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Majungasaurus crenatissimus v Megaraptor namunhuaiquii
Topic Started: Jan 18 2012, 09:47 AM (7,967 Views)
Wolf Eagle
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Megaraptor namunhuaiquii
Megaraptor was initially described as a giant dromaeosaur, known primarily from a single claw (about 1 ft/0.30 m long) that resembled the sickle-shaped foot claw of dromaeosaurids. The discovery of a complete front limb, however, showed that this giant claw actually came from the first finger of the hand. The hands were unusually elongated, bearing sickle-shaped claws even more recurved than those of spinosaurids. The hand is quite distinct from other basal tetanurans, so it was not initially clear whether Megaraptor was an allosaurid, a carcharodontosaurid, a spinosauroid, or something else entirely. Subsequent studies, as well as the identification of close relatives with similar large claws on the forelimbs (see below), have helped identify Megaraptor as a highly advanced and lightly-built allosauroid, and a member of the family Neovenatoridae.

I read here that Megaraptor reached about 26 feet and weighed 1-2 tons. I don't know if it's a reliable source though.


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Majungasaurus crenatissimus
Majungasaurus (pronounced /məˌdʒʌŋɡəˈsɔrəs/ mah-JUNG-gə-SOR-əs "Mahajanga lizard") is a genus of abelisaurid theropod dinosaur that lived in Madagascar from 70 to 65 million years ago, at the end of the Cretaceous Period. Only one species (M. crenatissimus) has been identified. This dinosaur was briefly called Majungatholus, a name which is now considered a junior synonym of Majungasaurus. Like other abelisaurids, Majungasaurus was a bipedal predator with a short snout. Although the forelimbs are not completely known, they were very short, while the hindlimbs were longer and very stocky. It can be distinguished from other abelisaurids by its wider skull, the very rough texture and thickened bone on the top of its snout, and the single rounded horn on the roof of its skull, which was originally mistaken for the dome of a pachycephalosaur. It also had more teeth in both upper and lower jaws than most abelisaurids. Majungasaurus was a medium-sized theropod that typically measured 6–7 meters (20–23 ft) in length, including its tail. Fragmentary remains of larger individuals indicate that some adults reached lengths of more than 8 meters (26 ft). Scientists estimate that an adult Majungasaurus weighed around 1,875 lbs. (850 kilograms).

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7Alx
Jan 18 2012, 03:22 AM
Megaraptor vs Majungasaurus


Here it is!
Edited by Taipan, Nov 17 2016, 04:40 PM.
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Jinfengopteryx
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Dark allosaurus
Aug 26 2012, 06:31 AM
Jinfengopteryx
Aug 26 2012, 05:25 AM
jj5893
Aug 18 2012, 02:55 PM
I saw a youtube video of a megaraptor mauling a t-rex
Was it one of these pivots?
I doubt it. I tried searching up Megaraptor vs T.rex on Youtube and there were no pivot fights answering
But maybe this was the vid, from the video game Warpath: Jurassic Park
I doubt this is a better analogy than a pivot.
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Makaveli7
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Megaraptor has speed, agility, claws and can get up after an attack.
Majungasaurus has durability and possibly power.
Megaraptor 65/35
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Jinfengopteryx
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It looks like jj5893 wanted to use it as a reference.
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DarkGricer
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Megaraptor wins easily. It's bigger, stronger, faster, more agile and more well armed. Majungasaurus maybe has a stronger bite and maybe has a durability advantage. But overall, it's outclassed.

Megaraptor wins 85% of the time.
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Spinodontosaurus
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The Ulna measurements for Megaraptor and Australovenator on the Theropod Database imply the former is about 24% longer... so based on this skeletal we are looking at an axial length of under 7 meters.

I don't think Megaraptor would be much bigger than Majungasaurus, if at all.
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DarkGricer
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In that case, I guess It's closer. But I still think Megaraptor wins 80% of the time.
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thesporerex
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Jinfengopteryx
Sep 11 2013, 11:00 PM
It looks like jj5893 wanted to use it as a reference.
It doesn't seem he wanted to use it as referance, it looks like he is meerly stating that he saw a video which is either a poorly made pivot video or the jurassic park equvilant of street fighter or teken.
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Jinfengopteryx
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Look at the whole comment, there you can see that it was part of his argumentation:
http://carnivoraforum.com/single/?p=8352569&t=9349428
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thesporerex
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SpinoInWonderland
Sep 11 2013, 11:06 PM
thesporerex
Sep 11 2013, 04:55 PM
Jinfengopteryx
Aug 28 2012, 03:38 AM
Dark allosaurus
Aug 26 2012, 06:31 AM
Jinfengopteryx
Aug 26 2012, 05:25 AM
jj5893
Aug 18 2012, 02:55 PM
I saw a youtube video of a megaraptor mauling a t-rex
Was it one of these pivots?
I doubt it. I tried searching up Megaraptor vs T.rex on Youtube and there were no pivot fights answering
But maybe this was the vid, from the video game Warpath: Jurassic Park
I doubt this is a better analogy than a pivot.
Oh for fuck sake its a fucking game its not supose to taken seriously, its also a jurassic park fighting game it does not need to be realistic.
He(jj5893) also claimed that a mammoth can break a Tyrannosaurus' skull with a hit from it's trunk.

A Tyrannosaurus would kill a Megaraptor even if it had it's mouth locked shut.
He isn't the brightest is he(neither I am though)

Also for your second statement is almost common knowledge.
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Taipan
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Das Dinosaurier
Sep 29 2016, 01:00 AM
So what about Megaraptor vs. Majungasaurus?


Here you go.
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Finderskeepers
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Sorry guys I accidentally voted for majungasaurus instead of megaraptor could someone change that?
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Carnotaur
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Thanks Taipan.

Apparently,Megaraptor got downsized to under 7 meters in length based on relatives.However,latest articles also downsized Majungasaurus to a body length of 5,6 meters.That said,Majungasaurus(likely) would've been the smaller animal.Now,lets see some characteristics of the theropods and how they compare to each other:

As for strengh:Majungasaurus was very robust,being a member of the "stout legged abelisaurs":it had very thick lower legs(tibiae and feet),a exceptionally strong neck and expanded scapula when compared to other theropods,which would give it powerful back muscles in life.

But how about Megaraptor?Many people think it was ligthy built-mainly because of the name and because one of its relatives was gracile-but in reality,it was very bulky,having strong arm elements,short and thick cervicals-which suggests a thick neck musculature-,thick lower leg elements(given the structure of the fourth metatarsal) a stout pubis with a a exceptionally big pubic foot-which suggest big abdominal musculature-and a craniocaudally expanded scapula-coracoid.Take a look at one excerpt of:Phylogenetic status of Megaraptor namunhuaiquii :

"...a particularly interisting combination of a bulky construction of the body(as suggested by cervical vertebrae,proportions of scapula-coracoid,hands,pubis,metatarsal IV)with exceptional raptorial abilities in the hands."

How do they compare?The abelisaur likely totally outclasses Megaraptor in neck musculature,but the latter have much more robustly build pubis(bigger abdominal muscles),dwarfs the abelisaur in arm strength and would have stronger legs(since the legs in the Megaraptor are much larger-both in absolute and in proportional terms).

What about agility and stamina?

The abelisaur could had better stamina,due to its more developed bird like respiratory sistem(I said could because Megaraptor had a close relative that had extremely pneumatic bones,and the former could have a pneumatic skeleton too,though certainly not as well developed as its relatives),but the same can't be said for agility:Majungasaurus had a very elongated torso and an almost sauropod like neck(when compared to other theropods).These would make Majungasaurus have a terrible rotational inertia and thus terrible turning ability when compared to Megaraptor,that likely had more "standart" body structue.Though the abelisaur likely would have better acceleration.

Majungasaurus skeleton reconstruction by Hartman:
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Murusraptor,a megaraptoran:
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Now,about weaponry:

Majungasaurus was a very unusual predator with unusual weapons.It had short,but very strong skull,short but thick teeth and a strong neck.How it would use those is a matter of debate but,in my opinion,it would bite an animal,use its strong neck musculature and strong,bending resistant skull to hold the bite and not realease it until it is forced to do that or the animal die.During the hold,the teeth would keep cutting the flesh and weak the animal attacked.This would be,in my opinion, very efficient against sauropods,that were powerful creatures.

Megaraptor was very different:the skull was longer but,according to relatives,it wouldn't be very resistant,and the teeth weren't very numerous neither big.But that because it likely wasn't using them as the main weapons:Megaraptor had very well developed arms,that were muscular,had good range of motion and beared huge and sharp claws.However,many say that arms weren't the main weapons of theropods,but this could not have been the case on megaraptorans,take a look:

"Digit I has a deep and widesulcus on the ventral surface of phalanx I (Fig.1).This sulcus suggests the existence of a strongligament uniting phalanx I (18.4cm long) withflexor tuberculum of ungual phalanx I (42cm long).Moreover, the enlarged laminar olecranon processof the ulna in M. namunhuaiquii indicates theinsertion of a massive triceps (Fig.2). This musclewould give a higher force to Megaraptor handduring extensional movements. The triceps andflexor ligament would be efficient in seizing prey(Fig.3). Unfortunately, the humerus of Megaraptorwas not preserved; however, the scapula and thecoracoid preserved are morphologically similar tothose of Baryonyx Charig & Milner, 1986."

"One important feature of Megaraptor is thepresence of a sharp ventral border on its ungualphalanx of the digit I, finger I, indicating efficientraptorial abilities (Fig.4). This character isabsent in other theropods in which the ventralborder is rounded (Fig.5). The phalanx of digit Ihas a wide dorsal surface, strong enough tosupport a massive extensor muscle. Thephalanges of digit II have smaller dorsal surfacesthan those of the digits I and III. It suggests thatthe movement during hyperextension of theungual phalanx was very strong, a conditionneeded to animals with raptorial habits. A clawwith a sharp ventral surface is also present indromaeosaurids (OSTROM, 1969; NOVAS & POL,2005) as Deinonychus Ostrom, 1969 andNeuquenraptor Novas & Pol, 2005. Thischaracteristic is only observable in the claw IIof the pes of these animals since the other clawshave flat ventral surfaces."

"Due to the shapeobserved in the ventral border of Megaraptormanus, we deduce that the claw of phalanx Ihad the same function to that observed inDeinonychus and the claws II and III could alsobe related with the body support."

-From NEW INFORMATION ON MEGARAPTOR NAMUNHUAIQUII(THEROPODA: TETANURAE), PATAGONIA:CONSIDERATIONS ON PALEOECOLOGICAL ASPECTS.

"This orientation positions the glenoids ventrally, which prevents the humerus from being able to extend past the sub-horizontal . Conversely, the enlarged deltopectoral crest likely permitted powerful retraction of the entire forelimb. The antebrachium was capable of swinging through an arc of 78° (maximum extension of 144°, maximum flexion of 66°;). A similarly high elbow ROM occurs in basal Maniraptoriformes (95° in Ornitholestes [20] and dromaeosaurids 68° in Bambiraptor and 99° in Deinonychus .

"The recurved manual unguals of Australovenator were capable of significant extension, in particular, manual ungual II-3, which had hyperextension capabilities distinctly greater than in any other theropod ".

-From Forearm Range of Motion in Australovenator wintonensis(PLOS one).

These excerpts,among others,show that the arms and digits of megaraptorans would've been not only strong,but also would have decent range of motion.Also,the great claws were very peculiar in shape(and size),being similar in cross-section to the killing claws of the raptors,fact that screams that the claws were very sharp in life.Summarizing,Megaraptorans were like dromaeosaurs on steroids,but with the killing claws on the forearm,and these likely were used as its main weapons.

So,who had the better weaponry in this combat?I think Megaraptor would have the advantage here:not only it could use,unlike the abelisaur,both jaws and claws,but,if my bite and hold theory for abelisaurs is correct,then it would have a hard time killing its opponent,since it could be damaged by the enormous claws in the process

The verdict:I think Megaraptor would win:not only it had,in my opinion,better weaponry,it also had a size and likely agility advantage.




Edited by Carnotaur, Oct 26 2016, 02:47 AM.
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LionClaws
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Das Dinosaurier
Oct 4 2016, 03:01 AM
Thanks Taipan.

Apparently,Megaraptor got downsized to under 7 meters in length based on relatives.However,latest articles also downsized Majungasaurus to a body length of 5,6 meters.That said,Majungasaurus(likely) would've been the smaller animal.Now,lets see some characteristics of the theropods and how they compare to each other:
Everybody, like Das Dinosaurier's post! He's considering factors other than size in a theropod vs theropod matchup, something we need to see more of around here.

Okay, I don't have too much time, but I can make some basic responses. I've got more questions than I do arguments this time, so let's have a crack at it!

Regarding leg strength, how does the ludicrously massive caudofemoralis muscle of most abelisaurid theropods change things? Is it possible that our quasi-cursorial friend's tail musculature could give him the edge in hindlimb power? It has long been established on these forums that grappling ability in the forelimbs is effectively determined by the muscle mass powering the limb divided by the length of the limb, so short limbs and high muscle mass may well be a winning combination for "useable strength" in the hind limbs.

Regarding rotational inertia, my views on its relevance have been evolving. I'm still convinced that theropods would have been slow turners, but check this out:

Posted Image

This image was originally posted by Vobby. Notice anything funny about T-rex's allegedly cursorial femur? Look at how wide it is when viewed from the front (mediolateral diameter), and compare it to how wide it is when viewed from the side (anterioposterior diameter). Notice anything funny?

If you're about to say "it's wider than it is long," you get a cookie. Sorry, I can't give you any over the internet, I don't have that power on this site. You'll have to ask one of the Admins. ;)

This is odd because, when it comes to modern cursorial predators, the long bones are "longer than wide" in cross section to help deal with the anterioposterior stresses incurred during running. When we look at rexy's femur, the most obvious conclusion we can draw is that mediolateral stresses were a bigger problem for Tyrannosaurus than anterioposterior ones. While Tyranotitan's femur is thinner overall, it seems to have the same "wider than long" structure, and it is thus safe to assume that the same goes for the giant carnosaurs.

So what does the fact that mediolateral stresses were a bigger problem for the femur of a giant theropod than anterioposterior ones actually mean? Well, one possibility is that, when engaging in active locomotion, giant theropods spent a lot of time "crab-walking." This conclusion is even more impressive when we take into account the fact that Tyrannosaurus could abduct its femur from 0o to 45o, allowing it to take three-meter sideways strides with ease. If the morphology of the femoral head is anything to go by, Tyrannotitan could practically do the splits! (my pet theory is that the carnosaurs were unleashing sideways kicks at prey items) So while theropods were fairly slow turners, their all-around mobility may still have been quite impressive.

So if you can get some images of Abelisaurid and Neovenatorid hindlimbs, we may be able to figure out who really has an agility advantage here.

Regarding Majungasaurus' "bite and hold" strategy, I think I agree that that's what it would have done, but I would add that it would likely have done more than just hold. That powerful neck and well-reinforced skull could make it a powerful "mouth-grappler." When I have more time, we can discuss which animal would have been more capable at controling the other: Majungasaurus with its mouth, or Megaraptor with its claws.

Regarding Megaraptor's big claw, it does indeed appear to be "ventrally tapered" like dromaeosaur claws, and may well have been an effective weapon.

We'll have to discuss forelimb anatomy later, because I have to get going. Great post, and I look forward to the upcoming exchange!
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Ausar
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Quote:
 
This conclusion is even more impressive when we take into account the fact that Tyrannosaurus could abduct its femur from 0o to 45o, allowing it to take three-meter sideways strides with ease.
Is there a reference for this femur abduction figure I can see? It sounds interesting.
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Carnotaur
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Thanks Lion Claws!
I also think abelisaurs would have been good mouth-grapplers,not only because of the strong neck and skull,but I also think the relatively high degree of flexibility in the lower jaw,which is not exclusive to Majungasaurus in the Abelisaurids,should help it.

As for the femur abduction in T.rex:Interesting.Perhaps it was using it not only to bigger side steps,but also for the use of legs for subduing prey or hold onto carcasses?

Regarding the leg strength:Caudofemoralis muscles pulls the thigh bone backwards when contracted,so it is indeed important in leg strength and on the dinosaur's running abilities,particularly short-burst sprinting,although it likely didn't had a direct use in combat.However,I'm not sure if Majungasaurus had these muscles so well developed as we see in Carnotaurus,since the authors of the article "Dinosaur Speed Demon" only compared Carnotaurus' caudofemoralis to other abelisaurs of south america,and didn't mentioned Majungasaurus.I think its possible that the later would have well developed caudofemoralis since,like Carnotaurus,it is a very derived abelisaur,though Majungasaurus likely didn't needed sprint ability like that of its cousin.However,I think the proportional size of the leg of the megaraptoran should let its leg musculature be,well,proportionally bigger,fact that should make it easier to "carry its body",although,as you said,it wouldn't help much in the leg strengh used for combat("Leg grappling").

Regarding you 'pet theory':I think your theory that the carnosaurs were unleashing sideways kicks at prey items could be rigth,considering that the foot structure of carnosaurs were thick and strong when compared to tyrannosaurs and the claws were specially sharp.I think that this wasn't limited to carnosaurs and tyrannosaurs could do it as well,but less frequently,and monstruous footed theropods like Torvosaurus perhaps were specially adapted to do that.I also think that they could use them to subdue prey,as I said before.

PS:I made some small changes in my post
Edited by Carnotaur, Oct 5 2016, 01:42 AM.
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