Wedgenose
The Wedgenose split from its ancestor and, finding no competition in its range for the herbivore niche, quadrupled in size. It has better-developed salt retention as a juvenile, and as a result it no longer has to return to the sea to reproduce—the local river suffices. It has developed a wedge-shaped horn on its nose, which it uses to break into its favorite source of food—Petrolignopsid trunks.
The Wedgenose uses its namesake, which has a dense bone core, to whack away at the trunks of Petrolignopsids. It may aim at holes created by Petro-Boring Knightworms, widening them. After it has created some splinters, it picks at them with its lateral mandibles to widen the opening so that it may begin to rasp at the insides with its long, toothy tongue. If a given individual has babies in the nearby river or stream, it will temporarily store some of the food in a small gular pouch under its tongue and spit it out later to feed its babies.
Though still very semi-aquatic, the Wedgenose is generally more adapted for terrestrial life than its ancestor. It has lost its back fin, and while its gills still need to be wetted periodically they are resistant to permanent damage from being out of water too long. Even while in the water, it rarely swims, preferring to just lay or crawl around in the mud.
Like its ancestor, the Wedgenose raises its young, One parent stands guard in case of predation or other disaster, while the other goes out to get food. They take turns in this, and both stay in the water with their babies overnight. Like its ancestor, the Wedgenose gives live birth, its babies are radial, and they mate by “holding hands”—accomplished by pulling back the fin membrane between the anal fingers to free them up.