A New Species of Pachyrhinosaurus is Announced

A Polar Pachyrhinosaurus – horned dinosaur of the Arctic

Scientists from the Museum of Science and Nature (Dallas, Texas) are going to announce at the annual meeting of the Society of Vertebrate Palaeontology in Las Vegas that they have discovered a new species of horned dinosaur.  The fossilised remains of at least ten individuals have been excavated from a dig site well inside the Arctic circle.

The new species will be formally named Pachyrhinosaurus perotorum, in recognition of the Perot family (Margot and H. Ross Perot and their children), who have demonstrated a long history of supporting science and science education for the public and for their financial support of the museum.

In conjunction with the announcement, a draft of the paper that describes the find was posted recently at the website of Acta Palaeontologica Polonica, an international quarterly journal that features papers of general interest from all areas of palaeontology.  Jointly submitted by Anthony R. Fiorillo, Ph.D., the Museum’s chief curator and director of research, and Ronald S. Tykoski, Ph.D., chief fossil preparator at the Museum, the paper is entitled “A new species of the Centrosaurine Ceratopsid Pachyrhinosaurus from the North Slope (Prince Creek Formation: Maastrichtian) of Alaska.”

Hard at Work Preparing the Fossils for Transport

Hard at work in the Arctic

Picture Credit: Museum of Science and Nature

The new dinosaur was discovered on lands managed by the Bureau of Land Management, this site has yielded some extraordinary evidence providing scientists with an insight into the lives of polar dinosaurs.  The research was funded by the National Science Foundation Office of Polar Programmes.   The final paper, once reviewed will be published at the end of this year.

The Upper Cretaceous strata of the Prince Creek Formation contain the highest concentration of polar dinosaur fossils known.  This new species of Pachyrhinosaurus has been described based on differences between the skulls of known Pachyrhinosaurs – P. canadensis and P. lakustai.  This new species, shares characteristics with each of these two types of horned dinosaur, but the differences in anatomy and skull morphology are enough to permit the research team to propose a new species.

An Illustration of a Typical Pachyrhinosaurus

Two adult Pachyrhinosaurs

Picture Credit: Mike Fredericks

Interestingly, based on an analysis of the rock strata, this new species of Ceratopsian is the youngest known Pachyrhinosaurus.  The rocks which yielded the fossilised bones have been dated to around 70-69 million years ago (Maastrichtian faunal stage), perhaps this type of horned dinosaur was able to survive as a specialist herbivore living at high latitudes, whereas other types of Pachyrhinosaurs were replaced by different types of horned dinosaur such as the larger Triceratops at lower latitudes.

Dr. Fiorillo, one of the authors of the scientific paper commented:

“Discovering hundreds of bones from all these Pachyrhinosaurs in one spot was unbelievably exciting, and we really thought the expedition was an incredible success.  To later realise that we had unearthed a whole new species was one of the best days of my career.”

Dr. Fiorillo  and his colleagues unearthed the remains of this new species during a return excavation in 2006 in the far north of  Alaska, many miles north of the Arctic Circle.  The location had been explored on numerous previous expeditions, the team’s time at the site being restricted because of the harsh working conditions, the remote location and the continuous threat of bad weather.

A Map Showing the Fossil Site Location

Dinosaurs from Alaska

Picture Credit: Museum of Science and Nature

A film crew fortuitously captured the unearthing of the skull and hundreds of surrounding fossils that came from at least ten Pachyrhinosaurus individuals.   Alaska has provided scientists with some fascinating evidence indicating that there were resident dinosaurs this far north during the Late Cretaceous.  The lush polar conifer forests were also a seasonal home to large numbers of Hadrosaurs that migrated north, probably to take advantage of the twenty-four hour days that this region had during the polar summer.  It is not known whether these Pachyrhinosaurs were seasonal migrants or present in the area all year long.  The numerous fossil bones all found in one locality indicate herding behaviour, but it is uncertain whether these large dinosaurs were permanent residents.  Recently, isotope evidence taken from the teeth of Camarasaurids was claimed to show migration behaviour in Jurassic Sauropods.

To read more about this: Camarasaurids – Evidence for Seasonal Migration

Once that season’s dig was completed, Fiorillo and his team meticulously packaged the precious cargo in plaster-burlap jackets (although getting plaster to harden in sub-zero temperatures proved challenging), then painstakingly airlifted these precious artefacts by helicopter to a nearby airstrip where they were flown back to Fairbanks (Alaska) before continuing their long journey south towards Texas.   Perhaps, in a reflection of what took place seventy million years ago, these rhino-sized dinosaurs were once again migrating south.

Upon their arrival in the palaeontology laboratory at the Museum of Nature and Science, the jackets were handed over to Dr. Tykoski, who spent the next several years meticulously whittling away the 70 million-year-old sediment that entombed the dinosaur bones.

Dr. Tykoski described the preparation process as:

“It’s as if someone took 15 Pachyrhinosaurs, dumped them into a blender for 30 seconds, poured all the mess out into a ball of concrete, then let it solidify for seventy million years.”

In early 2011, Dr. Tykoski, Dr. Fiorillo and their colleagues were stunned and excited when the newly cleaned and reassembled pieces clearly showed they had found a new species of the Pachyrhinosaurus.  A reconstruction of the Pachyrhinosaurus (P. perotorum) will form part of the new dinosaur hall that is being constructed at the museum.  This id due to open in early 2013.

A Model of a Pachyrhinosaurus

A Pachyrhinosaurus Model from Papo of France

Picture Credit: Everything Dinosaur

Analysis of the skull material, the size of the fenestrae in the skull and the morphology of the skull bones led to researchers to conclude that their Pachyrhinosaurus fossils did indeed, represent a new species.

Comparative Line Drawings of Reconstructions of the Three Known Pachyrhinosaur Species

Comparisons in skull Morphology

Picture Credit: Museum of Science and Nature

The drawings although not to scale show morphological differences between the skulls of these three different types of Pachyrhinosaurs.  The areas filled in grey on the drawing of P. perotorum indicate hypothetical morphology not preserved in currently known specimens of P. perotorum.

It is very difficult to assign fossil material of a Certopsian to a new species.  The arduous task of comparing the size and shape of the fossil bones between specimens is complicated by the fact that the size and shape of the neck frill and other parts of the skull changed considerably as the animals got older.  The first species of Pachyrhinosaur was formally named and described by C. M. Sternberg in 1950, from a series of fossil specimens found in North America.  The second species to be named P. lakustai was only formally described just a couple of years ago.  P. lakustai was named after the school teacher who first found the bones of this new dinosaur species, to read more about this discovery: New Pachyrhinosaurus Species Honours Discover

Camarasaurids – Evidence for Seasonal Migrations

Camarasaurids – Oxygen Isotopes Preserved in Fossilised Teeth Indicate Migration

The greatest mammal  land migration seen today might be the 1.5 million wildebeest (Connochaetus taruinus) or thereabouts, that seasonally migrate from the Masai Mara in Kenya to the Serengeti of Tanzania in search of fresh grazing.  However, additional evidence to support the long-held theory that dinosaurs also migrated has been found following an extensive study of Sauropod teeth.

The Sauropods, were plant-eating dinosaurs (Saurischians), with small heads, long necks and long tails.  Their massive bodies were supported on immense trunk-like legs.  It had been postulated that these animals, some species of which were the largest terrestrial land animals known to science, did migrate in such of food.  These enormous creatures would soon deplete an area of vegetation and so they would have to move on in search of more food.

Now data from a study of Camarasaurid teeth (a type of Sauropod), suggests that some species may have migrated hundreds of miles in seasonal migrations.

Camarasaurid Teeth (keys provide scale)

Isotopes of Oxygen indicate Migrations

Picture Credit: Handou Museum

Given their enormous appetites and water needs, their ability to survive in lowland flood plains affected by seasonal dry spells and drought has puzzled scientists, the only explanation offered was that these animals must have migrated to find more suitable feeding areas, when the lowland plains were subjected to the seasonal dry spell.

Now researchers have learned at least one Sauropod species made regular journeys between lowland to highland habitats covering several hundred miles.

The evidence is in the teeth of Camarasaurus, a large sauropod which grew to a length of 2o metres and is a relative of the better known Brachiosaurs.

Fossilised Camarasaurus teeth, found in the US states of Wyoming and Utah, contained a chemical record of the animals’ movements during the Late Jurassic period around 150 million years ago.

As different atomic versions of oxygen, or isotopes, occur in the surface water of lowland and highland regions, any isotopes found in the fossilised teeth of these dinosaurs would provide an indication of where these animals travelled to.

These differences remained imprinted in the oxygen from drinking water deposited in the Camarasaurus teeth.

An Illustration of a Typical Camarasaurid Dinosaur

The Teeth tell a Tale.

Picture Credit: Everything Dinosaur

Comparing the oxygen isotopes to those in ancient soil, lake and wetland samples revealed a picture of the dinosaurs’ migration patterns.

The researchers, led by Dr Henry Fricke, from Colorado College, (United States) commented about the migrating dinosaurs in the scientific  journal Nature:

“Camarasaurus populations… must have directly occupied high-elevated regions for at least part of the year before returning to the basin where they died.”

Camarasaurus fossils are some of the more common (relatively) Sauropod fossils found in the Upper Jurassic rocks of the famous Morrison Formation of the western United States.   An analysis of the isotopes of oxygen preserved within the fossilised remains of the teeth of these herbivores provides scientists with an understanding of their seasonal movements.

The team studied the ratio of oxygen isotopes in Camarasaurus teeth.  The oxygen comes from surrounding soil, lakes and wetlands and the isotope ratios are specific to a particular area.  The isotopes are laid down in the enamel as the tooth grows. The oldest enamel is at the tip and youngest at the base. So, the isotopes recorded in the enamel become a sort of time-line.  By comparing oxygen isotope ratios in the tooth enamel with those preserved in the animal’s surroundings, scientists can tell where the animal was living at particular times.

The team found, at seasonal points, the isotope ratios in the Camarasaurus teeth differed from those in its home habitat.  Instead, it corresponded to those from highlands nearly two hundred miles away.  This evidence suggests that these creatures did indeed migrate.

A spokesperson for Everything Dinosaur noted:

“This new study adds weight to the theory that certain types of dinosaurs migrated just as many mammals and birds do today.”

A herd of huge, twenty tonne Camarasaurs walking slowly across the lowland plain to the richer feeding of the upland areas would have been a wonderful sight.   However, these plant-eaters probably did not migrate alone.  Just as many other plant-eating animals travel with the wildebeest in eastern Africa (zebra, buffalo, antelopes) in search of grazing it is likely that a number of other types of dinosaur migrated with the Sauropods to find better feeding areas.

The Everything Dinosaur spokesperson added:

“If large numbers of plant-eaters migrate, then we see the formation of predator trails to, with the meat-eaters adapting their behaviour to cope with this seasonal fluctuation in prey animals.  It is likely that these behaviours were also adopted by the predatory dinosaurs in the region, animals such as the fearsome Allosaurus.”

This is not the first time that an analysis of isotopes found in dinosaur teeth has provided scientists with new information about prehistoric animals.    In June, we published information on the work carried out by another group of American researchers (California Institute of Technology) who had examined Sauropod teeth found in Africa, in a bid to determine whether these animals were warm-blooded.

To read more about this research: American Researchers use Teeth to Find Evidence of Warm-Blooded Dinosaurs

Everything Dinosaur’s Web Log Linked to Main Website

“B” is for Blog Button or should that be “E”

Our collective photoshop skills are getting better, slowly but surely.  What a powerful tool this CS5 is and we are only just scraping the surface, a feeling that we get when we start the long, arduous and meticulous process of fossil preparation.  The main Everything Dinosaur website: Everything Dinosaur has long been linked to this blog site, but for the first time as part of the company’s on-going development there is a button on the home page.

As part of Everything Dinosaur’s work on the social media sites of YouTube and Facebook we have linked our main website to our other pages on these platforms.  In addition, this blog now has a button too.

The Everything Dinosaur “Blog Button”

Blog Button

Picture Credit: Everything Dinosaur

The “E” shape is from our logo, which was originally taken from a modified drawing of a three-toed dinosaur footprint (Theropod), it is interesting to note how this logo can be adapted to fit new roles.  The Everything Dinosaur blog has operated since late May 2007 and it now contains over 1,580 published articles and news stories featuring dinosaurs and other prehistoric animals.  Our intention is to put up a post every single day, it is hard work and we do have to divert resources away from our dinosaur toys and games, but we would not want to let down our many thousands of readers.

Getting to Grips with Social Media

Everything Dinosaur Homepage Links to Social Media Sites

Today saw the realisation of a long held ambition of the Everything Dinosaur team members.  The home page of Everything Dinosaur’s website has been linked up to the company’s Youtube and Facebook accounts.  Timing could not be better as there are an additional two video reviews of Safari Ltd products to view on Everything Dinosaur’s Youtube channel – “DinoaurMike1″.  One video is a review of the Prehistoric Sealife Toob made by Safari, the second is a brief review of the new T. rex model, that forms part of the “Wild Safari Dinos” series.

The Facebook pages are regularly updated and contain some of the more quirky things that the company and the staff have been involved with.  We put up fresh material as often as we can and we love looking at the other posts from those “Facebookers” (if that is the right phrase) who we are linked to.  Social media makes a great place for the Everything Dinosaur dinosaur model reviews and videos.

This blog remains the main focus for posting up dinosaur and prehistoric animal news stories, after all we have nearly 1,600 articles on in it already – covering virtually every conceivable subject area, or as a colleague put it “from Aardonyx to Zupaysaurus”.  A spokesperson from Everything Dinosaur stated that very shortly:

“There would be further integration between Everything Dinosaur’s web presences including a link to the blog from the website’s home page and some changes in the layout and design of the websites to make them more intuitive and user friendly”.

We wait to see what the developments will be…

Recommended Posting Dates for Christmas Gifts

Royal Mail Guidelines for Posting Gifts for Christmas

As we approach Halloween, and what with Bonfire Night just around the corner, it seems that a timely reminder might be helpful to all those Everything Dinosaur customers who want to purchase Christmas gifts including dinosaur toys and games.

Our packing teams work seven days a week at the moment, keeping on top of all the orders.  We try our very best to pack and despatch parcels as quickly as we can.  Each autumn/winter we publish tables produced by Royal Mail as to the recommended last safe posting dates for parcels going abroad and within the UK to ensure an arrival before Christmas.

For USA, Canada, H0ng Kong, Singapore and South Africa customers, the last recommended safe posting date for international surface mail passed on the 18th October.  Goods purchased after this date and requested to go by international surface mail are unlikely to reach their destinations in time for the big day.

The Royal Mail Table of Christmas Posting Dates 2011

Recommended Posting Dates Christmas 2011

Source: Royal Mail

We have more details regarding shipping posted up on the Everything Dinosaur website, we urge all customers to be aware of shipping issues when sending packages abroad and we suggest they consider carefully the suitability of any postal option chosen before placing their order.

Everything Dinosaur shipping information: Delivery and Shipping Information

Archaeopteryx Gets Back to Its Perch

“Maximum Likelihood” Study Suggests Archaeopteryx is a Bird and Not a Dinosaur

Archaeopteryx (A. lithographica) is perhaps one of the most studied species known.  An amazing amount of research has been carried out on this creature, whose fossils are associated with lithographic limestone deposits in Germany.  A few weeks ago we reported that a study carried out by a team of Chinese scientists, in the light of a new Theropod dinosaur discovery, placed Archaeopteryx in the Dinosauria taxon and not with the Aves (birds).   However, in a new study, this crow-sized, feathered creature has once again been defined as a primitive bird.

A Beautifully Preserved Archaeopteryx Fossil

With bird-like features and reptilian features is it a bird or a dinosaur?

Picture Credit: Stanford University

The new research appearing this week in the scientific journal ” Biology Letters”  has been carried out  by evolutionary biologist, Dr. Michael Lee of the University of Adelaide and the South Australian Museum and Dr. Trevor Worthy of the University of New South Wales.  These Australian based scientists contradict the findings of the Chinese team, from the Chinese Academy of Sciences, that only a few weeks ago placed Archaeopteryx in the dinosaur family tree.

The Chinese researchers compared the fossils of Archaeopteryx with those of a newly discovered non-avian, Chinese Theropod dinosaur Xiaotingia zhengi.   This newly discovered, fast-running, meat-eater is believed to be closely related to Archaeopteryx, but it was a non-flying, feathered dinosaur.  This put into doubt the widely accepted scientific view that Archaeopteryx was one of the first birds to evolve.

To read more about this Chinese Theropod and the implications for Archaeopteryx: Is Archaeopteryx about to be Knocked Off its Perch?

Commenting on the uproar and excitement caused when the first nearly complete fossil of Archaeopteryx was discovered 150 years ago, Dr. Lee stated:

“It was immediately recognised as half bird-half reptile when it was first discovered.”

However, the discovery of X. zhengi led to the proposing of a  new, remodelled evolutionary tree that placed Archaeopteryx in a group with bird-like dinosaurs such as the Dromaeosaurs.

Summing up the implications for A. lithographica as a result of the new phylogenetic analysis, Dr. Lee stated:

“Archaeopteryx lost its exalted place in bird evolution.”

The problem that concerned the Australian team, was that this new Chinese study placed the flying Archaeopteryx, an animal capable of sustained, powered flight in with a group of dinosaurs that were either ground dwelling, gliders or weak fliers that may not have flown in the same bird-like manner as Archaeopteryx.

Dr. Lee commented that, it meant that bird flight most probably evolved more than once and Archaeopteryx possibly evolved flight independently of birds in a case of what’s called “convergent evolution”.  As far as evolutionary theory goes, such scenarios are not particularly elegant.  So Lee and his colleagues carried out a new analysis of the data to see what further analysis could reveal.

Once the study had been concluded, the team discovered that Archaeopteryx had roughtly the same number of traits as birds as it did with dinosaurs.  Archaeopteryx may have been a transitional fossil in every sense of the word -

Dr. Lee said:

“If you just count the number of traits it’s basically a 50:50 call.”

The traditional method of building an evolutionary trees, what amounts to a phylogenetic study, weighs each trait equally and tries to find a tree that fits the majority of them – a best fit scenario giving all traits equal weighting.  For the Australian team, they considered this approach to be not the best plan of attack in this case because some traits are more reliable than others, because they evolve slowly and are more likely to be conserved through time.

Dr. Lee explained, that for example, a back bone is likely to evolve just once, but a particular fur colour could evolve multiple times, and is thus a less reliable trait for building evolutionary trees.  The Australian team used a statistical analysis  technique called ‘maximum-likelihood’, which is used to build evolutionary trees based on genetic data and applied this methodology to the fossil data.  This technique can determine the rate of evolution of different traits and gives extra weight to more reliable slow-evolving traits, in essence it provides a weighting so that more important, slowly evolving traits have a higher value in the analytical work.

The team found the bird traits in Archaeopteryx were more reliable than the dinosaur traits and when this weighting was taken into consideration.   You get an evolutionary tree that restores Archaeopteryx to its original position as “first bird“.

He went onto state:

“It puts it [Archaeopteryx] back where people have always thought it belonged.”

The researchers comment that despite these findings, the exact position of Archaeopteryx in the evolutionary tree is hard to pin down because there’s a whole swarm of fossils that lie between dinosaurs and birds.  However, the findings do suggest that the “maximum-likelihood” method is a useful tool for analysing the fossil record.  The research team hope to use the same methodology to study in detail the evolutionary relationships between early mammals in a bid to help define more precisely the exact phylogenetic relationships between Mesozoic mammals.

A Review of the Wild Safari Dinos Tyrannosaurus rex Model

Updated Tyrannosaurus rex Model Available

It is always a pleasure to see a new model of Tyrannosaurus rex introduced.   It seems no prehistoric animal model series is complete without at least one version of this, most famous of all dinosaurs within its ranks.  We have prepared a short, five minute video review of the new T. rex model made by Safari Ltd.

Safari Ltd have added an updated replica of Tyrannosaurus rex to their Wild Safari Dinos range.  It may be more than 100 years since this particular dinosaur was formally named and described but T. rex’s popularity shows no signs of waning.  Virtually every major Natural History Museum in the world has a Tyrannosaurus rex exhibit as focal point within their collections and for this Tyrannosaur we can confidently state that “rex”remains the most popular dinosaur of them all.

Everything Dinosaur’s Video Review of this New T. rex Model

Video Credit: Everything Dinosaur

This video is one of twenty-two videos that we have made.  There are all available on Everything Dinosaur’s YouTube channel (Everything Dinosaur – “DinosaurMike1″), as always we welcome comments.

Tyrannosaurus rex may be the most iconic of all the dinosaurs, but the Tyrannosaur family are a bit of an enigma, how these large, Late Cretaceous predators evolved has remained very much of a mystery to palaeontologists.  However, over the last ten years or so, our understanding of these most famous of all the dinosaurs has grown tremendously as new discoveries have been made and new research techniques to existing fossils applied and this new model brings the latest research into T. rex into dinosaur fan’s model collections.

Bullyland Brachiosaurus Model to be Retired

Museum Line Brachiosaurus to be Retired

Bullyland, the German based manufacturer of models and figures is to retire their scale model of the Sauropod Brachiosaurus in 2012.  This model, part of the company’s “Museum Line” range of prehistoric animal models is not going to be available once current stocks run out.

The  ”Museum Line” collection is developed in co-operation with the National Museum for Natural History in Stuttgart, Germany and has earned a deserved reputation for quality and for introducing unusual models such as the recent introduction of the early Theropod Liliensternus and the bizarre, carnivorous Arizonasaurus.

Bullyland Brachiosaurus to be Retired

Due to be Retired

Picture Credit: Everything Dinosaur

Back in 2010, this model was revised and given a make over with the original brown paint replaced with a dark, metallic green colouring, but after two years this model is being retired.

The Original Museum Line Brachiosaurus Colouration

The Brown “Museum Line” Brachiosaurus

Picture Credit: Everything Dinosaur

As yet, we have not been told what new models this German company intend to launch in 2012.  A lot of model manufacturers have been focusing on producing merchandise for the London Olympic games, but we are confident that Bullyland will be working on new prehistoric animals and we look forward to hearing more from them.

Modern Cycads Not as Old as Previously Thought

Extant Cycads may not be “Living Fossils”

Cycads are palm-like seed plants with massive stems which produce a crown of fern-like leaves.  These strange looking plants may be relatively short, but fossil data indicates that some extinct species may have grown to more than fifteen metres tall.   A new study indicates that those species alive today are not closely related to the cycads that were grazed by the Dinosaurs and other Mesozoic herbivores.  It seems that extant cycads may have evolved from species that diversified to exploit changing world climates around 5-12 million years ago.

That is the conclusion from a study led by Utah State University scientists, the term “living fossil” so often used when referring to organisms that resemble those preserved in the fossil record may not apply to the cycad family.

The evolutionary origins of cycads remains unclear, they are probably descended from Pteridosperms (seed ferns) and their are fossils to indicate that these plants were around during the Permian Period, although they may actually have evolved earlier, in the Carboniferous.

A Grove of Modern-Day Cycads

A Cycad Grove

Picture Credit: OU/Everything Dinosaur

Commenting on his research findings, Hardeep Rai, a post-doctoral research fellow with Utah State University’s department of Wildland Resources stated:

“The current form of cycads looks very much like cycads did when they were at their peak 150 million years ago in terms of the number of species and their coverage of the Earth.”

However, the research team concluded that of the three hundred or so known species alive today, these plants resulted from a fairly recent branching of the cycad family tree.

Discussing the research findings, Nathalie Nagalingum of the Royal Botanic Garden in Sydney, New South Wales said:

“Today’s species did not exist during the reign of the dinosaurs.  They evolved independently of dinosaurs only ten million years ago.  The recent radiation of cycads radically changes our view of these emblematic living fossils.”

It is very likely that the feeding activities of dinosaurs and other herbivores during the Late Palaeozoic and into the Mesozoic affected the evolution of plants, just as the grazing of mammals influences flora today.  However, this study suggests that those cycad species alive today are not directly related to more primitive cycad genera.

The study arose from the National Science Foundation-funded Gymnosperm Tree of Life project.  Co-authors of the research include Berkeley’s Charles Marshall and Tiago Quental and Damon Little of the New York Botanical Garden.

We at Everything Dinosaur, discussed the cycad family back in July when we produced an article commenting on the presence of cycads today.  We may have to re-write this piece in the light of this research.

To read more about cycads: Yes, we have Cycads Alive Today

Cycads were most abundant during the Jurassic and Cretaceous, before the evolution of the flowering plants (Angiosperms) led to the decline of this type of flora.  Extant cycads are classed into eleven genera found in three families and certain types of cycad are popular plants with gardeners, although they are high maintenance in a chilly UK climate.

Prior to this new study, the fragmented distribution of modern cycads was thought to indicate that the modern species are the descendants of previously more widespread genera.  The fossil record shows that cycads were particularly widespread during the Mesozoic, even making up a significant proportion of the flora to be found in polar regions.   However, unlike their modern equivalents, these prehistoric polar cycads lost their leaves in winter and they had vine-like stems.

Although, cycads superficially resemble palms and have branching, pinnate, fern-like leaves they are not closely related to palm trees or indeed to ferns.

The research team used a method called molecular dating to analyse the DNA of about two hundred living cycad species.  Scientists calibrated these species’ genetic profiles against the fossil record and found they branched off from a common ancestor between five and twelve million years ago.

The concept of a molecular clock is that evolutionary change occurs at regular time intervals.  If it is assumed that the rate of genetic change (mutation) in the DNA of an organism does not change, i.e. the rate is relatively constant, the molecular genetic difference between two species can be measured and the time when they diversified from a common ancestor calculated.  Using this data, Hardeep Rai and his fellow researchers were able to calculate when these species of cycads in the study diverged from their common ancestor.

Rai said:

“The hypothesis that dinosaurs are responsible for the approximately 300 species of cycads we know today no longer fits.  Some worldwide event caused an explosion of evolutionary change.   The question is: What happened?”

The scientists have postulated that climate change triggered this burst of speciation with the help of specialised insect pollinator, weevils and beetles that underwent evolutionary change at the same time.

Around 12 million years ago, the world’s continents reached their current positions.  Instead of warm climates around the globe, temperate zones emerged at the higher latitudes and climates became seasonal.  Diversification seen in today’s cycads many have occurred in response to these environmental changes.

Tyrannosaurus rex – Bigger than Previously Thought

Tyrannosaurus rex – All Nine Tons of It

A joint US and UK research team using sophisticated, three-dimensional laser mapping have calculated that Tyrannosaurs were heavier than previously thought.  Using Tyrannosaur fossil skeletons, including that of “Sue” the most complete Tyrannosaurus rex (and the biggest) found to date the scientists concluded that these Late Cretaceous predators could reach weights of up to 9 tons.

Using three-dimensional laser scans and computer modelling, British and U.S. scientists “weighed” five Tyrannosaur specimens, including the Chicago Field Museum’s “Sue.  They concluded that Tyrannosaurus rex grew faster and weighed more than previously thought.  The discovery of sub-adult specimens in recent years has enabled palaeontologists to understand a little more about the ontogeny (growth) of these Theropods, for example, it is now widely accepted that just like us humans, Tyrannosaurus rex underwent a growth spurt in its teenage years.

New Body Mass Estimates for Tyrannosaurus rex

Estimates of up to 9 tons in weight

Picture Credit: Everything Dinosaur

A number of studies have been published in recent years, providing evidence on the remarkable growth rates of different dinosaurs.  One recent study focused on the ontogeny of Hadrosaurs (duck-billed dinosaurs), animals that were on the menu for the Tyrannosaurs.  This study suggested that the herbivorous Hadrosaurs actually grew faster than the predators, a strategy for survival when being small and young meant being a potential dinner for a hungry T. rex.

To read this article: Duck-Billed Dinosaurs Grew Up Fast to Avoid Being Eaten

In the light of this Anglo/American research which suggests that T. rex may have been up to thirty percent bigger than previously estimated, so of these older papers may have to be revisited.

In an interesting twist to the T. rex growing fast and enormous research, the scientists have estimated that the smallest and youngest specimen of a Tyrannosaurus rex known, actually weighed less than previously thought.  This study indicates that T. rex grew more than twice as fast between 10 and 15 years of age as suggested in a study five years ago.  The University of California (Berkeley) conducted research into the growth of another dinosaur genus, an Ornithopod called Tenontosaurus.  This research team concluded that dinosaurs may have reached maturity earlier than previously expected, their work, which involved studying the growth rings preserved in fossilised dinosaur limb bones suggested that dinosaurs did grow up fast, perhaps another survival strategy in the brutal Mesozoic.

University of California research into dinosaur growth: Dinosaurs Grew Fast, Lived Fast and Died Young

The study, published in the online scientific journal PLoS One, (Public Library of Science) was conducted by a team of scientists led by Professor John R. Hutchinson of The Royal Veterinary College, London, and Peter Makovicky, PhD, curator of dinosaurs at The Field Museum of Natural History in Chicago.  ”Sue” the biggest Tyrannosaurus rex is housed at the Chicago Museum.

“Sue” at the Field Museum (Chicago)

Super heavy T. rex

Picture Credit: Everything Dinosaur

According to Professor Hutchinson, who commented on the spurt growth of Tyrannosaurus rex during its teens:

“T-rex grew at 3,950lbs per year (1,790 kg) during the teenage period, which is more than twice the previous estimate.”

However, these predators sacrificed speed for power and strength as they got bigger according to this study.  The researchers concluded that heavy, adult Tyrannosaurus slowed down as they grew, but speeds around fifteen miles an hour, about as fast as a footballer can run were still possible.

The velocity that these animals could achieve slowed as they got bigger because the Tyrannosaur torso became longer and heavier while its limbs grew relatively shorter and lighter, shifting its centre of balance forward.   This relates to an aspect of ontogenic studies called “distal growth”, it also explains why young animals have proportionately longer limbs than adults, try comparing a foal to its mother and you will see the difference in body proportions.

Professor Hutchinson added:

“The total limb musculature of an adult T. rex probably was relatively larger than that of a living elephant, rhinoceros, or giraffe, partly because of its giant tail and hip muscles.  Yet the muscles of the lower leg were not as proportionately large as those of living birds, and those muscles seem to limit the speed at which living animals can run.”

When commenting on the growth spurts of these apex predators, during their teenage years, Professor Hutchinson stated:

“At their fastest, in their teenage years, they were putting on 11 pounds or 5 kilograms a day.  Just think how much meat that is.  That’s a hell of a lot of cheeseburgers … it’s a whole lot of duck-billed dinosaurs they needed to be chowing down on.”

Such high demands for food to fuel their rapid growth may have had an impact on Tyrannosaur behaviour.  A huge appetite would suggest that each T. rex or Tyrannosaur group would need a massive territory to hunt in.  Each animal would need access to a substantial amount of potential prey – so as one spokes person for Everything Dinosaur put it:

“Tyrannosaurs may have been few and far between.”

The rapid teenage growth spurt also suggests these reptiles must have had a high metabolic rate, fuelling the idea they were endothermic (warm-blooded).

The researchers, led by Professor Hutchinson and Dr. Makovicky used scans of skeletons to build digital models and then added flesh using the structure of soft tissues in birds and crocodiles as a guide.  A number of composite models were then developed, to provide a spread of potential body masses, computer models to assess the body mass of less muscular dinosaurs and models to look at the maximum musculature that these skeletons could theoretically support.

One of the problems the team encountered was that the fossilised bones of many Tyrannosaurs, including those of “Sue” from the Field Museum (Chicago) had been compressed during the fossilisation and preservation process, so assessments of the actual “life-size” of bones had to be calculated before an assessment of body mass could be carried out.  The study is further complicated by the fact that scientists believe that male and female Tyrannosaurs had very different body forms.   It has been suggested that the more robust, bigger specimens represent females, smaller more gracile forms are males.   Female Tyrannosaurs are believed to have been larger as they needed wider hips to allow the storage and passage of eggs.  Such dimorphism is common in Aves – close relatives of Theropod dinosaurs.

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