In this Earth, rather than just Ungulates, these clades of mammals diversified compared to the Boreoeutheria. Among them was a greater range of species with prehensile anatomies around the mouth, nose, and tail. This is where the sapients come from, sharing a few traits with the order elephants come from.
In a strange path of evolution, both the proboscis and tails gain greater emphasis. Most people are already familiar with the elephants, sea cows, some might even know the Hyrax. Among them, the mouth regions are very unique, not just tusks including those found in the Hyrax, but how the elephants and manatees put more into grasping with the front of their faces. Even more distant relatives of these species in the Afrotherian groups like aardvarks and elephant shrews have traits with a big proboscis lean. But what happens when these traits get more support?
Of course, we have to mention there are other developments. In the same areas with the Hyraxes, more animals emerge. Some of the ground dwellers have noses similar to a star-nosed mole but less pronounced.
Then there are the more predatory relatives, with molar tusks adapted into killing prey. This serves as one of their main weapons because they lack claws. Some resemble foxes but with noses more similar to an elephant shrew’s.
Even more omnivorous diets open up including with our sapient species.
In ways that boggle the mind, forelimbs are not the primary manipulators of this species. Instead both the trunk and a prehensile tail hold that honor. Also much like how humans are left or right handed, being trunk or tail dominant can happen.
But we need to back up for a moment. Studies have shown that despite trunks being good for grasping things in trees above the head, they seem more adapted for checking the ground. If anything a tail is usually what reaches upwards. So what could cause a development like this?
It starts with a terrestrial herbivore with a mobile snout for rooting out food and enhancing smell. Looks almost like an elephant shrew.
But being on the ground also means dealing with predators and a big competition for food. So enough of them move into scrubby trees, mangroves, and coastal forests. As evolutionary pressure starts to mount up, the ones that can grasp with their tails start to emerge. This made it easier for stability and manipulating hanging fruit.
But why stop there when the snout becomes a trunk? A dexterous one at that. This along with an arboreal adapted tail basically naked at the tip like a spider monkey’s.
So what about the legs?
The front limbs become more locomotor. …What’s that?…Oh it’s saying that they can’t be precisely controlled. As for the back legs, they stay strong, especially for supporting tail anchoring.
In order to get finer control of a trunk and a tail, massive sensory and motor cortex development happens over generations. With more complex social behaviors and environmental manipulation along the way, this leads to encephalization. By this point the trunk and tail become capable of tool use like opening tough surfaces and throwing projectiles. Not only that but object exchange and communication gestures.