[1] Ymeria is primarily known from a partial holotype skull including the lower jaws and palate, as well as impressions of the shoulder girdle.

It came from a talus slope or pile of rock fragments at the base of Mount Celsius, encased in a pale red sandstone.

In 1988, English paleontologist Jennifer Clack was the first to propose that the material represented a third type of tetrapod from Greenland, based mainly on the teeth.

While the skull shape is closest to Ichthyostega, the teeth are smaller, more numerous and less curved, indicating the two exploited different foods.

Rostrals and tectals are small skull bones scattered around the snout, which are present in tetrapodomorph fish but lost in true tetrapods.

Bones of the palate (roof of the mouth), such as the vomers, palatines, ectopterygoids, and pterygoids, are poorly preserved, but similar to those of other Devonian stem-tetrapods (in terms of both shape and dentition) when visible.

Preserved fragments of the shoulder girdle resemble those of Ichthyostega, such as smooth clavicles and a pointed rear stalk of the interclavicle.

The outer (marginal) tooth row was present solely on the dentary bone, which was narrow and had alternating regions of light and absent texturing.

Another unique feature of Ymeria is the presence of a large patch of tiny tooth-like denticles on the prearticular bone, which lies directly under the inner main tooth row.