From 2speccers2tools wiki

The blundergus is a clongus which has specialized even more for its diet. The most notable new feature is its ability to shoot multiple small pellets at once instead of one big one, a feature aided by its larger number of gut diverticuli and blunderbuss-like snout. This makes it more likely for it to hit a vulnerable part of the organism it’s hunting with fewer shots.

Though the blundergus’ main adaptation is most notable, its other adaptations are worth noting too. The blundergus also retains its atavistic ears entirely, allowing it to listen for predators and prey alike. Its eyes are enlarged and are positioned in a way that gives them view to their sides and straight above. Its digestive patch has moved to the underside, which has allowed its body to truncate so that the blundergus can be more steady while aiming.

The blundergus’ snout points upwards, and can only move enough to track its prey in the air, meaning that it is no longer able to eat with its mouth. Though this may seem to be a serious problem, its highly wrinkled digestive patch and largely sedentary lifestyle makes up for it. It has a lower metabolism too, being more mesothermic rather than a full endotherm. The blundergus’ truncated body also hinders movement, prompting the evolution of its 8 leg-like nubs, which are derived from its ancestral foot. These nubs are soft, being made entirely out of muscle.

Because of these advantages, the original clongus has become rarer, and evolutionary pressure on it is high.