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Re: questions and comments about new research



Greetings,

Just a few quick comments on the discussion regarding my abstract for SVP.
I'll limit it primarily to items that are found just in the abstract, as the
paper is in the works.

Tim Donovan wrote:

>Andy Farke notes differences between ceratopsid and bovid horns which call
into question the supposed use of the former in intraspecific combat. In
view of J. Happ's study, isn't it likely that most ceratopsid horns evolved
as antipredator weapons? This does appear to be proof that T. rex actively
hunted ceratopsids."

Well. . .I don't necessarily discount the possibility of intraspecific
combat--I just question that every little feature of the ceratopsid skull
has an analog with bovid skulls. Bovid intraspecific combat may not be a
good model for ceratopsids. . .but then, what is a good model (aside from my
plastic ones)? :-)

I agree with David Marjanovic's statement that there is no "proof" of
anything here. The only thing my abstract really addresses is intraspecific
confrontations, anyway. Perhaps I'll throw the interspecific stuff in if
relevant. . .

And. . .I've included my abstract text below, just to clarify what exactly
the abstract is talking about (for those who haven't read it in the abstract
volume).

Best wishes,

Andy

CERATOPSID DINOSAUR CRANIAL MORPHOLOGY AND BEHAVIOR REINTERPRETED:
EVALUATING THE BOVID PARADIGM



Since their discovery over 100 years ago, ceratopsid dinosaurs have been
compared to bovid mammals, primarily due to the common presence of horns in
both groups. This "bovid paradigm" has colored interpretations of ceratopsid
behavior, sexual dimorphism, systematics, functional morphology, and
pathology. However, a critical comparison of horn morphology in bovid
mammals and ceratopsid dinosaurs has not been undertaken. Ceratopsid
postorbital horns typically point rostrally and dorsally, whereas bovid
horns point caudally or laterally. Additionally, the cornual sinus within
the postorbital horns of ceratopsids is a simple tube extending for no more
than one-third of the horn's length. This contrasts with the internally
strutted, frequently extensive cornual sinuses seen in bovid horns. These
differences have important implications for ceratopsid behavior,
particularly if it is assumed that at least some ceratopsids engaged in
intraspecific combat. Work with scale models of ceratopsid skulls allows
exploration of possible fighting modes. In addition to horn locking, skull
roof contact is an important component of combat in many bovids. Such skull
roof contact was impossible in some chasmosaurine taxa, such as Triceratops,
due to near-vertical postorbital horn orientation, the presence of a nasal
horn or boss, and limitations in skull mobility. Also, this horn orientation
would have made frontal charges and head butting (as in Bison or Capra)
nearly impossible to execute without great risk of injury. The presence of a
nasal horn in many ceratopsids also complicates the bovid analogy.
Ultimately, the wide range of ceratopsid horn morphologies illustrates the
difficulties of inferring dinosaur behavior and evolution from modern
analogues. For instance, some centrosaurine ceratopsids, such as
Pachyrhinosaurus, may have evolved flank butting from a "jousting" fighting
style. This possibly counters previously proposed, bovid-based models of
ceratopsid horn evolution, in which flank butting behavior is hypothesized
to evolve inevitably into jousting and horn locking. Many aspects of
ceratopsid horn use likely will remain unknowable.
__________________
Andrew A. Farke, Graduate Student
Department of Anatomical Sciences
Stony Brook University
T8 040 Health Science Center
Stony Brook, NY  11794-8081

Phone: 631-444-7364

Home address:

17 Union Street, #2
Port Jefferson Station, NY  11776

Phone: 631-928-1630
E-mail: andyfarke@hotmail.com