Tuesday, July 19, 2011


Tiktaalik was an unusual genus of lobe-finned fish from the late Devonian period. This image shows how tetrapods (four-legged animals) evolved from lobe-finned fish. First, there were lobe-finned fish like Eusthenopteron, then Panderichthys, then Tiktaalik, then Acanthostega, then Icthyostega.

Tiktaalik had lungs, a moveable neck, and a ribcage like a tetrapod, but it also had gills, fins, and scales like a fish. So this makes it a transitional fossil between lobe-finned fish and tetrapods.

Tiktaalik probably crawled along the bottoms of shallow freshwater habitats, like ponds and swamps, then waited for prey to come by. But it may have occasionally even crawled up onto land using its leg-like fins to walk.

Tiktaalik was about 3 to 9 feet long, and most likely a predator eating fish, and maybe some small terrestrial arthropods. Tiktaalik could have been related to Panderichthys, which is a similar transitional fossil between the lobe-finned fish and the tetrapods. 


  1. The story behind the discovery of the fossils in the Canadian Arctic is a really good one. Neil Shubin (who lead the team) wrote an amazing book called "Your Inner Fish".

    I have ready many popular accounts of evolutionary biology, and Your Inner Fish really brought a lot of things into focus for me, in a very fun way.

    If anyone has not read this book, I highly recommend it.

  2. Thank you. We don't have that one, so I just ordered it for Art.

  3. I'm loving all of these posts, and learning a lot. I especially liked this one; Tiktaalik has been a favourite ever since I first heard of it from another person working on it, Per Ahlberg.

    Keep up the good work, Art!

  4. One of the coolest fossils ever. Tiktaalik is one of the clearest examples of a "transitional form" (although everything is transitional), and it's one of those key pieces in the great puzzle of life.

  5. Everyone loves Tiktaalik!

  6. There's a song about this creature as well: http://www.youtube.com/watch?v=B9h1tR42QYA