was a t-rex a hunter , scavenger or both

[rock]

i would have to say that t rex was both a hunter and scavenger because there are bite marks on other dinosaurs like triceratops indicating that t-rex was a carnivore , not  omnivore and definitely not a herbivore. anyhow if we look at this image i found it clearly shows that the t-rex took a bite out of the triceratops near the horn area


you could say that this could have been a bite from a t-rex eating a dead triceratops , but what this tells to me is that since there was a bite on the triceratops area around the horn this would say there was a struggle  , if the t-rex was scavenging it would have bit near the stomach area to get to the juicy guts and not near the horn [most likley to disable it]. as for evidance t-rex is a scavenger is that t-rex had a very strong bite but likley rarley hunted alone as new evidance suggests that they were quite slow and not the best for chasing after fast herbivores like triceratops , however t-rex had a very large brain indicating that they were very smart animals and hunted in packs with young t-rex chasing down triceratops and then the adults deilvering the fatal bite although it is more likley that lone t-rex did scavange on dead bodies insted of hunting.

[dinosauria101]

IMO, it would've preferred scavenging, but hunted as necessary

[rock]

May 27, 2019 22:25:08 GMT 5 dinosauria101 said:

IMO, it would've preferred scavenging, but hunted as necessary

i think it was both but more of a hunter then a scaveneger

[Infinity Blade]

@rock

The one source I can find for that image says that that injury was caused by a Triceratops horn.

But you're definitely right that Tyrannosaurus would have done both, scavenging when the opportunity arises and hunting when that option was not available. You're also right that there is direct evidence of hunting by Tyrannosaurus in the form of healed bite marks on giant herbivorous dinosaurs.

However, I would like to make a note on which it would have had to rely on more. There was a 2011 study that found that Tyrannosaurus rex (which you could apply to other similarly gigantic theropod dinosaurs by extension) would have been unable to compete with smaller carnivores in scavenging. Based on calculations of how much ground an adult Tyrannosaurus would have covered daily, carcass distribution, and the percent distribution of carcass size (i.e. just under half of all herbivorous carcasses in the T. rex-community would have weighed between 55-85 kg), the authors predicted that it would have taken Tyrannosaurus on average* just under 6 days to find a 75 kg carcass. It would have taken ~55 days to find a 700 kg carcass. It would have taken, on average, over a full year to find a carcass weighing 5 tonnes, and five times that amount to find a 25t one! On average, smaller theropods (and any other smaller scavengers in the ecosystem; e.g. azhdarchids) would have gotten to carcasses first and fully consumed them before T. rex even got there. Even if we ignore competition from smaller scavengers, the calculations for carcass search rates and detection ranges indicate that carcasses would have substantially, if not completely rotted by the time T. rex found them (Carbone et al. 2011).

*So there would, of course, be below average instances where it would not need to travel as far and take as long to find a carcass of a given size. However, the fact that an adult T. rex would have to rely on such below average instances to get meals out of scavenging just goes to show you how unreliable it was as a subsistence strategy.

A 2016 study suggests that, from an energetics standpoint, the ideal size range for scavenging in theropod dinosaurs was between 27 and 1,044 kilograms; those below or above this threshold would not have been as efficient at scavenging and would have been less likely to be driven by such behavior (Kane et al. 2016). Obviously, a fully grown Tyrannosaurus is well out of this range, easily surpassing the upper end by six, if not seven or over eight fold. Another study with the same authors (plus another one) from the same year seems to corroborate this view (Kane et al. 2016).

So yeah, Tyrannosaurus would have hunted when need be, and scavenged when the opportunity arose. Although, from the looks of it, scavenging opportunities would have been much less common than times when hunting was necessary, making, in Kane et al.'s own words, "a specialized hyperpredator role more likely".

[rock]

May 27, 2019 23:49:49 GMT 5 Infinity Blade said:

@rock

The one source I can find for that image says that that injury was caused by a Triceratops horn.

But you're definitely right that Tyrannosaurus would have done both, scavenging when the opportunity arises and hunting when that option was not available. You're also right that there is direct evidence of hunting by Tyrannosaurus in the form of healed bite marks on giant herbivorous dinosaurs.

However, I would like to make a note on which it would have had to rely on more. There was a 2011 study that found that Tyrannosaurus rex (which you could apply to other similarly gigantic theropod dinosaurs by extension) would have been unable to compete with smaller carnivores in scavenging. Based on calculations regarding how much ground an adult Tyrannosaurus would have covered daily, carcass distribution, and the percent distribution of carcass size (i.e. just under half of all herbivorous carcasses in the T. rex-community would have weighed between 55-85 kg), the authors predicted that it would have taken Tyrannosaurus an average of just under 6 days to find a 75 kg carcass. It would have taken ~55 days to find a 700 kg carcass. It would have taken, on average (so not every single time, of course), over a full year to find a carcass weighing 5 tonnes, and five times that amount to find a 25t one! On average, smaller theropods (and any other smaller scavengers in the ecosystem; e.g. azhdarchids) would have gotten to carcasses first and fully consumed them before T. rex even got there (Carbone et al. 2011).

A 2016 study suggests that, from an energetic standpoint, the ideal size range for scavenging in theropod dinosaurs was between 27 and 1,044 kilograms; those below or above this threshold would not have been as efficient at scavenging and would have been less likely to be driven by such behavior (Kane et al. 2016). Obviously, a fully grown Tyrannosaurus is well out of (particularly above) this range. Another study with the same authors (plus another one) from the same year seems to corroborate this view (Kane et al. 2016).

So yeah, Tyrannosaurus would have hunted when need be, and scavenged when the opportunity arose. Although, from the looks of it, scavenging opportunities would have been much less common than times when hunting was necessary, making, in Kane et al.'s own words, "a specialized hyperpredator role more likely".

good findings and thank you