I imagined a hypothetical mammalian species of the *Cetartiodactyla* order and of the *Ruminantia* suborder: adnaps. They are the opposite of giant pandas: if giant pandas are vegetarian carnivores (they mostly consume bamboo and fruit, but they have the digestive system of a hypercarnivore), adnaps are meatarian herbivores (they mostly scavenge other tetrapods, but they have the digestive system of a ruminant). They are my ogres. Some basic characteristic of my adnaps include:

1. Are as solitary as polar bears;
2. Are as nomadic as great white sharks;
3. Are mostly scavengers, but they sometimes act as ambush predators, and exceptionally as pursuit predators;
4. Despite their reputation as the only carnivorous mammal of the *Ruminantia* clade, they will exceptionally eat herbs, leaves, and fruits;
5. Females weigh an average of 200 kilograms (440 pounds), and are 8 to 12 % smaller than males;
6. Have an average lifespan of 23 years, and have a slow metabolism;
7. Compared to humans, they have a better sense of smell, and a better sense of eyesight, but they do have a worse sense of taste (they cannot taste sweet, and umami, they only taste bitter, sour, fat, and salty), and a worse sense of hearing;
8. They mostly live in East Asia (mainly in China, but not in Japan), but they can sometimes be found in South-East Asia (like Thailand), Central Asia (like Kazakhstan), and exceptionally in South Asia (like India);
9. They have pig-level intelligence;
10. They are both extremely poor climbers (like elephants) and extremely poor swimmers (like giraffes).

Given these characteristics, what species could they have evolved from, and what evolutionary pressures would lead to them?