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Semiaquatic Fish-eating Anchylosaurid; Mother Nature M'lady. What the actual craccle did you smoke?
Topic Started: Aug 29 2016, 07:05 AM (1,663 Views)
kepperbob
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- Pure Shardana -

These ''fat lizards'' we call dinosaurs are never going to amaze us

http://en.cnki.com.cn/Article_en/CJFDTotal-JSDZ201602028.htm
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BossMan, Jake
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Son of God

Well we had herbivorous theropods only a matter of time before we had carnivorous Ornisthchians
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heliosphoros
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Very skeptical for a variety of reasons, from ignorance on how turtle shells evolved to teeth not really being different from those of other herbivorous theryophorans
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Acinonyx Jubatus
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I AM THE UNSHRINKWRAPPER!

But there's fishy gut content. Smoking gun, I think.

I have an image in my head of a tiny, matamata-style ankylosaur slurping down a Hyphalosaurus. It is an amazing image.
Edited by Acinonyx Jubatus, Aug 29 2016, 12:35 PM.
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heliosphoros
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They do admit it's ambiguous. And it could have been ingested opportunistically, like with Microraptor.
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TheNotFakeDK
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200% Authentic

The status of those "fish" as gut contents is still pretty debatable. Most, if not all vertebrate palaeontologists I've seen discuss this specimen are pretty sceptical those fish represent true gut contents, citing a hadrosaur specimen from the Dinosaur Park Formation with a gar inside it. The alternate explanations for how fish ended up in the carcass aren't adequately dismissed and are still possibilities.

I'm going to stress the point before about other vertebrate palaeontologists (e.g. Naish, Holtz, Witton, Arbour,) all maintaining scepticism until further, more conclusive evidence is provide, and I advise we do the same.
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heliosphoros
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Plus, I think their argument, based on comparisons to turtles, is very ignorant:

- It is now thought that turtle shells evolved within a terrestrial, fossorial context

- Turtles are ectothermic, ankylosaurs are endothermic. Granted, crocodiles evolved from endothermic ancestors, but there is nothing to suggest that Liaoningosaurus became ectothermic
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the dark phoenix
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King of wonderlandia

Well we have seen elephants eat fish on purpose. The dinosaur park hadro-gar could be that the gar died while scavenging the hadrosaur when it came to the bottom of a lake. If the fish this ankylosaur ate is reasonable in size compared to the mouth, then I'd guess it took a opportunity to have some extra protein. Otherwise the hadro-gar idea stands.

Either it had sushi or it was current serf former turf for some fish to eat and die in.
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CyborgIguana
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It REALLY bugs me when people take bits and pieces from a fossil record that I must stress is still VERY incompletely known, and act like it gives us the total picture of an extinct animal's life and behaviour. Because one individual may have consumed fish on one occasion does not make the entire species a semi-aquatic piscivore.
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Incinerox
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Āeksiot Zaldrīzoti

Firstly, that paper is terrible:

> Ventral plate was long established to be preserved skin, not bone.
> Comparisons with turtle shell evolution is wrong from both a dinosaur and chelonian standpoint.
> The presence of fish scales underneath the specimen's ribcage is not a sure fire indicator of diet.
> Their assumptions on tooth and jaw mechanics is outright terrible.
> Their assumptions on morphology and aquaticness all cite juvenile traits rather than ACTUAL aquatic adaptations. The genus itself is known entirely from babies only about 34cm long.
> The so called gut contents are up by the god damn arm pit, and are a black, scaly mess. More likely the scales of the ankylosaur itself.
> The weird, forked shaped tooth crowns are seen in other nodosaurids.

Secondly, I hate the argument "well, X-Herbivore has been observed eating Y-food item or partake in unusual Z-behaviour". It's a terrible argument. Yes, we've seen deer or cattle munch on baby birds, and yes, elephants have been observed fishing. But it is in absolutely no way an indicator for species norms - when a herbivore turns to omnivory, it's almost an almost guaranteed sign that the otherwise herbivorous animal in question is going through times of abnormal hardship.

So making a point that an ornithischian was a habitual omnivore purely because of we've observed one-in-a-thousand omnivorous habits in otherwise completely herbivorous animals is simply madness. Hell, a 250 page thesis by Sereno found the most likely omnivorous ornithischians, the heterodontosaurids, to have been 100% herbivores on all accounts based on tooth wear, isotopes and jaw mechanics. And remember, this was a clade everyone thought was an omnivore because of its grasping hands and ACTUAL CANINE TEETH.

So comparing a blatantly juvenile ankylosaur with a one in a million turtle-like fishing-elephant because it got preserved above some fish scales (assuming they even are fish scales) is ridiculous.
Edited by Incinerox, Aug 29 2016, 04:38 PM.
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heliosphoros
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One of these guys is also behind the romanian Thalassodromeus shenigans, right?

They should be fired for incompetence.
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Incinerox
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Āeksiot Zaldrīzoti

... What did they do to Thalassodromeus...
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Acinonyx Jubatus
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Incinerox
Aug 29 2016, 08:19 PM
... What did they do to Thalassodromeus...
I believe he was referring to Thalassodromeus sebesensis, a chunk of supposed pterosaur crest from Romania that turned out to be nothing more than a turtle plastron.
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heliosphoros
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Yes. They also made a weird claim about frugivorous thalassodromedids evolving in response to the arrival of flowering plants.

Ignoring how the idea of thalassodromedids being frugivores is entirely based on their supposed relationship to tapejarids, it's on hell of an inference.
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the dark phoenix
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King of wonderlandia

I think thalassodromedids basically developed to fit a role that azdarchids took over elsewhere. We only have one from South America so the rarity here would make sense for these guys to kinda get into that role. Quetz with a fancier head dress basically.

Also why are they comparing the diets? That's like comparing a toucan to a giant crested stork.
Edited by the dark phoenix, Aug 29 2016, 11:16 PM.
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