Cretaceous

The **Cretaceous** time period was a time period in Earth's history and the third and final time period of the Mesozoic Era. It was preceded by the Jurassic and followed by the Paleocene Epoch. It began 145 million years ago and ended 65 million years ago, lasting about 80 million years. This period is notable as its end marked the end of the reign of the dinosaurs. During the Cretaceous, reptiles were by far the dominant group, with them ruling the land, sea, and skies.

## Facts

Throughout the entire 80 million years of the Cretaceous Period, dinosaurs were more across the world than ever before, living one every part of the planet.

### Wildlife

#### Early Cretaceous

Known for being an extraordinary period in the Earth's history, the Cretaceous was a remarkably diverse world. The mountains in the Himalayas, even Mount Everest itself, had not yet existed and the Atlantic Ocean was only half as wide compared to today. There wasn't any grass, only conifer woodlands as well as fern grasslands. Following the beginning of the Early Cretaceous, the movement of the continents was not only breaking up the giant northern and southern landmasses, but it continued to push up sea levels. This had opened new seaways and coastlines. In most parts of the world, there were ragged cliffs as opposed to solid land, which often buzzed with various species pterosaurs.

This is the list of fauna that lived during the Early Cretaceous Period:

* Dinosaurs
* Marine Reptiles
* Pterosaurs

* *Baryonyx*
* *Deinonychus*
* *Hypsilophodon*
* *Iguanodon*
* *Polacanthus*
* *Sauroposeidon*
* *Utahraptor*

- *Pleisopleurodon*

- *Caulkicephalus*

- *Ornithocheirus*

- *Tupandactylus*

#### Middle Cretaceous

During the Middle Cretaceous, dinosaurs had become more wide-spread than ever before, reaching every part of the world. However, one place in particular was a unique challenge for all fauna in the Cretaceous; the South Pole. At this time, a giant continent that was a combination of South America, Australia, and Antarctica was kept warm via ocean currents forced down from the equator to encircle it. As opposed to ice caps, there was lush rainforests. Unlike the unchanging tropical tropical climates elsewhere, Antarctica had seasons; from hot summers under the midnight sun to cold winters of complete darkness. Additionally, in South America, dinosaur had taken on their biggest forms thus far, more so than the Late Jurassic giants.

This is the list of fauna that lived during the Middle Cretaceous Period:

* Dinosaurs
* Mammals
* Prehistoric Amphibians
* Prehistoric Reptiles

* *Argentinosaurus*
* *Australovenator*
* *Barosaurus*
* *Carcharodontosaurus*
* *Giganotosaurus*
* *Leaellynasaura*
* *Macrogryphosaurus*
* *Muttaburrasaurus*
* *Ouranosaurus*
* *Spinosaurus*

- *Steropodon*

- *Koolasuchus*

- *Geosternbergia*

- *Ornithocheirus*

- *Sarcosuchus*

#### Late Cretaceous

Towards the Late Cretaceous, since this was a world before grass, volcanoes dominated the landscapes. Near the end of the Cretaceous period, the continents had already started to take on their modern appearance. But the ceaseless movement of the Earth's crust had also begun to produce a surge in volcanic activity across the entire world. Massive eruptions that lasted for centuries had laid waste to landscapes and filled the air with poisonous gasses and debris. This desolate world was still ruled by dinosaurs, as it always had been for the past 160 million years, but they were nearing the end of their reign. Life on Earth was literately choking to death.

This is the list of fauna that lived during the Late Cretaceous Period:

* Birds
* Crocodilians
* Dinosaurs
* Fish
* Mammals
* Marine Reptiles
* Pterosaurs

* *Hesperornis*

- *Deinosuchus*

- *Sarcosuchus*

- *Thoracosaurus*

- *Ankylosaurus*

- *Chasmosaurus*

- *Dakotaraptor*

- *Daspletosaurus*

- *Dromaeosaurus*

- *Edmontosaurus*

- *Euoplocephalus*

- *Gallimimus*

- *Gorgosaurus*

- *Lambeosaurus*

- *Maiasaura*

- *Mononykus*

- *Ornithomimus*

- *Pachycephalosaurus*

- *Pachyrhinosaurus*

- *Parasaurolophus*

- *Saichania*

- *Saurolophus*

- *Stegoceras*

- *Styracosaurus*

- *Tarbosaurus*

- *Thescelosaurus*

- *Therizinosaurus*

- *Torosaurus*

- *Triceratops*

- *Troodon*

- *Tyrannosaurus*

- *Velociraptor*

- *Squalicorax*

- *Xiphactinus*

- *Alphadon*

- *Didelphodon*

- *Gypsonictops*

- *Archelon*

- *Elasmosaurus*

- *Halisaurus*

- *Mosasaurus*

- *Tylosaurus*

- *Nyctosaurus*

- *Pteranodon*

- *Quetzalcoatlus*