Knightia

Knightia belongs to the same taxonomic family as herring and sardines, and resembled the former closely enough that both Knightia alta and Knightia eocaena were originally described as species of true herring in the genus Clupea. As with modern-day clupeids, Knightia spp. likely fed on algae and diatoms, as well as insects and occasionally smaller fish. The genus is also known from two additional species described from China dating to the Eocene and Late Cretaceous respectively. The Eocene species Knightia bohaiensis was described in 1985 from the Bohai Bay Basin region, while "Knightia" yuyanga was first identified as Eocene when described from the Itu region in 1963. The age of "K." yuyanga has been revised with the placement of the species' type locality in the Late Cretaceous Paomagang Formation. Additionally the species placement in Knightia has been questioned, and the species is now treated as "Clupeid incertae sedis". The Cretaceous genus Ellimma from Brazil was formerly synonymized into Knightia as Knightia branneri by Schaeffer (1947). This placement was rejected by Grande (1982) and subsequent authors, and the species moved back to Ellimma branneri. ==Anatomy==

In Knightia fish, rows of dorsal and ventral scutes run from the back of the head to the medial fins. They had heavy scales and small conical teeth. Their size varied by species: Knightia eocaena was the longest, growing up to 25 cm (10 in), though most specimens are no larger than 15 cm. K. alta was shorter and relatively wider, with specimens averaging between 6 and 10 cm. ==Predators==

A small schooling fish, Knightia made an abundant food source for larger Eocene predators. The Green River Formation has yielded many fossils of larger fish species preying on Knightia; specimens of Diplomystus, Lepisosteus, Amphiplaga, Mioplosus, Phareodus, Amia, and Astephus have all been found with Knightia in either their jaws or stomachs. ==Gallery==