Tiktaalik Roseae is the first fish which has transitioned to land, as per the research data of Professor Neil Shubin of the University of Chicago. This creature is the most compelling example of the fish transition to a tetra-pod till date, which, until now, has baffled the scientists. Discovered in 2004 by Prof Shubin, this creature looks like a semi-crocodile and has existed for about 375 million years.
Dr Farish A. Jenkins, Jr., of Harvard University; Dr Edward Daeschler of Drexel University; and Prof Shubin discovered this animal 10 years back and researched on its morphology. This fossil fish has developed a pelvis region due to evolutionary process and has front fins, which look more like legs. The leg-like front fins were only normal fins before, but went on to become an enhanced leg-like structure all through these 375 million years. That’s evolution.
Tiktaalik roseae lived in Devonian period and has a flattened body and crocodile like structure. With sharp teeth, this creature was a predator back in time, but became servile with passing time. The peculiar fish was discovered inEllesmere Island in Nunavit, Canada, and a classical example of lobe-finned fishes.
According to Sci-news.com, Tiktaalik had mobile neck, fins, scales, gills, primitive lungs, and robust ribcage. With elbows and partial wrists the creature gets more control over its movement and locomotion. It also had large fore fins and well-formed shoulders. The overall morphology of the fossil fish is quite interesting to the scientists and Shubin mentioned that there are ample amount of scope to research about the creature. It is quite baffling that this creature is showing a typical evolutionary process from a fish to a tetra-pod.
Evolution itself is a natural process, and the fins of the Tiktaalik Roseae metamorphosed into an enhanced hind limb, took a long time. The change may seem to be a very minute one, but it has an immense biological significance. To mention a few parts, front and rear appendages, fins, and pelvis had considerable changes which were noticed by the scientists. The Pelvis region in particular, had a lot of similarities with the early tetra-pods which attracted a lot of attention to the creature.
Shubin, main author of the study said, “They’re largely committed to water.” He added saying, “We saw a series of ribs that fit very much with the front block and then ………..saw this giant pelvis.” Although the initial expectations were not much, the animal’s hindquarters gave a lot of crucial information to the scientists. The crawling ability of the fish earned the creature a nickname called “fishapod.”
Tiktaalik, an Inuit expression for “big, freshwater fish” had a skeletal structure and it helped the fossil fish to “walk” with the support of rear and front fins. One professor said, “The other entity that the initial tetra-pods have but Tiktaalik doesn’t is a bone termed as the ischium.” He was surprised to see the pelvis and commented, “The size of that pelvis totally surprised me,” saying he expected a much smaller version. The initial results of Tiktaalik Roseae can be baffling, but the long term scientific research on this fossil fish can lead to many other solutions to evolutionary mysteries.
By Sunando Basu