Tiktaalik, the missing link from water to land

Tiktaalik: Iconic fossil's rear parts described

author: Jonathan Amos

source: http://www.bbc.co.uk/news/science-environment-25713538

Summary: A now extinct fish that lived around 375 million years ago, which is called the Tiktaalik, is thought to be a species that most land mammals descend from. This fossil provides lots of insight into life's move from the water onto the land. Although the discovery of this species is not very new until, it was first discovered in Canada in 2004, now only the front parts of the fossil have been found. Recently, however, new fossils have been found that have the rear section still intact. The most interesting of this back half to look at are the tail fins and the pelvic bone because they show how the Tiktaalik propelled itself through the water. Although its appearance looked fishy because of its scales and fins much of its body resembles the land mammals to come after it. Its flat head and shoulders, its forearms, and wrist bones all show this relationship. The Tiktaalik was recently discovered to have two strong back fins that helped propel this organism along with its front fins. The scientists that discovered this species even speculated that it is possible that the Tiktaalik used these to push itself along a shallow bottom of a body of water or even to quickly move to another water course. It is easy to see how these fins may have developed into legs however the scientists say that this fish is by no means built to live on land because its sensory system, hunting and breathing all are reliant on the water. However this species does show an important connection between the land and the water

connection: This species connects to a lot of what we were learning about in class. This is a great example of evolution because it shows how an example of an organism could adapt to living on the land. This also shows homologous structures that have formed between the Tiktaalik and  many four legged mammals today. Finally this new discovery shows how species could adapt to a new niche because this species is going from the water to a new niche as an animal that lives on the land