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Alioramus remotus v Dilophosaurus wetherilli
Topic Started: Jun 24 2013, 09:20 PM (5,206 Views)
Taipan
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Alioramus remotus
Alioramus is one of the least known Asian tyrannosaurids. It was a stretch-snouted tyrannosaurid with a very rugose (bumpy) nose. In fact, there seem to be 6 prominent bumps on the nose. Otherwise, it probably looked very much like a T. rex. It has a very high tooth count (for a tyrannosaur, at 18 maxillary teeth), which lends credence to it being a primitive tyrannosaurid. Alioramus is known from an incomplete skull and some foot bones collected from Nogon-Tsav in Mongolia.. As the name says, it is not a well known tyrannosaurid. It may have been an early version of the Asian tyrannosaur family as it has a braincase very similar to Tarbosaurus bataar. Like Albertosaurus in North America, this early tyrannosaur was not as large as its later cousins. So little is known of this dinosaur that the there is even an argument as to whether it belongs as a tyrannosaurid. Dr. Phillip Curie wrote that the taxonomic status of Alioramus is uncertain because of the incompleteness and immature nature of the specimen.

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Dilophosaurus wetherilli
Dilophosaurus (play /daɪˌlɒfɵˈsɔrəs/ dy-lof-o-sawr-əs or /daɪˌloʊfɵˈsɔrəs/; Greek: di for "two", lophos "crest", and sauros "lizard") was a theropod dinosaur from the Sinemurian stage of the Early Jurassic Period, about 193 million years ago. The first specimens were described in 1954, but it was not until over a decade later that the genus received its current name. It is one of the earliest known Jurassic theropods and one of the least understood. Dilophosaurus measured around six meters (20 ft) long and may have weighed half a ton. The most distinctive characteristic of Dilophosaurus is the pair of rounded crests on its skull, possibly used for display. Studies by Robert Gay show no indication that sexual dimorphism was present in the skeleton of Dilophosaurus, but says nothing about crest variation. The teeth of Dilophosaurus are long, but have a fairly small base and expand basally. Another skull feature was a notch behind the first row of teeth, giving Dilophosaurus an almost crocodile-like appearance, similar to the putatively piscivorous spinosaurid dinosaurs. This "notch" existed by virtue of a weak connection between the premaxillary and maxillary bones of the skull. This conformation led to the early hypothesis that Dilophosaurus scavenged off dead carcasses, with the front teeth being too weak to bring down and hold large prey.

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Edited by Taipan, Aug 1 2013, 09:34 PM.
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Jinfengopteryx
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Aspiring paleontologist, science enthusiast and armchair speculative fiction/evolution writer
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Doesn't this apply to other theropods as well (i.e. smaller ones have more slender teeth)?
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theropod
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Not sure, but there is likely some allometric trend towards larger animals having more robust structures in general (including teeth). I have mentioned that regarding the (often overhyped) tooth morphology of the Carcharocles lineage.
I remember it was not clear why there were convergences between Allosaurus and Gorgosaurus, similar size or similar niche partitioning were mentioned. I think it is a bit of a combination; of course the smaller size plays a role, and also the feeding style.

However undoubtedly T. rex is the most specialised of the tyrannosaurs, this is reflected by its whole morphology (bulkiest body, widest head, supposedly strongest bite force, longest, largest teeth etc.), and the ancestral state in coelurosaurs and tyrannosaurs were certainly slicing teeth, so we can assume smaller tyrannosaurs were more of slicers than T. rex, tough how much more I don't know.

Nevertheless, based on the skull-shapes we see, I'll wager most derived Tyranosaurs are more adapted for crushing than carnosaurs are, and tooth morphology can be expected to follow skull morphology in terms of robusticity and function.
eg. in an animal with a thick skull like T. rex', adapted to deliver a powerful bite force and to excert strong lateral forces you will hardly find thin, bladelike teeth, nor will you find T. rex-like teeth in the laterally flattened skull of an Allosaur, built for quick slashing and pulling motions, not holding onto prey and crushing it; everythignng else would be disadvantageous for biting efficiency, a tyrannosaurs teeth would produce redundant hindrace while pulling through flesh, an allosaur's teeth would break while puncturing large bones or employing lateral shaking.
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Temnospondyl
Stegocephalia specialist.
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Compare these skulls
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Carcharadon
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Shark Toothed Reptile
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^ And alioramus obviously has a much more powerful skull
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theropod
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It is also pretty elongate and certainly wouldn't have a particularly strong bite force, but you can see the bones and teeth are much more robust, so it probably relied more on force than tooth lenght.
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Temnospondyl
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Don't forget, that Dilophosaurus had longer arms, that could be used like a weapon.
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theropod
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I´m certainly the last person to deny the use of powerful, clawed forelimbs in a fight, but those arms
http://pinkubentobox.com/nagi/images/dinowiki/dilophosaurus_skeleton_01.jpg
Don´t look like weapons. The claws are too small, the overall structure to gracile and the digits too short. I doubt it could inflict lethal injuries using them, they are for grasping, not a replacement for dangerous jaws.
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thesporerex
Kleptoparasite
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alioramus wins
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Soopairik
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I think Alioramus can pull this off.
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