|Scientific name||Mesonyx obtusidens|
|Home era||Mid-Late Eocene|
|Appearances||The Shards of Time|
Mesonyx was a large, hooved, wolf-like mammal from the Eocene Epoch with large, tusk-like fangs on its lower jaw.
A pair of Mesonyx come through an anomaly and slaughter the guests at a birthday party.
Sean is attacked by one, causing him to break its neck in self-defence, while the other, after killing at least two guests, follows Sean back through the anomaly.
Unfortunately for the Mesonyx, the other side of the anomaly is a clifftop location, and thus when it pounces at Sean, but Sean leaps out of the way, the Mesonyx falls over the edge of the cliff to its death.