What killed off the Megalodon, supernova radiation or the Great Whites?

February 16, 2019 3:49 PM

2.6 million years ago, a nearby supernova impacted earth around the time of a significant die-off of large ocean animals at dawn of Pleistocene, in a newly documented marine megafaunal extinction (press release) tied to the presence of Iron-60 (Wikipedia). The research is reported in Astrobiology: Muon Radiation Dose and Marine Megafaunal Extinction at the end-Pliocene Supernova. A notable example of extinct marine megafauna is the currently popular Megalodon, but another recent study disputes the supernovae explanation for Meg's extinction, instead linking it to the rise of the Great White Shark (NatGeo): The Early Pliocene extinction of the mega-toothed shark Otodus megalodon: a view from the eastern North Pacific (PeerJ).
posted by filthy light thief (16 comments total)

I'm pretty sure it was Jason Statham
posted by ActingTheGoat at 4:26 PM on February 16, 2019 [8 favorites]

Statham’s gonna play the supernova in the Meg prequel.
posted by GenjiandProust at 4:28 PM on February 16, 2019 [5 favorites]

Neat. Maybe we can have a fossil month like we had a poop month?
posted by bonobothegreat at 6:28 PM on February 16, 2019 [4 favorites]

With Moby Dick having played a central role in my college thesis, I find the controversy about whether the Megalodon still exists to be delightful:

A few reports of alleged encounters with large, unidentified sharks have been proposed as evidence for C. megalodon survival. One of the most widely cited is an extraordinary tale recounted by Australian naturalist David Stead (1963: 45-46):

In the year 1918 I recorded the sensation that had been caused among the "outside" crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing grounds---which lie in deep water---when an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, "pots, mooring lines and all". These crayfish pots, it should be mentioned, were about 3 feet 6 inches [1.06 m] in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as a indication of the state of mind which this unusual giant had thrown them into. And bear in mind that these were men who were used to the sea and all sorts of weather, and all sorts of sharks as well. One of the crew said the shark was "three hundred feet [90 m] long at least"! Others said it was as long as the wharf on which we stood---about 115 feet [35 m]! They affirmed that the water "boiled" over a large space when the fish swam past. They were all familiar with whales, which they had often seen passing at sea, but this was a vast shark. They had seen its terrible head which was "at least as long as the roof on the wharf shed at Nelson's Bay." Impossible, of course! But these were prosaic and rather stolid men, not given to 'fish stories' nor even to talking about their catches. Further, they knew that the person they were talking to (myself) had heard all the fish stories years before!

One of the things that impressed me was that they all agreed as to the ghostly whitish color of the vast fish. The local Fisheries Inspector of the time, Mr Paton, agreed with me that it must have been something really gigantic to put these experienced men into such a state of fear and panic.

This report initially sounds promising, especially considering Stead’s proclamation of the witnesses’ integrity. But how can we actually believe a report that speaks of a 150-300 ft (35-90 m) creature---longer than any other animal ever recorded? Shuker (1991, 1995, 1997) contends that, if the account is true---as he seems to believe---fear and surprise could have resulted in these unbelievable figures. Shuker expresses confidence that the actual size of the creature responsible must still have been gigantic to instil such a shock in the fishermen. Stead and Shuker propose that a living C. megalodon would be a near-perfect match.

With emphasis added, of course.
posted by Little Dawn at 6:29 PM on February 16, 2019 [15 favorites]

Maybe we can have a fossil month [...]?

I'll do my best to make Fossil February happen :)
posted by filthy light thief at 8:00 PM on February 16, 2019 [5 favorites]

"What killed off the Megalodon, Dad?" is a frequent topic of conversation at our dinner table.
posted by JamesBay at 8:27 PM on February 16, 2019 [6 favorites]

Because "radiation" doesn't grab the imagination of kids, "an exploding star" would probably be the summary here :)
posted by filthy light thief at 8:31 PM on February 16, 2019 [2 favorites]

The competition hypothesis for megalodon extinction was also discussed recently on PBS Eons (YouTube). It was a particularly good episode.
posted by biogeo at 9:37 PM on February 16, 2019 [3 favorites]

I sell Megalodon teeth at the Noordermarkt in Amsterdam. Coprolites too.
posted by humboldt32 at 11:02 PM on February 16, 2019 [1 favorite]

We're the new exploding star.
posted by bleep at 12:40 AM on February 17, 2019 [2 favorites]

I'm pretty sure it was Jason Statham

Mathowie spoilered that one when he mentioned that Statham doesn't punch the shark in Meg.
posted by srboisvert at 6:32 AM on February 17, 2019 [2 favorites]

There goes the (stellar) neighborhood.

~50 pc = ~160 light years. Pretty weird that muons from that distance can affect life hundreds of feet underwater. Guess it's kind of like a mean neutrino.
posted by RobotVoodooPower at 11:01 AM on February 17, 2019 [3 favorites]

Just wanted to say this was a really cool read, thanks for posting. :)
posted by mordax at 11:05 AM on February 17, 2019 [1 favorite]

Mathowie spoilered that one when he mentioned that Statham doesn't punch the shark in Meg.

Excuse me, sir and with all due respect to User 1, Statham puches him in the face with a pointed stick (after using his jet fighter submarine fin to slice it open and then rodeo riding the jumping Meg out of the water.)


filthy light thief, I second "an exploding star." Great post.
posted by ActingTheGoat at 12:09 PM on February 17, 2019

I took our younger son, 9, to see the Meg last summer. While I thought there might be some artistic compromises for the fact it was aimed mostly at a PRC audience, in the end it was a goofy, charming movie. I particularly liked the fact that there was parity onscreen for Western (i.e., "white") characters and characters from China. And they were all, within the constraints of the genre, "real" characters, and not racial stereotypes.
posted by JamesBay at 3:03 PM on February 17, 2019 [1 favorite]

It's great when two branches of Science can inform each other, but it seems odd they would focus on one species. I suspect that they just found a way to shoe-horn in the name of a popular mega-fauna as a way to get their paper noticed by the general public, which isn't necessarily a bad thing. Personally, I lean towards the competition hypothesis but as is usually the case, the truth will probably turn out to be a little from column A and a little from column B. It's a very interesting post and much food for thought.
posted by ambulocetus at 5:45 PM on February 17, 2019 [1 favorite]