The marsupials of Australia and the Americas are the only group left of a once diverse group known as Metatheria. Other members of this group include the now extinct sparassodonts and a few other groups. However, in this timeline, the marsupials and sparassodonts never evolved. Instead, very different groups evolved in Australia and the Americas, ranging from ground sloth-like herbivores to dangerous predators that looked similar to creodonts.
Magnatheres get they're name because most species are very large. In fact, one group of carnivorous magnatheres are the dominant group of predators throughout the Australia. Herbivorous members of this group include giants that resemble ground sloths and wombats. Also, most members of this group have females with pouches, similar to marsupials.
Their fossil record goes as far back as the Late Paleocene when South America, Antarctica and Australia were still connected. Just like hopper raptors, magnatheres traveled to Australia via Antarctica about 60 MYA. Unlike our timeline, the metatherians did very well during the Great American Interchange. This was because the eutherians weren't bigger than a deer in this alternate timeline since the effects of the K-T mass extinction were hindered due to the cold climate of the Late Cretaceous.
Tromakodonts (Order: Tromakodonta)Edit
The tromakodonts are the only carnivorous group of magnatheres. Despite being the only carnivorous group though, they are very diverse, having several families with over 160 species. Some are as small as a cheetah while some species grew about large as a Andrewsarchus. Due to their large size, these mammals are actually the dominant predators in Australia.
Groazatheres (Family: Groazatheriidae)Edit
The groazatheres are one of the two dominant group of predators in Australia. They're descended from a few South American tromakodonts that migrated to Australia. Most members live in small family groups containing around 12 members. These are mostly a dominant male, several females, a few smaller males and pups. Most species prey on large herbivores in packs such as spiked honkers and young titanosaurs. They also hunt smaller prey such as mikrosaurs and even hopper raptors if herbivores are scarce. Most groazatheres are about as big as a jaguar, yet some can run up to 40 MPH.
Parvadonts (Family: Parvadontidae)Edit
Unlike their groazathere relatives, most parvadonts are smaller than a cheetah. In fact, most aren't bigger than a wolverine. This is because since they are found the Americas, they're most pushed into the shadows of the larger canisaurs, false carnosaurs and cruncher beasts. Much like the American marsupials in our home timeline range from Southern Canada to the Southern tip of South America.
|Sauropsida||Archosauria||Theropoda||Abelisauroidea • Aves • Dromaeosauridae • Gigaraptornae (Dinosaurs of the Ice Age) • Ornithomimosauria • Therizinosauria • Tyrannosauroidea|
|Ornithischia||Ankylosauria • Ceratopsia • Ornithopoda|
|Lepidosauromorpha||Plesiosauria • Squamata|
|Mammalia||Eutheria • Metatheria • Monotremata|