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Post by elosha11 on Apr 19, 2014 12:41:44 GMT 5
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Post by elosha11 on Oct 29, 2015 0:38:17 GMT 5
From: www.fallsoftheohio.org/Fossil_Fish.html  Fossil Type: Shark Tooth in Whale Tail Bone Name: Carcharacles megalodon (Agassiz) in Unidentified Whale Vertebra Formation: Calvert Formation Age: Miocene epoch Location: Chesapeake Bay, Virginia coast Notes: While there is evidence that the greatest Great White Shark was a predator of whales seems pretty obvious, actual evidence is not common. This tooth apparently broke when the shark bit into the whale's tail. There is some evidence that the bone started to heal the wound. Close-up View Vertebra is ~11 cm long x 6.5 cm wide. Collected in 1971. Anonymous collection. Date Posted: September 18, 2012 |
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Post by elosha11 on Dec 15, 2015 11:13:57 GMT 5
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Post by elosha11 on Dec 15, 2015 11:18:23 GMT 5
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Post by elosha11 on Dec 15, 2015 11:35:53 GMT 5
From national geographic, news.nationalgeographic.com/2015/08/150820-fossil-whale-skull-paleontology-science/. See bold section below; it appears Megalodon may have killed this large whale: It's also interesting that in the NG article, it implies Godfrey believes that the whale was only 20-25 feet long, but paleontologist Osborne, who discovered the whale skull says in a youtube video that the skull at 7 feet long suggest a baleen whale around 40 feet long and approximately 30 tons. If true, that may make this the largest known probable predation from a Megalodon. Here's the Osborne video, followed by NG article. By Rachel A. Becker, National Geographic PUBLISHED Fri Aug 21 11:47:41 EDT 2015 How do you retrieve an ancient whale skull buried in a Virginia riverbed? The same way you recover a human body: with a body bag. But first … how did an ancient whale skull get into a Virginia riverbed? Millions of years ago, the Atlantic coastal plains on the eastern edge of the United States were submerged by oceans. As the oceans receded to where they are today, they left behind layers upon layers of fossils, cut through by veins of rivers. And it was in one of those rivers that avocational paleontologist Jason Osborne discovered a giant, fossilized whale skull. Osborne, co-founder and president of Paleo Quest, had been exploring geological formations underwater sometime around June, 2013, when he literally bumped into the bone: “I might have actually banged my head into it,” he says. The giant skull—around six or seven feet long—was clearly visible in the riverbed and reasonably intact, a rarity for these kinds of fossils. “I spent probably 20 minutes or so around the skull to kind of determine size, what I’d have to deal with, how would get this to the surface,” Osborne says. “At the time I was like this is going to be impossible to try to recover, as massive as it is.” It took over two years for Osborne to be able to go back and disinter the giant whale skull. He needed, of all things, a bigger boat—but one that was still small enough to travel up a river. Coral Edge Adventures, a scuba shop in Virginia, sponsored the expedition—and Osborne gathered a team that included a videographer. “I wanted to document this,” he says. “As far as I know, there’s no documentation in blackwater conditions of a lift of such a massive fossil.” To maneuver the giant skull without damaging it, he took a few pointers from the people who make a living doing underwater recoveries: the cops. He obtained a neutrally buoyant body bag, the kind police use to pull dead bodies from the river. The bag has a fine mesh to drain water, but it also catches any microfossils and teeth that might trickle out of the sediment surrounding the skull. “I don’t think anyone has used a body bag for fossil recovery before,” Osborne says. But it worked, and they managed to lift the water-logged skull that Osborne called “heavy as hell” into the boat. At the dive shop, Calvert Marine Museum paleontology curator Stephen Godfrey identified the skull’s source as a 5–6 million year old baleen whale that probably stretched 20–25 feet from nose to tail, about the size of a modern day minke whale. Godfrey and Osborne noticed enormous tooth marks along the whale’s jaw bone, probably from a massive and ancient shark called a megalodon. The wound never healed, Godfrey explains, which means it happened around the time of the whale’s death, or after.
“Did it die and then get consumed by sharks? Or was that the death—the shark itself?” Osborne asks.“There’s still a lot to be determined about what the significance of the critter is,” he says, including whether the animal the skull came from is a newly discovered species, or the first occurrence of that species on the Atlantic coastal plains. |
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Post by theropod on Dec 16, 2015 2:40:03 GMT 5
elosha11: I think it looks so similar because its the same vertebra, it’s identical from the overall shape right down to small details of the discoloured patches and the individual scratch marks’ relative positions. 6-7ft (1.83-2.14m) is comparable to, or slightly lower than, the length of minke whale skulls from the southern hemisphere reported here→, so I think 40ft is likely an overestimate. Based on the 19-25% of body length comprised by the skull in Minke whales as well as other rorquals according to the same source , everything from 7.3 to 11.2m is plausible for a "6-7ft" skull, which is quite a large range. For a better figure, the first thing that should be done is measuring the skull length accurately. That fits the size range of a minke whale anyway, but whether it’s more similar in size to an average sized minke whale or to the upper end of that size range is unclear.
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Post by elosha11 on Dec 17, 2015 22:59:53 GMT 5
elosha11: I think it looks so similar because its the same vertebra, it’s identical from the overall shape right down to small details of the discoloured patches and the individual scratch marks’ relative positions. 6-7ft (1.83-2.14m) is comparable to, or slightly lower than, the length of minke whale skulls from the southern hemisphere reported here→, so I think 40ft is likely an overestimate. Based on the 19-25% of body length comprised by the skull in Minke whales as well as other rorquals according to the same source , everything from 7.3 to 11.2m is plausible for a "6-7ft" skull, which is quite a large range. For a better figure, the first thing that should be done is measuring the skull length accurately. That fits the size range of a minke whale anyway, but whether it’s more similar in size to an average sized minke whale or to the upper end of that size range is unclear. Yes, after I posted the images of the bitten centra, I noticed they were likely the same. Was going to edit but you beat me to it. I know Mike Sivverson has stated he has seen centra at the Aurora fossil museum with bitten in half by Meg like a "chainsaw." I would assume those are different than the centra here, but who knows? As to the fossil skull, the paleontologist on the video who discovered it says it is 7 feet. Would be interesting to contact him and see how he came up with his figure while Godfrey's appears much more conservative and more in line with your opinion. |
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Post by theropod on Dec 17, 2015 23:35:58 GMT 5
I didn’t post any opinion about the whale’s skull size. Obviously I don’t have any opinion on that except for what your sources claim it to be; as it says in the article you posted, "around six or seven feet long".
Watching the video it appears 7ft is perhaps the better figure for the complete skull length, while the other one may just have been an initial eyeballing, so I can happily go with that, resulting in sizes between 8.5 (head 25% of body length) and 11.2m (19%).
Still Osborne’s figures seem overestimated, especially the 30t weight (consider that that’s about the weight predicted for a 14m great white, which, at least if this whale had rorqual-like proportions, would be more robust in built).
The skull isn’t any longer than a minke whale’s, and minke whales are a far cry from massing anywhere near 30t, or even 20t.
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Post by elosha11 on Apr 20, 2016 1:02:23 GMT 5
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Post by Life on Apr 21, 2016 18:29:34 GMT 5
Man, can you imagine the sheer force behind that impact? And the embedded tooth is not even large as per Megalodon standards. Some Megalodon teeth have been found that were bitten by the Megalodon themselves during predation effort: fossilcsi.blogspot.com/2014/02/megalodon-attack-bite-marks-indicate_19.htmlI believe that a tremendous bite-force would be needed to damage a Megalodon tooth in the manner as shown the links. Megalodon teeth were extremely durable. |
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Post by Ceratodromeus on Jun 1, 2016 1:44:49 GMT 5
This is pretty cool, from the paper A New Mysticete Genus and Species and Its Implications for the Origin of Balaenopteridae (Cetacea, Mysticeti) Figure 6. Skull of Fragilicetus velponi gen. et. sp. nov. in anterior view. A, photo; B, line drawing.
Abbreviations: bocc, basioccipital; bs, basisphenoid; desc sop, descending part of supraorbital process of the frontal; fm, foramen magnum; fr, frontal; max, maxilla; par, parietal; pt, pterygoid; soc, supraoccipital; sop, supraorbital process of the frontal; sq, squamosal; sqc, squamosal cleft; vom, vomer. Scale bar = 300 mm. Figure 3. Localizations and orientations of shark bite marks on the holotype skull of Fragilicetus velponi gen. et. sp. nov. as seen from the anterior view. The shark bite marks are in solid black. The skull is in anterior view; only the right side of the skull is shown because it is that part that bears the shark bite marks.
Abbreviations: ali, alisphenoid; fr, frontal; pal, palatine; par, parietal; pgl, postglenoid process of squamosal; pt, pterygoid; soc, supraoccipital; sq, squamosal; sqc, squamosal cleft; sq-par, squamosal–parietal suture; sq-pt, squamosal-pterygoid suture; tc, temporal crest; vom, vomer; zyg, zygomatic process of the squamosal. Scale bar = 100 mm.
Figure 14. Artistic interpretation of possible interaction between a large shark and Fragilicetus velponi gen. et. sp. nov. as suggested by the shark bite marks on the skull of the holotype specimen shown in Figure 3.
The human in the upper right corner serves as a size reference. Illustration by Mark Bosselaers.
doesnt appear to be open access, at least i didn't find an open access copy of it. novataxa.blogspot.com/2016/05/fragilicetus.html |
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Post by elosha11 on Jun 10, 2016 20:29:42 GMT 5
Megalodon bitten bone from Aurora Fossil Museum  Here's the accompanying text: "Scientist can interpret C. megalodon’s foraging habits as hunting and feeding on whales. This interpretation is due to the abundance of cetacean (whale) fossils, often with preserved feeding marks, typically found close to or in the immediate vicinity of C. megalodon remains." Also really great picture of a pathological Meg tooth from Aurora.  |
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Post by elosha11 on Jun 10, 2016 20:36:13 GMT 5
The evidence of Megalodon and other shark feeding on whales is not common, but more commonplace than what is generally believed. I have seen several sources, including the Aurora site above, suggesting that Meg teeth found in close association with whales bones is likely evidence of feeding, regardless of whether the particular bones show damage. The idea is that it is simply more likely that the tooth in close proximity to a whale bone came from feeding on that whale, rather than that the tooth randomly came to rest in near proximity to a whale carcass.
This thread shows it's not difficult to find Meg (or other shark's) whale bitten bones, but they are still relatively rare. But when you add teeth found in proximity to bitten and unbitten bones, the evidence of feeding is even more widespread.
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Post by elosha11 on Jun 10, 2016 21:01:57 GMT 5
Images no longer available at paleodirect.com but found archived at the waybackmachine.com Very large vertebrae described as that of a large sperm whale bitten by Meg  Here's other images of Megalodon bitten bones still preserved on waybackmachine.   |
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Post by elosha11 on Aug 15, 2016 5:25:23 GMT 5
Whale fossil vertebral centra, found in close association with a Megalodon tooth in a Florida phosphate mine.  |
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