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Re: Micropredatory Microraptorids (was Microraptor Wings (and sauropods()



When you think about it, the idea isn't all that 'out there'.  In
essence, it hypothesizes that microraptorines had behavior similar to
that inferred for larger dromaeosaurids like _Velociraptor_ and
_Deinonychus_ against large prey (e.g., _Protoceratops_,
_Tenonontosaurus_).  In the case of _Velociraptor_ and _Deinonychus_,
the predator leaped onto the prey, which was grasped with both hands
at once, while the jaws and feet (especially the sickle-claw) went to
work on the prey, to subdue it.  Alternatively, the sickle-claws were
used to grip prey (Manning et al., 2006 - which posits that the
sickle-claws served as crampons, to hold the predator in place) e.g.,
see 
http://scienceblogs.com/tetrapodzoology/2008/08/proof_dromaeosaurs_climbed.php


If microraptorines leaped onto sauropods, it was obviously not to
bring it down - and the arms and feet (aided and abetted the
sickle-claws) were simply used to to hang on, rodeo-style.  The arms
and feet could be used to grab onto the neck, and hold the
microraptorine in place while the jaws plucked off large parasites -
or the microraptorine bit through the hide to get a mouthful of flesh
or blood, meaning the microraptorine was itself a sauropod parasite.
In typical dromaeosaurid fashion, the arms and hands of
microraptorines were not very useful for grasping small objects, only
relatively large ones (using both hands at once) - such as the trunk
of a tree, or the neck or limb of a sauropod.


The aerial abilities of the microraptorine would be used to glide down
to the sauropod (such as from the vantage of trees), and/or to return
the microraptorine to the ground after the meal.


Hard proof could be hard to come by... unless a _Microraptor_ is found
fossilized with its arms wrapped around the neck of a _Dongbeititan_,
for example.





Cheers

Tim









On Wed, Jul 20, 2011 at 10:53 AM, Jonas Weselake-George <ee555@ncf.ca> wrote:
>
>
> Oddly enough, this is connected to a real thesis.
>
>
> Some time ago it occurred to me that microraptorids would be suitable
> micropredators (or groomers).
>
> A number of features support this:
>
> - They have the potential to glide from higher trees onto passing
>  animals
>
> - The tapering foot claws would be much less likely to be damaged on
>  hide than on bark
>
> - The stiff tail could be a crucial adaptation: Allowing the animal to
>  rotate once jumping (assuming an upward facing posture) off of its
>  host and glide out of range of footfalls
>
> - All faunas containing microraptorids have at least one group of
>  herbivores which would be unable to roll over easily
>
>
>
> Research that could test this idea:
>
> - Estimations of the mass, moment and direction of movement of the tail
>  to see if it would have been useful for re-orienting the body
>
> - Examining the bio-mechanics of microraptorid claws against hide
>  (smaller scale physics than the Deinonychus studies)
>
>
>
> It would be interesting to try and examine the micropredatory vs.
> groomer hypotheses.
>
> However, I am not sure how this could be done. If they were
> micropredators, than one might expect to see armouring geared to weak
> but price attacks in herbivores found in the same formations. However,
> the micropredators might still have found some weak spots where their
> small and numerous teeth might have been adapted for raking tissues and
> releasing blood. The groomer hypothesis would be even harder to test -
> But, we can say that it seems plausible that backs, as well as trees,
> may have been available for the evolution of flight.
>
>
> Feel free to take this over if your interested in it,
>
>
> -Jonas Weselake-George
>
>
>
> ----- Original Message -----
> From: Jaime Headden <qi_leong@hotmail.com>
> Date: Tuesday, July 19, 2011 3:53 am
> Subject: RE: Microraptor Wings (and sauropods(
>
>>
>>   You misunderstand how soft, squishy, and weak sauropods, and by
>> extension their skulls, are? Do you not notice that their bones
>> are sponges? That's what the news reports all say, so it must be
>> true! If I take a sponge in my hand, does it not squish? Squeeze
>> it, does gushy brainmatter not pour forth? Much like whale bone,
>> they are not but fluids with elastic "bone" cases surrounding
>> sections of them, coated in blubber and goo!
>>
>>   Plus, they're not as cool as oviraptorosaurs.
>>
>> Cheers,
>>
>>  Jaime A. Headden
>>  The Bite Stuff (site v2)
>>  http://qilong.wordpress.com/
>>
>> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
>>
>>
>> "Ever since man first left his cave and met a stranger with a
>> different language and a new way of looking at things, the human race
>> has had a dream: to kill him, so we don't have to learn his
>> language or
>> his new way of looking at things." --- Zapp Brannigan (Beast With
>> a Billion Backs)
>>
>>
>> ----------------------------------------
>> > Date: Tue, 19 Jul 2011 07:10:11 +0000
>> > From: keenir@hotmail.com
>> > To: qi_leong@hotmail.com; dinosaur@usc.edu
>> > Subject: RE: Microraptor Wings (and sauropods(
>> >
>> >
>> >
>> >
>> >
>> > > From: qi_leong@hotmail.com
>> > > To: keenir@hotmail.com; dinosaur@usc.edu
>> > > Subject: RE: Microraptor Wings
>> > > Date: Mon, 18 Jul 2011 21:27:54 -0600
>> > >
>> > >
>> > > Perhaps, like some wasps, it used its claws to "probe" certain
>> parts of the sauropod brain and steered it like the sauropod was a
>> giant zombie bus. Theropods rule, sauropods (literally!) drool.
>> This zombie-esque quality, unfortunately, likely resulted in an
>> unhealthy taste for [sauropod] brains, which explains the relative
>> lack of preserved sauropod skulls. So sad.
>> >
>> > Very.
>> >
>> > But one question lingers: I thought sauropods only had weak
>> teeth suitable for nipping leaves off trees. Surely the best
>> supporting evidence would be sauropod teeth getting stronger and
>> more durable after the rise of microraptors/protoavians.
>> >
>> >
>> >
>>
>>
>