Ypresian genus first appearances

Hyracotherium ( ; "hyrax-like beast") is an extinct genus of small (about 60 cm in length) perissodactyl ungulates that was found in the London Clay formation. This small, fox-sized animal is (for some scientists) considered to be the earliest known member of Equidae before the type species, H. leporinum, was reclassified as a palaeothere, a perissodactyl family related to both horses and brontotheres. The remaining species are now thought to belong to different genera, such as Eohippus, which had previously been synonymised with Hyracotherium.

Leptictidium is an extinct genus of small mammals that were likely bipedal. Comprising eight species, they resembled today's bilbies, bandicoots, and elephant shrews, and occupied a similar niche. They are especially interesting for their combination of characteristics typical of primitive eutherians with highly specialized adaptations, such as powerful hind legs and a long tail which aided in locomotion. They were omnivorous, their diet a combination of insects, lizards, frogs, and small mammals. Leptictidium and other leptictids are not placentals, but are non-placental eutherians, although

Proxiuber is a genus of sea snails, marine gastropod molluscs in the family Naticidae, the moon shells. The genus is endemic to New Zealand, with fossils dating back to the early Eocene, found in primarily in New Zealand, with one fossil species in Australia.

Rhynchaeites (Greek for "beak fossil") is an extinct genus of wading bird, a stem-group threshkiornithid, which lived in Europe and North America during the Eocene epoch. The genus contains three species, R. messelensis, R. litoralis and R. mcfaddeni. It is one of the oldest members of the ibis family known from fossil remains.

Eolates ("dawn Lates") is an extinct genus of prehistoric lates perch from the Paleogene of Europe. It contains three species, two marine and one freshwater, known from the early-middle Eocene and Late Oligocene. left|thumb|Specimen of E. gracilis The following species are known:

extinct genus of fishes