Anonymous
Anonymous asked in Science & MathematicsZoology · 1 month ago

How do we know tiktaalik was a transitional species for sea animal to land animal if the only fossil we have is of its head and its torso?

8 Answers

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  • Anonymous
    1 month ago

    Because we have seen that he came up for the air and said "air."

  • Ray
    Lv 6
    1 month ago

    We don't know if Tiktaalik was the transition species, but we do know its limbs were strong enough to haul itself on land from its fin fossil. 

    That doesn't mean it was a transition fossil but we know that shortly after [carbon dating] amphibians proliferated. What i love about nature is that it has left branches likely from transition fossils which give us clues. There are some salamanders which still have gills! 

  • 1 month ago

    But scientists have found not one incomplete fossil of Tiktaalik but three nearly complete fossils--head, torso, and pelvis.  Maybe you should reread you copy of The Watchtower to make sure that you have correct information.

  • Tiktaalik is a good representative of what the form would be for a transitional species from a marine environment to a land environment.

    That does not mean that tiktaalik IS that actual transitional species. One has to understand that evolution frequently results in several branches from an original ancestor, and those branches can evolve differently. Sometimes one branch will retain most of the ancestral characteristics whereas other branches will evolve different characteristics that help them to live in different environments.

    Tiktaalik could well belong to a branch that retained the ancestral characteristics, while another branch or branches had earlier evolved into more advanced forms that were more terrestrial.

    The problem is that fossils are rare and not all types are found.

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  • Anonymous
    1 month ago

    Tiktaalik and fossils like Acanthostega and Ichthyostega lived in freshwater marshes, not the sea.  Tiktaalik has traits found in fish (gills and fins) and traits that are found in land animals such as limb bones. Scientists do not agree as to whether Tiktaalik was in fact the ancestor of land vertebrates or not. One problem is that it does not have finger bones, but instead thin bones where the fingers bones should be. We do not know if those thin bones were the precursor to finger bones or not. It may or may not be a mere side branch with no living descendants and therefore it may not be the direct ancestor of living land vertebrates. We simply do not know for sure. It is not a complete fossil but enough of it is found to suggest it may have a close relationship with land vertebrate. There is a possibility that amphibians had already evolved and that Tiktaalik coexisted with early amphibians. Even though humans evolved from an ape and apes evolved from a monkey, apes, humans and monkeys are coexisting right now. Therefore the ancestor of Tiktaalik may have been the real ancestor of land vertebrates. 

  • 1 month ago

    "Sea" animal? Hardly. Tiktaalik was definitely an amphibian and could not have survived in seawater for any length of time. I'm no expert on amphibians but even I could tell that it is an amphibian, given just the skull. Amphibians are intermediate between fishes (freshwater) and reptiles. The easiest way to ID one is to look at the bones that are in the jaws of fishes and gradually migrate to the middle ear in other vertebrates.

  • CRR
    Lv 7
    1 month ago

    If by transitional you mean in the direct line of descent between amphibians and the first tetrapods then it isn't. There are trace fossils of tetrapods dated millions of years before Tiktaalik. 

  • Anonymous
    1 month ago

    From what I have read, the spiracle openings on the top of the head suggest that it may have had lungs and the robustness of the ribcage would have given it the support required to live without the buoyancy of water. The bone structure of it's front 'arms' seem very similar to the legs of crocodilians. 

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