A notable feature of "Tiktaalik" is the absence of bones covering the gills. These bones would otherwise connect the shoulder girdle with skull, making the shoulder girdle part of the skull. With the loss of the gill-covering bones, the shoulder girdle is separated from the skull, connected to the torso by muscle and other soft-tissue connections. The result is the appearance of the neck. This feature appears only in tetrapods and "Tiktaalik", not other tetrapodomorph fishes. "Tiktaalik" also had a pattern of bones in the skull roof (upper half of the skull) that is similar to the end-Devonian tetrapod "Ichthyostega". The two also shared a semi-rigid ribcage of overlapping ribs, which may have substituted for a rigid spine. In conjunction with robust forelimbs and shoulder girdle, both "Tiktaalik" and "Ichthyostega" may have had the ability to locomote on land in the manner of a seal, with the forward portion of the torso elevated, the hind part dragging behind. Finally, "Tiktaalik" fin bones are somewhat similar to the limb bones of tetrapods.