1. Depends upon the species under consideration, cannot generalize about the mass of mosasaurs in this way. Some mosasaurs were more robust than others.
Weight does not tell much about the predatory capabilities of an animal regardless. A mosasaur - assuming 9m TL - is a very large and deadly predator in its own right at this stage. Mosasaurs even in the 6m - 8m TL range, were large and deadly predators.
Ginsu shark was at par with modern Great white shark in size; 25 foot long Ginsu shark were most likely freak individuals. 8m TL specimen sound unrealistic.
2. Not sure!
Cardabiodon did not co-exist with Kronosaurus, but a Late Cretaceous shark.
Cardabiodontidae is among the lesser known and understood family of sharks in history. Preservation bias in fossils seems to be a factor.
1: Oh, sorry. By 'mosasaur', I actually meant Tylosaurus, which coexisted with the Ginsu and which we have evidence of interspecific interaction. Tylosaurus is approx 1.1 tons at 9 meters when scaled down from 'Bunker', see the Tylosaurus vs Deinosuchus thread (
here).
And what I actually meant by that is a predator killing another predator 1/3 its size does not mean it's superior at parity. I agree mosasaurs of all sizes were deadly predators
About Cretoxyrhina size, not quite. Looks like, as per recent analysis
here (which elosha11 considers reliable), it's a bit over 2.5 tons average (going from a 6 meter, 2.5 ton GWS), and does indeed get to 3.4 tons, not as a freak
2: Hmm...strange. I got the impression that they coexisted from the Cardabiodon vs Kronosaurus sympatric thread.
What may it have lived with then?
1. Thanks for the share.
Well, a Mosasaur at 9m TL weighing just 1.1 tons, seems to be an underestimate to me
but my contention is that the Mosasaurs were built for maneuverability on average. To be more clear, maneuverability factor compensated for lack of mass in Mosasaurs on average. The
Prognathodon FAMILY of Mosasaurs were an exception though (robust physiology).
Anyways;Taking on and killing a relatively longer Mosasaur, is an impressive feat of predation for any shark in my books - assuming both are adults and seasoned hunters. I do not disregard the 'mass factor' in this fight but WE need to factor-in seemingly unique biology of Mosasaurs [as a whole] in our assessment, these animals were highly maneuverable and capable of killing large sharks IN THEORY to say the least. To look at this matter from another perspective; it would take a very capable shark to take its chances with Mosasaurs in general.
Ginsu shark was a very impressive and capable macropredator featuring a good mix of large size and maneuverability (Newbrey et al., 2013).
To give you an idea, an estimated 2.5m TL Ginsu shark caught and killed an adult
Pteranodon whose wings measured 7.5m from tip to tip. Illustration for reference:
www.nature.com/articles/d41586-018-07832-wImagine that.
Yes;One known Ginsu shark fossil specimen suggest an individual approaching 8m TL in life (Newbrey et al., 2013); largest known and reported specimen in scientific literature). You got this part right.
Dare I say that the largest known Ginsu shark were capable of killing even the largest known Mosasaurs? Not far-fetched in my books.
2. Evidence of this implied co-existence does not exist, and that thread must be moved to the appropriate section (or) locked with the disclaimer stating that this isn't a sympatric contest.
Last known
Kronosaurus fossils = about 99.6 million years old
Earliest known
Cardabiodon fossils = about 95 million years old
Cardabiodontidae appear to be very strong sharks, built for speed but not as maneuverable as the Ginsu shark (Newbrey et al., 2013). Still, these sharks are akin to MUSCLE CARS of the sharks. These sharks had a broad distribution but were sensitive to environmental conditions (i.e. water temperature). Unfortunately, fossil record of
Cardabiodontidae is scarce due to odd distribution pattern around the world as well as cartilage not fossilizing well.
However,
Cardabiodontidae are only a part of the larger but very murky story of the
Lamniformes responding to evolutionary pressures from pliosaurs and mosasaurs with combination of gigantism and/or raw power at different points in time.
The popular impression that pliosaurs and/or mosasaurs had no peer at any point in time, is patently FALSE and misleading. Large sharks of these times are underrepresented and underappreciated in our constructs, and their impact on relevant ecosystems is also overlooked. A bundle of thanks to Dr. Michael Siverson for bringing these sharks to our attention.
Unknown shark specimens OMNH 68860 and KUVP 16343 respectively, say hello.
Fossil remains of OMNH 68860 at a glance below:-
These unknown sharks were actually contemporary with Kronosaurus.
KUVP 16343 in particular was a gigantic shark, approaching the size range of the late
Otodus obliquus.
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REFERENCES
Newbrey, M. G., Siversson, M., Cook, T. D., Fotheringham, A. M., & Sanchez, R. L. (2013). Vertebral morphology, dentition, age, growth, and ecology of the large lamniform shark Cardabiodon ricki. Acta Palaeontologica Polonica, 60(4), 877-898.
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KUVP 16343 laugh at the mighty Kronosaurus and punch it in the face. Kronosaurus whimpers and retreats...
Max Hawthorne cry himself to sleep.
Greyelosha11theropodAre any of these cases
confirmed predation on
reasonably sized (who can be reasonably estimated to be at least as big as the big Sharks during that time) Mosasaur? Bite marks that can be attributed to scavenging or that are on small Mosasaur do not mean anything for a parity contest. Also, you should perhaps consider that there may be bite marks of Mosasaur on those Sharks as well but they just never reserved due to the Shark cartilaginous skeletons that would just dissolve (along with all the evidences of interactions) as soon as the animals died. So the reality of how these animals may interact is probably not as one-sided as what you're suggesting here.
Mike Everhart (on Ocean of Kansas) even suggested that Mosasaur may have something to with Sharks extinction:
oceansofkansas.com/Greatrep.htmloceansofkansas.com/RapidMosa.htmlGo through my response above in full. You will have a clear understanding of my views about this subject.
Of-course, trophic interactions involving sharks and mosasaurs are documented and elaborated.
An excellent source material:
www.cambridge.org/core/journals/netherlands-journal-of-geosciences/article/sharks-eating-mosasaurs-dead-or-alive/C82A23CE060F2EA7980DC8532254E0F4"The amount of bone repair in KUVP 1051 is minimal. The slight bone remodelling, restricted to the edges of the wound confirms that the mosasaur survived the attack - it takes at least two weeks for bones to manifest any sign of visible reaction (Resnick, 2002). Absence of more extensive remodelling suggests that the mosasaur died soon after. The location of the bite marks provides clues to the morphology of the shark's dental arcade. The orientation of the bite marks suggests that the attack was directed downwards towards the upper surface of the tail.
The attacks described here were directed from above the mosasaur and the shark and mosasaur were meeting each other, rather than the shark pursuing from behind. (Of course, if the mosasaur was ascending from a dive while it was bitten, the attack would have been directed from the "back'). This suggests that the mosasaur was swimming at some depth before the encounter and perhaps met the shark while surfacing. In at least one case (KUVP 1094), the angle of the shark attack is strongly inclined to the mosasaur vertebral column.
What can we learn from shark injuries on mosasaurs? The survived injuries described here are from sharks between two and three metres in length. Attacks from larger sharks (if any) were probably fatal, e.g. in FHSM VP-13283, figured by Shimada (1997, fig. 4), that includes five vertebrae severed from the middle of the back of a 7-metre mosasaur. The mosasaurs that survived bite injuries are not large, ranging in length from five to seven metres. All of these survived bites are on the tail. It seems likely that attacks including bites elsewhere were normally fatal. Survival of the mosasaur suggests that it successfully defended itself. Sharks may have geared their attacks to moments when the mosasaur was more vulnerable."So Mosasaurs up to 7m in TL could withstand attacks from sharks up to 3m in TL in the tail section? However, bigger sharks proved too much for Mosasaurs in the same size range (5m - 7m in TL).
Now, it is realistic to assume that very large Ginsu Sharks (5m in TL and above) could kill very large Mosasaurs. However, these instances are/were mistaken for scavenging by people including some paleontologists? I do not get this mindset at all, particularly in writing.
There is also evidence of large Mosasaurs killing and eating small sharks. One such example in this link:
oceansofkansas.com/tylo-prey.html"The partially digested remains of a teleost fish (Bananogmius), a marine bird (Hesperornis), a small mosasaur (Clidastes) and a shark (teeth of Cretalamna?) were reported by Martin and Bjork (1987) as the preserved stomach contents of a large Tylosaurus proriger from the Pierre Shale (Middle Campanian) of South Dakota."---
Now tell me why a very large shark cannot kill another very large animal? Why these type of trophic interactions are mistaken for scavenging in literature by default? Based on the behavior of modern great white sharks? People are really stupid, it seems. WE do not really know how aggressive some of the ancient sharks were, most likely very aggressive and powerful.
I believe even the great white shark is capable of more than it seems. Depends upon how it will cope with potential changes in modern ecosystems in the future.
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Extinction is not a sound parameter to consider in deciding how a confrontation between two macropredators will play out. Extinction can be due to numerous factors and pressures which are very difficult to unmask and/or understand.
Ginsu shark's extinction had little impact in the grand scheme of things because other large sharks continued to thrive and provide competition to Mosasaurs in diverse environments. Cardabiodontidae for instance, were large robust sharks that could catch virtually anything. To Mosasaurs, these sharks proved to be a much harder nut to crack in comparison to the Ginsu shark. Competitive pressures from large lamniformes in diverse environments coupled with the pressures of the KT extinction event proved too much for Mosasaurs in the end. However, even the freaking KT extinction event could not do much to lamniformes.
Life: Do you have any evidence that
Cretoxyrhina preyed on mosasaurs 9 m long? All the pathologies reported in the literature seem to pertain to relatively small mosasaurs, max around 7 m, and were quite possibly smaller than an adult
Cretoxyrhina in terms of mass.
One Tylosaur specimen having a 3 feet long skull bear imprints of an attack by a Ginsu shark.
"The lower jaws and premaxillary of a 36 inch Tylosaurus sp. skull. (1) The bones from the large Tylosaur skull shown above have the tips of at least three Cretoxyrhina teeth embedded in them; one each in the outside of the left and right dentarys, and one in the premaxillary. This specimen consisted of the skull, lower jaws and several upper limb bones. Since it was badly weathered before discovery, much of the evidence of shark bites may have been lost. There are, however, several tooth marks across the muzzle (premaxillary), and the most anterior bite may have taken off a large chunk of the bone. The shark bites visible on the skull were not fatal and it is possible that this mosasaur survived this encounter with the shark, and died later of other causes."
Source:
oceansofkansas.com/bite.htmlNot sure how big this shark was but this wasn't a small Mosasaur.
Largest known Tylosaur specimen have a 4 feet long skull - if I am not wrong.