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Re: Velociraptor scavenged azhdarchid pterosaur



Feeding preferences of primary carnivores have been studied in neontological 
samples, in fact.  I don't have the references handy at the moment, (my main 
library is on another drive - far too large to keep it on my laptop) but I can 
dig up a few.  In the meantime, I do agree that paleontological studies often 
take things for granted with regards to ecology that they should not - however, 
the examples you listed don't strike me as the most egregious examples.  A 
better example of a real stretch in paleontology would be the repeated claim 
that various Mesozoic predators consistently killed adults of various types.  
That is completely contradictory to the neontological observations (i.e. 
juveniles are disproportionately predated in almost all cases).  

--Mike Habib


On Mar 3, 2012, at 11:04 PM, Mickey Mortimer wrote:

> 
> Saying primary consumers rarely go for things like wing phalanges sounds like 
> "common knowledge" that I'd like to see validated by studies.  When Komodo 
> dragons kill a deer, do they all go for the belly and upper legs, or do some 
> wrench off hooves and swallow the foot whole?  As a useless anecdote, my cat 
> Little One once caught a starling and ate off its basically meatless lower 
> tibiotarsi and feet, leaving the bird to die otherwise intact besides 
> whatever wounds the initial capture caused.  There's just way too much taken 
> for granted in these feeding studies (arboreal birds are usually caught in 
> trees; partially articulated corpses usually aren't scavanged whole; 
> predators usually won't eat extremities) that needs support from the 
> neontological literature before I'd buy it as meaning something for fossils.
> 
> Mickey Mortimer
> 
> ----------------------------------------
>> From: qi_leong@hotmail.com
>> To: mickey_mortimer111@msn.com; dinosaur@usc.edu
>> Subject: RE: Velociraptor scavenged azhdarchid pterosaur
>> Date: Sat, 3 Mar 2012 20:51:53 -0700
>> 
>> 
>> Without having read the paper, I'd like to note something:
>> 
>>  Primary consumers at a carcass rarely, if ever, go for the hard, crunchy 
>> bits. They will process much of the leg meats and some of the choicier 
>> innards before leaving the carcass for the secondary consumers, who may 
>> themselves go for the bones if specialists. This is largely true of cats, 
>> however, who have narrow carnassials and are essentially hypercarnivores, 
>> leaving little bone to their diet or capability to process. Dogs, on the 
>> other hand, including their jackal cousins, are great hypocarnivores with 
>> broader carnassials and more capable jaw muscles for processing bone. So 
>> wolves tend to be able to process several stages of a carcass, unlike cats. 
>> *Velociraptor mongoliensis* (I'm assuming the specimen is *mongoliensis*, 
>> authors continue their trend of not talking about species and opting for 
>> "generic" useage instead) has very, very slender teeth and are not at all 
>> like the broader, more resistant teeth of *Dromaeosaurus albertensis*, and I 
>> am thinking their diet is ve
> ry heavily meat based, making them unlikely to be secondary or tertiary 
> consumers (scavengers). Despite this, bone bits suggest maybe they are 
> consuming already processed bone fragments (for nutrition) and/or the 
> specimen accidentally choked on the bones while processing fleshier remains 
> (which makes the argument for scavenging apt).
>> 
>>  But again, I haven't read the paper (uncorrected proof, recall -- it can 
>> still be emended!), so I am not aware of the arguments the authors made.
>> 
>> 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: Sat, 3 Mar 2012 19:35:21 -0800
>>> From: mickey_mortimer111@msn.com
>>> To: dinosaur@usc.edu
>>> Subject: RE: Velociraptor scavenged azhdarchid pterosaur
>>> 
>>> 
>>> But flesh doesn't preserve in the sediments that preserve Velociraptor, so 
>>> how do we know its stomach wasn't full of tasty pectoralis muscles and such 
>>> in addition to a wing phalanx?
>>> 
>>> Mickey Mortimer
>>> 
>>> ----------------------------------------
>>>> Subject: Re: Velociraptor scavenged azhdarchid pterosaur
>>>> From: jeff@jeffhecht.com
>>>> Date: Sat, 3 Mar 2012 21:35:29 -0500
>>>> CC: dinosaur@usc.edu
>>>> To: mickey_mortimer111@msn.com
>>>> 
>>>> I've read the paper, and the authors argue that if the velociraptor had 
>>>> brought down such a large prey, it would have eaten flesh rather than 
>>>> bone, and suggest that little flesh was present by the time the dinosaur 
>>>> got there.
>>>> 
>>>> - Jeff Hecht
>>>> On Mar 3, 2012, at 8:18 PM, Mickey Mortimer wrote:
>>>> 
>>>>> 
>>>>> Scavenging's certainly possible, but since the closely related 
>>>>> Deinonychus is generally accepted as predating Tenontosaurus (which is 
>>>>> about as heavy compared to Deinonychus as Quetzelcoatlus is compared to 
>>>>> Velociraptor), I don't see how we can favor one hypothesis over another. 
>>>>> Sure I'm assuming that the Velociraptor was found singly, but if Roach 
>>>>> and Brinkman (2007) are correct that Deinonychus did not live in packs 
>>>>> but merely aggregated to kill, then a lone dromaeosaurid with parts of a 
>>>>> large animal in its belly is just what we'd expect.
>>>>> 
>>>>> Mickey Mortimer
>>>>> 
>>>>> ----------------------------------------
>>>>>> From: MHabib@Chatham.edu
>>>>>> To: mickey_mortimer111@msn.com
>>>>>> CC: dinosaur@usc.edu
>>>>>> Date: Sat, 3 Mar 2012 19:36:28 -0500
>>>>>> Subject: Re: Velociraptor scavenged azhdarchid pterosaur
>>>>>> 
>>>>>> It is. I've seen David Hone's presentation on this study a few times 
>>>>>> now, and it was quite a big azhdarch that the velociraptor was chewing 
>>>>>> on. Highly unlikely it predated something like that.
>>>>>> 
>>>>>> --Mike H
>>>>>> 
>>>>>> Sent from my iPhone
>>>>>> 
>>>>>> On Mar 3, 2012, at 7:15 PM, "Mickey Mortimer" 
>>>>>> <mickey_mortimer111@msn.com> wrote:
>>>>>> 
>>>>>>> 
>>>>>>> Hopefully the evidence the azdarchid was scavenged is better than the 
>>>>>>> evidence the enantiornithine Microraptor ate (O'Connor et al., 2011) 
>>>>>>> was predated.
>>>>>>> 
>>>>>>> Mickey Mortimer
>>>>>>> 
>>>>>>> ----------------------------------------
>>>>>>>> Date: Sat, 3 Mar 2012 12:03:05 -0800
>>>>>>>> From: bcreisler@gmail.com
>>>>>>>> To: dinosaur@usc.edu
>>>>>>>> Subject: Velociraptor scavenged azhdarchid pterosaur
>>>>>>>> 
>>>>>>>> From: Ben Creisler
>>>>>>>> bcreisler@gmail.com
>>>>>>>> 
>>>>>>>> A new online paper:
>>>>>>>> 
>>>>>>>> David Hone, Takanobu Tsuihiji, Mahito Watabe, Khishigjaw Tsogtbaatr 
>>>>>>>> (2012)
>>>>>>>> Pterosaurs as a food source for small dromaeosaurs.
>>>>>>>> Palaeogeography, Palaeoclimatology, Palaeoecology (advance online 
>>>>>>>> publication)
>>>>>>>> http://dx.doi.org/10.1016/j.palaeo.2012.02.021
>>>>>>>> http://www.sciencedirect.com/science/article/pii/S0031018212000946?v=s5
>>>>>>>> 
>>>>>>>> Stomach contents preserved in fossil specimens provide direct evidence
>>>>>>>> for the diet of extinct animals. Such exceptional fossils remain rare
>>>>>>>> for predatory non-avian dinosaurs and each can add significantly to
>>>>>>>> our understanding of trophic interactions between various taxa. Here
>>>>>>>> we present evidence for the dromaeosaurid theropod Velociraptor
>>>>>>>> scavenging on the carcass of an azhdarchid pterosaur, with a long bone
>>>>>>>> of the pterosaur being found as gut contents of the dinosaur. Despite
>>>>>>>> previous inferences of dromaeosaurs as hyper-predators, scavenging
>>>>>>>> appears to have been an important part of their ecology.
>>>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> 
>>> 
>> 
>                                         

Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181