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Post by Infinity Blade on Apr 14, 2014 5:53:50 GMT 5
So......
It appears Gastornis' diet has become a topic of debate. Some people now believe the evidence points to it being a herbivore, whereas some people still believe some meat was in its diet. What is your opinion?
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Post by Supercommunist on Apr 14, 2014 8:37:36 GMT 5
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Post by theropod on Apr 14, 2014 14:44:46 GMT 5
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Post by Infinity Blade on Apr 15, 2014 2:27:19 GMT 5
I recall on Carnivora that there was evidence presented that the hook at the tip of the beak may very well have been present in life (purely made of keratin, thus it, along with the sheath of the beak, rotted away), not to mention you don't exactly need a hooked beak tip to consume meat (look at azhdarchids and Marabou storks), so the "lack of a hooked beak" argument may very well be invalid. The lack of talon marks in the footprints of a Gastornis also doesn't have much ground IMO, as sediments might have filled in where the talons made their mark, and if it happened to this T.rex footprint  then it could have happened to that particular Gastornis trackway. So these features may very well have been present. And of course, the skull seems to indicate that it was capable of eating meat. The isotope analysis is interesting, but I don't believe they've compared it to the bones of omnivores. So I think there's some pretty good evidence that it, at times, ate meat. Though, Taipan has a pretty odd definition of evidence, and you can clearly see that if you look in the Carnivora thread of the same topic. |
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Post by Supercommunist on Apr 15, 2014 22:35:42 GMT 5
Well the absurdly large beak of this bird may not have anything to do with feeding, but intraspecies conflict within the species. After all last time I recall hippos don't need arm sized tusks to eat grass.
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Post by Infinity Blade on Apr 16, 2014 1:15:03 GMT 5
Yeah, I don't really think you need a skull like that just to kill, let alone more likely drive away or force into submission conspecifics.
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Post by Supercommunist on Apr 16, 2014 2:43:18 GMT 5
Then there must have been some giant ass hard nuts to warrant the size of that beak.
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Post by Infinity Blade on Apr 16, 2014 3:57:53 GMT 5
Then there must have been some giant ass hard nuts to warrant the size of that beak. Or maybe it ate some meat and gnawed some bones. |
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Post by theropod on Apr 20, 2014 15:47:44 GMT 5
This is the paper about the footprints: nwgeology.files.wordpress.com/2012/11/giant-eocene-bird-footprints-paper-palaeontology.pdfThere are several reasons why the footprints are ambiguous for inferring diet: • clawmark preservation on theropod footprints isn’t even close to a certainty, due to roofing, collapse, erosion and insedimentation • we are not sure whether these were actually made by Gastornis, that’s merely an educated guess based on their geological and geographical range. The correct name to refer to those prints is Rivavipes giganteus• Its beak and jaw are massive and robust, it may not have required claws for its predatory habits, just as abelisaurids and tyrannosaurids didn’t require raptorial forelimbs. That prominent claws are so often found on the feet of herbivorous birds (ostrich, cassowary, emu...) suggests they aren’t really strongly correlated with carnivory. Even if the prints were left by the feet of a Gastornis, and even if those feet really had no claws, that doesn’t mean it couldn’t have been a facultative carnivore. The isotopic analysis remains the only compelling argument imo, but I’d like to see it elaborated before making conclusions from it. Its possible that it behaved like bears. Its also possible some populations and some species were more carnivorous than others. |
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Post by theropod on Apr 20, 2014 15:58:34 GMT 5
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