The dinosaurs. You know them, the big, mostly feathered animals that lived throughout the Mesozoic. Only to be extinct at the end of the Cretaceous, some 65 million years ago. A commonly asked question around this is: What if this never happened? What if the KT extinction was avoided?. This scenario will be looked at with the Dinosaurian Tertiary.
The Present Day Edit
The world without the KT extinction is a odd one. There is no sign of any asteroid, let alone a crater. Since the end of the cretaceous, there has been different changes through out the fauna of the world. Some groups, like the Pterosaurs, have diversified into different niches. Others, like the Rodents and Ungulates, have never got their chance to rise 'n' shine. Tyrannosaurs, albeit descendants from Nanuqsaurus and Alectrosaurus, have diversified into creatures you wouldn't have thought of. New dinosaur groups, like the Neoscanisoropterygians and the Courtosaurs, both descendants of the Early Cretaceous Kakuru, have popped up in the pacific.
Another notice is that there are two moons, The Moon and Chicxulub (Which is the KT asteroid), instead of one. Instead of it spiralling into earth and causing doom to all non-avian dinosaurs, it was put in orbit around the earth by the moons different orbital position around the earth, compared to what it was in HE. This saved ancient groups, like Tyrannosaurs and Sauropods.
Fauna of Dinosaurian Tertiary Edit
Without any extinction (With the exception of the Deccan Traps, witch killed the Abelisaurs and Sauropods of India), the dinosaurs, crocodiles, mammals, reptiles etc diversified. The following is a overview of the Fauna of the Dinosaurian Tertiary.
Terrestrial Fauna Edit
The animals of the world have changed. The Elasmarians, basal ornithopods, have diversified in South America, much like the Meridiungulates,which are also present, albeit in severe competition with the Elasmarians, as the Iguanodonts have had more of a chance to diversify. The Abelisaurs of the continent, such as Carnotaurus, have either moved on to Africa, where they still exist, or have gone extinct, due to competition with the Sebecians, massive sized predatory crocodilians who hunt the Elasmarians. In North America, the Cimolestans have also changed, with the Pantodonts and co. remaining odd critters. In fact, the Pantodonts have been restricted to the Arctic and Canada, where they positively thrive in the cold environment. Tyrannosaurs, those big sized predators of the cretaceous, have shrunk in size, and are around 1- 8 metres long these days, with the exception of the Miocene- Pleistocene Tyrannosuchus, which was around 13 metres long, as big as the biggest Tyrannosaurus individuals of the Cretaceous. Edmontosaurus and Ugrunaaluk descendants have made the clade Edmontosauria, who are found in the Americas, although they are rare in South America, with competition of the Elasmarians. In Eurasia, the Tyrannosaurs are present in Europe and Asia, although are usually found in the northern reaches, due to Abelisaur descendants of Arcovenator and Maisakasaurus, in which the latter's descendants probably migrated from Madagascar via Island Hopping. Large dinosaurs are usually found to be the Artiodactylopods, descendants of the Hadrosauroids Tethyhadros and Zalmoxes of Cretaceous Europe. They are accompanied by the Neodosaurs, descendants of Struthiosaurus that are now common across the Eurasian continent. The other Ankylosaurs, descendants of Minmi, are only present in Papua New Guinea, Australia and the Pacific. The other predators of the continent are either Dromaeosaurs or Abelisaurs, which the latter have came from Arcovenator. In Madagascar, the only familiar group are the Primates, although, even they have diversified. The Choristodera, a.k.a the Champsosaurs, have also survived, albeit restricted to Australia, where there are no inland Crocodilians. Other fauna of Madagascar includes dwarf Aquasaurs, water adapted sauropods, along with the Gigasuchians, giant herbivorous descendants of Simosuchus, a pug like crocodilian of the Cretaceous. Australia is filled with descendants of Leaellynasaura, which have become the Australiornithopoda, the dominant herbivores of the continent, or the Heterovenatora, which are the dominant predators of Papua New Guinea and Australia. In New Zealand, Mesitornithiformes have been blown across the Pacific from Madagascar, and have become the dominant herbivores. Dinosaurs were once present on the islands, but with the sinking of New Zealand in the Miocene, they were doomed. A order of flightless Palaeognathes, the Terribliornithes, have become the dominant carnivores.
Oceanic Fauna Edit
The oceanic critters have also changed. Elasmosaurs, which were once so common, have been replaced by their cousins, the Polycotylids, who have also diversified in their own way. The Mosasaurs are still the biggest predators, although they have become a new order; the Reptilicetea. Abyssal fauna is the exact same as it is in HE, however, some forms, such as the Ammonites and Beleminites, have been new additions to the trenches. Dinosaurs, especially the Duogonisaurids, have become additions to the oceans, and behave like Dugongs and Manatees of HE. Pterosaurs, mainly the Aeroazhdarchids, albeit they are rare, due to competition from the Ichthyornithiformes and Hesperornithes. The massive Protostegids, common relatives of Turtles, have also made their mark in the oceans. Descendants of Hybodontiformes, which are commonly called Hybodonts, have been forced down into the abyssal zones as well. The replacement of the Whales of HE are the Mosasaurs, but other filter feeders, such as the Pachycormiformes, are even present in the Abyssal Zones. Other creatures, like the Ichthyodectids, are also present in every oceanic environment. Many creatures have had their play in the oceans. The Cretoxyrhinid sharks have been pushed into the Abyssal Zones as well.
The Orders of Life Edit
Other (Places and Fossil Taxa) Edit