The setting includes the return of pleistocene megafauna to the continent. I have two different ideas as to why this should be. The original idea reaches into either pure Fantasy or into Magic Realism and while I think it's thematically more robust, there are some possible issues concerning the presentation of certain cultures and I'm not sure I want to step into that snakepit. The other idea, while leaning fully into the laboratories of Science Fiction, it's also missing the thematic facet of the first idea. This second idea is much safer to write, but it's total weak-sauce.
* Metatherians - All those mammalian creatures more closely allied to marsupials and monotremes (inclusive) than to placentals.
These are the primary predators of Stralyon and Sepilon. There are several species that come in a range of sizes from something close to a very large housecat (25 lbs) to something akin to a jaguar (350 lbs). Despite having a name that's similar to the thylacine (marsupial wolf), they are not closely related other than also being metatherians. Leos belong to diprotodontia, represented in our times by the macropods (everything that is or resembles a kangaroo), and also more specifically they are closely allied with the vombatiformes, which are the wombats and koalas. Leos have a strikingly unique dental formula (I 3/1, C 1/0, P 3/3, M 1/2) with their incisors serving the role that canines serve in other predators, and their premolars and molars are highly reduced to a single, huge, blade-like carnassial (upper, lower, left and right) and a secondary, smaller carnassial behind the larger one.
Leos are only moderately affected by stone glyphs. They understand, but are not wont to obey.
Though thylacines are not technically megafauna and they did survive all the way to the modern era, a story like this that doesn’t include them would feel like a crime, and they’ve already been subject to the worst of criminal extinction. Thylacines are another predatory metatherian we encounter. They belong to dasyuromorphia a very different lineage of metatherian than the leos, represented in our time by quolls, dunnarts, numbats, and the Tasmanian devil. They famously exhibit convergent evolution with canines, which are not remotely related at all, thylacines being marsupial metatherians and canines being placental carnivores (in the case of canines, carnivore refers to both their eating habits and also the order to which they belong). Thylacines are nocturnal and also crepuscular. In the story, small groups of them are kept in shelters near the opening of underground settlements as guard animals.
They are as sensitive to stone glyph as leos, but much more receptive.
Donnas are rhino-sized wombats. They serve mainly as a narrative analogue for horses, riding animals. Donnas are very sensitive and obedient to stone glyphs, often seeming to be mesmerized by the patterns out of a sense of aesthetic appeal. Domesticated donnas are even-tempered creatures with a personality somewhere between a horse and a dog. Biologically, like the leos, they are metatherians also belonging to diprotodontia for which they are the namesake. Like most large mammals that show sexual dimorphism, the females live in groups with young of both genders, ousting the young males when they start to show adult characteristics. Only females are suitable for domestic use. Adult males keep away from humans but will sometimes come close when a domestic female is receptive, though the oestrus cycle of donnas can be interrupted through use of stone glyphs.
Donnas can travel roughly 25 miles (40 km) in a day.
Blokes are giant short-faced kangaroos. These are sthenurine macropods, which are not represented at all in our world. Sthenurines are markedly different from hoparoos like the grey and red kangaroos, or climbaroos like the rock wallabies and tree kangaroos. Sthenurines are unique in that they were walkaroos. They had a gate somewhat similar to a human walking on the balls of its feet. The morphology of the rear extremities, especially the feet, show a creature that was unguligrade rather than plantigrade like modern kangaroos. Unguligrade means walking in the tips of hooved toes like a horse or a cow. A much less flexible spinal column, immense size, and a very different center of gravity all point to a creature that walked, one leg at a time, bipedally, like us. They even show a certain degree of convergence with bipedal hominids with respect to the layout of the pelvic girdle. It was hard to find a good image of one since they seem to suffer from iguanodon syndrome. No matter that their morphology very clearly points to a very different locomotion and lifestyle to modern roos, they are still nearly always depicted incorrectly resting on the whole of their back feet (plantigrade), when it seems very unlikely they could manage this stance even for short periods, or bounding across the landscape like a modern roo, which they inarguably could not have done in the least.
Though blokes are sensitive to stone glyph, they are shy creatures who prefer to remain as far from us as they can, typically seen on hilltops or other prominent topography, keeping a keen eye on us.
Like the leos, thunderbirds are represented by several species ranging in size from something close to a cassowary to the great runners of the plain measuring 9 feet tall and weighing in at close to 600 lbs. Of all the megafauna, thunderbirds are the most dangerous. They are completely oblivious and immune to stone glyphs. Though they are not strictly predators, tending more to scavenging dead animals and consuming plant matter, they are aggressively territorial and when they chase, they chase to kill. They are wary of the full grown donnas, but not enough to think of them as protection.
More to come...
Just a little Puerto Rican guy living on a coffee plantation in the middle of the Caribbean.