Weights of Large Predatory Dinosaurs

[Lizerd]

So I found an article(below) that suggested that T.rex was larger in mass and weight than Giganotosaurus was and possibly Spinosaurus. I do not know how legitimate it is but it definitely is an interesting subject that brings up a fair point. What would this mean? It would likely suggest something on their lifestyles. Any information on the articles legitimacy and possibilities of what this would mean would be appreciated, enjoy the conversation!

http://www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013
the article

[spinosaurus1]

that's a pretty old blog post, but the results still remain legitimate. from the specimens that have, the largest Tyrannosaurus individuals are all qualified to be the heaviest non- avian theropods discovered.

[Lizerd]

So if this brings in such a large point, why is it not well known?

[spinosaurus1]

So if this brings in such a large point, why is it not well known?

depends on what you mean by well known. in terms of everything pertaining to paleontology and paleo- enthusiast, tyrannosaurus being among the heaviest theropods ever discovered isn't anything new and been known for quite a while. tyrannosaurus had some of the widest torsos out of any theropod. the insane girth makes them proportionally much bulkier than other theropods of similar sized.

the reason why it isn't too generally well known to the public is the fact that spinosaurus, giganotosaurus, and even carcharodontosaurus had at one point or another been publicized as newly discovered dinosaurs bigger then tyrannosaurus.

[Lizerd]

Makes sense, also I am probably really terrible at reading the news 

[suspsy]

Without a complete skeleton of Spinosaurus, it's impossible to say if T. rex was heavier. But if the Ibrahim/Sereno restoration is indeed accurate, then the answer would be yes. Spinosaurus would still win out in terms of length though, just as how the reticulated python edges out the heavier green anaconda.

[Simon]

What TRex loses (slightly) in terms of length vs the largest Allosauroids and more decisively vs the largest Spinosaurids it more than makes up in terms of width.  Seen from above side-by side it is striking how much more robust and wide a full grown TRex was vs, say, a Giganotosaurus, or Spinosaurus ... so the largest TRex specimens are still, to the best of our knowledge, the "King" terrestrial predators...

... of ALLLLL TIIIMEEE!!!! 

[Lizerd]

*Casually picks up t.rex and giganotosaurus toy* whispers to them: you lied to me.

Pretty interesting still about how t.rex was bulkier. But what would it use this extra muscle for?

[Andreioli]

Hey, the 2016 Wild Safari T. rex weighs 471 grams while the 2016 Wild Safari Giganotosaurus only weighs 362 grams and I believe they are the same scale to each other.
'Nuff said

[Lizerd]

You're right! O.o
They did their reading then

[CityRaptor]

Well, given all the tough and often armored prey animals Tyrannosaurus lived with, a little extra bulk seems like a good thing to have. I can also imagine that they might have used it to fight each other.

[Lizerd]

Well, given all the tough and often armored prey animals Tyrannosaurus lived with, a little extra bulk seems like a good thing to have. I can also imagine that they might have used it to fight each other.

Thanks for the information! That would make sense!

[Neosodon]

I think Spinosaurus had greater bone density. So it could be that Spinosaurus was the heaviest while T. rex had the largest volume. Now that would really heat up the debate between the Spinosaurus and T. rex fanboys. 

Fanboy 1: "Spinosaurus was totally the most awesome. It was the heaviest of any carnivore dinosaur ever!"

Fanboy 2: "But T. rex would totally have won in a fight. It had the larger body size!"

[Simon]

I think Spinosaurus had greater bone density. So it could be that Spinosaurus was the heaviest while T. rex had the largest volume. Now that would really heat up the debate between the Spinosaurus and T. rex fanboys. 

Fanboy 1: "Spinosaurus was totally the most awesome. It was the heaviest of any carnivore dinosaur ever!"

Fanboy 2: "But T. rex would totally have won in a fight. It had the larger body size!"

There's really little left to be debated regarding a head-to-head contest between these monsters.  Anatomy is instructive on the point. 

TRex had the most powerful jaws/skull that was designed to crush bone.  Neither Spinosaurid nor Allosauroid jaws/skulls could match that.  One had a thin long skull/jaws for catching fish and the other one a narrow skull/jaws designed for slicing flesh off of sauropods.

In a head-to-head "stand-off" contest between two full-grown predators, the head or neck area would be the most likely point of initial engagement.

TRex could probably survive a head bite from either of the other two critters (we know that TRexes survived bites from other TRexes based on fossil finds).  The reverse is not true. If a TRex got its jaws around the jaws/skull of a SPinosaurid or Allosauroid the result would be broken bones and the game would be over.  Advantage - TRex 

[Lizerd]

I think Spinosaurus had greater bone density. So it could be that Spinosaurus was the heaviest while T. rex had the largest volume. Now that would really heat up the debate between the Spinosaurus and T. rex fanboys. 

Fanboy 1: "Spinosaurus was totally the most awesome. It was the heaviest of any carnivore dinosaur ever!"

Fanboy 2: "But T. rex would totally have won in a fight. It had the larger body size!"

This will sound weird, but even dense bone is lighter than muscle. Muscle is REALLY heavy, so the more muscle, the heavier the animal. Take us humans (and lizardmen, nah just kidding), only around 15% of our weight. Anatomy is weird...

[PumperKrickel]

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[Halichoeres]

That's probably true for most dinosaurs because of all the pneumatization. But medullary bone in mammals is probably around 1.5 kg/m³, whereas muscle is only a little denser than water, which makes sense because muscle is mostly water, so around 1.07 kg/m³. Pneumatization can make a huge difference, though: a typical bird's skeleton weighs less than its feathers.

[amargasaurus cazaui]

I seldom pay much attention to theropod discussions or for that matter invest in them mentally but this one does require a few points to be made.....We have elements of something along the lines of 50-75 Tyrannosaurus rex specimens, in various stages of completeness.  The sampling allows us to fairly understand the size and general outlines of this particular animal fairly well. Quite true...however...then attempting to compare it to animals like Spinosaurus for which there are precisely no known skeletons and only scattered very fragmentary remains, and a holotype blown to dust during world war 2, or an animal with only one known specimen...i.e Giganotosaurus , which is also incomplete  , is somewhat........questionable.
        Until we have a better sampling of evidence from other species, it is perhaps best to say , that tyrannosaurus rex was , given the limited evidence available one of the larger predators.
   It is possible the specimens we do have for Spinosaurus, as well as Giganotosaurus might represent smaller samples within their size range, and larger members were common...we do not know for sure. There is nothing wrong with saying...we do not know.....we don't. Until we have more evidence, best keep an open mind . Remember all those fragmentary large predator elements discovered that lack descriptions or proide us only with a glimpse that there were likely  larger predatory dinosaurs, be it allosaurid, or spinosaurid.

[ITdactyl]

I'm curious about 2 things related to this topic:
1. Do tyrannosaurs regularly attain Sue size upon maturity or are there factors that also limit their size (similar to how Salties exceeding 15ft are now rare due to human related factors)
2. do other theropods display different morphotypes, similar to how Tyrannosaurs "seem" (big emphasis on seem) to have the gracile and robust morphs.

[Lizerd]

I'm curious about 2 things related to this topic:
1. Do tyrannosaurs regularly attain Sue size upon maturity or are there factors that also limit their size (similar to how Salties exceeding 15ft are now rare due to human related factors)
2. do other theropods display different morphotypes, similar to how Tyrannosaurs "seem" (big emphasis on seem) to have the gracile and robust morphs.

So for the first question can be answered as follows, likely yes. However due to the fact that we can be fairly certain Sue was an adult, we can also assume that it would have been still growing, as all reptiles grow all their lives (at least at different rates), so an older t.rex would be massive. However there are things that can stump an animals size. An example with humans (not the best comparison) is how in recent times we are massive compared to our ancestors even a few hundred years ago. Why? Access to food, and disease. Lack of food and disease can shorten an animal. This does not just apply to humans but all animals. Take crocodiles, in the wild they do get large, but in captivity they can get giant except for a few bizarre exceptions, such as Gustave the man eater. We can assume on the off chance that in captivity a T.rex could grow to be larger, maybe about 5 feet larger and definitely bulkier. Take say leopard geckos, a wild one is smaller but take my captive one is over 10 inches. Captivity can make (usually) an animal much much larger. So to recap: we can assume that an average adult T.rex would be similar size to Sue (if we can assume Sue is an adult), perhaps smaller or bigger. An older individual would be larger. But a captive T.rex would be far larger (and live much longer).

As for your second question, I really don't know enough information to answer that. My guess is the sizes were for hunting different prey.