The New Zealand Bears are a family of bear-like insectivores descended from the European Hedgehog. They are omnivorous, though some are more carnivorous/herbivorous than others and live in all habitats of New Zealand. All species are solitary, with the obvious exception of a mother caring for her hoglets.
The largest species is the Mega-grizzly (Gigaerinaceus atrox). It is 3-4ms long and weighs about 500kg. Though it is primarily herbivorous, browsing on high and low vegetation, it will also scavenge meat, scare smaller predators away from their kills and even fishes in rivers and the sea.
The smallest species is the New Zealand Pixie Bear (Arctoerinaceus nanus). It is 120cm long. It eats small birds, reptiles, mammals and insects.
Another example is the New Zealand Panda (Phytarctos lentus). It is 1.3-1.8ms long. It eats the leaves and shoots of low growing plants.
And do these species still have quills?
I found an article about the correlation of the masses of land and the weight of endothermic carnivores and herbivores. Maybe it can be useful:[link]