Ichthyostega stensioei is an early tetrapod, notable for its blend of aquatic and terrestrial features. It possessed robust limbs, a fish-like tail, and lungs, enabling it to navigate both water and land environments. Its strong ribcage suggests it could support its body out of water.

Ichthyostega stensioei is an extinct genus of early tetrapods that lived during the Late Devonian period, approximately 365 million years ago. Fossil evidence of Ichthyostega has primarily been found in what is now Greenland, indicating that this region was its native area during that time.

During the Late Devonian period, the area that is now Greenland was part of the supercontinent Laurussia. The climate during this period was likely warm and humid, with extensive coastal regions and swampy environments. The region would have had abundant freshwater systems, such as rivers and lakes, which supported a diverse array of aquatic and semi-aquatic life.

Ichthyostega is considered one of the earliest tetrapods, bridging the gap between lobe-finned fish and terrestrial vertebrates. It likely inhabited shallow, swampy waters and transitional environments between land and water. Its morphological features suggest adaptations for both swimming in water and limited movement on land, indicating it occupied a niche where it could exploit resources in both aquatic and terrestrial settings.