Welcome Guest [Log In] [Register]
Welcome to Carnivora. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,163 Views)
Wolf Eagle
Member Avatar
M E G A P H Y S E T E R
[ *  *  *  *  *  * ]
Tyrannosaurus rex
Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 65.5 million years ago.[1] It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators. By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running in paleontology. Tyrannosaurus rex was one of the largest land carnivores of all time; the largest complete specimen, FMNH PR2081 ("Sue"), measured 12.8 metres (42 ft) long, and was 4.0 metres (13.1 ft) tall at the hips. Mass estimates have varied widely over the years, from more than 7.2 metric tons (7.9 short tons), to less than 4.5 metric tons (5.0 short tons), with most modern estimates ranging between 5.4 and 6.8 metric tons (6.0 and 7.5 short tons). Packard et al. (2009) tested dinosaur mass estimation procedures on elephants and concluded that dinosaur estimations are flawed and produce over-estimations; thus, the weight of Tyrannosaurus could be much less than usually estimated. Other estimations have concluded that the largest known Tyrannosaurus specimens had a weight exceeding 9 tonnes.

Posted Image

Spinosaurus aegyptiacus
Spinosaurus is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. Spinosaurus may be the largest of all known carnivorous dinosaurs, even larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres (41 to 59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. The skull of Spinosaurus was long and narrow like that of a modern crocodilian. Spinosaurus is thought to have eaten fish; evidence suggests that it lived both on land and in water like a modern crocodilian. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display. Dal Sasso et al. (2005) assumed that Spinosaurus and Suchomimus had the same body proportions in relation to their skull lengths, and thereby calculated that Spinosaurus was 16 to 18 meters (52 to 59 ft) in length and 7 to 9 tonnes (7.7 to 9.9 short tons) in weight. The Dal Sasso et al. estimates were criticized because the skull length estimate was uncertain, and (assuming that body mass increases as the cube of body length) scaling Suchomimus which was 11 meters (36 ft) long and 3.8 tonnes (4.2 short tons) in mass to the range of estimated lengths of Spinosaurus would produce an estimated body mass of 11.7 to 16.7 tonnes (12.9 to 18.4 short tons).

Posted Image
Edited by Taipan, Apr 24 2015, 10:10 PM.
Offline Profile Quote Post Goto Top
 
Replies:
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
I think that no better scaling than Dal Sasso has been done yet. It may be weak, but it is still the strongest assumption we have got.

This animal may or may not be close to the type of S. aegyptiacus. But the point is, assuming it isn’t would be entirely hypothetical.
Offline Profile Quote Post Goto Top
 
Vobby
Member Avatar
Omnivore
[ *  *  *  *  * ]
theropod
Feb 11 2014, 04:50 AM
I think that no better scaling than Dal Sasso has been done yet. It may be weak, but it is still the strongest assumption we have got.

This animal may or may not be close to the type of S. aegyptiacus. But the point is, assuming it isn’t would be entirely hypothetical.
Both your sentences, especially the first, are obviously debatable. I feel that discussing them here would be kinda off topic, since it is not Spinosaurus aegyptiacus what we are talking about, and to see if MSNM would win or loose against T. rex is not the most important thing to find out about it...
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
My point was that this thread was S. aegyptiacus sensu Dal Sasso et al 2005=S.(cf) aegyptiacus, not S. aegyptiacus sensu Headden 2014
Ergo I am discussing the former.
Offline Profile Quote Post Goto Top
 
Vobby
Member Avatar
Omnivore
[ *  *  *  *  * ]
Well, as you please... but I don't get what this the point in debating the fight between a giant theropod and a rostrum with an unknown body.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
Does "S. aegyptiacus sensu Dal Sasso et al 2005" actually exists? they never referred the rostrum to S. aegyptiacus per se, cf is the latin confer abbreviated and means compare, from what I understand, in taxonomy it implies the identification is uncertain and it needs to be compared to the taxon mentioned to resolve its affinities.
Edited by blaze, Feb 11 2014, 06:49 AM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
@blaze: thed did. tentatively, but they write the following:
Quote:
 
The only other specimens of Spinosaurus for
which skull material is known are the type specimen of S. aegyp-
tiacus, which includes a piece of maxilla with four alveoli (not
figured but described by Stromer [1915]), and a referred maxil-
lary fragment described by Buffetaut (1989). S. aegyptiacus is the
only species of Spinosaurus that we regard as valid and to which
we refer the new specimens MSNM V4047 and UCPC-2. First-
hand comparison of the craniodental material previously re-
ferred to Spinosaurus (isolated teeth [Bouaziz et al., 1988]; max-
illa fragment [Buffetaut, 1989]; snout [Taquet and Russell, 1998];
dentary fragment [Buffetaut and Ouaja, 2002]) with that of
MSNM V4047 and UCPC-2 do not reveal significant differences
within this genus. At present there is no evidence for the occur-
ring of more than one species of Spinosaurus in the Albian-
Cenomanian of North Africa.

I know that’s what I’m always writing, but differences remains entirely hypothetical. Parsimony would suggest to us that these were of the same taxon, or at least closely related and similar.

@vobby
You can always use the argument that taxon X is too fragmentary to debate it. But where do you draw the line? Half a skull is too little? But from a single vertebra you think we can deduce a reliable weight?
Later you might see that you were missing out on something right in front of your eyes, that you could actually have inferred something about. My point that this thread is about MSNM V4047, the animal estimated at 16-18m, just as much as IPHG VIII 1912 19, the one estimated at 12.5-14m, still stands. That is the animal that I will discuss, or rather the animal that for now I have discussed sufficiently.
Edited by theropod, Feb 11 2014, 07:39 AM.
Offline Profile Quote Post Goto Top
 
theropod
Member Avatar
palaeontology, open source and survival enthusiast
[ *  *  *  *  *  *  *  * ]
I’m getting a bit tired of this.

Let’s put it this way:
I disagree that one could just extrapolate body masses from centrum diameter, due to the many factors complicating this, especially in this case, arriving at estimates like 45% the weight of FMNH PR 2081 for the holotype of S. aegyptiacus.
I wholeheartedly agree with you that a tyrannosaurine would be a superior opponent to a spinosaurine that’s 30-20% less massive, and I do agree that IPHG VIII 1912 19 is probably about that much smaller than sue.
I do however think it is likely, based on the material of MSNM V4047, that the largest african Spinosaurines, S. aegyptiacus or not I’m not sure, were at least 50% more massive than T. rex (probably 70% or so), which would make them too much of an opponent even for big-barrel-chested spike-tooth to handle.

I don’t know whether you still disagree with me about the first point. I know you don’t agreewith me on the last, be it because you think MSNM is to incomplete and indeterminable, but I do not share this view.

Can you live with this?
Edited by theropod, Feb 11 2014, 10:45 PM.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
Weird, the text says something different to the systematics they used mmm

I can live with that but it still rubs me wrong the idea of a 19m 18 tonne something Spinosaurus, specially one with a rostrum so punny (IMO) as that of the milan rostrum. Of course, you can shave length from the neck, the tail and the rest could be taken from the proportionally smaller head to get it down to 17m but still.
Offline Profile Quote Post Goto Top
 
Vobby
Member Avatar
Omnivore
[ *  *  *  *  * ]
theropod
Feb 11 2014, 08:16 AM
I’m getting a bit tired of this.

Let’s put it this way:
I disagree that one could just extrapolate body masses from centrum diameter, due to the many factors complicating this, especially in this case, arriving at estimates like 45% the weight of FMNH PR 2081 for the holotype of S. aegyptiacus.
I wholeheartedly agree with you that a tyrannosaurine would be a superior opponent to a spinosaurine that’s 30-20% less massive, and I do agree that IPHG VIII 1912 19 is probably about that much smaller than sue.
I do however think it is likely, based on the material of MSNM V4047, that the largest african Spinosaurines, S. aegyptiacus or not I’m not sure, were at least 50% more massive than T. rex, which would make them too much of an opponent even for big-barrel-chested spike-tooth to handle.

I don’t know whether you still disagree with me about the first point. I know you don’t agreewith me on the last, be it because you think MSNM is to incomplete and indeterminable, but I do not share this view.

Can you live with this?
Luckyly enough, there are other things which I can't live with. It is not the case to be so upset. I don't want you to be like that becouse of me, so I think I'll leave this thread for a while, if not forever, also becouse in my opinion there is not still much to debate.

But since you decided to be so clear, I'll do the same: I want to point out, theropod, that you cannot treat yourself and other fans (I mean "dinosaur enthusiasts", obviously not "fanboy") like a source. You were so convinced that Cau is wrong to believe immediately that the completely wrong comparison made by fragillimus proved your point, and you're so sure that Headden is wrong to stick with your own chart of Spinosaurus skull. Now you still believe that the Milan rostrum is Spinosaurus aegyptiacus, not even noting the striking contraddiction between the holotype 30% smaller and MSNM 50% bigger than Sue. Not even noting that, if we could really extrapolate mass from a snout, sue would be not 2, but 3 or 4 times heavier than your biggest spinosaurine. Reflect about what you write yourself: you don't think that we can extrapolate body masses from vertebrae, despite the fact that their purpose is weight bearing, but you think you can estimate a theropod 50% heavier than Tyrannosaurus from just a rostrum?

No bad feelings of course, bye.
Offline Profile Quote Post Goto Top
 
TheMechaBaryonyx789
Member Avatar
Herbivore
[ *  *  *  * ]
Um... Well I'm lost here.
Offline Profile Quote Post Goto Top
 
Canadianwildlife
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
So does this mean that the t-rex wins? I'm really confused with what Blaze, Theropaud, and Vobby are saying.
Offline Profile Quote Post Goto Top
 
Ausar
Member Avatar
Xi-miqa-can! Xi-miqa-can! Xi-miqa-can!
[ *  *  *  *  *  *  *  * ]
I just think they're debating Spinosaurus size again.


Well, mind you, should Spinosaurus really turn out to be no bigger than T.rex, I think latter wins (probably even nearly (if not absolutely) easily).
Offline Profile Quote Post Goto Top
 
TheMechaBaryonyx789
Member Avatar
Herbivore
[ *  *  *  * ]
Well I'm just waiting for Scott Hartman's GDI.
Offline Profile Quote Post Goto Top
 
blaze
Carnivore
[ *  *  *  *  *  *  * ]
I will stop debating Spinosaurus size from now on lol I promise
Edited by blaze, Feb 12 2014, 09:29 AM.
Offline Profile Quote Post Goto Top
 
Canadianwildlife
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
blaze
Feb 12 2014, 09:29 AM
I will stop debating Spinosaurus size from now on lol I promise
No, its alright. I'm just wondering about the conclusions you came too. Is the argument that the largest specimen of t-rex was bigger than the largest specimen of spinosaurous conclusive? I'm just curious. I got lost through all of this, so I'm just waking up to all of it.
Offline Profile Quote Post Goto Top
 
2 users reading this topic (2 Guests and 0 Anonymous)
Go to Next Page
« Previous Topic · Dinosauria Interspecific Conflict · Next Topic »
Add Reply

Find this theme on Forum2Forum.net & ZNR exclusively.