All Todays description on kangaroo
Fossils of these mammals have been found throughout Australia, New Zealand, and possibly in Europe and Great Britain as small species, but fossils of these kangaroo-like animals in Europe and Great Britain could have been very large early rats (ancestors of today's rats) of the Holocene-Anthropocene. They have bizarre-looking feet that had baffled paleontologists for decades as no vertebrate alive today have such similar looking bones. However, their feet could have been splayed out feet with webbings, suggesting an aquatic lifestyle, but their feet could have not been webbed and may have stayed close to each other, suggesting that they would be mostly terrestrial. Most paleontologists agree that kangaroos would have walked like the mesozoic non-avian theropods, but few suggested that they weren't built for walking and instead could have hopped, something that no modern large animal could do today, due to its bizarrely long legs. These animal's skulls have been found with molars missing, but sharp teeth lying nearby, suggesting that, if they're fully terrestrial, kangaroos were carnivores that preyed on animals larger than themselves, if hunting in packs, but they could have had strong molars for crushing shellfish if they're aquatic. They were the most common predator of Oceania islands and (possibly) Europe and Great Britain, since their fossils are very abundant, suggesting that they were among the very successful hunters of the Holocene-Anthropocene. In Australia, it was much hotter than today, so only few large prey animals flourish such as camels, so that could have been a reason why kangaroos grew so large in Australia, unlike in New Zealand, and (possibly) Europe and Great Britain. Their braincases showed that they were about as smart as the myna birds (which are still alive today since the Holocene), so they would have had outsmarted their prey items such as camels. They most likely had laid hard-shelled eggs much like today's birds and they would have been warm-blooded (unlike other mammals of the Holocene-Anthropocene), making them the first ever mammals discovered to have been warm-blooded, so they could have had much shorter lives than most mammals, about 50-60 years. It is unknown why the kangaroos had suddenly became extinct.
Introduction to real life North America
Since real life humans had introduced all todays kangaroos to real life North America, these animals now coexist alongside real kangaroo species. Unlike their ancestors, all kinds of all todays kangaroos species are now peaceful to any sapient species/beings and to dylanusids, as they adapted into human settlements and learned to tolerate human activities and among others, so they now flourish alongside real kangaroo species and are now very tame towards any sapient species.