Chicken skull colorized

Updated February 05, 2015 with a revised illustration of the chicken skull following further study. See comparisons on the blog post dated 02/05/2015.

Figure 1. Chicken skull (Gallus gallus) with fused and semi-fused skull bones colorized. Postorbital = orange. Squamosal = tan. Lacrimal = brown. Prefrontal = purple. Quadrate = red.

Figure 1. Chicken skull (Gallus gallus) with fused and semi-fused skull bones colorized. Postorbital = orange. Squamosal = tan. Lacrimal = brown. Prefrontal = purple. Quadrate = red.

The chicken (Gallus gallus) was recently added to the large reptile tree. Like most birds several skull bones fuse in adults. Other bones are greatly reduced, losing their old theropod dinosaur appearance. The antorbital fenestra is confluent with the orbit. The  ascending process of the jugal is unossified. Like mammals, birds have a greatly enlarged brain and cranium and that coincides with a reduced quadrate.

This is an example of how DGS (digital graphic segregation) can help illustrate a very common taxon. Earlier mistakes were examples of naiveté as I have avoided studying bird skulls until just recently.

 

 

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5 thoughts on “Chicken skull colorized

  1. Look, I said I wouldn’t comment here again, but that interpretation is just too painful. Anyone familiar with bird anatomy will see the errors, making this an indictment of DGS as opposed to a positive example of it. Most of your maxilla is the premaxilla, the prefrontal was reduced and lost long ago, and your UTF is just the top part of the LTF, etc.. The actual UTF doesn’t exist anymore, as the squamosal process was lost and the postorbital doesn’t exist either. Your Jeholosaurus from before was just as bad. I’d give you good references for the genera, but then you’d just replace your figures and act as if those were always your reconstructions (e.g. Daemonosaurus, Eosinopteryx). So I’d rather have these dinosaurs as examples of how DGS fails when you don’t have expertise in the clade.

  2. Just one more thing: the jugal being a dermal bone, it cannot be partially unossified. Dermal bones form directly, not by ossification of a cartilage; when they’re not ossified, they don’t exist. The middle part of Meckel’s bone can be unossified; the middle part of a jugal cannot, unless (trivially) if the jugal as a whole is absent.

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