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Re: Khaan's paleoecology



Luc Bailly (aspidel@infonie.be) wrote:

<I'm beginning a _Khaan_ drawing, and I think I'll draw it in quite "steppic" landscape, eating
_Gingkoales_ or conifer seeds.


Will it work like that?>

No. The Ukhaa Tolgod locality is a dune field with outcroppings, most likely, and would have
resembles parts of the northern Sahara, edges of ergs, with a little more water. Plants are not
well-studied, but appear to be more scrub-land or rocky-desert types.

Ephedra!

If you've ever been in the American West, you've probably seen it. Very cool, weird non-angiosperm (gnetophyte) which looks like a brushy bunch of green twigs growing out from woody sticks. Chinese have used it for a long time for the stimulant, known of course as ephedrine. Apparently, in Nevada, where just about everything else is legal (gambling, prostitution, beer that isn't watered down like in Utah), ephedrine is *illegal* w/o prescription. Something to keep in mind if you pick it up over the counter there. Very bizarre as it's also known as Mormon tea, I guess the Church disapproves of caffeine but not ephedrine?; anyhow it makes a very nice tea if you boil the stems with a bit of lemon and some honey as a sweetener. Unfortunately, although it is a cool plant it is impossible to root from cuttings and difficult to transplant, which is weird considering that it grows around alkali flats and in the Chihuahuan desert and all. If it's not the state tree (well, shrub) of Utah, it ought to be.
That makes me think... the stuff has a heck of a distribution, and it's probably been around a while, so its a decent bet its been growing in deserts for a long time. I wonder if oviraptorosaurs chewed on the stuff, they look capable of handling some pretty tough vegetation; those jaws clearly were designed for a very high bending resistance. It's pretty obvious looking at dicynodonts that oviraptorosaurs were up to the same thing (like Cracraft argued), there are a number of remarkable convergences in the jaw structure, palate, and jaw articulation. Which would be handy if we figure out what dicynodonts were up to... Ephedra doesn't look too tasty but ground sloth coprolites have been found full of the stuff and I think cattle will gnaw on it, it's also very abundant where it grows. "Abundant" in the sense that it may not be that abundant but not much, and sometimes nothing, else is growing with it. Welwitschia-type plants? Welwitschia is an interesting one, its habit of growing from the base as in grass looks like an anti-grazing adaptation. Unless its primitive or something, many monocots, e.g. aloe do the same thing... it's too damn bad it's so hard to grow since it's an extraordinarily cool plant. 6$, aridlands.com, but don't try it without being able to maintain constant high temperatures (100+ during the day is optimum with a cool night) and daily waterings. Seeds available by the dozen or 100 from saseeds.co.za. Do either of these guys have any fossil record at all?


        Other notes:

First reference on secondary flightlessness in dromaeosaurs is Paul, 1984; I think the journal is Hunteria. Also check out Kurzanov's suggestion that the oviraptorosaur Avimimus was feathered and up to something that may have ultimately given rise to flight; it is possible to find English versions of some of his short articles on the animal. Often review articles on flight origins are pushing an agenda rather than conducting a review in my opinion (minority views are often simply treated as if they do not exist) but check out Witmer's for actual review of the problem, very thorough.

Teeth in alvarezsaurs are small, straight, unserrated. They are present pretty extensively in the dentary. They are absent from the posterior maxilla, where instead a sharp bony ridge (beak?) was present. I'm not sure if there were any in the jaw tips. Sorta suspect not; to the extent that they are toothed (myrmecophages are weird in either eliminating teeth, or actually increasing them- giant armadillo has one of the highest tooth counts in mammals), myrmecophages tend to be gap-toothed, e.g. sloth bear, numbat. Numbat is kind of cool in that the incisors move laterally to eliminate teeth from the front of the mouth, rather than eliminating any teeth, the molars have multiple simple, conical cusps lined up and therefore function as a series of simple teeth. Incipient myrmecophagy for David Letterman is supported, but as in the aardwolf appears to lack the fossorial specializations to open termite mounds and therefore may specialize on colonial insects exposed on surface. Feeding behavior of the talk-show host in natural habitat will be required to confirm or reject this biomechanical scenario.