recursal/Fanatic-Fandom huggingface dataset:
Desmatosuchus

Desmatosuchus is a stagonolepidid aetosaurian reptile from the Late Triassic of the United States of America. It was named in 1921 by Ermine Cowles Case. It was one of the most unique Triassic reptiles to ever walk the earth, due to the fact that its anatomy was considerably different from that of other reptiles.

## Physiology

Desmatosuchus was a reptile with a broad body, long legs, and a small head with large jaws. Perhaps the most defining traits of this reptile were the large spines on its shoulders. Its body would have been covered in scaly skin, with body armor covering its back and tail.

## Diet

Desmatosuchus was an herbivore, feeding on soft vegetation. Its shovel-like snout was used to dig up plants from the ground, while its blunt teeth were used to chew on them.

## Ecology

Due to many small bone beds containing lots of Desmatosuchus individuals, we can assume that the stagonolepidids lived in herds. However, this herding behavior would have not protected it in any way, as the apex predator of the area, Postosuchus, would have also hunted in groups; another defense the aetosaurs would have had against the rauisuchids were their hard body armor, and even then, Desmatosuchus scutes found in Postosuchus skeletons would tell us that the paracrocodylomorphs would have been able to penetrate their defenses. As well as this, Desmatosuchus had huge spines on its shoulders (just above its front legs); despite the fact that they would have been able to protect from predators, they were most likely used for display. It also preferred to feed near rivers, as that was where soft plants grew; it would use its broad snout to dig them up from the ground, right before grabbing them with the front of its jaws (which were toothless) and grinding them up with the teeth in the back of its jaws.

## In popular culture

Desmatosuchus was featured in the 1st episode of the 2001 documentary *When Dinosaurs Roamed America*, where it is shown as actually being able to defend itself against predators with its armor-plated tail. Due to this, it was hard for any predator in the Triassic forests to take a bite out of the aetosaur, no matter if it was small or mid-sized.
Megalograptus

This article is in need of updating.It contains info that may no longer be accurate, and will be revised to be more in line with modern research.

## Other Attributes

### Diet

Carnivore

Megalograptus is a megalograptid eurypterid merostomate arthropod from the Late Ordovician of the United States of America. It was named in 1874 by Hugh Miller. It was one of the earliest eurypterids, and was confused for being a graptolite, right before people discovered that it was a eurypterid.

## Physiology

Megalograptus had a build very similar to generic eurypterids, with a rounded cephalothorax, large eyes, long arms, a pair of paddles for swimming, and a long tail ending in a fork-like telson (also used for swimming). However, it had a few major differences; for example, it had 2 regular pairs of walking instead of 4 (the 1st and 3rd pair were vestigial), and instead of regular eurypterid claws, it had extended, spiny arms that were capable of folding. Its body would have been covered in a hard, chitinous exoskeleton.

## Diet

Megalograptus was a predator, preying mainly on fish, trilobites, small orthoconic cephalopods, smaller eurypterids, and other small invertebrates. The many spines on its arms were long and pointy; along with the ability of the arms to fold, this would help it grab onto struggling prey (with an even lower chance of its meal escaping).

## Ecology

Megalograptus's long, spiny arms were used for catching fish, trilobites, and other small animals, as well as snagging worms out of the sandy seafloor; in . It is often assumed that it would have used its big arm spines to feel the sand and mud, detecting any prey in the way; however, eurypterids that rake through the sediment to catch prey are not very visually-oriented, as opposed to Megalograptus itself, which had large, forward-facing eyes on its cephalothorax (thus making it very visually-oriented). Like all eurypterids, Megalograptus had a telson (last segment in an arthropod tail); although Megalograptus' telson bore a slight resemblance to a large pincer, it was not used for capturing prey, and it would have used its arms to rip its prey apart. Its telson was most likely used alongside its paddles to propel it through the water.

## In popular culture

Megalograptus was featured in the 1st episode of the 2003 documentary *Chased by Sea Monsters*, where it is shown as holding middle ground in the food chain, being bested by Cameroceras. As well as this, it was shown as behaving similarly to horseshoe crabs, stepping out of the sea to mate and lay eggs.
Metriorhynchus

Metriorhynchus is a metriorhynchid reptile from the Late Jurassic of the United Kingdom, France, Switzerland, and Germany. It was named in 1832 by Christian Erich Hermann von Meyer. It was a unique crocodylomorph, as it was heavily adapted to life in the ocean, even losing all its osteoderms in exchange for swift swimming.

## Physiology

Despite being a crocodylomorph, Metriorhynchus had a build similar to that of ichthyosaurs and mosasaurids. It had a sleek, streamlined body, 4 flippers, a long tail with a shark-like fin on its end, and a long, conical head with a mouth filled with sharp, interlocking teeth. Its body would have been covered in scaly skin.

## Diet

Metriorhynchus was a predator, preying on fish, cephalopods, and pterosaurs. Its sharp teeth were used for getting a hold of slippery prey, as well as tearing into their flesh.

## Ecology

Like many marine reptiles, Metriorhynchus had anatomical features that allowed it to live life in the water, such as a slender, streamlined body, legs that evolved into flippers, and a large tail fin; in fact, it even devolved its osteoderms in order to not be weighed down while swimming. Of course, it is often debated whether Metriorhynchus was able to crawl onto land and lay eggs in a similar manner to a turtle; with a build so similar to the plesiosaurs and ichthyosaurs it lived with, it is unlikely that it would do so, being fully aquatic and giving birth to live young instead. Further evidence that Metriorhynchus had a seagoing lifestyle is the presence of salt glands; with salt glands removing excess salt from its blood, it would have been able to drink seawater and eat saltwater prey without dehydrating. A plesiosaur skeleton with tooth marks belonging to Metriorhynchus was found, and had reflected upon an explanation that the crocodylomorph had scavenged the plesiosaur's carcass; this shows that Metriorhynchus was capable of diving down to the seafloor in order to scavenge.

## In popular culture

Metriorhynchus was featured in the 3rd episode of the 2003 documentary *Chased by Sea Monsters*, where it (along with a Hybodus) launches an attack on a weakened Leedsichthys (which was inaccurately oversized). Of course, this is artistic license, as the scenario of a 3 meter long crocodylomorph preying on a 9 (or 25, in the documentary's case) meter long bony fish would be quite unlikely.
Ichthyornis

Ichthyornis is a bird from the Late Cretaceous of the United States of America and Mexico. It was named in 1872 by Othniel Charles Marsh. It is one of the most important fossil discoveries, as it has allowed some insight into the evolution of birds; as well as this, it is one of the more taxonomically derived Mesozoic birds known from more than a few specimens.

## Physiology

Ichthyornis likely resembled a tern with teeth. It had a small, sleek body, moderately long legs, a short, feathery tail, long wings, and a small head with a long, toothy beak. Most of its body (excluding its beak and legs) would have been covered in long, vaned feathers.

## Diet

Ichthyornis was a predator, preying on small fish and cephalopods. Its teeth had knife-like serrations from back to back, and were used to cut prey into smaller chunks.

## Ecology

Despite having teeth on its jaws, Ichthyornis's head was very similar to modern birds; its upper beak could rotate upwards as its mouth opened, allowing it to grab prey and preen itself. This shows that the avian feeding apparatus evolved earlier than expected, and predated the full transition into toothlessness. [1]Similarly to Hesperornis, another relatively derived, toothy marine bird from the Late Cretaceous, Ichthyornis exhibited continual tooth replacement that involved growing new teeth under its old ones (similarly to crocodilians); however, Hesperornis' teeth had small ridges from back to back and had firmer root attachment, meaning that it likely used its teeth to grab onto slippery prey before swallowing them whole, while Ichthyornis had sharp, knife-like serrations running down its teeth for cutting its prey into smaller, more digestible chunks of flesh before eating them.[2] Ichthyornis' brain had more in common with that of non-avian dinosaurs such as Velociraptor rather than that of modern birds, with a smaller cerebellum than that of a modern bird brain; it is hypothesized that a bigger cerebellum put the ancestor of modern birds at an advantage over more basal birds such as Ichthyornis, thus allowing the former to survive the extinction while the latter was not able to.[3]

## References

1. Field, D. J., Hanson, M., Burnham, D., Wilson, L. E., Super, K., Ehret, D., Ebersole, J. A., & Bhullar, B.-A. S. (2018). Assembly of the Avian Head. Nature Letters, 557.
2. Dumont, M., Tafforeau, P., Bertin, T., Bhullar, B. A., Field, D., Schulp, A., Strilisky, B., Thivichon-Prince, B., Viriot, L., & Louchart, A. (2016). Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis, the “last” toothed birds. BMC Evolutionary Biology, 16(1), 1–28. https://doi.org/10.1186/s12862-016-0753-6
3. Torres, C. R., Norell, M. A., & Clarke, J. A. (2021). Bird neurocranial and body mass evolution across the end-Cretaceous mass extinction: The avian brain shape left other dinosaurs behind. Science Advances, 7(31), 1–10. https://doi.org/10.1126/sciadv.abg7099
Seymouria

Seymouria is a seymouriid seymouriamorph amphibian from the Cisuralian-Guadalupian of the United States of America and Germany. It was named in 1904 by Ferdinand Broili. It was another of the missing links between amphibians and reptiles; in fact, it had so many reptilian features that it was actually considered to be a reptile.

## Physiology

Seymouria had a build that reflected its relations and evolution. It was a lizard-like animal with 4 legs, a long, broad, fin-less tail, a broad body, and a long head with big jaws. Its body would have been covered in scaly skin.

## Diet

Seymouria was a predator, feeding mainly on insects and smaller amphibians, and sometimes subsisting on reptile and synapsid eggs. Its teeth were small yet sharp, and were used to get a hold of struggling prey as the amphibian swallowed them whole.

## Ecology

Despite its amphibian classification, Seymouria was more adapted to land, as its legs were long and muscular, and the structure of its ears would have worked best out of water. As well as this, it would have been able to excrete excess salt out of its body through its nose, similar to modern reptiles. Along with that, male Seymouria had thick skulls used for ramming into rivals during mating season; after the mating process, females would return to the water to lay their eggs. There, the eggs would hatch into aquatic tadpoles, which would hunt in the water until they would gain the strength to walk onto land.

## In popular culture

Seymouria was featured in the 2nd episode of the 2005 documentary *Walking with Monsters*, where it is shown as an ovivorous carnivore that spied on the nest of a female Dimetrodon, waiting for the predatory pelycosaur to get caught off guard so it could eat her eggs. When it finally got the chance to do so, it got eaten by a male Dimetrodon that came near the nest.
Sinornithosaurus

Sinornithosaurus is a dromaeosaurid theropod dinosaur from the Early Cretaceous of China. It was named in 1999 by Xu Xing, Wang Xiao-Lin, and Wu Xiao-Chun. It was another of the first confirmed feathered non-avian dinosaurs to be found, and, as time went on, would prove to be among the more interesting.

## Physiology

Similar to its close relative Microraptor, Sinornithosaurus was a very bird-like theropod with a sleek, streamlined body, long legs with a sickle-shaped claw on each foot, a moderately long tail, a moderately long neck, and a long, bird-like head with a mouth containing lots of teeth; along with this, its arms were long, feathery, bird-like wings that it flew around with (similarly to Microraptor), although it did not have the large leg wings that Microraptor had. Most of its body (excluding its feet and snout) would have been covered in long, vaned feathers; its body would have been different shades of reddish-brown, yellow, black, and gray in color (which body part was what color is yet to be known).

## Diet

Sinornithosaurus was a predator, preying on lizards, small mammals, and possibly primitive birds. Its teeth had knife-like serrations from back to back, and its sickle claw was used for restraining smaller prey.

## Ecology

Similarly to the later Microraptor, Sinornithosaurus had large, feathery wings that it used to fly through the air with, and, like its later relative, would have possibly taken to the air by running up a steep slope while flapping its wings before entering an airborne phase. However, Sinornithosaurus lacked the large leg wings that Microraptor had, meaning that it would not have been as adept in the air as its later relative, while conversely being considerably more agile on the ground; this indicates that Sinornithosaurus was either a more primitive microraptorine, or was part of a lineage of microraptorines that secondarily started to evolve to fit a more ground-based niche. For a while, it has been suspected that Sinornithosaurus had a venomous bite similarly to a snake, based on the notion that the upper teeth were long and fang-like, had prominent grooves running down their outer surface, and were situated just under a cavity that could have housed a venom gland; however, this has been disproved, as the teeth weren't nearly that long in life (they may have partially slid from their sockets), the grooves weren't unique to the genus (as many other theropods had them), and the cavity just above the upper teeth, in fact, did not actually exist. A comparison of its sclerotic rings to those of modern reptiles and birds indicates that it was cathemeral.

## In popular culture

Sinornithosaurus was featured in the 2nd episode of the 2011 documentary *Planet Dinosaur*, where it is shown chasing a Microraptor (which itself was attempting to eat a small lizard) through the air and attempting to eat it; in reality, this kind of scenario would not have happened, as Sinornithosaurus went extinct 2 million years before Microraptor evolved. The show also erroneously depicts it with a venomous bite, which it utilizes (along with hunting in packs) to take down a juvenile ornithopod.
Ankylosaurus

Ankylosaurus is an ankylosaurid ankylosaurian thyreophoran dinosaur from the Late Cretaceous of the United States of America and Canada. It was named in 1908 by Barnum Brown. Even though multiple specimens of this dinosaur have been unearthed, a complete skeleton has never been found, leaving it to be modeled off of more complete relatives.

## Physiology

Ankylosaurus was a broad, robust thyreophoran with 4 erect legs and an almost completely armored body. It had a wide skull with horns pointing out from the sides of the head, a small beak in front of its mouth, and a large club on the end of its tail. Most of its body would have been covered in thick osteoderms, while its underside and legs would have been covered in regular scales.

## Diet

Ankylosaurus was an herbivore, feeding on leaves and fruits. Its wide snout was used for browsing on plants low to the ground, and since a few fossil teeth of this dinosaur were heavily worn, it was presumed that it was able to chew its food.

## Ecology

Ankylosaurus had a good sense of smell, which would have been great for detecting predators, since its eyes would have been barred by vegetation. As well as this, its body was heavily armored (even its eyelids were armored); osteoderms ran down its body, its neck was covered in bony half-rings (with smaller pieces in between to allow normal neck movement), and horns had protruded from the sides of its head (mainly for defense and display). The tail club it is famous for was a piece of vertebra covered by large osteoderms, and was used as a defense against predators. To use it, it would have stepped aside so its flank faced its attacker, proceeding to swing its tail with brute force, hitting the predator and, depending on how big the thyreophoran was, breaking its bones.

## In popular culture

Ankylosaurus was first introduced to the public through the 1947 *Age of Reptiles* mural, where it was featured in a Cretaceous segment alongside the likes of Edmontosaurus, Tyrannosaurus, Triceratops, and Pteranodon. Since then, it has been taken into media and featured in movies and documentaries like *The Land Before Time*, *Jurassic Park* (especially *Jurassic World*), and *Walking with Dinosaurs*; with the very former being the exception, all of those pieces of media show it as an armored behemoth that would defend itself against any predator coming to attack it.
Plesiosaurus

Plesiosaurus is a plesiosaurid plesiosaurian reptile from the Early Jurassic of the United Kingdom. It was named in 1821 by William Daniel Conybeare. It was one of the first marine reptiles (nicknamed antediluvian reptiles at the time) known to science, and, like its ichthyosaur and lizard counterparts, it was a wastebasket taxon.

## Physiology

As earlier descriptions had told, Plesiosaurus resembled a snake stuck in a turtle's body. It had a sleek, streamlined body, 4 flippers, a short tail with a small fin on its end, a long neck, and a small head with a mouth filled with sharp, interlocking teeth. Its body would have been covered in scaly skin.

## Diet

Plesiosaurus was a predator, preying on fish and cephalopods. Its sharp teeth were used to get a hold of slippery prey, and its long neck would have helped it snake into schools of fish.

## Ecology

Plesiosaurus had a short tail comparable in size to its large flippers; due to this, it would have propelled itself by moving its flippers up and down (similarly to sea turtles), as opposed to the other marine reptiles, which propelled themselves by moving their tail from left to right. People even reconstruct it as able to crawl onto land and lay eggs on the shore like a turtle; however, it lacked the skeletal features in order to perform that task, and so, the most accepted reconstruction is a fully-aquatic reptile that gives birth to live young. As well as this, Plesiosaurus' neck was thought to be very flexible, right before being theorized to be very rigid; however, due to a study done on its semi-close relative, Elasmosaurus, it is now assumed that Plesiosaurus' neck was still somewhat flexible. In order to hunt, Plesiosaurus would swim near a school of fish and flex its neck to select an individiual before grabbing its target with its jaws.

## In popular culture

Plesiosaurus was one of the 1st Mesozoic animals discovered, so it was featured in Crystal Palace Park (a pleasure ground in London), alongside Iguanodon (depicted as a horned dragon), Megalosaurus (also depicted as a dragon), Pterodactylus, Ichthyosaurus, and Mosasaurus (depicted as a giant, iguana-like squamate). Since then, it has managed to become the archetypical plesiosaur (and by extension, the archetypal Mesozoic marine reptile), and has featured in major pieces of media such as the original *Journey to the Center of the Earth novel* (where it fought with an Ichthyosaurus), *Fantasia*, and the *The Lost World* novel; it was even planned to be in *Jurassic World* before it got cut. As well as this, it even inspired the creation of a cryptid called the Loch Ness Monster; however, for the rest of its publicity, it would be overshadowed by its semi-close relative, Elasmosaurus.
Epidexipteryx

Epidexipteryx is a scansoriopterygid theropod dinosaur from the Middle-Late Jurassic of China. It was named in 2008 by Zhang Fucheng. It was one of the most unique dinosaurs, as it had a unique build and integuement.

## Physiology

Epidexipteryx was a unique theropod. It was a small, bipedal saurischian with a small body, a short tail, long arms with 3 fingers (of differing lengths), and a large head with mid-sized jaws. Most of its body (excluding some of its legs and all of its snout) would have been covered in long, vaned feathers, with some extremely long, strap-like feathers protruding from its tail.

## Diet

Epidexipteryx was a predator, preying on insects. The only teeth it had were in the front of its mouth, and protruded from its jaws; this would allow it to get a hold of struggling prey.

## Ecology

Epidexipteryx had one of the most unique ecologies of any theropod. It had a uniquely beak-shaped mouth, as well as a downwards-curving lower jaw that moved away from the upper jaw, indicating that it might have been the ancestor of even more bird-like dinosaurs such as Oviraptor; as well as this, its lower jaw had huge front teeth and smaller back teeth, which might have allowed for a special prey capture method. Unlike those of other bird-like dinosaurs, the longest feathers on Epidexipteryx were not on its wings, but rather, they were on its tail; these feathers were only for display. Nevertheless, there is a chance that Epidexipteryx may have been capable of gliding from tree to tree, with the help of large membranes of skin stretching from its fingers all the way to the sides of its body; another, closely related theropod, Yi, had those membranes, and was capable of gliding as well.

## In popular culture

Epidexipteryx was featured in the 2nd episode of the 2011 documentary *Planet Dinosaur*, where it was shown as an arboreal animal that used its long fingers to pry beetle larva out of trees; as well as this, one individual gets its food stolen by a larger Epidexipteryx, and the two start fighting by assuming intimidating postures. Eventually, the smaller scansoriopterygid accidentally drops another larva onto the ground, only for another one to steal it; in turn, the food-stealer gets eaten by a sub-adult Sinraptor.
Amphibian

The amphibians were the first tetrapod vertebrate animals to exist. They have limbs for walking on land (a vast improvement over the fish), as well as lungs for taking in oxygen from the air (another improvement). However, later animals of this class evolved very smooth skin, so they had to enter the water for short periods of time. Having been descended from lobe-finned fish in the Devonian, the amphibians started improving quicker than most animals at the time, and just became ferocious predators a million years after they came into the scene. As time would pass, the amphibians would evolve into yet another group of animals: the reptiles.

## Amphibians Throughout Time (note that those are not all the ones that exist)

### Devonian Amphibians

* Acanthostega
* Ichthyostega
* Hynerpeton

### Carboniferous Amphibians

* Crassigyrinus
* Westlothiana
* Proterogyrinus
* Diplocaulus
* Platyhystrix
* Eryops

### Permian Amphibians

* Seymouria
* Rhinesuchus

### Triassic Amphibians

* Broomistega
* Mastodonsaurus
* Cyclotosaurus
* Anaschsima

### Cretaceous Amphibians

* Koolasuchus
* Beelzebufo
Scelidosaurus

Scelidosaurus is a scelidosaurid thyreophoran dinosaur from the Early Jurassic of the United Kingdom. It was named in 1859 by Richard Owen. It was the earliest thyreophoran to exist, as well as the earliest complete dinosaur.

## Physiology

Scelidosaurus was a broad thyreophoran with 4 erect legs, a moderately long tail, and a small head with a small, beaked mouth. Most of its body would have been covered in osteoderms, while its head, underside, and legs would have been covered in scaly skin.

## Diet

Scelidosaurus was an herbivore, feeding on plants low to the ground. Its beak was used to clamp onto plants and strip them off, while the many teeth in the back of its mouth would cut them into pieces.

## Ecology

As the earliest thyreophoran, Scelidosaurus had many noteworthy features that would pass on to later thyreophorans. Of course, the most notable feature it had were the many osteoderms on its body, which were used for protection against sharp-toothed predators; in time, this would also pass on to many other thyreophorans such as Denversaurus, Stegosaurus, and Ankylosaurus. As well as this, it also had a small, narrow head with primitive teeth and simple jaws (similarly to Stegosaurus), which would infer that the thyreophoran preferred to eat highly nutritious plants. This type of lifestyle is much different from the semi-aquatic, piscivorous ecology that older scientists have given it.
Tropeognathus

Tropeognathus is an anhanguerid pterosaurian reptile from the Early Cretaceous of Brazil. It was named in 1987 by Peter Wellnhofer. It was the biggest pterosaur to fly the skies of the Early Cretaceous, only being beaten in size by a few Late Cretaceous azhdarchids; as well as this, it is sometimes regarded as a species of the now-dubious pterosaur genus "*Ornithocheirus*", although not everyone is in agreement about this.

## Physiology

Tropeognathus resembled the generic Early Cretaceous pteranodontoid, a large pterosaur with 4 legs (2 of which served as wings), 4 fingers on each hand (one of which was elongated and supported the wing membrane), a small body, a small crest, a short tail, and a long, toothy beak. As well as this, it had rounded, keel-like crests on the tip of its beak, with the crest on its upper beak being larger than that on the lower beak. Most of its body (excluding its beak, crest, and wings) would have been covered in a fur-like covering called pycnofibers.

## Diet

Tropeognathus was a predator, preying on small fish and cephalopods. Its teeth were small yet sharp, and were used to get a hold of slippery prey.

## Ecology

Tropeognathus' habitat was a coastal, swampy rift valley; while pterosaurs such as Tapejara would have lived further inland, Tropeognathus would have frequented the shoreline, flying down to the surface of the water and foraging for fish like modern seabirds do. As a seafaring pterosaur, it had exceptionally long wings (even longer than those of the later Pteranodon), and thus was a similarly exceptional soarer, exploiting wind currents off the ocean surface to travel long distances without flapping its wings; similarly to Pteranodon, it may have also been capable of taking off from the surface of the water, as it may have directly hunted for food in the seas. Tropeognathus had 2 rounded, keel-like crests situated on the tip of its beak, with its upper beak having a larger crest than its lower one. It is theorized that these crests were used to stabilize it snout as it dove into the water; however, seeing as these crests were larger in males than they were in females, it is also very likely that they were used for sexual display (in this case, attracting mates).

## In popular culture

Tropeognathus was featured in the 4th episode of the 1999 documentary *Walking with Dinosaurs*, where it is dubbed "Ornithocheirus" and featured as an aerial giant as large as Quetzalcoatlus; this was nowhere near as egregious of an oversizing as the Liopleurodon from the previous episode (as Tropeognathus would have been considerably large in real life), but it was still relatively questionable, having been chosen for spectacle. In the episode itself, an elderly male flies across the globe all the way back to his mating grounds in what is now Spain, and comes across many different creatures, from Tapejara and Iguanodon to Utahraptor and Iberomesornis; when he finally reaches his destination, he is unable to secure an ideal spot for himself in the breeding site, and eventually suffers a tragic death at the hands of starvation, exhaustion, heat stress, and old age.
Gastonia

Gastonia is a nodosaurid ankylosaurian dinosaur from the Early Cretaceous of the United States of America. It was named in 1998 by James Kirkland. It was one of the best preserved nodosaurids, and its remains have helped us gain a general idea of what they looked like.

## Physiology

Gastonia was a broad, robust thyreophoran with 4 erect legs and an almost completely armored body. It had a wide skull with a small beak in front of its mouth, as well as large, thorn-like spikes running down its back and the sides of its body. Most of its body would have been covered in scaly skin, with a large clump of osteoderms covering its lower back.

## Diet

Gastonia was an herbivore, feeding on leaves. Its wide snout was used for browsing on plants low to the ground, and the many cheek teeth in the back of its mouth were used for processing plants.

## Ecology

So far, all we know about Gastonia is that the many scutes on its back were used for defense (particularly against large predators like Utahraptor), and it also may have used them for intraspecific combat during the mating season (where the back spikes would be used for intimidation, and rival males would have head-pushing contests in order to determine who was the strongest); as well as this, due to a small bonebed containing a few individuals grouped together; we can assume that the ankylosaurs moved in groups.
Carcharodontosaurus

Carcharodontosaurus is a carcharodontosaurid theropod dinosaur from the Late Cretaceous of Algeria, Egypt, Morocco, and Niger. It was officially named in 1931 by Ernst Stromer. It was one of the largest theropods (in terms of physical dimensions), and was thought to be a species of Megalosaurus before finally being described as its own genus.

## Physiology

Carcharodontosaurus was a giant theropod with a semi-bulky body, a long tail, short arms with 3 fingers on each hand, and a large head with a mouth containing lots of big teeth. Its body would have been covered in scaly skin.

## Diet

Carcharodontosaurus was a predator, preying on iguanodonts, mid-sized sauropods, small crocodylomorphs, small pterosaurs, and dromaeosaurs. Its teeth had knife-like serrations from back to back, and had vaguely resembled those of a great white sharks's, hence the meaning of its name, "shark-toothed lizard"; those teeth would have been used to slice off pieces of flesh from the bodies of large prey.

## Ecology

Like its cousins, Allosaurus and Acrocanthosaurus, Carcharodontosaurus was a large theropod that ruled over its territory as a terrestrial apex predator. Although it didn't have the forward-facing eyes that Tyrannosaurus boasted, it was still a visually-oriented carnivore, as shown by a large optic nerve. Due to its leg proportions, it wasn't an extremely fast runner; however, this would not have affected its hunting success rate in any way, as it was able to keep up with many of its prey items. Once it tracked down a large herbivore, it would rush up to it, bite a large chunk of flesh off its body with its jaws, and let the herbivore attempt to run away, as the great amount of blood loss would soon weaken it and allow for the theropod to finish it off.

## In popular culture

Carcharodontosaurus was featured in both the 1st and 5th episode of the 2011 documentary *Planet Dinosaur*; in the first episode, it is shown as rutting with rival males in order to achieve hunting rights to a herd of (inaccurately misplaced) Ouranosaurus. Meanwhile, in the 5th episode, it tussles with a Sarcosuchus (also misplaced through time) over a juvenile Paralititan; after a few seconds, it wins and drives the pholidosaur away, but immediately gets scared off by a large herd of the sauropods that were advancing towards it in order to get their offspring back.
Cephalaspis

Cephalaspis is a cephalaspid cephalapsidid jawless fish from the Early Devonian of the United Kingdom, Canada, the United States of America, and Ukraine. It was named in 1843 by Louis Agassiz. It was one of the last jawless fishes to exist, as well as one of the most unique.

## Physiology

Cephalaspis had a build very similar to generic jawless fishes, with a mobile tail, an oval-shaped body, and a toothless mouth. However, it had a few major differences; for example, it had an armored head with eyes positioned very close to each other, and instead of being in the front of its head, its mouth was on the bottom of its head. Its body would have been covered in scaly skin, with bony plates protecting its head.

## Diet

Cephalaspis was a predator, feeding on small invertebrates by sifting through the seafloor and sucking them up. As well as this, it would sometimes settle for detritus suspended in the water.

## Ecology

Cephalaspis's head shield was used as a defense against predators, since it was a slow swimmer. As well as this, it had sensory organs on the rim of its head, which were used for feeling the sand and mud, detecting any prey in the way. It lived in freshwater streams and estuaries, preferring to feed on the riverbed. In order to hunt, it would move its head from side to side, launching up sand and mud, as well as digging up any worms or crustaceans hiding in the ground.

## In popular culture

Cephalaspis was featured in the 1st episode of the 2005 documentary *Walking with Monsters*, where it escapes the claws of a marauding Brontoscorpio; as well as this, it was depicted as an anadromous marine fish, migrating into freshwater in order to breed. However, in the show, Cephalaspis was depicted as starting out in the Silurian, while in reality, it started out in the Devonian; as well as this, it was an entirely freshwater fish, and did not live in the seas.
Cambrian

After the Earth had turned from a sterile ball of gas into a fertile, aquiferous planet (with the help of crashing meteorites and a collision with the planet Thea), the Cambrian period started. During this time, life on Earth had exploded, and millions of organisms had transformed from the simple, single-celled organisms that they were in the Precambrian into the complex, multi-celled organisms that would rule Earth for the rest of time. While the land was uninhabited (and uninhabitable), the oceans were filled with a diverse collection of life. The main rulers of the waters were the arthropods; the most prominent arthropods were the trilobites (which were a diverse class of animals that would flourish in the oceans for the rest of the Paleozoic) and the radiodonts (which were the apex predators of the time). However, they were not alone, as they shared these waters with the fish (which started out small, and would remain small for 2 more periods) and the mollusks. As well as this, many echinoderms, corals, and aquatic plants evolved. Soon, the warm temperatures that were present in this beautiful period would drop, driving many genera to extinction and giving rise to the Ordovician.

**Lasted from 541-485.4 mya**

## Terrenuevian Animals (note that those are not all the ones that exist)

* Haikouichthys
* Trilobites

## Series 2 Animals (note that those are not all the ones that exist)

* Hallucigenia
* Anomalocaris

## Series 3 Animals (note that those are not all the ones that exist)

* Waptia
* Opabinia
* Marrella
* Pikaia
Meganeura

Meganeura is a meganeurid meganisopteran insect arthropod from the Pennsylvanian of France, the United Kingdom, and Canada. It was named in 1885 by Charles Brongniart. It was one of the biggest flying arthropods of all time, thanks to the great conditions of the late Paleozoic era.

## Physiology

Meganeura resembled modern dragonflies. It was an arthropod with a slender body, a large head with big eyes, long antenna, and small jaws, 3 pairs of walking legs, 2 pairs of long wings, and a long tail ending in a clasper. Its body would have been covered in a hard, chitinous exoskeleton.

## Diet

Meganeura was a predator, preying on reptiles, small amphibians, and smaller arthropods. Its toothed jaws were used for biting into prey, and it had a specialized, flap-like upper lip capable of shooting out to catch its victims.

## Ecology

As a giant insect, Meganeura owed its large size to a lack of aerial predators to prey and/or compete with it, and an evolutionary arms race between it and its prey. In general, it was quite similar to modern dragonflies, being a fast aerial predator that often fed on prey by biting them on the head (knocking them out), carrying them to a perch, and eating them head first; in fact, even the nymphs of this griffinfly were similar to modern dragonfly nymphs, as the mouthparts of both are identical. However, there are many slight difference between the two; for instance, Meganeura had longer legs, wings, antennae, and claspers than modern dragonflies did. Along with this, the wings of Meganeura lacked the gliding cell found in the wings of modern dragonflies, and had a much simpler vein pattern than that of modern dragonfies.

## In popular culture

Due to documentaries and books focusing on prehistoric animals, Meganeura has soared to a great height among popular prehistoric arthropods, only being slightly overshadowed by the diverse and widespread trilobites. Since then, it has been featured in major pieces of media such as such as *Prehistoric Park* and *First Life*. So far, its biggest public appearance was in the 2nd episode of the 2005 documentary *Walking with Monsters*, where it flies in to steal a Petrolacosaurus carcass from the fangs of a giant mesothele spider.
Lungfish

The lungfish are a successful subclass of widespread lobe-finned fish from the Early Devonian-Holocene of the entire world. They, as a whole, were named in 1844 by Johannes Peter Müller. They are one of the most successful groups of animals to ever live (living for about 400 million years and still living today), and are famed for their ability to go onto land and form mucous cocoons in order to survive droughts.

## Physiology

Lungfish are unique lobe-finned fish. They have a large, bulky body, a semi-small head with small jaws, and large, fleshy, lobe-like fins; however, instead of genuine teeth, they have large odontodes (dermal teeth) extending from their jaws, and their dorsal, anal, and caudal (tail) fins are all fused into one large caudal fin. Their bodies are covered in scaly skin.

## Diet

Lungfish are omnivores, feeding on insects, crustaceans, worms, mollusks, amphibians, smaller fish, and plant matter. Even though they lack teeth, the odontodes extending their jaws are used for different purposes, depending on the order; some are designed for crushing hard food, while others are designed for cutting up small prey.

## Other Attributes

### Diet

Omnivore

Dipterus is a dipterid dipteriform lungfish from the Late Devonian-Late Triassic of Belgium and the United States of America. It was named in 1828 by Adam Sedgwick & Roderick Murchison. Unlike modern lungfish, its dorsal, anal, and caudal fins were still separated; as well as this, its fins faced backwards and its caudal fin faced upwards, allowing it to gain small bursts of speed (as well as reducing any chance of its tail rubbing the bottom of its river habitat.

## Other Attributes

### Diet

Omnivore

Ceratodus is a ceratodontid ceratodontiform lungfish from the Late Triassic-Eocene of the entire world. It was named in 1837 by Louis Agassiz. It was one of the most successful lungfish genera to exist, surviving the deadly extinction events of the Triassic, Jurassic, and Cretaceous, and surviving up to the middle Paleogene; as well as this, the sharp true teeth on its jaws possibly indicate that it was more carnivorous than other lungfish genera.

## Australian Lungfish

Side view of the Australian lungfish (credits to Fishes of Australia)

## Other Attributes

### Diet

Omnivore

The Australian lungfish (*Neoceratodus forsteri*) is a neoceratodontid ceratodontiform lungfish from the Oligocene-Holocene of Australia. It was named in 1870 by Johann Ludwig Gerard Krefft. It is the only surviving genus of ceratodontiform lungfish (all the other surviving genera are lepidosireniforms), and has gone unchanged for more than 28 million years (making it more of a living fossil than the West Indian Ocean/Indonesian coelacanth); as well as this, it is unable to secrete a mucous cocoon, and so, it is incapable of surviving droughts. This makes it different enough from the African lungfish (*Protopterus* species), which can secrete a mucous cocoon; this also makes it different enough from the South American lungfish (*Lepidosiren paradoxa*), which does not secrete a mucous cocoon, but does burrow into the mud and slow down its metabolism into a complete state of hibernation.
Dimetrodon

Dimetrodon is a sphenacodontid pelycosaur synapsid from the Cisuralian-Guadalupian of the United States of America and Germany. It was officially named in 1878 by Edward Drinker Cope. It is the most famous synapsid to exist, and is also one of the most studied.

## Physiology

Dimetrodon had the generic pelycosaur synapsid build, with 4 legs, a moderately long tail, a somewhat slender body, and a big head with large jaws. However, it had one major difference; it had a large sail on its back. Its body would have been covered in scaly skin.

## Diet

Dimetrodon was a predator, preying on sharks, small amphibians, small reptiles, and in some cases, insects. Its jaws had two kinds of teeth, hence the meaning of its name, "two measures of teeth"; at the front of its jaws, it had large, serrated teeth designed for slicing flesh, while at the back of its jaws, it had smaller teeth designed for grabbing prey.

## Ecology

In a similar case to Edaphosaurus's sail, the function of Dimetrodon's sail remains open to debate. The prevalent theory at the time was that it used its sail to regulate its body temperature; however, thanks to a(n immediately disproven) study that said that it had a set of bony prongs rather than a proper sail, the most widely accepted theory is that it possibly was just used for display. However, it's certain that it was a successful predator, as its two teeth were very useful for eating; its smaller back teeth were used for getting a grip of slippery prey such as Xenacanthus and Diplocaulus, while its bigger front teeth were used for cutting into their flesh. As well as this, it is unknown whether Dimetrodon was a terrestrial or amphibious predator; however, chemical traces on its bones suggests that it was the former, feeding on land and near the riverbanks.

## In popular culture

Dimetrodon was first introduced to the public in the *Rite of Spring* segment of the 1940 Disney musical movie, *Fantasia*. Since then, it has been featured in major pieces of media like *The Land Before Time* and the 1959 adaptation of *Journey to the Center of the Earth*, where it is inaccurately featured as an archosaurian reptile that lived alongside dinosaurs such as Stegosaurus, Triceratops, Pteranodon (which is actually not a dinosaur, but is listed as one), and Tyrannosaurus; it was even planned to be in *Jurassic World* before it got cut. So far, Dimetrodon's biggest appearance was in the 2nd episode of the 2005 documentary *Walking with Monsters*, where it is shown as a terrestrial predator able to eat other synapsids such as Edaphosaurus, as well as a caring (albeit cannibalistic) mother; at the end of the segment, it evolves into Inostrancevia over a course of 26 million years.
Plateosaurus

Plateosaurus is a plateosaurid sauropodomorph dinosaur from the Late Triassic of Germany and Greenland. It was named in 1837 by Christian Erich Hermann von Meyer. It was one of the first dinosaurs discovered; however, due to being poorly known at the time, it wasn't considered to be a dinosaur until later.

## Physiology

Despite being related to sauropods, Plateosaurus more resembled an ornithopod dinosaur. It was a bipedal dinosaur with long legs, moderately long arms, a moderately long tail, a long neck, and a small head with jaws. Its body would have been covered in scaly skin.

## Diet

Plateosaurus was an herbivore, feeding on leaves. Its flat, leaf-shaped teeth were used to slice into plants and mash them before the sauropodomorph swallowed them.

## Ecology

For a while, there was a debate as to how Plateosaurus moved, with a few reconstructions showing it walking on two legs (and on its toes), walking on four legs (and on flat feet), and even hopping around like a kangaroo; today, the former prevails as the most accurate reconstruction for it. As well as this, due to its leg proportions, it was a relatively fast runner; however, instead of full-out sprinting like modern mammals, it increased its speed through quick strides. Due to a large, muddy bonebed containing many individuals, we can assume that the plateosaurids lived in herds; when they attempted to wade across the muddy bogs, larger individuals sunk and drowned, while smaller individuals were able to cross without sinking. A comparison of its sclerotic rings to those of modern reptiles and birds indicates that it was cathemeral.

## In popular culture

Plateosaurus was first introduced to the public in the *Rite of Spring* segment of the 1940 Disney musical movie, *Fantasia*. Since then, it has been featured in many books focusing prehistoric animals, with an occasional movie appearance. So far, its biggest public appearance was in the first episode of the 1999 documentary *Walking with Dinosaurs*, where a huge herd of the plateosaurids get attracted to the once-again lush river; in this case, it was misplaced through space, as while Eurasia was connected to North America at the time, Germany was quite a distance away from the United States, and the narrator had not explained that the sauropodomorphs migrated there.
Silurian

After an ice age brought the Ordovician period to an end, the Silurian period started. During this time, everything had made a great change. The land was now ready to be colonized, and plants had diversified, making food through photosynthesis. Meanwhile, the fish had evolved to look even more modern, and at the end of the period, they grew jaws, finally starting to take small steps towards domination of the seas. As well as this, the arthropods had changed a lot. The eurypterids had diversified, and had grown to extreme sizes, making their current dominion of the seas absolute. Smaller arthropods, such as the scorpions and millipedes, had brought out one of their greatest advantages: stepping out of the sea and making a home on land. Meanwhile, the trilobites were still diverse, and were still limited to the water. Now, the land and sea were both perfectly filled with a plethora of wildlife.

**Lasted from 443.8-419.2 mya**

## Llandovery Animals (note that those are not all the ones that exist)

* Birkenia
* Thelodus

## Wenlock Animals (note that those are not all the ones that exist)

* Eurypterus
* Pterygotus

## Pridoli Animals (note that those are not all the ones that exist)

* Guiyu
* Megamastax
* Stylonurus
* Brontoscorpio
* Acutiramus
* Eoarthropleura