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Re: Archaeopteryx teeth, claws and their TV viewing habits



>>1. Archaeopteryx had feathers identical to those of modern birds, whereas
>>theopods had none
>
>   I thought I read/saw somewhere that Archaeopteryx feathers lacked a
>feature in modern birds that allows the feathers to lock with each of its
>neighbors.  Anybody know if this is true?  (We need not address whether
>theropods in general had feathers.  I know what to say about that.)

The microstructure of Archie's feathers have all the same features as modern
birds'.

>>2. Archaeopteryx had a hypertrophied furcula (fused clavicles);theropods do
>>not have one
>
>   The modifier "hypertrophied" throws me a bit.  Is this modifier
>necessary, or would all furculae be considered "hypertrophied?"  I'm curious
>if the use of the word "hypertrophied" would cause problems in trying to use
>the furculae of Oviraptors and Allosaurs as a rebuttal.

As you note, several theropods have a furcula.  Archie's does appear to be
proportionately larger to its size than do those of other nonavian
theropods, but this may be a size feature.

>>3. Manus claws of Archaeopteryx differ markedly from those of predatory
>>dinosaurs (Feduccia, 1993)
>
>   Anybody know if this is true?  If so, does it really matter?  I thought
>there were all sorts of different claws in the Dinosauria.  I'm also curious
>as to how similar the claws are to Dromaeosaurid claws.

Patently, and demonstrably false.  For those features which can be measured
in Archaeopteryx, the claws fall well with the nonavian theropod range.
Feduccia's hypotheses, while interesting, do not stand up to further
evaluation, as I showed at SVP a year or two ago.  These data will be
published eventually, but I have other priortities right now.

>>4. Archaeopteryx had a fully reversed hallux, the large rear toe, with a
>>strongly curved claw on the ungual phalanx, which is typical of modern
>>perching birds and unlike any known theropod dinosaur (Feduccia, 1993)
>
>   I don't think we need to rehash all of this, but I would like to know
>what "ungual phalanx" means, and whether other dinosaurs had them.

The ungual phalanx (a repition, since the ungual is simply the last phalanx,
aka the claw or hoof) is almost fully reversed in some theropods (take a
look at the T. rex footprint some time!).  However, it is more fully
reversed in Archie and later birds.  Wow, amazing: Archaeopteryx shares a
few characters with other birds not shared with its outgroups!

(This is, of course, no surprise, if Archaeopteryx is ancestral to later
birds).

>>unserrated, the waist present, the root expanded, and the tooth replacement
>>resorption pit oval to circular. On the other hand, in the reptiles
>>Pseudosuchia and Coelurosauria, the crowns were serrated, the waist absent,
>>the root straight and unexpended, and tooth replacement resorption pit
>>elongate (Brown 1987, p. 78)
>
>   I have no bloody idea what any of this means.  Comments?  Did all
>dinosaurs have the same kind of tooth replacement mechanism, thus making
>this important/unimportant?

This means the author has never looked at the diversity of coelurosaur
teeth!!  Some taxa (Compsognathus, Ornitholestes to a certain degree, some
dromaeosaurids, etc.) have tooth forms identical save for size to those of
Archaeopteryx.

Basically, this goes to show that the people who want to reject the
coelurosaurian ancestry of birds are happy and willing to ignore the
pertinent evidence.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084