Basal tetrapods revised with more taxa

Full resolution during a Heuristic search was not enough.
Full resolution with high Bootstrap scores was the goal. Reexamination of the data would hopefully get to that goal, as it did so many times before. Sometimes it takes awhile. It’s a learning process, and I learned a lot over the last several weeks, sometimes from difficult and scrappy data. Here’s the result:

Figure 1. Subset of the large reptile tree (LRT) focusing on basal tetrapods.

Figure 1. Subset of the large reptile tree (LRT) focusing on basal tetrapods.

Some interesting results here. 

  1. Large temnospondyls are now split in two  (with, as before, many former small temnospondyls joining the equally small lepospondyls).
  2. Ichthyostega, now not so primitive, nests closer to Reptilomorpha.
  3. New reconstructions are offered for some taxa, like Tuditanus and Utaherpeton.
  4. Basal diplocaulids, like Keraterapeton, were added.
  5. Two taxa known as Trematosaurus, one with a shorter rostrum, one with a longer one, are split apart on the tree. Gavial-like snouts are not monophyletic at present, but long-nouted forms do not have long snouts as juveniles. This is a well-known quagmire I may get into later.

Look for more basal tetrapods with legs, not fins in the Late Devonian.
Not sure where they are, but they are out there. Apparently there were several ventures onto land, not just one fin-to-finger transition.

In a few days
I’ll start with some of the interesting details as time allows, but basically this completes the task, the tree, and the broad strokes that hypothetically echo the origin of reptiles and the variation that followed thereafter.

 

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2 thoughts on “Basal tetrapods revised with more taxa

  1. Full resolution with high Bootstrap scores was the goal. Reexamination of the data would hopefully get to that goal, as it did so many times before.

    I would rather recommend adding characters. For example, Jason and I long ago proposed a long list of tetrapod features to test your ridiculous “Paratetrapoda”. I see you still haven’t added them to your matrix. Why not? Are you afraid of something?

    Apparently there were several ventures onto land, not just one fin-to-finger transition.

    Ventures onto land and fin-to-finger transitions aren’t the same thing anyway.

    In a few days
    I’ll start with some of the interesting details as time allows

    Test them first by adding characters.

    That’ll take more than a few days. I’m adding characters to my own matrix, and it’s tedious… but worth it.

    • you wrote: Why not? Are you afraid of something?
      Yes. Wasting my time. You can tell some taxa by partial fossils. You can nest partial fossils. AND YOU KNOW THAT. You don’t need to belabor the situation when you already have full resolution and it makes sense. When issues arise I’ll revisit.

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