Ichthyostega poseía una combinación única de características anatómicas que lo distinguían tanto de los peces acuáticos como de los tetrápodos terrestres posteriores

Unlike Arctodus simus

marking the early establishment of the group's typical characteristics

lo que le otorgaba estabilidad al desplazarse dentro del agua

Thylacinus cynocephalus Variant:Hand-painted Ichthyostega poseía una combinación únicaThylacinus cynocephalus, known as the thylacine or "Tasmanian wolf," was a recently extinct carnivorous marsupial whose general morphology remarkably converged with that of placental canids. Its cranial anatomy constitutes one of the species' most characteristic and functionally relevant aspects. The skull of Thylacinus cynocephalus was elongated, narrow, and relatively low, with an almost straight dorsal profile. It could reach approximately 2124 cm