Knightia eocaena Fossil Fish cm 11.2 Matrix - cm 5.2 - 5 - 3.8 Fish (8)

Knightia is a genus of Extinct Fish belonging to Actinopterygii. It lived between the middle Paleocene and the middle Eocene (60-45 million years ago) and its fossil remains are plentiful in the United States (Wyoming and Montana).
The appearance of this fish was very similar to that of a herring or sardine, with which it is closely related. Rarely exceeded 20 cm in length. The Knightia body was lean and agile, equipped with fins that suggest a fast and active swimming.
Knightia is a typical representative of Clupeiformes, a large order of fish currently represented by numerous species, including herring, anchovies and sardines. In particular, Knightia would seem to be a member of the subfamily Pellonulinae, currently comprised of various forms of freshwater.
The Knightia fossils are the most common among those found in the famous Green River formation in Wyoming, where the remains of fish are perfectly preserved.
As today's herring, also Knightia had to feed predominantly very small, such as algae and insects, and formed numerous benches organisms. In the center of the Fossil Lake reservoir, where it is assumed there are the deeper areas of the lake, were found piled hundreds of individuals, side by side. Probably this is the result of mass die-offs, occurring perhaps to changes in temperature or changes of chemical values ​​in the water, caused by the proliferation of algae. This case arose from the fact that today's herring do not adapt to sudden changes in temperature. This fish was exceptionally important in the ecosystem of Green River because it was included in the diet of most fish predators of the same habitat.
The specie Knightia alta is distinguished by its similar Knightia eocaena for the wider belly, in addition to being more rare than the latter.
The genus Knightia is the fossil of the State of Wyoming.