaurs Feeding

Researchers from South Korea claim to have found the longest and deepest tooth marks left by a carnivorous dinosaur in the fossilised bones of a plant-eating dinosaur.  The scientists have postulated that the deep grooves cut into the fossil bone by the as yet unidentified meat-eater are evidence of carcase scavenging.

The researchers say they have found the world’s longest and deepest carnivorous dinosaur tooth-marks ever documented in Hadong, South Gyeongsang Province, a location rich in Cretaceous strata and one that has already revealed a number of new dinosaur discoveries.  The team led by Professor Paik In-sung (Professor of Sedimentary Geology at the Dept. of Environmental Geosciences at Pukyong National University), have published an analysis of the deep marks left in a caudal vertebra of a large Titanosaur known as Pukyongosaurus.

The Tooth Marks on the Caudal Vertebra

Picture Credit: Pukyong National University

The picture shows the deep grooves and scratches made in the fossilised tail bone of a herbivorous dinosaur by an unknown genus of Theropod, the picture on the right is an enlargement showing the feeding marks in more detail.

The tooth-marks measure 17 centimetres in length, 2 centimetres wide and up to 1.5 centimetres deep, which is the longest and deepest known in the Dinosauria fossil record, Professor Paik stated.  Although it cannot be proved either way, it is unlikely the teeth marks were made as the predator attacked the Titanosaur.  It is more likely that these marks were left when a Theropod scavenged the carcase, certainly, the corpse of such a large animal would have attracted scavengers from miles around to feed on the remains.

The evidence of dinosaur feeding was discovered in late 2008, but the research into the feeding behaviour of dinosaurs was only completed recently, leading to the publication of a scientific paper.

Professor Paik added:

“These tooth-marks provide insight into the feeding behaviour of dinosaurs that scavenged the bodies of large, adult dinosaurs.”

Lobbyists are trying to get parts of the geology of South Korea granted UNESCO World Heritage status, so as to gain formal recognition for the extensive fossil rich strata.

To read further about this topic: Attempting to Gain UNESCO World Heritage Status

Potential New Ankylosaurid from Late Cretaceous Montana

Discovery could be New Genus of Armoured Dinosaur

A dig site near to the town of Jordan (Montana, USA) could provide palaeontologists with a new genus of armoured Ankylosaur to study, thanks to the excavations of two brothers from Kansas.  The Ankylosaurs were a group of Ornithischian dinosaurs, that evolved during the Late Cretaceous, they were descended from earlier armoured dinosaurs that are known collectively as the Thyreophora (shield bearers).  These plant-eating dinosaurs were widespread across the northern hemisphere by the end of the Mesozoic.  The proliferation of Ankylosaurids across Asia and North America suggests that these herbivores lived in an era that was dominated by big Theropod predators (the Tyrannosaurs), these animals needed heavy armour and powerful tail clubs to protect themselves from these predators.

An Illustration of a Typical Late Cretaceous Ankylosaur

Picture Credit: Everything Dinosaur

The two Kansas based brothers, both keen fossil hunters think they have found something new while digging in the fossil rich strata of Montana.  According to Jim Kirkland, a state palaeontologist at the Utah Geological Survey, who has examined photos of the fossil that Robert and Alan Detrich are uncovering it looks like a new type of Ankylosaur.

Jim stated:

“This thing is worthy of note.  There is no doubt about it.  In my mind it’s clearly a new one.”

The brothers have been digging for several weeks.  So far they have uncovered the Ankylosaur fossil’s skull, part of its leg, ribs, armoured plates and some vertebrae (back bones.  Based on the fossils found so far, scientists are suggesting that this specimen could represent an animal some ten metres in length, making it one of the biggest Ankylosaur fossils discovered to date.

Brother Robert commented:

“It’s huge! It’s bigger than any of the specialists have seen so far.  It’s got everybody pretty excited.”

Kirkland and the Detrich brothers hope a person or institution will step forward to buy the fossil for a museum, which would allow for further study to determine if it is indeed unique.  The effort would involve cleaning the fossil and comparing it against related animals from the fossil record to make sure it is not just a variation of a previously discovered dinosaur.  If these fossils do represent a new genus of Ankylosaurid, then the brothers as the finders would have the opportunity to name this dinosaur.  Robert Detrich said, if given the opportunity, he would like to call it “Enormasaurus” in memory of his late mother Norma.

Robert added:

“It’s exciting.  It really is.  When he came back and said it’s pretty clearly a new genus, and these guys write papers on Ankylosaurs so they know their stuff.”

Robert Detrich, who is from Wichita, and his brother, who lives in Lawrence, plan to return to Kansas in about three weeks.  Besides the Ankylosaur fossil, the brothers also have been digging up a Triceratops fossil.  Perhaps the brothers will be able to find the front limbs of their Triceratops, as the forelimbs of these horned dinosaurs are rarely found in association with other elements of the specimen.

Piecing Together Ornithocheirus

The Confusion over Ornithocheirus

The Pterosaur known as Ornithocheirus is perhaps more familiar to dinosaur fans than many other types of flying reptile.  It appeared in the ground breaking documentary television series “Walking with Dinosaurs”, in fact it was the star of one of the episodes “Beneath a Giant’s Wings”.  It is regarded my many as one of the largest Pterosaurs known to science with many young dinosaur fans often quoting the text from the many BBC publications associated with the original television series that state that Ornithocheirus was “the size of a small plane”.

As with most aspects of palaeontology the known facts are not permitted to get in the way of a good story.  It is true that some exceptionally large Pterosaur fossil fragments were found in the Santana Formation of north-eastern Brazil and it was from this evidence that the BBC were able to depict Ornithocheirus as such a huge animal.  However, as far as we know those fossils have yet to be fully researched and although they are associated (for the moment), to the Ornithocheirus genus, claims for a twelve metre long wingspan for a member of this particular genus of the Pterosauria are doubted by many palaeontologists.

A Drawing of Ornithocheirus

Ornithocheirus “Bird Hand”

Picture Credit: Everything Dinosaur

The trouble with Pterosaurs and with Ornithocheirus in particular is the fragmentary and often highly eroded nature of their fossilised bones.  The English palaeontologist Harry Govier Seeley was given the task of trying to classify the many hundreds of Pterosaur bones that had been found in the Cambridge Greensand deposits of England, a project that he started in 1869.  He was commissioned sort out the flying reptile fossils of the Sedgwick Museum in Cambridge on behalf of the museum itself and Cambridge University.  The young, enthusiastic Seeley was beset with problems from the very beginning.  These rocks (Cambridge Greensand) represent marine sediments deposited by encroaching sea water over what was to become England during the early Cretaceous Period.  The highly fragmentary and eroded nature of the fossils has led a number of scientists to conclude that the Pterosaur fossils were eroded out of older strata on the sea shore and redeposited.  From over 1,000 fossils, Seeley attempted to characterise and classify individual species of Ornithocheirus.  His original work has been re-examined by numerous other scientists over the years and something like forty separate species of Ornithocheirus are now listed but most of these are “Nomen dubia” – a name given to an organism whose validity is in doubt.

From the fossils discovered to date, Ornithocheirus type Pterosaurs were particularly widespread with fossils found in Europe, Australia and Africa, the largest of their kind probably has wingspans of approximately six metres, not the size of a small plane but still large for a Pterosaur.

To view models of Pterosaurs and other dinosaur toys: Dinosaur Toys – Dinosaur Models

Fossils Show South American Origins of Eucalyptus

Eucalyptus Fossils from Argentina

Eucalyptus trees may be restricted to Australia and its outlying islands these days but new fossil evidence suggests that this ancient type of tree may have flourished in South America.  Fossils of leaves, flowers, fruits and buds found in Patagonia (Argentina) indicate that this type of tree was around in the Palaeogene and they represent the only scientifically validated Eucalyptus macro-fossils identified from outside Australasia.

The fossils have been dated to approximately 52 million years ago and represent a sub-genus of Eucalyptus known as Symphyomyrtus, which makes this sub-genus much more ancient than previously thought.

The Fossilised Imprint of a Eucalyptus Leaf

Picture Credit: Maria Gandolfo

The research team identified a number of structures characteristic of Eucalyptus in the morphology (shape) of imprints of plant material preserved as fossils.  Some key features included, long, thin leaves with smooth edges, dots on the leaves that reveal oil glands and scars on the fruits where petals and sepals fell off.  The evolution of the Eucalyptus and its relatives has been poorly documented, due to the lack of fossil evidence.  In the past, a few scientists had claimed to identify Eucalyptus fossils from South America but those records failed to hold up to formal scientific scrutiny using modern research techniques.

Maria A. Gandolfo, a senior researcher in the Dept. of Plant Biology at Cornell University and one of the lead authors on the paper stated:

“The genus Eucalyptus is restricted to Australia and a few surrounding islands, and it is completely extinct in South America which makes this discovery very significant not only for botanists and palaeobotanists but also for [its] biogeographical implications.”

The fossils were found at a site called Laguna del Hunco, northwestern Chubut Province in Patagonia.  Although petroleum exploration geologists first discovered fossils at this site in 1932, a team of researchers from the United States and Argentina including Gandolfo and Elizabeth Hermsen, a postdoctoral associate working in Gandolfo’s lab, collected important fossils in 2009 that included fruits, branching structures that support the fruits, three flower buds and a flower.

Fossilised Fruiting Bodies of Eucalyptus

Picture Credit: Peter Wilf

Elizabeth, who is also a lead author on the scientific paper detailing the research team’s work said:

“The buds provided important information that placed them within the genus Eucalyptus; they really helped clinch the identity of the fossils.”

The researchers also used a computer programme and analysis of the morphology to create a phylogeny, a branching diagram that depicts the evolutionary relatedness among groups of organisms (species, populations and so on), of Eucalyptus.  Because the researchers were able to accurately date the fossils and then place them in a phylogenetic context in relation to living plants, the findings may now be used as a reference point to test the results of recent molecular dating studies that have calculated the age of the Eucalypts.

The research was conducted in collaboration with colleagues from Pennsylvania State University, the Denver Museum of Nature and Science, the Universidad de Buenos Aires and Museo Paleontológico E. Feruglio, Argentina.  The work was funded by an American Recovery and Reinvestment Act Grant from the National Science Foundation to Gandolfo.

The Wandering Duck-billed Dinosaur

Early Duck-billed Dinosaur Discovery Adds to Debate over Evolution of Hadrosauridae Crests

Scientists have a new clade of duck-billed dinosaur to study, and thanks to two almost simultaneous fossil discoveries in the United States; more information on the evolution of Hadrosauridae head crests could emerge as well as a better understanding of the geographical distribution of Ornithischian genera in the western United States during the Late Cretaceous.

The duck-billed dinosaurs, so called as they had beaks that resembled the broad beaks of a duck, were a very successful group of plant-eating dinosaurs that evolved during the Cretaceous and rapidly diversified into numerous genera.  These types of dinosaur are broadly divided into two main sub-families, the hollow crested Lambeosaurinae and the predominately solid crested or crest absent – Hadrosaurinae.  The discovery of a new genus of duck-billed dinosaur named Acristavus gagslarsoni has led to the establishment of a new clade of Hadrosaurs, the Brachylophosaurini and may shed light on the origins of these dinosaurs and how they diversified into two main sub-families.

The first fossil specimen was found in Montana in 1999 by the Old Trail Museum staff and volunteers, including a group of “junior palaeontologists” from the University of Chicago and was excavated in 2001 and 2002 from the Two Medicine Formation (Montana) by study co-author Rebecca Hanna for the Museum of the Rockies in Bozeman, Montana., where it now resides.  By an extraordinary coincidence, a second specimen of the same dinosaur species was discovered just a a year after the Montana specimen (2000).  This discovery was made in the Grand Staircase Escalante National Monument strata (Wahweap Formation – southern Utah) by an entomologist from Brigham Young University C. Riley Nelson (who has also co-authored the published paper on this new dinosaur with Rebecca).

The strata at these two sites date from the same geological time (Campanian faunal stage) and the two finds have been dated to approximately 79 million years ago.  This makes A. gagslarsoni the oldest known Hadrosaur from North America and it is remarkable that two specimens of the same dinosaur species were found within a year of each other, but at locations more than six hundred miles apart.

Terry Gates, a research associate at the Chicago Field Museum stated:

“To find two specimens six hundred and fifty miles apart that lived at virtually the same time, and were discovered within a year of each other is extremely rare in dinosaur palaeontology”.

With elements of the skull to study including the frontal and postorbital bones along with the dentary (lower jaw) scientists have noted that there is a lack of any cranial ornamentation (no crest),  which is in stark contrast to virtually every other of genus of Hadrosaur dinosaur discovered to date.  This discovery, an early type of Hadrosaur, what is believed to be a basal North American duck-billed dinosaur lacking any form of head crest or ornamentation adds weight to the theory that the two sub-families of this type of dinosaur, the Lambeosaurinae and the Hadrosaurinae independently evolved head crests and ornamentation.

As for explaining why the fossils were found so far apart a spokesperson for Everything Dinosaur commented:

“There could be a number of reasons why these specimens were found so far apart.  For example, most scientists believe that these dinosaurs lived in herds and they may have made extensive migrations in search of seasonal feeding opportunities or indeed travelling to favoured nesting sites.  Secondly, this type of basal Hadrosaur may have had a wide geographical distribution, perhaps it had an inherent advantage over other types of plant eating dinosaur around at the time, which made this particular type or herbivore very successful.”

A Simplified Hadrosaur Family Tree

Tracing the Evolution of Duck-Billed Dinosaurs

Picture Credit: Everything Dinosaur

The Brachylophosaurini consists of three Hadrosaur genera, Acristavus plus Maiasaura, whose fossils have also been found in Montana and Brachylophosaurus from which the clade gets its name. This dinosaur was again widely distributed with a known range from Montana in the south to Alberta (Canada), in the north.  These dinosaurs together constitute the earliest clade of North American Hadrosaurs.  The Acristavus fossils indicate that this dinosaur had anatomical characteristics seen in both Brachylophosaurus and Maiasaura specimens, but not necessarily shared between them.  This suggests that Acristavus may be ancestral to these other dinosaur genera

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