Named By: Edward Drinker Cope - 1877.
Synonyms: Clupea humilis, Clupea theta, Clupea vectensis, Copeichthys, Diplomystus analis, Diplomystus pectorosus, Diplomystus theta.
Classification: Chordata, Actinopterygii, Clupeiformes, Ellimmichthyidae.
Species: D. dentatus (type), D. altisomus, D. birdii, D. dartevellei, D. dentatus, D. dubretreiti, D. humilis, D. kokuraensis, D. primotinus, D. shengliensis, D. vectensis.
Diet: Small invertebrates and small fish.
Size: Up to 65 centimetres long.
Known locations: USA, Wyoming - Green River Formation. Also Japan - Third Formation, Italy and Morocco - Akfabou Formation.
Time period: Lower Eocene.
Fossil representation: So numerous no one knows for certain how many specimens have been recovered.
are thought to be related to modern day herring, and like them their
strongly upturned mouths suggest that they fed in open water rather
than feeding off the bottom. Although Diplomystus
are known to have
grown up to sixty-five centimetres long, fossils of Diplomystus
usually smaller with fossils even revealing the presence of Diplomystus
Diplomystus are often found in association with other Eocene fish from the Green River Formation, particularly the genus Knightia. In fact fossil evidence suggests that Diplomystus preyed upon Knightia. Like Knightia, Diplomystus are quite common and are often found for sale on the fossil market.
- Early Cretaceous freshwater fishes from Northern Kyushu, Japan I. Description of two new species of the clupeid genus Diplomystus - T. Uyeno - 1979.
- Early Cretaceous Freshwater Fishes From Japan and Korea - Yoshitaka Yabumoto, Seong-Young Yang & Tae-Wan Kim - 2006.