Carcharodon
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Allosauroidea Enthusiast
Posts: 211
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Post by Carcharodon on Dec 19, 2013 17:56:27 GMT 5
Albertosaurus sarcophagusAlbertosaurus is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, more than 70 million years ago. The type species, A. sarcophagus, was apparently restricted in range to the modern-day Canadian province of Alberta, after which the genus is named. Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species. As a tyrannosaurid, Albertosaurus was a bipedal predator with tiny, two-fingered hands and a massive head with dozens of large, sharp teeth. It may have been at the top of the food chain in its local ecosystem. An adult Albertosaurus may have weighed as much as 2 to 3 tons, and about 8 to 9 metres long.  Baryonyx walkeriBaryonyx was the first carnivorous dinosaur to be discovered in England. It was an unusual theropod with huge foot-long claws on its hands. Most theropods had S-shaped necks, but Baryonyx had a long straight one that was fairly inflexible. The design of its hips and pelvis suggests that it was bipedal for the purposes of walking from place to place. However, its forelimbs were absurdly large for a theropod, suggesting that it also spent much of its time on all fours. It had a long long tail and a low-slung body. Skull & Jaws: The skull was set at an acute angle, not the 90° angle common in similar dinosaurs. The long jaw was distinctly crocodilian, and had 96 teeth, twice as many as its relatives. Sixty-four of the teeth were placed in the lower jaw (mandible), and 32 large ones in the upper (maxilla). The snout probably bore a small but distinctive crest. Baryonyx was about 8.5 m (28 ft) long and weighed in the region of 1,700 kg (3,700 lbs). However, analysis of the bones suggests that the most complete specimen was not yet fully grown, so Baryonyx may have grown even larger. 
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Post by Godzillasaurus on Dec 21, 2013 0:54:19 GMT 5
Given the fact that baryonyx had considerably less adept dentition for piercing deeply that was recurved and serrated as opposed to straightened and spike-like (which was very well-designed for both piercing deeply and resisting forces alike. Example: spinosaurus dentition), spinal damage to the tyrannosaurid is highly unlikely. Because of this, I do not see the baryonyx dealing much damage to the tyrannosaurid in this case.
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Post by Runic on Dec 21, 2013 0:59:23 GMT 5
^ you repeated the same thing 3 times in one post.
Anyways imo tyrannosaurs > spinosaurs
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Post by Godzillasaurus on Dec 21, 2013 1:00:03 GMT 5
^ you repeated the same thing 3 times in one post. Anyways imo tyrannosaurs > spinosaurs Haha, didn't realize that. I will edit |
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Post by Runic on Dec 21, 2013 3:19:28 GMT 5
^ you repeated the same thing 3 times in one post. Anyways imo tyrannosaurs > spinosaurs Haha, didn't realize that. I will edit Ok. And anyways baryonx was a fish eater too right? So why didn't it have spike teeth like spinosaurus? |
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Post by Godzillasaurus on Dec 21, 2013 3:29:18 GMT 5
Haha, didn't realize that. I will edit Ok. And anyways baryonx was a fish eater too right? So why didn't it have spike teeth like spinosaurus? The teeth of baryonyx were actually slightly recurved and serrated, designed more-so for cutting and ripping (although I am unsure as to how laterally compressed they were) as opposed to puncturing deeply and gripping. Spinosaurus, on the other hand, possessed teeth that were quite straight, lacked carinae (serrations) altogether, and were perfectly designed for piercing deeply into the hide of a prey animal efficiently, given their rather slenderized shape, sharp point, and round base (in cross-section). But I of course am referring mainly to the frontal teeth, as the posterior ones were very short and were likely almost useless in life. Because of these factors, spinosaurus' dentition would be much more effective in damaging the spinal cord of a prey animal (even though neither its snout or dentition was designed for crushing, the specialized puncturing ability/robusticity of its teeth in conjunction with its highly resistant rostrum to vertical forces would make for a very deadly combination after it bit a prey animal). |
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Post by theropod on Dec 21, 2013 17:16:00 GMT 5
Baryonychines have conical teeth with pretty rounded cross-sections, they show more or less subtle labiolingual flattening and obviously are not designed for slicing, but for gripping, whereby they show paralells to Tyrannosaurid dentition but are much more gracile and smaller. However, as a key difference to the more derived Spinosaurines, their teeth are somewhat recurved, much smaller, more numerous and they show serrations. They are closer to the ancestral state for spinosauria, which can be nicely seen in Ostafrikasaurus: blogs.smithsonianmag.com/dinosaur/files/2012/04/ostafrikasaurus-teeth-large.jpgCompared to Spinosaurus, they are shorter and less robust and would not be as effective in puncturing deeply, but more so in tearing (which also explains to some degree that Baryonychines have deeper but narrower rostra, and shallower mandibles, less indicative of reliance upon bite force than Spinosaurines but perhaps more well-suited for tearing motions). Baryonyx was likely an oppurtunistic feeder, just like other Spinosaurs, and would have eaten fish butn evidently also terrestrial dinosaurs as long as it could kill or scavenge them. |
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Post by Godzillasaurus on Dec 21, 2013 19:46:49 GMT 5
Cutting and tearing can be synonomous in some aspects. I am unsure of what separates them from one another. That is what serrated dentition would have been very good at. It doesn't necessarily have to be able to rip apart a prey animal, but be adept at simply ripping into its hide, which it appears baryonyx was very well adapted for. I seem to have thought that cutting was the same thing as tearing. I read about baryonychines having much less broadened snouts than spinosaurines before. But then the paper stated the exact opposite. Let's look at the facts side-by-side, shall we Baryonyx:  It is definitely more gracile than this spinosaurus specimen:  I don't know why the paper claimed that. Maybe it was because, again, they were only using the diastema region of the rostrum? And that area in baryonyx was considerably more broad. Whereas in spinosaurus it was very specialized and thin. That just struck me. I feel as if they used the entire rostrums as opposed to just a portion of them, it would have yielded very different results. Oh yea, and not that this matters, but again, spinosaurus did not possess a monstrously powerful bite or crushing adaptations unlike tyrannosaurus (as evidenced by its very narrow snout in general for the latter) |
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Post by theropod on Dec 21, 2013 23:22:28 GMT 5
The paper "did not state the opposite". They correctly noted that spinosaurs "were not obligate piscivores with diet being determined by individual animal size". it has to be carefully distinguished between misunderstandings on our and on their part. Baryonyx has a deeper but narrower rostrum than Spinosaurus, with the anterior end being deepened and the diastema less marked (thus, also wider than in Spinosaurus). Overall, the rostrum of spinosaurus is significantly wider, it bears more robust teeth and the mandible is also much more robust.  If there was such a thing as "vertical shaking", one would expect a deepened instead of a broadened rostrum, to increase bending resistance in that direction. On the other hand reliance on traditional biting seemingly requires a balance between depth and width. Precise, controlled puncturing by the teeth in a classic bite is the most likely option, not reliabce on raw power or extensive tissue damage. The necessary bite force could easily be reached, and there's really nothing suggesting otherwise. Actually, the argument against a strong bite in Spinosaurus was the one of the weak rostrum, not the mandible (which is among the most robust theropod mandibles I know of). As we both agreed the snout was not weak, (albeit certainly not extraordinarily strong either), but comparable to crocodilians that are capable of excerting somewhat powerful bites ( Gavialis, Tomistoma, Mecistops). |
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Post by Godzillasaurus on Dec 21, 2013 23:28:38 GMT 5
I just found this link that describes the differences between skull anatomy in Spinosaurines and Baryonychines and discusses their food sources a bit:
Spinosaurus and Baryonyx
This source says, in a way, that spinosaurus would have been better off scavenging as opposed to killing other animals in itself. The main problem I have with this is the fact that, contrary to what the source says, significant injury to spinosaurine jaws is not as imminent as it says. Spinosaurus specifically was obviously very robust and would have been particularly more resistant than baryonyx and slender-snouted crocodilians at the centermost part of the rostrum: While the source is certainly not inaccurate, I feel that much more emphasis on the actual killing style of spinosaurus needs to be examined more thoroughly. What spinosaurus in general appeared to have been capable of doing was withstanding decent amounts of vertical and lateral stress in comparison with the animals that I listed. Its dentition was very well designed for, as we both said, piercing deeply and yet retaining its resistance. While the bite force of spinosaurus was certainly not exceptionally high, its dentition can be put to very good use under the right circumstances. Scavenger behavior is not completely out of the question, but spinosaurus was designed, first and foremost, to be a generalist piscivore, that was big and powerful enough (also inclusive in tooth and jaw structure) to kill small-medium sized dinosaurs. |
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Post by Godzillasaurus on Dec 21, 2013 23:39:46 GMT 5
The paper said that baryonyx had a more robust rostrum than spinosaurus, didn't it? I thought it said that... Oh well
Well in the case of spinosaurus, it was clearly reasonably resistant in both directions. Its rostrum was actually a good deal more robust proportionally than the animals that we talked about earlier. But what it did lack was an EXCFEPTIONALLY powerful biting force, as it was again a piscivore. Its dentition and jaws were not designed for crushing, as one would normally expect from an animal designed to do so (example: American alligator or tyrannosaurus). Its dentition was more-so designed for puncturing deeply into the hides of animals (but not necessarily fatally) and its snout, being relatively shallow and narrow compared to the majority of non-spinosaurid macro predatory theropods, was clearly designed to decrease total drag in water. Spinosaurus simply did not need a very powerful bite (although it was probably higher than the bite of carcharodontosaurus or giganotosaurus).
Huh, I thought it was the mandible. Anyway, spinosaurus clearly did not have a weak rostrum OR mandible, but they, again, were designed for functions aside from crushing.
But in the case of those genera, spinosaurus had the more robust snout compared to all of them. In the case that it had a similar biting strength, its overall snout robusticity would be more relevant.
BTW, where did you find the picture?
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Post by theropod on Dec 22, 2013 0:12:33 GMT 5
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Carcharodon
Junior Member
Allosauroidea Enthusiast
Posts: 211
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Post by Carcharodon on Dec 22, 2013 4:15:33 GMT 5
Albertosaurus should win, it is taller, more agile and has a much deadlier bite.
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Post by creature386 on Dec 22, 2013 15:26:45 GMT 5
The paper said that baryonyx had a more robust rostrum than spinosaurus, didn't it? I thought it said that... Oh well It did, but read theropod's post carefully. It was only talking about the rostrum, not the mandible, hence it didn't say the whole skull was weak. |
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Post by Godzillasaurus on Dec 22, 2013 20:34:09 GMT 5
The paper said that baryonyx had a more robust rostrum than spinosaurus, didn't it? I thought it said that... Oh well It did, but read theropod's post carefully. It was only talking about the rostrum, not the mandible, hence it didn't say the whole skull was weak. While there is less emphasis on its skull being wide (it was very narrow), the main reason why it appeared to have been more robust was because they had much less material to work with. And when that gets size correctedÂ… That is one flaw that the paper has; spinosaurus had a much wider rostrum relative to length and depth than baryonyx and suchomimus (although somewhat irrelevant here). |
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