Flying reptiles.

Hello and welcome to my latest publication, a celebration of the incredible pterosaurs which ruled the skies during the Mesozoic era. From the tiny to the enormous the diversity of these reptiles is truly staggering as was their success. The fact they filled so many niches is testament to their adaptability and resilience. It is no exaggeration to say that the skies of the Mesozoic would have made a truly astounding sight. I hope you enjoy this piece and as always feel free to give feedback.

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAYQjB1qFQoTCLPq3IzC3cgCFQo_GgodKrAEQQ&url=https%3A%2F%2Fpterosaur.net%2Frestoration.php&bvm=bv.105841590,d.d2s&psig=AFQjCNHB0leq5CBEcRvt9jLIA-XmUV0iTw&ust=1445858851592853

The emergence of pterosaurs.

From the moment reptiles appeared on earth there has always been the potential for species to attempt to utilise the possibility of flight. It was not however until the late Triassic period where true flight in reptiles appeared in the incredibly diverse form of pterosaurs. Pterosaurs are divided into two groups– rhamphorhynchoid pterosaurs and pterodactyloid pterosaurs. Characteristics of – rhamphorhynchoid pterosaurs include a short wrist bone which resulted in the weight of the wing predominantly based on the elongated fourth finger. The bones of the finger itself were as thick as the arm. Rhamphorhynchoid wings were typically longer and thinner than those of pterodactyloids. Rhamphorhynchoids also possessed a stiff rod of vertebrae which was characterised by a diamond shaped fin at its end. The purpose would have been to help with steering during flight. This is a trait not found on pterodactyloids.

Pterodactyloids wrist bones were often as long as those of their humorous. Consequently the fingers were found further along the leading edge of the wing. In both wings an extra bone at the base of the wing it is theorised, would have supported a membrane which stretching in front of the arm bones and positioned between the wrist and base of the neck. The main advantage of this would have been to manipulate air flow over the wing, providing maneuverability.

The earliest known pterosaur –Preondactylus.

Preondactylus is the earliest known pterosaur. The species was discovered by Nando Buffarini during the year of 1982 in the Preone valley situated in the Italian Alps. The tail remains share the same trait as all other rhamphorhynchoids. The vertebrae is made up of tendons which have over time solidified into one. This would have been utilised for balancing and steering.

Early diversity.

Peteinosaurus.

This diminutive pterosaur is thought to provide one of the earliest examples of diversity in pterosaurs. It is considered likely the majority of peteinosaurus diet was made up of insects rather than the predominantly fish based diet many other pterosaurs favoured. Despite its size, it has been suggested this species could be the ancestor of dimorphodon. 

Pterosaurs of the Jurassic.

Dimorphodon.

Having recently made an appearance in Jurassic World, dimorphodon may well now be one of the most notorious pterosaurs discovered. The first specimen of this species was discovered in the cliffs of Lyme Regis by Mary Anning in 1828. The only other confirmed remains of dimorphodon have also come from the Dorset Coast. Present day birds which possess the same deep faced trait as ptersoaurs such as dimorphodon could provide living examples of how these reptiles may have used colouration for signalling purposes. The strong claws on the feet and hands are thought to be an adaption for a life living on cliffs.

An end to the warm blooded debate.

The argument over where pterosaurs were warm blooded as strongly suspected due to their lifestyle came to an end with the discovery of sordes. So well preserved were the remains a fur like covering was clearly apparent, a tell-tale sign of a warm blooded animal. This trait would not only have helped with body temperature regulation, the fur would have helped to minimise the noise of flying a useful advantage for an aerial predator.

http://www.google.co.uk/url?sa=i&source=imgres&cd=&cad=rja&uact=8&ved=0CAcQjhwwAGoVChMI-rvVs8LdyAIVAWsUCh2HWQnl&url=http%3A%2F%2Fwww.palaeocritti.com%2Fby-group%2Fpterosauria%2Fsordes&psig=AFQjCNFfuS2yo8wBanEkL6lWdXPZaUkl9A&ust=1445858936515369

Aerial agility.

Rhamphorhynchoids were predominantly fish eaters, batrachongnathus however was adapted to an altogether different lifestyle. With blunt teeth, broad scoop like jaws and a diminutive body perfect for aerial hunting batrachongnathus was perfectly designed for hunting down insects over lake surfaces. Experts have likened their hunting technique to that those of modern day swallows.  

The Cretaceous.

Advanced filter feeding- Pterodaustro.

The first pterosaur to be found in South America came in the unusual form of pterodaustro. A filter feeder, its long, thin jaws would have sweeped upwards in a bow shape. The lower jaws were filled with up to as many as five hundred bristles. The upper jaws possessed blunt teeth were perfect for moving the prey towards the mouth. It has been speculated the fur of pterodaustro was pink as a result of the pigmentation caused by feeding on crustaceans, flamingos provide a modern day example of this.

Mysteries unsolved.

Tapejara has caused experts plenty of headaches. The short mouth opens up two possibilities as far as its feeding preferences are concerned. Tapejara may have been a fruit eater and as a consequence would have played an important role in the ecosystem with seed dispersal, or on the other hand its diet might have been made up of carrion and fish. The unusual crest has also been a subject of debate. The immediate assumption is that the purpose of such an ornament was for display however the crest may have been employed to aid with aerodynamics. Tupuxuara comes from the same area as tapejara – North Eastern Brazil and both existed during the early Cretaceous. The similarities continue anatomically as well as tupuxuara also possessed a crest. This possessed plentiful blood vessels inside which indicated an ability to change colour in accordance to activity and mood. Despite this further research has revealed that this bizarre pterosaur was not part of the same family as tapejara as previously thought, and more closely related to one of the giants of the skies, quetzalcoatlus. 

In the shadow of a giant.

The sheer size of quetzalcoatlus is almost impossible to comprehend, the fact an animal of such a size ever took to the air is nothing short of mind blowing. The wingspan alone would have been the length of a bus and when on four limbs would almost have been able to make eye contact with a giraffe. The weight of this goliath is a subject of debate and estimates have ranged significantly from 250 kg to 70 kg still the weight of an average sized human. The size of the animal initially raised doubts if flight were even possible. Recent research has found the arm bones were so strong that, even at the peak of the weight estimates they would still have been capable of allowing quetzalcoatlus to get airborne. From a standing position on all fours, this giant was able to generate enough explosive power to take off.

These animals were truly incredible. They ruled the skies for millions of years and would have installed fear in the animals they hunted. Their diversity was truly remarkable and we are lucky we have the clues they have left behind to try and understand how they lived their extraordinary lives.

I hope you have enjoyed this publication and thank you for reading all the best, George.

Twitter - ReallyWildWykes

Email- grwykes@gmail.com

References

The Illustrated Directory of Dinosaurs and Other Prehistoric Creatures. 

The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures.

Dinosaurs The Grand Tour.

Latest discoveries in the world of paleontology.

Hello and welcome to my latest blog. Apologies for the large time frame between this post and my last one but life has been pretty hectic recently. During this time some amazing paleontological discoveries have been made and it is these that make up the content of this publication. As always I hope you enjoy it.

Platypus dinosaur.

A close relative to the infamous Tyrannosaurus Rex, has been found in Chile. Chilesaurus diegosuarezi is named after its country of origin and seven year old Diego Suárez who made the discovery at the Toqui Formation in Aysén. These rocks were left at the end of the Jurassic Period and are estimated to be 145 million years old.

Chilesaurus diegosuarezi is nicknamed the platypus dinosaur as a result of its staggering range of characteristics from varying dinosaur groups. Examples of this include two fingered hands attributes belonging to dinosaurs such as T.rex however its feet more closely resemble early sauropods. The pelvic girdle is similar to those of orithischian dinosaurs however the species is actually classified as a saurischian dinosaur.

What makes this find so special is despite this species being a theropod, a group of dinosaurs predominantly made up of carnivores, Chilesaurus diegosuarezi was a herbivorous grazer. Previously the only known herbivorous theropods were close relatives to birds. This find reveals herbivorous theropods were present historically earlier than previously thought.

 Fernando E. Novas, Leonardo Salgado, Manuel Suárez, Federico L. Agnolín, Martín D. Ezcurra, Nicolás R. Chimento, Rita de la Cruz, Marcelo P. Isasi, Alexander O. Vargas, David Rubilar-Rogers. An enigmatic plant-eating theropod from the Late Jurassic period of Chile. Nature, 2015; DOI: 10.1038/nature14307

Sexual dimorphism.

The topic of sexual dimorphism in dinosaurs had previously caused much debate amongst scientist. Previous claims have been dismissed because other explanations such as the age of the individual being a factor could not be ruled out. Now for the first time strong evidence has come to light in the case of sexual dimorphism in dinosaurs. The study was conducted by Evan Saitta, who had previously worked for numerous summers on a Stegosaurus “graveyard” in central Montana.

Some Stegosaurs had tall plates while others had wide ones. The latter of which could be as much as 45% larger overall. In the remains at the excavation site in Montana, these were the only skeletal differences, if the remains were of different species other differences for separate ecological niches would have been likely to have been observed.

Further support for the case of sexual dimorphism in Stegosaurs emerged after CT scans and microscope analysis ruled out growth as an explanation. In both plates the bone tissues were no longer growing, nor where the plates growing into each other. Saitta theorises that with the greater investment in ornamentation usually found on males, the wider plates were likely found on them. The taller plates may have been used by females as an anti- predation strategy.

http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Stegosaurus_Senckenberg.jpg/250px-Stegosaurus_Senckenberg.jpg

1. Saitta ET (2015). Evidence for Sexual Dimorphism in the Plated Dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA. PLoS ONE, 2015 DOI: 10.1371/journal.pone.012350
2. 
   

Yorkshire cliffs reveal Britain's oldest sauropod.

Experts from the University of Manchester have identified Britain's oldest sauropod after a vertebrae fell from a Yorkshire cliff face .The dinosaur came from the Middle Jurassic Period and is estimated to be 176 million years old.

As a consequence of the find being a solitary bone at this time, it is not possible to give the find a species name. Until more remains are found, the specimen will be nicknamed “Alan after Alan Gurr who found the vertebrae. Nether the less, this is still a very special find as Middle- Jurassic rocks are sparsely found and predominantly in countries including China and Argentina.

http://www.sciencedaily.com/releases/2015/06/150601141523.htm

New horned dinosaur discovered.

Scientists have discovered that remains found in a cliff next to Alerta’s Oldman river some ten years previously, belong to a previously undiscovered species of horned dinosaur. The dinosaur has been named Regaliceratops peterhewsi after Peter Hews who made the initial discovery and as a result of its unusual ornamentation.   

The find is as special as it is unique for a catalogue of reasons. Horned dinosaurs had never previously been found in the previously mentioned region of Alberta. This immediately indicated an important new find said Dr. Caleb Brown of the Royal Tyrrell Museum of Palaeontology. It was not until further laboratory work had been completed did the team realise just how remarkable their new find was.

The species shared many similarities to the infamous horned dinosaur triceratops. Where they differed significantly however was the size of its facial horns and a frill shaped shield situated at the back of the skull. The nose horn is smaller and the horns over the eyes have been described as almost comically small. The frill which Brown descried as looking “like a crown” consisted of pentagonal plates which radiated outwards and a spike in the centre.

Regaliceratops peterhewsi also shows the first example of convergent evolution in horned dinosaurs. The species belongs to the group of horned dinosaurs known as Chasmosaurines which had a small horn over the nose along with much bigger horns over the eyes, however was anatomically more similar to species found in the group known as Centrosaurines. As these two groups existed in different time periods, this indicates similar features evolved independently.

A New Horned Dinosaur Reveals Convergent Evolution in Cranial Ornamentation in Ceratopsidae. Current Biology, 2015 DOI:10.1016/j.cub.2015.04.041

Close relative of Velociraptor discovered.

 Steven Jasinki from the University of Pennsylvania made the discovery while working on a specimen thought to be Saurornitholestes langstoni, a member of the theropod dinosaurs in the Dromaeosauridae family. The remains had initially been discovered in 1999 by Robert Sullivan in the Bisti/De-Na-Zin Wilderness Area of New Mexico.

 Jasinski, using comparative analysis with other specimens was able to discover some slight differences. Most eye catching of which was the surface of the skulls correspondence with an abnormally large olfactory bulb. This would indicate a strong sense of smell was an important part of this predators armoury.

  S. sullivani was of modest size, estimated to be around six foot in length and less than three foot at the hip. Using studies on similar species, it is deemed likely this species would also have been fast, agile and may well have hunted in packs. Originating from the Late Cretaceous period, this is the first example of a named Dromaeosaur being discovered from this time frame in North America south of Montana.

http://www.sciencedaily.com/releases/2015/05/150511125312.htm

   That is all for this occasion, I hope you found these new discoveries as interesting as I did. Thank you for reading,

   George.
https://www.facebook.com/reallywildwykes?ref=hl

Dinosaur predatory and defensive adaptions.

Hello and welcome to my latest edition of this paleontology blog. This time I have chosen to write about some of the amazing predatory adaptions dinosaurs employed to take down their prey and the equally amazing measures prey species took to try and protect themselves against this. As always I hope you enjoy reading the publication.

Spinosaurus.

Potentially reaching up to 18 metres in length and with an enormous sail on its back, spinosaurus would have been a formidable sight. In fact this may have been the largest carnivorous dinosaur to have walked the planet. There were two species of spinosaurus, Spinosaurus aegyptiacus and Spinosaurus maroccanus. The name spinosaurus translates as spine lizard, which is appropriate as their massive spines  could have measured up to seven feet in length.  It is widely suspected that they were connected to each other by skin to form the sail. No one can be certain what the purpose of the sail was however theories have included courtship displays and for thermoregulation.

In 2010, research on isotopes found in spinosaurus teeth showed that this dinosaur spent a substantial amount of time in water, further supporting the mounting evidence to suggest this. Spinosaurus remains have also revealed a variety of adaptations which would have aided its predatory lifestyle. With nostrils high on its snout spinosaurus would have been able to largely submerge itself in water, while pressure sensors it the skull would have alerted it to nearby prey. Conical teeth were perfectly adapted for catching the aquatic prey spinosaurus would have hunted, which included ; coelacanths, lungfish, sawfish and sharks although evidence has also been found to suggest this dinosaur was not above scavenging non aquatic prey. Other adaptions for a lifestyle in and around water included an open medullary cavity for buoyancy control and flat bottomed pedal claws associated with foot movements in water. This awesome predator would have terrorised any prey unfortunate enough to cross its watery path and without a doubt deserves its fearsome reputation.

http://media1.s-nbcnews.com/i/newscms/2014_37/661471/140911-spino5_b5ac60e2f46805dfd895cfee61e4341c.jpg

http://www.sciencemag.org/content/345/6204/1613.short

Science Uncovered - Dinosaurs Rediscovered.

http://www.livescience.com/24120-spinosaurus.html

A free meal is an easy meal.

Jurassic Park may have portrayed Tyrannosaurus Rex as a fearsome predator, the truth for a long time however has been a lot less clear cut. The anatomy of tyrannosaurs have caused debate as to whether they were predominantly scavengers or predators. The tyrannosaurs brain possessed a large olfactory bulb essential for processing smells, while strong teeth for breaking and puncturing bones and small forelimbs would also point potentially towards a scavenging way of life. A publication in 2013 however proves definitive evidence that of the tyrannosaur species, t-rex at least did actively hunt prey. A tyrannosaurus tooth was found embedded in the tail vertebrae of a duck billed hadrosaur in the infamous Hells Creek Formation. This sort of find is not necessarily unusual. What made this find special was the clear evidence of bone growth around the tooth. This would seem to prove the hadrosaur not only escaped but also lived for a considerable period of time afterwards. It is deemed likely that predatory dinosaurs were similar to modern day predators in that they may have taken live prey as a preference however would not have turned down the opportunity of an easy meal through scavenging.

Velociraptors made infamous by Jurassic Park, are an example of a notoriously lethal predator who also took advantage of a free meal on occasion. When bite marks courtesy of a velociraptor were found on the remains of a protoceratops along with the loss of two of its own teeth, it provided the evidence needed for experts to confidently say this was an occurrence of scavenging behavior. David Hone of Institute of Vertebrate Paleontology and Paleoanthropology of China in Beijing points out that with so much meat on offer to the predator responsible for the kill, it would have made no sense to start feeding on some of the less preferable parts of the body. He is confident the velociraptor would have discovered this kill with very few scraps of meat remaining hence the effort taken to access them. These remains are in sharp contrast to the famous and amazing find of velociraptor and protoceratops frozen it time in the middle of a battle to the death.

http://dx.doi.org/10.1073/pnas.1216534110
http://www.livescience.com/11006-velociraptor-frozen-time-scavenging-larger-dinosaur.html
http://paleobiology.si.edu/dinosaurs/info/everything/behavior.html

A lethal claw.

The second claw on hawks and eagles may closely resemble the shape and function of the sickle dromaeosaurids employed to help them dispatch prey. While small prey can largely be dispatched through crushing, larger prey requires a forceful grip to prevent an escape and the victim is usually subsequently eaten alive. This may be a grim modern day example of how dromaeosaurids would have predated on larger prey as experts  state they lacked any obvious adaptions to otherwise kill their prey.

An example of how initially similar anatomically dinosaur groups adapted of fill different niches would be the troodontids and the dromaesaurids. Troodontids opted for speed as a result of a longer metatarsus along with an accurate albeit weak grip meant potentially a preference for small prey. Dromaeosaurids with their stronger and slower feet would likely have relied on ambush tactics and targeted larger prey.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028964#pone-0028964-g011

Venom.

It was thought that a pocket found at the base of the sinornithosaurus fang may have provided evidence that this predator may have used venom to subdue its prey. This has since been disputed however so consequently there remains no conclusive proof of the use of venom by dinosaurs.
Explore Magazine - Dinosaurs Undiscovered. 

Majungasaurus - The  cannibal.

Roughly seventy million years ago the island of Madagascar provided a home for one of the most fearsome predators to have ever walked the planet. Majangasaurus was an albelisaur and possessed the characteristic larger blunt skulls and horn associated with these dinosaurs. The narrower skulls found in most theropod dinosaurs would have restricted movement in the neck and meant that prey would have been taken down by repeated much bites much like wolves do today. Majangasaurus on the other hand with its bulkier skull, would have been able to dispatch its prey with a single bite to the skull or neck in the same way big cats do.

Majangasaurus was the top predator of Madagascar and the fossil record provides compelling evidence that this dinosaur was not adverse to predating on its own kind when prey supplies were short. Their remains have been found with teeth marks in the same pattern and manner to those found on herbivorous dinosaurs in the same area. As there were no predators capable of challenging the domination of Majangasaurus on the island, these can only be the results of an act of cannibalism. This is the only non avian theropod dinosaur known to have resorted to this behavior and perfectly illustrates its ruthless resourcefulness it would have needed to to survive.

http://www.oldearth.org/curriculum/dinosaur/majungasaurus.jpg

Science Uncovered - Dinosaurs Rediscovered.
Explore Magazine - Dinosaurs Undiscovered. 

Teeth shape. 

The teeth of some tyrannosaurs may have been even more lethal than they originally appeared. It is now believed they may have been specially designed to trap scraps of flesh and subsequently provide ideal conditions for bacteria to breed. As a result of this even an initially non fatal bite could cause death within days as the wound would have turned gangrenous and failed to heal. Once the prey  succumbed to its injuries, the predator would have been able to feed at its leisure. 

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Defense.

Armour.

Think Armour and Ankylosaurus and Euoplocephalus immediately come to mind. The ankylosaurus when threatened with a predator had at least two defensive strategies. An ankylosaur could potentially position itself low to the group meaning the only way its vulnerable underbelly could have been attacked would be to flip it over. Perhaps its most iconic defensive strategy however was the club which has been found on the end of the tail. This would have been made as a result of fused vertebrae and tendons supported by bony deposits. Although we will never know for certain the amount of damage the club could cause to potential attackers, it is possible with enough force it could have broken the thickest dinosaur bones around. The use of armour was even employed sauropods which although was nowhere near the extent of the previously mentioned ankylosaurs, may still have helped to fend off attacks by packs of raptors.  

Stegosaurs also used armour in the form of a thagomizer- an arrangment of spikes found on the tail. The number and the direction the spikes pointed was species dependent. Evidence of the damage this weapon could inflict  has been found as a result of puncture marks to the tail vertebrae of an allosaurus. It is not unusual for spike specimens to be found with evidence of heavy use implying they were employed on a regular basis. Scientists also believe stegosaurs may have flushed blood into their plates along their backs to intimidate predators. 



http://upload.wikimedia.org/wikipedia/commons/3/33/Ankylosaurus_magniventris.jpg

Explore Magazine - Dinosaurs Undiscovered. 

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Tail.

The giants of the dinosaur world the sauropods moved in herds and would surely have been a sight to make any potential predator think twice about attacking. The enormous tails acted as a counter balance for their equally large necks and potentially to loose unwanted heat as a result of their large surface area. They may also have acted as an extra form of defense, with scientists speculating they could have been used as a whip to cause terrible injuries to attackers. Others have theorised the sound alone these tails could have caused by flicking their tails may have caused a noise travelling far and wide as a warning to dinosaurs with predatory intentions.



http://scienceline.org/wp-content/uploads/2013/02/1033477755_05a94f77e4_z-e1361769534208.jpg

Explore Magazine - Dinosaurs Undiscovered. 

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Camouflage.

Exams of camouflage in the modern day natural world are everywhere. It is possible that camouflage was used as a defensive strategy for dinosaurs as well. Striped hadrosaur skin has revealed at the very least their tails were striped.  Considering the difficulty stripes make identifying a prey animal for predators in the modern world, it may not be unreasonable to theorise the stripes may have covered the vast majority of the hadrosaurs body.

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Explore Magazine - Dinosaurs Undiscovered. 

Vocalisation.

Crested skull hadrosaurs for example parasaurolophus, are likely to have used vocalisations over large distances by bellowing and subsequently warning the rest of its herd of imminent danger.

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Size.

For sauropods size alone would have made them almost immune from the threat of predation. The chances of reaching adulthood would have been slim however as the youngsters were very vulnerable. For example for every thirty eggs laid by a diplodocus, only one or two or youngsters would have survived to become an adult. 

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

Quick growth rate.

Hypacrosaurus, with no natural defenses and the description of the Thompson's Gazelle of the Late Cretaceous, may well have been very vulnerable to an array of predators. The hadrosaur did however have one antipredation strategy which may have improved its chances of survival research has revealed. As a comparison of growth rates which were assessed by counting growth rings on sections of leg bones each ring accounting for one year of life. It was discovered the hadrosaur grew between three and five times faster than any potential predator living at the same time. 

In the time it would have taken a tyrannosaur to become half grown, Hypacrosaurus would have been fully grown and as a result there would have been an enormous difference in size. As well as this the hadrosaur also reached sexual maturity early - typically between two and three years of age. 

http://www.sciencedaily.com/releases/2008/08/080805192720.htm

Speed.

Running is possibly one of the simplest but also one of the most instinctive forms of defense in the face of danger. We know hadrosaurs were capable of making a hasty retreat on two legs and although ascertaining from the fossil record how fast a dinosaur could move is very tricky, comparisons can be made with modern day animals. Galliminus for example shares similar traits to ostriches including a long neck and muscular, powerful legs. Ostriches can run at speeds of up to 45 miles per hour and with Galliminus reaching up to eight metres in height, it may not be unreasonable to assume they could also reach similar speeds.


Explore Magazine - Dinosaurs Undiscovered. 

http://dinosaurs.about.com/od/dailylifeofadinosaur/a/dinocombat_2.htm

There is little doubt that world of dinosaurs would have been a harsh and unforgiving place where only the fittest survived. We are just lucky we have the evidence they left behind to give us an insight into their incredible world.

 That is all for this time, as always I hope you enjoyed reading and all the best,

 George.

  Twitter @ReallyWildWykes

Dinosaur orders.

Hello and welcome to my first blog on the wonders of the world of paleontology. The University of California Museum of Paleontology, states paleontology  can be described  as a study of how fossils can educate us about past ecologies, evolution and where humans stand in the world. It is certainly a subject which is capable of capturing the imagination of those young and old. I remember as a young child entering London's Natural History Museum for the first time and being instantly awestruck by the famous Diplodocus cast "Dippy". It as many people would testify, is an incredible experience and cannot fail to make the mind wonder in an attempt to imagine a world where magnificent  beasts such as these would be common place. It was dinosaurs which triggered my interest in paleontology and it is this subject which  seems a good place to start my first few publications in this blog. I hope you enjoy reading them and I always appreciate feedback whether it be positive or constructive criticism. 

Dinosaur orders.

Dinosaurs roamed the Mesozoic era which started 250 million years ago and ended 65 million years ago. The fossil records show that throughout this time they would have appeared in an incredible variety of shapes and sizes. Their success is evident today in the form of their modern day relatives birds. Dinosaurs are separated into two orders,  ornithischian and saurischian dinosaurs  and it is those of the saurischia order who are the ancestors of birds.

Saurischian dinosaurs.

Saurischian dinosaurs the earliest on historical record, are also known as lizard hipped dinosaurs. Their pubis bone pointed downwards and forwards in contrast to ornithischian dinosaurs which had a pubis bone pointed downwards and backwards. Saurischian dinosaurs are divided into two groups, sauropods and theropods.

Sauropodomorphs.

Sauropods grew to colossal sizes which lived from the late Triassic to the end of the dinosaur era. They were incredibly successfully and populated across all continents and a variety of habitats including deserts, forests and polar regions. Sauropods  had long necks, small heads, small brains, long tails and four to five toes. Despite being at least semi quadruple, all sauropods would have been able to rear up on their hind legs. Sauropods were predominantly herbivorous. They would have used their long necks, specially designed teeth and their ability to stand on their back legs to reach and strip vegetation out of reach for other herbivores. Gizzard stones have been found with sauropod remains and it is widely thought these would have been used to grind ingested food items.




http://www.nhm.ac.uk/resources-rx/images/1007/dippy-banner_125459_2.jpg


Theropods.

Although predominately  made up of carnivorous species, this group also includes and omnivores and out and out herbivores. All theropods would have walked on two legs, and most would have had three claws. Their head shape and size of their heads were variable. Skull bones were often loosely attached to each other. Theropod feeding behavior  ranged from acts of predation, scavenging and herbivorous feeding. Consequently,  teeth size and shape  showed large variations. 




http://www.amnh.org/var/ezflow_site/storage/images/media/amnh/images/permanent-exhibitions/fossil-halls/hall-of-saurischian-dinosaurs2/tyrannosaurus-rex/150313-1-eng-US/tyrannosaurus-rex_dynamic_lead_slide.jpg


Ornithischian dinosaurs.

Ornithischian dinosaur species were mainly herbivorous and had a special predentary bone to help them with this lifestyle. This formed on the lower jaw and helped to form a beak, which was used for slicing, while the teeth grinded and chewed food at the back of the jaw. As previously mentioned, in contrast to saurischian dinosaurs, ornithischian dinosaurs or bird hipped dinosaurs pubis bone faced backwards. This would have allowed extra room for an enlarged digestive track. Ornithichians were highly adaptable and lived in a variety of habitats. 

Lineages of Ornithischian dinosaurs.

Ceraptopsians -  The earliest ceratopsians were small and bipedal, while later species would have lived life as large quadrupeds. Species such as the famous triceratops had bony protective frills and horns. Horns may also have been used as a way for species to identify each other. Ceraptopsians had narrow skulls and parrot like beaks, while their teeth would have sheered and sliced plants. 

http://www.ucmp.berkeley.edu/diapsids/ornithischia/zunicer_skull.jpg


Hadrosaurs - Hadrosaurs were Iguanodontoids which possessed a characteristic duck bill and a specialized dental battery.  This comprised of a minimum  three teeth in each position forming a grinding pavement, made up of hundreds of teeth. These were used to crush vegetation. These dinosaurs were present in the Americas, Eurasia and Antarctica during the late Cretaceous. Hadrosaurs laid up to twelve eggs in a pit nest with soil deposited on them.





http://museumvictoria.com.au/pages/8750/MM-hadrosaur-illustration-BIG.jpg


Ankylosauria - Ankylosaurids lived in North America and Asia during the Cretaceous period.  Their body armor was truly amazing, with  osteoderms all over their body, their heads were armored with triangular hornlets, and in some cases even their eyelids were reinforced. Some species also used modified tail clubs. As well as being used for protection, it has been suggested that  tail clubs may have been used for display and for fighting among themselves. The front of the upper jaw possessed no teeth and the teeth that were present in other parts of the jaw were small and leaf shaped. 

Images taken by author.

Stegosauria - Stegosaurids had a wide range throughout the late Jurassic and early Cretaceous period. Like ankylosaurs, they no teeth at the front of their upper jaw and the teeth they did have were small and leaf shaped. Their skulls were small, long and narrow. Early stegosaurs had spikes along their backs while later species would develop plates made of osteoderms. 



http://blogs.smithsonianmag.com/dinosaur/files/2011/03/stegosaurus-carnegie.jpg


Pachycephalosaurids -   These dinosaurs lived during the Cretaceous period and would have been found in the northern hemisphere. Pachycephalosaurids are separated into two groups, flat headed and dome headed. It is considered likely that the flat headed group may be just young or female individuals from the dome headed group. It is theorized these skulls were used for species recognition and or as a battering ram. 

http://cdn4.sci-news.com/images/enlarge/image_1247_1e-Pachycephalosaurus.jpg

Well that concludes my first publication for this blog. I really hope you have enjoyed reading it. Next week I will go into more detail about dinosaur predatory and defensive adaptions. As I said earlier any feedback is massively appreciated, and thank you for reading.
George.
Twitter- reallywildwykes.  

Information was sourced as a result of my own studies online with  Coursea, Dinosaurs a Field Guide by Gregory S Paul and from this link http://www.ucmp.berkeley.edu/paleo/paleowhat.html.