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Post by coherentsheaf on Jun 3, 2013 20:31:27 GMT 5
Regarding MoA, I'm still take McHenry's work : smaller than Cumnor. Good point regarding Kronosaurus proportions but if the skull was really that long, that's substantially larger than the skull of K. boyacensis... On the other hand larger than both Kronosaurus and P. funkei, at least according to vertebral width. |
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Post by coherentsheaf on Jun 3, 2013 20:39:59 GMT 5
I don't have the McHenry thesis on the hand but if I remember right K. boyacensis skull is estimated at 2,36 m, comparable to P. kevani and the larger P. funkei individual. If K. queenslandicus had a 2,85 m skull, using Knutsen regression, that may explain why the publication argues the Early Cretaceous pliosaurs were the largest. Yeah, they do not comment on McHenry's more detailed analysis. He restores the Skull of Kronosaurus with great detail. The restoration is shorter than 2.85m. Anyway cranial remains are probably worse at determining total size than vertebral remains. |
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Post by elosha11 on Jun 3, 2013 20:48:00 GMT 5
Great discussion here. I'm slowly absorbing more information on pliosaurs from all of you, and will read the paper when I have the time. I'm curious if anyone has compared/estimated the width of these various pliosaur jaws? Are the shorter jaws any more or less robust than the longer ones? It would be very informative to get an estimate of the maximum volume of the pliosaur's bite, compared to say, a Megalodon or Livyatan. Maybe our math whiz coherentsheaf could spin up a comparative estimate.  These pliosaurs obviously all had immensely powerful bites and extremely long jaws, but their jaws also appear to be quite thin. As far as the overall volume of aquatic macropredators' bite, I think Megalodon is quite likely to have the largest known bite, followed either by Livyatan or these huge pliosaurs. Livytan's jaws are long, but do not seem as long as the 2.5 to 3 meter pliosaur range. (Correct me if I'm wrong, I don't remember the length estimate of the actual jaw remains of Livyatan). On the other hand, Livyatan's jaws seem thicker and perhaps a bit more robust than those of the pliosaurs. So I'm not sure if the cetacean or the pliosaurs had the larger bite... |
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Post by Grey on Jun 3, 2013 20:55:36 GMT 5
If I remember right, the 1,83 m skull of a young Kronosaurus is narrower than the skull of Sue which is approx. 90 cm wide. I count too on coherentsheaf skills for found some interesting numbers  So we can suggest, coherentsheaf, that MoA is larger than all these pliosaurs except the Cumnor guy ? |
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Post by theropod on Jun 4, 2013 1:16:10 GMT 5
To me the skull of P. kevani seems much more robust than that of the Kronosaurus in McHenry's thesis. T. rex has an extremely expanded posterior cranium, 80-90cm in width. Or maybe I should say it is very short compared to the width of the skull?
In terms of volume, I highly doubt any predator known even comes close to C. megalodon, since it has very wide jaws. The rostra of Pliosaurs or cetaceans are comparatively narrow, which is normal for tetrapods of course, but very robust by any standart. I think a skull comparison in dorsal, lateral and anterior view would be very helpful.
It depends. To me, the Weymouth skull, tough huge, doesn't seem to compare to that of Livyatan. It is quite possible there are somewhat larger specimens (MoA and Cumnor) tough.
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Post by Grey on Jun 4, 2013 5:50:11 GMT 5
You can remark, though, that Adam Stuart Smith considers the head of P. kevani as "rather gracile".
On the basis of this reconstruction IÂ’ve also had a go at restoring the life appearance of the head of P. kevani in profile. Despite its large size and massive teeth, the head is rather gracile.www.plesiosauria.com/news/index.php/pliosaurus-kevani-the-weymouth-bay-pliosaur/I agree that no pliosaur's head would rival the bulk of Livyatan's skull, especially considering its spermaceti chamber. Also, the largest teeth of Livyatan are way thicker. Forrest told me the teeth in the Svalbard and Dorset material were around 7 cm in diameter, and the teeth in the MoA around 5,5 cm. The biggest teeth in Livyatan are 12 cm in diameter. But it would be interesting to see the comparison of the jaws and jaws muscles. The jaws muscles in P. kevani are so huge that Forrest said he could stand within those. He also pointed on that in Livyatan, a part of the space in the skull is dedicated to the larger brain. That's why, I do not rule out that some pliosaurs with a skull approaching the 3-m mark ( P. macromerus, Kronosaurus ?, MoA?) can still rival Livyatan in pure bite force. This is even very probable IMO |
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Post by Grey on Jun 4, 2013 8:21:45 GMT 5
Here is a reproduction of the Aramberri pliosaur. Don't know the background behind this reconstruction, if it's been somewhat advised by Buchy or others, but it seems to be too large if we follow McHenry thesis. Still, gives an idea of what a 15 m pliosaur would look like.  Source |
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Post by theropod on Jun 4, 2013 17:01:46 GMT 5
You can remark, though, that Adam Stuart Smith considers the head of P. kevani as "rather gracile".
On the basis of this reconstruction IÂ’ve also had a go at restoring the life appearance of the head of P. kevani in profile. Despite its large size and massive teeth, the head is rather gracile.www.plesiosauria.com/news/index.php/pliosaurus-kevani-the-weymouth-bay-pliosaur/I agree that no pliosaur's head would rival the bulk of Livyatan's skull, especially considering its spermaceti chamber. Also, the largest teeth of Livyatan are way thicker. Forrest told me the teeth in the Svalbard and Dorset material were around 7 cm in diameter, and the teeth in the MoA around 5,5 cm. The biggest teeth in Livyatan are 12 cm in diameter. But it would be interesting to see the comparison of the jaws and jaws muscles. The jaws muscles in P. kevani are so huge that Forrest said he could stand within those. He also pointed on that in Livyatan, a part of the space in the skull is dedicated to the larger brain. That's why, I do not rule out that some pliosaurs with a skull approaching the 3-m mark ( P. macromerus, Kronosaurus ?, MoA?) can still rival Livyatan in pure bite force. This is even very probable IMO I agree. yeah, I read that. Rather gracile doesn't equal not being massive tough. The whole skull is elongate, but look at crocodilians and their bite force. And yeah, that think must have had gigantic jaw muscles. In terms of bite force, I could very well imagine them rivaling, perhaps exceeding L. melvillei, despite being overally less massive. The temporal fossa in Livyatan is large, but the attachment areas in Pliosaurus seem even larger. The teeth of Livyatan are also disproportionally large. Another interesting pliosaur as regards size is the one known from the 45cm tooth (hinted by you and I think coherentsheaf back on carnivora). A skull approaching 3m is still possible for at least some. Much about MoA is dubious, that's why we definitely need a full description. I am not sure about McHenry's statement about its size tough, the little figures we have definitely suggest something huge. Maybe McHenry is a bit conservative concerning the sizes in general, but we'll have to wait. Very nice shots of the mount, would be great to know where it is! That definitely looks very impressive. It doesn't necessarily have to base on a lot of factual evidence tough. |
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Post by theropod on Jun 4, 2013 17:20:50 GMT 5
I've changed the title so we can just use this to discuss pliosaurs in general.
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Post by theropod on Jul 21, 2013 2:08:12 GMT 5
dml.cmnh.org/2001Feb/msg00891.htmlthis is from McHenry on DML The Peterborough vertebra and BMNH symphysis are mysterious, the latter could be a pliosaur approaching the 15m mark-if it was a pliosaur, whch is still unclear. I'd whish for some more detailed data on the Aramberri specimen-and the Tübingen Liopleurodon for that matter. Also he seems to consider pliosaurs the most powerful biters in history, or at least that's what it seems like.
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Post by Grey on Jul 21, 2013 3:13:04 GMT 5
Yes I had read this. Don't forget that this (2001) was long before he'd finished his thesis (2009), all his work was not decisive at the time.
I had quoted his line about Liopleurodon killing apparatus. Pliosaurs are very likely the most powerful biters in history (let's wait the scan of P. kevani skull), despite that the larger Livyatan and meg bring some uncertainties on such a statement.
The main comment is that at equal size, their skulls were supreme predatory weapons. A small-sized pliosaur with a 1.2 m skull was able to cut in half a medium-sized ichthyosaur...nuff said.
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blaze
Paleo-artist 
Posts: 766
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Post by blaze on Jul 21, 2013 9:46:57 GMT 5
Regarding the size of the skull of Kronosaurus, I think McHenry's work is better than an estimate based on just two measurements, as awesome as a specimen with a skull 2.85m long might be, it doesn't really seem to be supported by comparisons with other specimens. Benson et al. (2013) noted that individual middle-posterior dorsal vertebrae of the Harvard specimen (MCZ 1285) are almost identical in size to those of the type of K. boyacensis (114-145mm vs 117-138mm), which has a skull 2.36m from premaxilla to supraoccipital according to Hampe (1992) (estimated 2.42m BSL), even then, this estimate is too long itself, comparisons with two specimens of K. queenslandicus and one of Brachauchenius lucasi lead McHenry (2009) to note that Hampe's reconstruction put the supraoccipital behind its actual position, enlarging the length of the skull, his estimate derived on photogrammetric data put the BSL of the type of K. boyacensis at "only" 2.21m. Now, we could say that K. queenslandicus had a proportionally bigger head but this clashes with what is found in the fairly complete specimen QM F10113, whose neck-torso region is 85% that of K. boyacensis but its skull is just 79% the size when using Hampe's reconstruction, though, it's also 85% the size when using McHenry's reconstruction. Meaning that both species had similar head/body proportions and if one actually had a proportionally bigger skull, it won't be K. queenslandicus. Even the femora of MCZ 1285 and K. boyacensis type are similar in size, 960-1060mm vs 977mm. Taking all of this into account, an skull length of 2.19m as estimated by Knutsen et al. (2012), 2.28m (BSL) as estimated by McHenry (2009) or even the originally mounted reconstruction at 2.23m (BSL, as measured by McHenry?) seem much more likely than Benson et al. suggestion of 2.85m. I'm thinking that since the mentions of Kronosaurus were from a month ago, I might sound like beating a dead horse.  References: Benson RBJ, Evans M, Smith AS, Sassoon J, Moore-Faye S, et al. (2013) A Giant Pliosaurid Skull from the Late Jurassic of England. PLoS ONE 8(5):
McHenry, C. R. 2009. Devourer of Gods: the palaeoecology of the Cretaceous pliosaur Kronosaurus queenslandicus. Unpublished Ph.D. Thesis, University of Newcastle.
Hampe O. 1992. Ein großwüchsiger Pliosauride (Reptilia: Plesiosauria) aus der Unterkreide (oberes Aptium) von Kolumbien. Courier Forschungsinstitut Senckenberg 145: 1-32.
Knutsen EM, Druckenmiller PS, Hurum JH. 2012. A new species of Pliosaurus (Sauropterygia: Plesiosauria) from the middle Volgian of central Spitsbergen, Norway. Norwegian Journal of Geology 92: 235–258. |
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Post by dinosauria101 on Dec 4, 2019 0:14:09 GMT 5
Here's a size charts of several pliosaurs, by Randomdinos  |
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Post by Ceratodromeus on Jan 2, 2020 4:49:11 GMT 5
A very happy new year for Pliosaur enthusiasts!
First evidence of a conical-toothed pliosaurid (Reptilia, Sauropterygia) in the Hauterivian of the Northern Calcareous Alps, Austria
Abstract The first pliosaurid finding in Austria is described from a Lower Cretaceous (Hauterivian) pelagic to hemipelagic limestone succession of the Northern Calcareous Alps (Bajuvaric Langbath Zone). The isolated tooth crown originates from the upper Hauterivian Balearites balearis Zone (Balearites angulicostatus Subzone). The finding sheds light on the diversity and distribution of pliosaurids in the Lower Cretaceous, being only the second occurrence of conical-toothed pliosaurid in the Hauterivian worldwide and the first pliosaur from Austria. The pliosaur reported is the first from the entire northern, central and western Alpine chain, and the first evidence of Cretaceous pliosaurids from the entire Alpine arc. www.sciencedirect.com/science/article/pii/S019566711930237X |
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These pliosaurs obviously all had immensely powerful bites and extremely long jaws, but their jaws also appear to be quite thin. As far as the overall volume of aquatic macropredators' bite, I think Megalodon is quite likely to have the largest known bite, followed either by Livyatan or these huge pliosaurs. Livytan's jaws are long, but do not seem as long as the 2.5 to 3 meter pliosaur range. (Correct me if I'm wrong, I don't remember the length estimate of the actual jaw remains of Livyatan). On the other hand, Livyatan's jaws seem thicker and perhaps a bit more robust than those of the pliosaurs. So I'm not sure if the cetacean or the pliosaurs had the larger bite...
