Gulper

Gulper are an evolutionary line of long-tongued plents. They all descended from the saggulper, a moderately-sized species of plent with atrophied wings and forelegs.

All living gulpers are descended from the woollycoat. As such, living species are active bipedal endotherms which usually have fuzzy integument.

Anatomy
Living gulpers are obligate bipeds with raised tails and no other limbs. The body is usually covered in cellulose-based fibers called "plent cotton".

One of the defining characteristics of gulpers is their mouth anatomy. The tongue is long and prehensile, acting like an arm. The lip-derived barbels present in all plenthogs dominate the upper jaw, and in living species they have spikes on them that allow them to serve as spider-like fangs.

Many living gulpers have a complete coat of fuzz as an adaptation for polar conditions, which would be a problem for any other plent, as plents urinate through their sweat. Cottoncoats have a marsupium-like "pee pouch" on the underbelly derived from skin, which functions as an enclosed bladder.

Breathing and Blood
Gulpers breathe through a posterior ventilation shaft located near their rear lovingly referred to as a "butt-nostril", which filters out carbon dioxide which they breathe in. Gulper blood is green from chlorophyll that exists within it.

Diet & Energy
Early gulpers were almost strictly carnivorous, with only a few deviations from this rule. These few-and-far-between species include the razor-tongue gulper and the  wrecking-ball gulper, both which evolved a strictly herbivorous habit. Due to the size of some species, they are classified as insectivorous as opposed to carnivorous, although this process still requires the consumption of meat. Many later gulpers evolved into omnivores, including the ankephalo gulper. The scavenger gulper is the only case of a gulper evolving specifically into a scavenger role to provide it with its main dietary needs.

Locomotion
Gulpers move about bipedally, suspended on their hind legs, while their front legs have atrophied, in most species entirely. Most evolved "wooden bones" to support their leg structure, allowing them quick movement that allowed them to become the dominant group of gulpers to have existed on Sagan IV.

Reproduction
Being plents, gulpers reproduce sexually, copulating and giving live birth through their mouths.

Extant
Cottoncoat tasertongues descended from the cottoncoat are the only living gulpers. They usually have a coat of cellulose-based monofilament fibers called plent cotton.

Marine woollycoats are superficially waterfowl-like cottoncoats which are largely semi-aquatic.

Killcoats are large predatory cottoncoats.

Tasermanes are various cottoncoats which often have reduced coats of plent cotton, with some exceptions.

Extinct
Armored gulpers were basal dome-headed gulpers which were covered in heavy defensive armor. Some species also utilized tail weaponry. They died out because of the gamma ray burst.

Hoofed gulpers were basal dome-headed gulpers which had hoofed feet and were largely herbivorous. They died out because of the gamma ray burst.

Horn gulpers were basal dome-headed gulpers which bore a single large horn on their heads. They were wiped out by the snowball event.

Succeeded
A group is considered "succeeded" if its living descendants lost or significantly altered their ancestral characteristics to no longer be the same "type" of creature. They can be thought of as evolutionary grades.

Basal gulpers retained their forelegs and sometimes leaves. They were largely lazy ectothermic creatures. They died out because of the gamma ray burst.

Startongues were the first endothermic gulpers. They ran on two legs and used their specialized tongues to sniff out their prey, but lacked the armored heads and electric tongues of later groups. They died out because of the gamma ray burst.

Basal dome-headed gulpers had domes on their heads but lacked electric tongues. Most distinct gulper offshoots from before the gamma ray burst were in this group. They died out because of the gamma ray burst.

Cottonless tasertongues were the immediate ancestors of modern cottoncoat tasertongues. They produced a sapient species. They died out because of the snowball event.