Iguanodon - Fingers and Thumbs

IGUANODON      

For this edition I thought we'd take a look at one of the Dinosaurs that first captured my imagination as a child - Iguanodon.

First discovered by Gideon Mantell in Sussex, England in the 1820's, the story of Iguanodon's discovery and classification is one of the more famous in palaeontology.
Initially, only some teeth were found (allegedly by Mantell's wife).
A few years later, a more complete skeleton was found, but as palaeontology was a very new science at the time, Mantell's reconstruction of the skeleton was initially incorrect - he imagined the creature as a gigantic Iguana, with a rhinoceros-like horn on it's snout.

                                                                          Mantell's initial reconstruction of Iguanodon

Later on, as better specimens were found, Mantell's mistake would become obvious - The "Horn" was in fact part of the foreleg, acting as a spike in the thumb position.
(One day, we'll focus more on this story, and how dinosaurs become classified)

                                                A more accurate depiction of Iguanodon (Picture (c) John Sibbick
                                         
Iguanodon was a herbivorous ornithopod from the early Cretaceous period, that was about 10 metres long and weighed an impressive 3 tons.
One of only a few dinosaur species able to move either bipedally or on all fours, enabling it to graze on the ground or reach food higher up in the trees.

The hand of Iguanodon is one of the more fascinating parts of any dinosaur species, and is wonderfully adapted to Iguanodon's habitat and lifestyle. The central 3 digits are relatively immobile, and grouped together, forming a hoof-like appendage not unlike that of modern-day ungulates. This would have allowed it to bear it's great weight when moving on all fours.
The 4th digit, equivalent to our pinky finger, was very dextrous, acting almost like an opposable thumb. (an evolutionary adaptation which is rare - even today, millions of years later). Allowing the Iguanodon to grasp food with it's hand, rather than using it's mouth would have allowed for greater care to be taken while eating, and possibly for manipulating other objects in the  creature's habitat.
The most striking feature of the hand though, is the giant thumb spike. This would have been used mainly as a defensive weapon against the large predators of the day, and with devastating effect - in a way it was comparable to the sickle-like claws of Deinonychus and similar "raptor" species.

                                             The wonderfully adapted hand of Iguanodon  (picture (c) Jack The Lizard)

So as you can see, Iguanodon is an important and fascinating find, because even though the initial discovery was thought to be an extremely large Iguana, the reality of the species turned out to be even more spectacular.

MONSTERS!!

With the new Godzilla movie getting a lot of attention in the media lately, I thought now would be a good time to take a look at some of the more fearsome dinosaurs.

Let's start with Spinosaurus Aegypticus, a large predatory theropod from the Cretaceous period.
As you may have guessed from it's name, this dinosaur lived in what is now Egypt, and across more of North Africa.
Spinosaurus was even larger than the more famous T-Rex, although whether the species was a voracious predator as it was depicted in Jurassic Park 3 or more of a fish-eater is still a matter of debate amongst palaeontologists. The structure of the  Spinosaur's teeth, and it's long snout (reminiscent of a crocodile) would suggest a fish-based diet, but it's physiology would suggest it was more than capable of hunting on land. and was more than likely a capable scavenger too.
The most striking feature of Spinosaurus is definitely the large spine "sail" on it's back, which may have been used for mating purposes or, more likely, as a means of temperature regulation, as a species of lizard this large would need a lot of thermal energy from the sun in order to function properly and a large sail would gather a lot of that energy efficiently.

                                                   Spinosaurus Skeleton (image courtesy of Wikipedia)
Another rather odd looking predatory species was Dilophosaurus (two-crested lizard), which some of you may recognise as the dino with a fancy frill around it's neck that spits venom at Nedry in Jurassic Park...Unfortunately this was the least accurate depiction of a species in that movie. The real Dilophosaurus was larger, up to 25ft in length and weighing half a ton. The real Dilophosaurus had no neck frill and was unable to spit venom at it's prey, although it was still an agile and fearsome predator.
The crests upon it's head were used mainly in attracting mates, rather than as weapons or as a means of temperature regulation.

                                             DIlophosaurus as seen in Jurassic Park (c) Universal Studios 
These gigantic monsters weren't just seen on land though...
In the prehistoric seas there were the predatory Mosasaurs, which weren't dinosaurs, but large aquatic lizards measuring up to 60ft in length,  larger than todays biggest shark, the filter feeding Whale Shark, and in fact bigger than many of the land based dinosaurs of the time (except Sauropods).

                                                  Mosasaurus skeleton (image courtesy of Wikipedia)
And in the skies there was the monstrously huge Quetzalcoatlus,named after the Aztec deity Quetzalcoatl. This was, like the Mosasaur, not a dinosaur but a species of flying reptile with a reputed wingspan of up to 50ft, although between 30-40ft is much more likely. This still places Quetzalcoatlus at roughly the size of a small aircraft, and considerably larger than any modern flying animal. It is thought that Quetzalcoatlus was likely to be a scavenger/hunter, rather like storks and vultures of today, and as such it was capable of hunting on land, albeit in a rather ungainly fashion. .

                                                     Hunting Quetzalcoatlus (image courtesy of Wikipedia)
So whilst there were no dinosaur species capable of destroying downtown Tokyo, there were definitely true monsters once roaming the Earth.

The Lost Valley

Seeing as it's Lady Lara Croft's birthday, I thought we'd take a special look at the Dinosaur-packed Lost Valley level of the original Tomb Raider.

Whilst exploring a large cave complex near Vilcabamba, Peru (killing some wolves along the way, naturally), Lara heads through into the Lost Valley itself - a beautiful, exotic area full of lush vegetation, one of the most visually striking areas of the game.
We have no time for sightseeing, however, as Lara is soon beset by a pack of hungry Velociraptors!

                                                                  Lara defends against a Raptor
The Raptors Lara comes across were fast, agile hunters. They had a large, sickle-like claw on each foot, which could be moved independently of the foot itself. These claws were used as weapons, for puncturing the hardened skin of, and latching onto their prey, in a similar way to a lioness using her large canine teeth to hold onto the throat of a zebra or Antelope that the pride have caught. But the claws also had another function - they enabled the raptor to climb trees and rocks with relative ease, which is probably a major factor in the success of the Dromaeosaurids (raptors). They were also intelligent, and probably hunted in small packs...So Lara was very lucky to have survived being ambushed by them in the Valley.
One major difference between the in-game Raptors and their real life counterparts, however, is that it is now believed that all Raptor species had feathers, and were early ancestors of modern day birds. Maybe this could explain why the crows in Tomb Raider II had such a vendetta against our girl...

The fast, agile raptors are no match for Lara, however, as she uses her  wits (and pistols!) to take them out after a rather tough battle.
As Miss Croft presses further on into the valley, the ground itself begins to tremble. She barely has time to wonder what could be causing it before a HUGE T-Rex comes around the corner, and it looks like Lara is back on the menu! :O

                                                                       Look out, Lara!! A T-Rex appears from nowhere!

The Name Tyrannosaurus rex means "King of the Tyrant Reptiles" - and this says it all.
At 40 feet in length and up to 15 feet in height, T. Rex is not just THE most iconic Dinosaur, it was also one of the largest land carnivores of all time. Incredibly, it is thought that this beast could run at speeds of up to 40km/h, Typically preying upon Hadrosaurs and Ceratopsians, T.Rex was also a scavenger, and would likely feed upon any uneaten prey left by other carnivores. So when Mama Rex sees Lara in the Valley, it is definitely thinking it has stumbled across an easy meal. Fortunately for us, Lara's a tough gal. :D

She runs for a small cave to the side, and juuust about manages to get inside safely before she becomes a snack for the valley's apex predator. From the safety of her hiding place, Lara is able to take out the gigantic toothy menace with her trusty pistols.

(Note: If she wasn't attempting to save the world from a megalomaniacal Atlantean Queen, I'm sure Lara would have reported this incredible scientific discovery to the relevant institutions :P)

Real T-Rex skeleton on display at the Field Museum, Chicago

                                                   
So is it possible that the Lost Valley could exist, and sustain the Dinosaurs that live there?
In the in-game world, definitely! The wolves have access beyond Vilcabamba, and would bring back prey to their den. The Raptors would then use their long claws to climb over the rocks, and either steal the food from the wolves, or just catch the wolves themselves, returning to the Valley with their catch, then in turn, have their meals cheekily scavenged by the Tyrannosaur. And of course, when She got hungry, Mama Rex always had those Raptors to catch...until Miss Croft came along and spoiled the Dino party! :D
In the real world though, of course, it's improbable that Dinosaurs have survived the extinction event at the end of the Cretaceous Period and lived to the modern day. The closest we will probably see are large reptiles like Crocodiles/Alligators, and the Komodo Dragon of Indonesia.

So while it's unlikely that a real Lost Valley exists, if it did, there's only one person who could survive the prehistoric perils... Happy Birthday, Lara. <3

Sauropods and Titanosaurs

Welcome Back!
This time we'll be looking at the Largest family of dinosaurs, the Sauropods.
These behemoths were not just the biggest dinosaurs, but also the largest land animals to have ever lived, absolutely dwarfing the largest land animals of today.
In basic terms they are very much like giraffes, in that the have elongated necks in order to reach the succulent leaves at the top of trees, and move in herds. But being dinosaurs, of course they are Much bigger.
The diplodocus is one of the most famous sauropods, probably due to the magnificent specimen kept in the main hall of the Natural History Museum in London. (below)

                                                     Diplodocus at the NHM, London. Image by Jasmin C
This amazing creature was, at over 100ft long, and weighing in at up to 40 tonnes, an incredibly large lizard. You may have noticed, the majority of it's length was made up by the incredibly long neck, and tail. (earning the species it's name - Diplodocus meaning "Double Beam" in latin).
As mentioned above, the long neck evolved in order to reach the fresh, nutrient-rich leaves at the top of
trees - As you can imagine, an animal this large needs a lot of nutrients in order to survive the harsh prehistoric conditions.
Diplodocus' would also use their necks in order to engage in battle with others of their species, whether conflict arose over mating rights, territory, or even position within the herd hierarchy.
But there was also another weapon, making the Diplodocus deadly from either end:- The incredibly long, thin tail. Used partially for balance, Diplodocus could also whip the tail at a great speed to attack any predator that came looking for a meal.Yes, even a lizard of this size would be vulnerable to a pack of hungry raptors or, worse yet, Allosaurs looking to pick off a youngster.

Another well known Sauropod Dinosaur was Camarasaurus, an ancestor of Diplodocus. It was smaller than Diplodocus, but you can see from the picture below how the Sauropods began to evolve into their massive sizes.

                                                      Camarasaurus at NHM, London. Image by Jasmin C
And yet, Diplodocus and Camarasaurus were far from being  record holders in terms of size. Later, during the Cretaceous period, a sub-group of Sauropods would evolve to truly dwarf any other creature that has ever set foot on land - The Titanosaurs.

The Titanosaurs were truly remarkable, for subtle differences in their anatomy enabled them to grow much larger than other sauropods. Their necks were more flexible than those of more primitive Sauropod species, instantly gaining more height over their brethren.

Combined with longer front legs, this also helped to make the neck (a vulnerable spot) harder to reach for 

predatory species, vital in a time when predatory dinosaurs were also becoming larger.

To put this size into perspective - the largest Titanosaur species would often weigh in at 90-100 tonnes, twice the weight of the Diplodocus, or to put in modern terms,TEN TIMES the weight of the largest recorded African Elephant. This makes these giants among the heaviest animals to have ever lived, comparable in weight to many large whales of today, and truly deserved the name "Titans".

                                                  Argentinosaurus. Image by Capt. Kodak

Among the best known Titanosaurs are Saltasaurus and Argentinosaurus but the Title of largest 

Dinosaur, and therefore largest land animal of all time, goes to....*drum roll*...

Amphicoelias!

Only known from one fossil, and notes of bones that have been lost, Palaeontologists have been 

able to determine that this species was possibly up to 200ft in length, and weighed over 130 tonnes.

 

Now that we've looked at the larger species, next time we will look at the smallest dinosaur species.

History of the Ceratopsians

History of the Ceratopsians

For the first post here, I thought we'd look at one of the most well-known and interesting Dinosaur groups, the Ceratopsians (horned faces). The Ceratopsians were a herbivorous family of dinosaurs that came into being at the end of the Jurassic/beginning of the Cretaceous period, and belong to the Ornithischia (bird-hipped) order of dinosaurs, as opposed to Saurischia (lizard-hipped) order. "But they are lizards, not birds!" I hear you cry.
This may be so, but this is an easy way of categorizing dinosaurs, as they have 2 distinct hip types..and the ceratopsians fall into the former category. *We'll look into the classification process at a later date*
So, what is a Ceratopsian? Well, for most people the best example of this order is Triceratops, or "Three Horned Face". This is the species with the 3 massive horns and a frill around it's neck, made famous in Jurassic Park as the dinosaur that got sick, and had everyone sifting through its poo.. :D

Triceratops is the classic shape for it's order. It has a "beak" rather than a traditional lizard mouth, walks on all fours and has horns and a frill around it's neck. The horns and frill were most likely used for defense against predators. the frill itself would enable the 'Ceratops to protect it's neck from being bitten by a large T-Rex, and the horns, much like on Wildebeest today, make for impressive weapons and would put off all but the bravest of predators.
Additionally, many palaeontologists believe these defensive weapons were also used in mating rituals, with the frill becoming brightly coloured during mating season, and that the males would engage their horns in deadly duels, much like rutting stags of today.

Some species of ceratopsian looked very similar to the Triceratops, for example Styracosaurus (spiked lizard) was very similar, except it had only one facial horn near it's beak, but had a frill covered in deadly spikes to compensate for the loss of the 2 remaining facial horns.
Conversely, Protoceratops (first horned face) had the frill and beak, but as it was an ancestor of the Triceratops, had not developed the horns, and thus looks much friendlier overall ;)
But if we look even further back through the ancestry of these species, we find that the earliest members of the Ceratopsian family were much smaller and lighter than the monstrously huge Triceratops. Psittacosaurus (parrot lizard) evolved in the early Cretaceous, was mostly bipedal, and had no frill at all, with just the distinguishing beak to mark it as an early example of a Ceratopsian.
(In fact, Psittacosaurus is much more akin to the more nimble Hipsilophodon than any of its tdescendants..)
And yet, looking at these species in order, the evolution from nimble biped to tank-like Triceratops is clear to see. And for that reason, the Ceratopsians remain one of my favourite dinosaur families.