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Re: [dinosaur] phylogeny tyrannosauroid dinosaurs

On 10/08/2016 06:08 AM, David Marjanovic wrote:
>> I don't know what ventral and anterior margins are and what angle is
>> being measured.
>> [...]
>> 13) Premaxilla, orientation and shape of anterior margin: smoothly
>> curved and projection posterodorsally, angle between ventral margin of
>> premaxilla and anterior margin is less than 90 degrees (0); smoothly
>> curved and projecting vertically or slightly anterodorsally, angle
>> between ventral margin of premaxilla and anterior margin is equal to or
>> greater than 90 degrees (1); projecting vertically or slightly
>> anterodorsally, with a discrete inflection point between a more vertical
>> ventral portion and a more horizontal dorsal portion (2). ORDERED
>> (Brusatte et al. 2010:13).
> "Anterior" is simply "front". "Ventral" is "down" in this and most other 
> cases: venter = belly. So, the ventral margin of the pmx is the one with the 
> teeth. You hold a ruler to the front side, another along the toothrow, and 
> measure the angle between them.
> The character could also be worded as "pmx pointed (0); blunt, rounded (1); 
> rectangular or slightly overhanging (2)", but that wouldn't be precise enough 
> to deal with borderline cases. (In my work I've encountered lots of 
> characters that were worded in such imprecise ways, and lots of borderline 
> cases that were hard to score for such characters.)

Thanks.  Is there a detailed diagram f the Tyrannosaur skull anywhere so
that I can follow this paper better?


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