what type of species is this former terrestrial predator that you mentioned?
It is one of two extant species in the genus "Alligator" within the family Alligatoridae.
American alligator
The American alligator ("Alligator mississippiensis"), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States, with a small population in Mexico. It is one of two extant species in the genus "Alligator" within the family Alligatoridae; it is larger than the only other living alligator species, the Chinese alligator.

what kind of habitat do river otters live in River otter is found in a wide variety of aquatic habitats, both freshwater and coastal marine, including lakes, rivers, inland wetlands, coastal shorelines, marshes, and estuaries. what is the geographic location of this river? UNANSWERABLE what kind of species is this? The North American river otter is a member of the subfamily Lutrinae in the weasel family (Mustelidae). where is it found? North America, coastal areas in Canada, the Pacific Northwest, the Atlantic states, and the Gulf of Mexico. is it nature playful? Yes - North American river otters are renowned for their sense of play. Otter play mostly consists of wrestling with conspecifics. Chasing is also a common game. what kind of threats do they face? Aquatic predators include the American alligator, American crocodile, killer whale. On land or ice terrestrial predators include the bobcat, mountain lion etc.
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American alligator [SEP] Introduction
It is distinguished from the sympatric American crocodile by its broader snout, with overlapping jaws and darker coloration, and is less tolerant of saltwater but more tolerant of cooler climates than the American crocodile, which is found only in tropical climates. American alligators are apex predators and consume fish, amphibians, reptiles, birds, and mammals. Hatchlings feed mostly on invertebrates. They play an important role as ecosystem engineers in wetland ecosystems through the creation of alligator holes, which provide both wet and dry habitats for other organisms. Throughout the year, in particular during the breeding season, American alligators bellow to declare territory and locate suitable mates.