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Fossil of dinosaur killed in asteroid strike found, scientists claim (bbc.com)
225 points by Hooke on April 10, 2022 | hide | past | favorite | 57 comments



A lot of doubt being expressed here. Tanis[0] was identified as potentially preserving the moment of the KT impact by 2013, and I believe this identification is now established beyond a doubt. The paper [1] makes the case for it. I've read it (review at the time at [2]), and it's solid, with multiple lines of evidence connecting it to the KT event. Most convincing to me is the tektites found in fish gills: these glass beads are considered a sure marker for the KT boundary, and the fact that they were taken in by fish in large numbers indicates they must have been floating in the water at the time of formation. If you don't trust me, on the authors list are Walter Alvarez, half of the pair that originated the impact hypothesis in the first place, and Jan Smit, another world-leading expert on it.

[0] https://en.wikipedia.org/wiki/Tanis_(fossil_site)

[1] https://www.pnas.org/doi/10.1073/pnas.1817407116

[2] https://news.ycombinator.com/item?id=19548093


Given that dinosaurs existed for hundres of millions of years and that we have found very few fossils, the probability of finding a fossil from a single day seems incredibly small.

But of course an asteroid strike may create very favorable conditions for fossilization.


The Tanis death assemblage contains land and river life mixed together with large amounts of mud — mud which is made partly of molten rock granules.

The hypothesis is that it was formed from the rapid drainage of a flooded plain, and that the flood was probably caused by the Chicxulub event.


Thanks for posting this. I didn’t know about it and it’s lead me down quite the Wikipedia rabbit hole.


The 90 minute documentary mentioned in the article aired this week, has the real fossils mixed with animations of the creatures and coverage of the excavation you may enjoy (Dinosaurs: The Final Day).


It also has salt-water fish mixed up with fresh-water fish.


It's a very good point and got me wondering, how do we know the dinosaurs were killed by a single asteroid strike? What if there were many within a relatively short time scale?

If you're going to answer "parsimony", what if these events aren't independent?

(I'm not a paleontologist)


Apparently, when the impact hypothesis was first presented as more than just speculation (i.e. with the iridium layer as evidence), a majority of paleontologists rejected it, preferring one based on long-term high-intensity volcanism in Asia. I believe this hypothesis still has a few proponents.

The collision of comet Shoemaker-Levy with Jupiter occurred as several distinct impacts, due to gravitational disruption of the comet in a previous close encounter with the planet. Something similar is clearly possible on Earth (perhaps even gravitational dispersion of a comet passing close to the Moon just before impact?) but the Chicxulub crater is large enough to explain the extinction event by itself (unless you hew to the volcanic explanation, I suppose), so the question is whether there is any evidence for multiple impacts. As far as I know, the global distribution of the physical evidence is indicative of a single source, but not definitively so.


At that point, they didn't even believe the volcanism hypothesis, the bias toward gradualism was so profound.



It’s a good theory, and may have occurred by large objects breaking up during atmospheric entry or it was a cluster of objects in space.


The K/T impactor had linear dimensions comparable to the scale height of the atmosphere. Unless the impact was at an extremely shallow angle (unlikely) breaking up in the atmosphere would have no significant effect. The mass of atmosphere that could potentially transfer momentum with the impactor before impact would be much less than the mass of the impactor.


Wouldn't the break up be more influenced by the gravitational acceleration imparted by earth? Most asteroids are rather loosely bound.


That would be tidal forces. There wouldn't be enough time for that.

Shoemaker-Levy orbited Jupiter for quite a while before it broke up and went in.


I think if something lived for millions of years, and impacts on earth are not uncommon, it was bound to happen at some point.

On a long enough timeline, improbable events are expected.


I don't think gp was questioning that, so much as the likelihood of finding more than one fossil from the same event, given all the times we could have found fossils from.


Wouldn’t this single event have a super high chance of generating fossils though giving that a) it wiped out a ton of life in one go and b) it released a huge amount of debris ready to cover things up nicely and preserve them?


Yes. What was incredibly lucky was the fossil stratum being exposed again at a time when we could spot them. There must be megatons more of this stuff, wholly inaccessible.


Not even single day, single hour ! (Violent water sloshing mixing marine, freshwater and land life caused by seismic waves rather than the "direct" tsunami.)


I have a mental image of them, frozen eternally into rock, looking up, pointing their little T-Rex hands skywards with a surprised look.


Your comment reminds me the final episode of Dinosaurs, where the try to dinosaurs accept their fate of the coming ice age and their impending unavoidable death.

Pretty heavy stuff for a comedy sitcom.

https://youtu.be/1VuovcM0Z20


The telling quote is:

"Dinosaurs: The Final Day with Sir David Attenborough will be broadcast on BBC One on 15 April at 18:30 BST. A version has been made for the US science series Nova on the PBS network to be broadcast later in the year."

say no more.


Over here that's PBS NOVA "Dinosaur Apocalypse: The Last Day" (2022) with Sir David Attenborough. https://www.pbs.org/wgbh/nova/video/dinosaur-apocalypse-the-...

It says "MAY 11, 2022 AT 10PM". Presumably that's EST or EDT.


This decent 25minute version will do until then. [https://www.youtube.com/watch?v=UChQHrjefVU] (Less a distinguished British accent. ;-> )


List of impact craters on Earth https://en.wikipedia.org/wiki/List_of_impact_craters_on_Eart...

Cretaceous–Paleogene extinction event (C-P or also K-Pg event) https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e... :

> A wide range of species perished in the K–Pg extinction, the best-known being the non-avian dinosaurs. It also destroyed myriad other terrestrial organisms, including some mammals, birds,[21] lizards,[22] insects,[23][24] plants, and all the pterosaurs.[25] In the oceans, the K–Pg extinction killed off plesiosaurs and mosasaurs and devastated teleost fish,[26] sharks, mollusks (especially ammonites, which became extinct), and many species of plankton. It is estimated that 75% or more of all species on Earth vanished.[27] Yet the extinction also provided evolutionary opportunities: in its wake, many groups underwent remarkable adaptive radiation—sudden and prolific divergence into new forms and species within the disrupted and emptied ecological niches. Mammals in particular diversified in the Paleogene,[28] evolving new forms such as horses, whales, bats, and primates. The surviving group of dinosaurs were avians, ground and water fowl who radiated into all modern species of bird.[29] Teleost fish,[30] and perhaps lizards[22] also radiated.

https://en.wikipedia.org/wiki/Near-Earth_object :

> A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU).[2] If a NEO's orbit crosses the Earth's, and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO).[3] Most known PHOs and NEOs are asteroids, but a small fraction are comets. [1]

Asteroid impact avoidance https://en.wikipedia.org/wiki/Asteroid_impact_avoidance :

> In 2016, a NASA scientist warned that the Earth is unprepared for such an event.[3] In April 2018, the B612 Foundation reported "It's 100 percent certain we'll be hit by a devastating asteroid, but we're not 100 percent sure when."[4] Also in 2018, physicist Stephen Hawking, in his final book, Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet. [5][6][7] Several ways of avoiding an asteroid impact have been described.[8] Nonetheless, in March 2019, scientists reported that asteroids may be much more difficult to destroy than thought earlier.[9][10] In addition, an asteroid may reassemble itself due to gravity after being disrupted.[11] In May 2021, NASA astronomers reported that 5 to 10 years of preparation may be needed to avoid a virtual impactor based on a simulated exercise conducted by the 2021 Planetary Defense Conference. [12][13][14]

- Nkalakatha the "#megamaser" (2022) https://www.sciencealert.com/extreme-megamaser-discovered-sh... ... (Can we harvest or collect and point - or pull against - such energy sources which are already present, using a minimum pertubative force in n-body idk QFT+QG fields in order to effectively read and write to points in stochastic spacetime, which is presumably all embedded in the horizon disc of one or more microscopic and larger black holes?)

Can a train of multiple solar collector + sails + lasers exceed (c + nlimit_approaching_c, or does that warp spacetime for NEOs, over their net effective path through spacetime?

- A QG Quantum Gravity duality for idk Gravitational lensing > Explanation in terms of spacetime curvature: https://en.wikipedia.org/wiki/Gravitational_lens

Claimed moons of Earth https://en.wikipedia.org/wiki/Claimed_moons_of_Earth

> Although the Moon is Earth's only natural satellite, there are a number of near-Earth objects (NEOs) with orbits that are in resonance with Earth. These have been called "second" moons of Earth. [3]*

> 469219 Kamoʻoalewa, an asteroid discovered on 27 April 2016, is possibly the most stable quasi-satellite of Earth.[4] As it orbits the Sun, 469219 Kamoʻoalewa appears to circle around Earth as well. It is too distant to be a true satellite of Earth, but is the best and most stable example of a quasi-satellite, a type of near-Earth object. They appear to orbit a point other than Earth itself, such as the orbital path of the NEO asteroid 3753 Cruithne. Earth trojans, such as 2010 TK7, are NEOs that orbit the Sun (not Earth) on the same orbital path as Earth, and appear to lead or follow Earth along the same orbital path.

> Other small natural objects in orbit around the Sun may enter orbit around Earth for a short amount of time, becoming temporary natural satellites. As of 2020, the only confirmed examples have been 2006 RH120 in Earth orbit during 2006 and 2007,[1] and 2020 CD3 in Earth orbit between 2018 and 2020. [5][6]

ʻOumuamua from ~Vega (2017)?: https://en.wikipedia.org/wiki/%CA%BBOumuamua


> Very few dinosaur remains have been found in the rocks that record even the final few thousand years before the impact. To have a specimen from the cataclysm itself would be extraordinary.

My understanding is, per an article in The Atlantic (and others I'm sure) a couple+ years ago, the modern theory is that excessive worldwide volcanic activity was already killing the dinosaurs for many years, the asteroid was simply the final death blow.

The fact that finding dinosaurs in the asteroid time frame seems to led support to the modern theory. That is, you can't find what wasn't there. The dino numbers were already significantly minimized.

Sidebar: The bonus I found in The Atlantic article is it got into the politics and (dare I say) close-mindedness of that "industry." For tbose fond of "trust the science" this article adds a darkside to that slogan.

https://www.theatlantic.com/magazine/archive/2018/09/dinosau...

https://massextinction.princeton.edu/


> the modern theory is that excessive worldwide volcanic activity was already killing the dinosaurs for many years,

There is no good evidence of this. Also, Keller is viewed as fringe, I believe.


Content marketing is really getting wild.


Side note: "scientists claim" (and Twitter is now full of "fact-checkers say").

Well, gee, I thought the ravings of crazy uncle Bob made it to BBC! Of course scientists claim. To quote George Carlin:

> News people like to say “police have responded to an emergency situation.” No they haven’t, they’ve responded to an emergency. We know it’s a situation.

This can't even be explained by the erosion of truth in recent years because, hell, even Andrew Wakefield was a senior lecturer, I daresay a scientist.


Scientists can hypothesize, they can speculate, they can opine; they can say a lot more things than claims.

But if you've read the article, it's apparent why, in this instance, these paleontologists would be claiming that these specimens lived thru the dinosaur extinction event as opposed to a more restrained verb.


It is more of a question whether a news source should report about the finding at this stage, or the "scientists <confirm/deny> with high degree of certainty that" step.


It's basically an adverisement for an upcoming TV show. Popular science needs to be accessible and entertaining, which is generally at odds with the cold hard facts. New Scientist often has me eye-rolling in this regard.


It's not like some scientist wannabes made up some stuff to be on BBC. They really found some evidence and started saying meaningful things.


What does that George Carlin quote even mean? Having trouble parsing it.


The bit that quote is from is about how people (particularly media reporters) use unnecessary filler words to dress up and dramatize what should be a simple statement.

I guess OP is saying that the BBC would obviously not be publishing the speculation of an unqualified layman, so the "scientists claim" is unnecessary. But doesn't seem to be to be the same thing Carlin was critiquing.


The research hasn’t yet been published in academic journals, or peer-reviewed. I believe that why that specific language was used.

Nonetheless I find these new discoveries fascinating.


The fossil site was a huge find that made a lot of news a couple years ago. There was a PNAS article about it, though it didn't discuss these particular specimens: https://www.pnas.org/doi/10.1073/pnas.1817407116


Since the scientists didn’t really see it happening, I would add “without evidence” to the title.


Maybe they should add “without evidence” to the title simply because temp8964 did not see it happen, and anything less is heresay.


The article explains some of the evidence, and their academic papers explain more.


Of course there is evidence. But today's journalists like to reject the evidence and add the 'Without evidence' catchphrase. I chose to not add "/s".


Havent read the article, but this title reminds me of the dialogue between the two guards in front of Jack Sparrow in The Curse of The Black Pearl:

Murtogg: [shoots Mullroy a confused look] The Black Pearl is a real ship.

Mullroy: [turns to Murtogg] No. No, it's not.

Murtogg: Yes it is; I've seen it.

Mullroy: You've seen it?

Murtogg: Yes.

Mullroy: You haven't seen it.

Murtogg: Yes, I have.

Mullroy: You've seen a ship with black sails, that's crewed by the damned and captained by a man so evil that Hell itself spat him back out?

Murtogg: ...No.

Mullroy: No.

Murtogg: But I have seen a ship with black sails.

Mullroy: Oh! And no ship that's not crewed by the damned and captained by a man so evil that Hell itself spat him back out could possibly have black sails, therefore could possibly be any other ship but the Black Pearl? Is that what you're saying?

Murtogg: [thinks, then smiles] ...No.

Mullroy: Like I said, there's no real ship as can match the Interceptor...

(taken from https://www.moviequotedb.com/movies/pirates-of-the-caribbean... )


Of course in that story the black pearl was real, right...


But what asteroid killed that dinosaur - could have been another one? or the main one?


> ...there are fish that breathed in impact debris as it rained down from the sky.

That... is either very poorly worded or obviously not true.

That said, I can't wait to see what we will think about these fossils a decade later. Right now the news seems a bit too sensationalist to be believed fully.


> I can't wait to see what we will think about these fossils a decade later.

That is actually I think the proper attitude towards cutting edge research.

> That... is either very poorly worded or obviously not true.

But fish do breath. They filter water through their gills to do gas exchange. This process is called breathing. Why do you think it is obviously not true? (Or rather how would you word it better?)


Added to that there are fish that breath normal air like we do. Those are known as labyrinth fish. A common example is the Betta (or Siamese fighting) fish.


I didn't mean to imply that fish don't breathe.

The part as it rained down from the sky, to me, means that they were breathing the particles while they were falling from the sky. Not possible unless they were above water (which, granted, is possible for short periods), which would go against the fact that they were fish.


>Not possible

Stuff rains down from the sky, stuff enters water, fish start breathing in the stuff that rained down from the sky as more of the same stuff continues to rain down from the sky I don't know, seems possible to me.


Presumably fish don't breathe things that are in the sky


Things that are in the sky can fall into the water. “Rained down from the sky” implies this pretty plainly when the context is talking about fish, who are generally understood to be down below the sky in… water. “Down from,” not “in” the sky.


Not to mention that the fish in question seem to have been in a shallow "sloshing flood" at the time.


It says "as it rained down" from the sky -- once it hits the water it is no longer raining down.


I think it’s a reasonable assumption that once they were breathing it, there was more of it concurrently raining down, so the description seems fine to me.


It would continue to fall through the water but a lower speed. The water would be filled with tectonic debris which the fish breathed in.


Many will automatically just believe this now because it says BBC and science. Poor journalism, they should put clearler disclaimers that this hasn't been peer reviewed at the top


But the article links to a peer-reviewed paper about the find?




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