Main Article: What if the Asteroid Missed?
The continent of North America, like in home earth, is a diverse place populated by a range of animals.
Unlike Eurasia, North America has kept its large theropods, and the tyrannosaurs still rampage about the continent, much as they did in the Cretaceous. The hadrosaurs are also found here in abundance.
Like most continents, the Coelurosaurs compose all of the theroopd fauna.
Maniraptorans of North America include the ever presant birds, but also several groups of non avian dinosaurs. The most common are the Nyctodromaeids.
This group of predators are descended from Dromeosaurs, and are related to the Eurasian Ultovenatorids. Despite the name, which translates as 'night runner', Nyctodromes are relatively slow compared to most maniraptors, though still capable of outrunning most humans. They are named because of their tendancy to hunt at night, and their persistance. Though usually solitary, related individuals may hunt together, and generally have a higher success rate than solitary individuals. Most species are quite small, similar to their ancestors, but some species from the Rocky mountains can be up to 8 metres long, and take over the niche of the larger Novotyrants, which are more at home on the plains.
- Thunderbird, Nyctodromaeus brontus
These dinosaurs superficially resemble Therizinosaurs, though are actually descended from Oviraptorosaurs, which took over therizinosaur niches in the Eocene. The Therizinavids, or 'Sasquarks', are large herbivores notable for their strange upright stance, and almost total lack of a tail. They often have large, brightly coloured feathers on their tail and arms, and have large claws for defence. Due to their upright stance, and long necks, the largest of these monsters can be up to 6 metres in height. The smallest species generally have a longer tail for their body size, allowing them to run fast. Most species also have crests of keratin on their heads, much like a cassowary. The therizinavids closest living relatives are the more generic Arctornithids, which they coexist with in Alaska.
- Alaskan Sasquark, Therizinavis alaskensis
- Eurasian Sasquark, Therizinavis sinensis
The Tyrannosaurids, like most late Cretaceous superstars, are long gone, though the group lives on in North America, as the Novotyrants
Despite the superficial resemblance to the famous Tyrannosauids of old, Novotyrannids are a more recent evolution, evolving in the early Miocene. These predators are, in many ways, more akin to Carcharodontosaurids than Tyrannosaurids, with most species having rather more blade-like teeth than the pulverising teeth of T.rex. Unlike most cretaceous tyrannosaurs, the novotyrants have a thick coat of feathers, like most coelurosaurs, and have long legs enabling them to run frighteningly fast for their size. Novotyrants are particularily common on the Great Plains of central North America, where their primary prey, the giant Hadrosaurs, are most common. Novotyrannids are by far the largest modern day theropods, rivaling even the famous tyrannosaurs of old, with large individuals of the Plains Novotyrant reaching 10 metres long, with unconfirmed reports of 12 metre individuals.
- Plains Novotyrant, Novotyrannus campus
- Appalachian Novotyrant, Novotyrannus oriens
- Great Lakes Novotyrant, Novotyrannus michiganensis
Ornithopods dominate the herbivore niches of much of North America, though northern Canada and Alaska are uninhabited bu these dinosaurs, which lack feathers, and are unable to like in a glacial climate.
The hadrosaurs compose of the other great group of dinosaurs found in North America, with seven genera and almost 30 species calling the continent home. Some, like the sauropod analogue Profundosaurs, are huge forest dwellers, others, the Bisornithopods, are heavy plains dwellers.
The titanic Profundosaurs are the largest living land animals, weighing up to almost 20 tons and standing 8 metres tall, they are in many ways more like sauropods than hadrosaurs. The three species of Profundosaur all prefer to live on the margins of forests, rather than the plains themselves. The largest species, the Woodland Profundosaur can reach almost 15 metres long and weigh 20 tons.
- Woodland Profundosaur, Profundosaurus silvestris
Smaller but more plentiful than the Profundosaurs, Bisornithopods are also more adapted to the open plains, and have adapted to eating grass. These dinosaurs have several features that enable them to tolerate plains living, such as a flattened beak to easily crop grass, and hoof-like claws on their front feet for more efficient walking.