#preolithic

[preolithic]

The snake that lived through the mass extinction

Palaeophis is a marine snake that is the type genus (The genus that defines the biological family) of the extinct snake family Palaeophiidae that lived from the Cretaceous period to the Eocene epoch (around 70.6 to 33.9 Million years ago) and was round In many countries such as England, France, Denmark, Morocco, Mali aswell as many parts of the United States. This means that Palaeophis saw the final days of the dinosaurs and potentially was prey and/or hunted Dinosaurs.

These species varied broadly in size; Palaeophis casei is the smallest at 1.3 metres of length, while Palaeophis colossaeus, known from isolated vertebrae, is the largest at the estimated size limits for the genus at over 9 m (29.5 ft) in length, making it one of the largest known snakes. However most species of the genus were not as big.

The first specimen of Pterosphenus Lucas was found in Alachua County, Florida and the fossils of this specimen shed lots of light on the specializations of this giant marine snake being fully aquatic, the marrow cavities are greatly enlarged with thinning of the vertebrae walls much more so than other species of Pterosphenus.

[preolithic]

Preolithic’s favorite prehistoric creatures part 1

Favorite Theropod

Therizinosaurus is my favorite theropod mainly because of how different it is compared to any other theropod that lived around its time. By the look of this scary devil chicken, you would think it would have been the apex carnivore of the time but this giant would have been a peaceful herbivore using its 3m long claws. Although we have only found the arms of it but comparing the size to other Therizinosauridae Therizinosaurus it would have been massive up to 6m tall.

Favorite Crocodile

Armadillosuchus was a small crocodile that lived during the cretaceous period in brazil, what is fascinating about this little croc was that is had armadillo-like plating which gives it it’s name. Unlike most crocodiles, it had a lot of mammal-like features in the jaw and teeth but was unrelated. Armadillosuchus in life would have been up to 6.6ft long.

Favorite Sauropod 

Shunosaurus was a very distinct looking sauropod and had a very unique feature, unlike other sauropods that used their size as a defense or used spikes around there neck to stop them getting bitten Shunosaurus had a spiked tail allowing it to attack predators. This is very rarely seen on sauropods and makes me think of them when people say “think of a sauropod”

[preolithic]

Bigger, Scarier, Fishier

Piranha 3DD is an unlikely film to have an accurate depiction of a prehistoric creature but between 10 to 8 million years ago a giant Piranha known as Megapiranha literally meaning “Big piranha” swam along the rivers of South America.

The only fossils of Megapiranha are the teeth from the premaxilla,‭ ‬the most forward portion of the upper jaw.‭ ‬Comparison of these teeth to other living Piranha species however has come to the conclusion,‭ ‬that assuming it had a similar body form‭ (‬and not just an oversized mouth‭) ‬it was up to one meter long,‭ ‬much bigger than modern piranha.

Megapiranha had a very here-and-there history, it was originally found in 1900 but then was discovered again in the 1980′s but still left unnamed only to be named in 2009.

It is very hard to find out the diet of Megapiranha, the teeth of Megapiranha  were serrated and arranged in a single zigzag line across the front jaw, these teeth lean towards a carnivorous diet but they are in the middle of having teeth like a herbivore and carnivore piranha.  

Megapiranha wasn’t the only giant of its time, South America during the  Miocene there were a lot of similar but huge animals, the world's largest crocodile to ever live known as Purussaurus and the largest flying bird in the fossil record called Argentavis.

[preolithic]

Acrocanthosaurus, High Spined Lizard

Acrocanthosaurus looks like many other theropod dinosaurs that also lived during the Early Cretaceous period but it had some very noticable differences like its name suggest it had natural spines on multiple of its vertebrae, it’s not known what the “hump” on its back was used for some of the theories are that it was used for temperature control as the temperature of the environment would turn into different extremes, the spines could have been used for display features to attract mates. 

Other than the spines it had a very similar skeleton to allosaurus and Carcharodontosaurus, 19 curved and serrated teeth lined each side of Acrocanthosaurus’s mouth and the shape of the jaw was like that of  Giganotosaurus. Acrocanthosaurus was a giant theropod and from head to tail reached up to 38 ft long and weighing as much as 7.25 metric tons, the skull alone was 4.3 ft long. 

From all of the different holotypes that have been found we are able to find out the growth of Acrocanthosaurus, it took 12 years for it to fully grow but when accounting for Harris lines it took 18-24 years to mature.

There are several definite locations that Acrocanthosaurus lived, fossils have been found in the twin mountains formation of Northern Texas, the Antlers Formation of Southern Oklahoma and the Cloverly Formation of north-central Wyoming and possibly even the Arundel Formation in Maryland, Using these formations to date Acrocanthosaurus it can be placed from 125 to 100 million years ago.

[preolithic]

What came first the Shark or the Tree?

It’s easy to assume that trees have been around since the dawn of time, it's hard to think that there was a time where the scary star of Jaws lived when natures oxygen generator where merely a dream. 

Even though it's hard to believe it was true, not only was it true it was a fact for 50 million years.

The first species that can be classified as a “Tree”  is the now-extinct  Archaeopteris that lived around 350 million years ago in forests where the  Sahara desert is now. 

Sharks have been swimming the vast oceans for 400 million years, they have managed to survive 4 mass extinctions along the way. Sharks are hard to track on the fossil record as they have a cartilaginous skeleton and only a few parts of their skeletons can become fossilised. 

[preolithic]

Saltasaurus, lizard from Salta

What was Saltasaurus?

Saltasaurus was a genus of titanosaurid sauropod dinosaur, a group of dinosaurs known for being a gigantic although Saltasaurus is the exception to this as it would only grow to 42 ft long and weigh up to 6.87 tonnes this was around the length of a Tyrannosaurus although the largest Sauropod Argentinosaurus which could reach a maximum length of 115 ft which dwarfs Saltasaurus.  

Saltasaurus also possessed osteoderms (Crocodile-like armour) which is strange to see on sauropods as size alone was enough for many of them to defend themselves from predators.

A sauropod nesting sight has been found in argentina, in this sight there are several hundred Saltasaurus dig holes where female Saltasaurus laid there eggs, this is one of the few Sauropod nesting sights that have been found

When did Saltasaurus live?

Saltasaurus lived in Argentina during the late cretaceous from 100.5 to 66 million years ago, Saltasaurus would have lived alongside classic dinosaurs like Triceratops and Tyrannosaurus 

[preolithic]

The Light Giants

The largest Dinosaurs that walked on land were the sauropods a giant group of dinosaurs that used size as their main defence against the many and vast predators that roamed during the Triassic, Jurassic and Cretaceous periods. The largest Sauropod was Argentinosaurus and could grow as large 115 ft from head to tail, this giant size meant that when it was fully grown it had no natural predator, although the giant adults had relatively nothing to fear when they were younger they had to rapidly grow to make sure they were safe. 

The giant size led to a giant weight but this weight wasn’t as much as many people would have thought, there are two main reasons are some sauropods had a system of air sacs to help them stay as light as possible, the sauropod bone density was also lowered allowing larger size.  

A non well known dinosaur is Katepensaurus, Katepensaurus was a late cretaceous sauropod and paleontologists have used CT scans and digital modeling to give a glimpse of what it would have looked like when it was alive and when looking at the bones it is clear that there is a distinct area the air sacs would have been and it makes a lot of sense for allowing it to keep the strength in its neck and tail but still making it as light as possible. 

without having a physical living Katepensaurus to be able to test there won't be a definitive way to test if this is what the uses were or if there was something in the place that hasn't fossilised.

[preolithic]

Aerosteon, Air Bone

erosteon was a member of Megaraptora, a group of lightly built allosaurids that are notable for having enlarged claws upon their hands. The name of this group is derived from the misidentification of first member of the group, Megaraptor being misidentified as a dromaeosaurid ‘raptor’ based upon the presence of a single large claw. however new discoveries including Australovenator allowed for correct idenitfication as well as the establishment of a new group.

      Aerosteon is very special both amongst this group and large theropods in general because ot the air filled spaces (a process called pneumatisation) within its bones. Not only would this have made the bones very light weight but it may have supported an avian type respiratory system similar to what we see in birds today. Aside from being more support for the descendency of birds from dinosaurs, this would have allowed a greater amont of airflow to and from Aerosteon’s lungs. Speculated to originally been an aid in temperature regulation, it would have allowed a faster rate of respiration with may infer a very active predatory lifestyle for Aerosteon.