Friday, July 23, 2010

* The Fossil Record

We have seen that the dino-to-bird based cladograms are not congruent with the fossil record.
The dino-to-bird enthusiasts say that is because the fossil record is incomplete.
But here is an interesting thing that comes to light in the Wills et al (2008) study:
The Modified Gap Excess Ratio (GER*) and the Stratigraphic Congruence of Dinosaur Phylogenies
The GER values for the actual dinosaur groups are "extremely high".
Check here:
Hadrosauridae .9561
Pachycephalosauria .9468
Sauropoda .9101
Ankylosauria .8971
Ceratopsia .8963
and so on

No problem with the fossil record there.
But when it comes to Paraves the value is .5579 (which the authors call "indistinguishable from random".)
The problem is not with the fossil record. The problem is with the dino-to-bird idea.


  1. You're quoting the GER figure but the whole point of the Wills et al study was to critique the inherent biases in the old GER construct and propose a modified version they call GER*. Using this you can see that Paraves scores 0.8785 which still makes it one of the lowest scores but higher than Stegosaurs and hardly "indistinguishable from random".

  2. Paraves scores 0.8785 and is just above the lowest value of 0.8463. I invite people to look at the other values in that column.

    The question is how good is 0.8785? Does that show a high degree of congruence? Anonymous, can you point us to a reference that tells us how to evaluate a GER* score of 0.8785?
    And since you have familiarity with these measures could you point us to a link that indicates how good an MSM* of 0.31 - 0.40 is?
    That would be very helpful.
    I am absolutely willing to work constructively with anyone.

  3. I was really hoping that Anonymous would stick around and contribute.
    If anyone can provide us with any reference about how to evaluate an MSM* of 0.31- 0.40 please let us know.