Another look at Ichthyostega

Perhaps the borders
of the skull bones in Ichthyostega need to be revisited. Sure the cracks and sutures are hard to figure out. And there may be mistakes here. But this is the way I see it for now, subject to future changes.

Figure 1. DGS applied to the skull of Ichthyostega (left). Compare to the original interpretation (right).

Figure 1. DGS applied to the skull of Ichthyostega (left). Compare to the original interpretation (right). Note the left premaxilla and maxilla are separated from the rest of the skull. And note the slight indentation of the sides at left that is not shown at right. Earlier, more basal taxa do not connect the lacrimal to the orbit. 

Short one today.
Meanwhile, adding taxa to the large reptile tree this weekend and correcting errors like those shown above as they come to my attention. More changes tomorrow.

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4 thoughts on “Another look at Ichthyostega

  1. The sutures do indeed need to be revisited; Clack’s preliminary reconstruction from 2007 is noticeably different from the classical one.

    But this isn’t a problem you or anyone could solve based on photos. The specimens are genuinely difficult. They’re crushed and squished and incomplete; on the other hand, there are lots of them (many of them never photographed, of course); on the third hand, there are three species according to the revision by Blom (2005), so people must be careful not to reconstruct a chimera.

    Judging from the work that has come out in the last 15 years, Clack & team have probably been CT-scanning the skulls and might publish results any year now. Stay tuned. And keep in mind that the difficulty of Ichthyostega is legendary.

    • But, dude, your photo is tiny. It’s too coarse-grained to really see any sutures.

      Ornamentation is good at hiding sutures. I’ve spent a few days with the huge Edops skull at Harvard. The sutures on the skull roof are really, really hard to trace; the few I could trace agree with the drawings by Romer & Witter, then I gave up and decided to trust the drawing.

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