Hesperornis Dossier
Common Name Hesperornis
Group Birds
Species Hesperornis avenatantes
Time Late Cretaceous
Diet Piscivore
Temperament Flippant
PC Release Date Not Yet Released
Tameable Yes
Rideable Yes

Appearing as something of a half-duck-half-dinosaur, Hesperornis is a medium-sized fish-eating bird, common in the rivers and lakes of the island. It would be about two-thirds the height of a human, if it stood tall, but it rarely does. Hesperornis spends most of its time gliding along the surface of the water, where it is much more maneuverable.

Hesperornis is barely a threat to any land-dwelling creature, as its legs are too short for it to move around effectively, but it is surprisingly fast on the water. It can easily hunt down fish and other small water-dwelling creatures.


Not particularly useful for hunting, and not being affectionate, Hesperornis is primarily kept for the specialized eggs it produces. When rendered correctly, the eggs separate into two distinct substances:

One is a protein substance high in calories, and the other is an oily liquid that is effectively the same as the oil found in the ocean!

— The Dossier

The Hesperornis is a small carnivorous (piscivorous) bird found on the Ark.

Wikipedia has a more detailed and comprehensive article on Hesperornis


  • The dossier was revealed on August 21, 2015.

Trivia not relevant for the game

  • Like Archaeopteryx, Hesperornis was a proto-bird, meaning it still retained some Dinosaurian features, such as teeth and visible fingers, which most modern birds lack.
  • In real life, Hesperornis was native to the shores of shallow shelf seas like the Western Interior Seaway and acted as an easy prey for ocean predators like Xiphactinus, Tylosaurus and Mosasaurus.



Patch 258 Hyaenodon, Megatherium, Megalania, Hesperornis, Yutyrannus, and More!

Patch 258 Hyaenodon, Megatherium, Megalania, Hesperornis, Yutyrannus, and More!