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Re: [dinosaur] Fwd: Re: T. rex hunting Alamosaurus




On Jul 1, 2019, at 5:59 PM, Gregory Paul <gsp1954@aol.com> wrote:

Large predators do attack large healthy adult prey fairly often.

Do you have a reference for this? All of the ecology literature I am familiar with indicates that predation on healthy adults is quite rare. Hone and Rauhut (2010) did a nice job of summarizing these modern trends in the context of implications for theropod feeding, specifically, and they concluded that predation on adults was probably rare. It also seems like attacking adults would be rather odd given the sea of vulnerable, mostly unguarded juveniles.

From a functional anatomy perspective, theropods donât really seem to have the traits that weâd expect from big prey specialists, either. Iâve noted this before on the list, and it seems to be a deeply unpopular notion for some reason, but I am so far unconvinced by the theropod super predator concept.

We know that Tyrannosaurus attacked an adult Triceratops that was healthy enough to survive the attack

Yes, but the tyrannosaur might not have survived that attack. A major source of mortality for subadult predators in the modern world is poor prey choice leading to injury. 

It is quite possible that the Paluxy trackway records an acrocanthosaur attacking an adult brachiosaur, possibly by biting its tail base to try to disable leg retractors.

Also quite possible that it was merely passing that way and had no intention of trying its luck against something that could murder it easily. Itâs highly speculative either way. Though admittedly fun to consider!


General point for this thread: The mechanical performance of large sauropods is chronically underestimated. The poor critters seem to be constantly reconstructed as super sluggish things that could barely move or react. But a kick, neck slam, or tail strike from a sauropod was probably reasonably fast and had a huge reach. I expect that most species were very dangerous when provoked. 

Cheers,

âMBH


-----Original Message-----
From: Dann Pigdon <dannj@alphalink.com.au>
To: dinosaur-l <dinosaur-l@usc.edu>
Sent: Mon, Jul 1, 2019 7:01 pm
Subject: Re: [dinosaur] Fwd: Re: T. rex hunting Alamosaurus


A 6 -10 tonne adult tyrannosaur likely wasn't agile enough to avoid a well-placed kick, tail slap or neck
bump from an adult sauropod either.

The sauropod would not only have the advantage of mass, but also of stability (four legs verses two). A
non-fatal glancing blow from a tyrannosaur would be unlikely to knock a large sauropod over (or even faze
it much), whereas a glancing blow from a large adult sauropod could completely topple a multi-tonne
biped, resulting in an incapacitating injury that might ultimately prove fatal to the predator.

Even if tyrannosaurs attacked as a group, with younger and more agile members harrying the adult
sauropod to exhaustion until the adult tyrannosaurs dared to approach to finish the prey off, there would
still have been the problem of separating the sauropod from its herd members first. Otherwise the
tyrannosaur group would lose their numerical advantage. A sauropod that was already sick or injured in
some way might lag behind the herd and become vulnerable to such a coordinated attack, however a
health adult sauropod accompanied by other healthy adult individuals would likely have been all but
immune to predation.

--
Dann Pigdon


On Mon, Jul 1st, 2019 at 5:02 PM, Poekilopleuron <dinosaurtom2015@seznam.cz> wrote:

>
> Yes, that sounds reasonable. But what if T. rex was just too hungry to wait
> any longer? Perhaps its mighty jaws could speed that process up a little.
> After all, 50+ tonne alamosaurs werenÃÂt agile enough to avoid a well-placed

> bite? Tom

>> If I was a tyrannosaur, I'd follow the herd around until something else
>> brought an adult down for me (disease,
>> injury, old age, etc). Such an event would have been the land-based
>> equivalent of a whale fall.
>>
>> --
>> Dann Pigdon