I like the theory that the earths rotational speed decreased as the earths diameter increased due to cooling of the magma.
Thus the weight of the dinosaurs increased dramatically since the centripetal force which counteracts the force of gravity decreased. A 500lb dinosaur suddenly came to weigh 1000lbs or more. (Of course this happened over a period of dozens, perhaps hundreds of years, but the rate of change was faster than the creatures DNA could adapt. Big dinosaurs produced big dinosaurs.)
Many died because their musculoskeletal framework could no longer protect the internal organs from crushing. Their ability to capture prey was drastically reduced because they were slower.
Many large dinosaurs moved into shallow lakes to help support their weight but their food supply became less. Smaller dinosaurs which lived in the water became long term survivors,like alligators.
Major changes in the ecosystem from the increased day and night periods caused huge populations to die out (or radically adapt). The days were hotter, and the nights became longer and colder.
Huge storm systems developed as the entire weather system was destabilized. Longer days absorbed more water into the atmosphere. Cloud cover and rain became continuous. Warm blooded creatures gained advantage.
Smaller creatures became survivors. Creatures with the greatest ability to use multiple food sources and move into a wider variety of geographic areas became the new kings of the ecosystem.
< /fun_speculation>
PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]
Weird find.
But neat.
Kinda like the flash frozen fish they found inland by the coal beds or some such (Exact info unremembered).
Thanks for finding and posting this.
Would love to see the stuff in situ, but few reporters think to try to get those kinds of photos.
I just checked out your homepage and I see you already have a previous written article waiting to pounce on me :-)
But as someone who has read and enjoyed your many fine post I am actually shocked to see you brought into the Asteroid hypothesis.
But this I wrote this previously and updated it a little bit on why an Asteroid didn't kill the dinosaurs or cause the Iridium layer, It should cover all your points and then some.
Iridium Layer
1) The Thin Layer of Iridium:
First and foremost, That "Thin" layer of iridium as it is described represents 10,000-100,000 years of sediment. How on Earth could iridium (a heavy metal no less) stay up in the atmosphere that long? It would at most wash out within months if not weeks or days.
2) The amazing prediction:
You consistanly hear something along the lines of "Result X is what you would expect to find from a carbonaceous chondrite meteor about 10 kilometers in diameter hitting the Earth 65 million years ago".
It isn't the amazing prediction they make it out to be.
a) Well why should we expect those results? Is there other 10 kilometer meteors that have hit the earth that we can compare the findings to?
b) The original Alverez paper that started this whole hypothesis guessed the Asteroid to be 6-15 km. Which is a wide range.
c) The Chicxulub crater exact size is still debated. I've seen values between 180 to 300 kilometers which is a pretty big range, So they can't even agree on the size of the crater so how can they guess the exact size of the meteror (If in fact it was one)?
d) The Radiometric dating that was carried out only one out of the ten samples gave a perfect date of 64.7 million years ago with other results spread over an eight million years. So they obviously just picked the one result that gave them the results they liked and fit their hypothesis (More on this in #7) and ignored the others.
3) Iridium spikes aren't uncommon:
a) Notice the larger than the KT iridium spike way later in the Paleocene (on the upper right side)
b) There are multiple Iridium at some locations
For example, Lattengebirge, Bavarian Alps, has three iridium anomalies, below, at, and above, the K-T boundary (Graup and Spettel, 1989). The oldest anomaly antedates the K-T boundary by 14,000-9,000 years. To which of these anomalies might the Rocky Mountain (and other) "K-T boundary" iridium spike be isochronous, if any? The Brazos River, Texas, locality has two iridium spikes, one at the K-T boundary, and one below (Ganapathy et al., 1981). At Gubbio, Italy, both the iridium and shocked minerals do not occur as a sharp K-T spike; enrichment begins 2 m below the boundary and extends 2 m above it for a total of about 400,000 years (Crockett et al, 1988; Rocchia et al., 1989)
4) Volcanos can also produce Iridium spikes.
For example the 1783 Lakigigar eruption produced an 18-fold iridium enrichment in the ice cores of Greenland which is well within the range of the iridium spikes of the K-T event. So volcanic activity can produce iridium spikes and boy was there monstrous volcanic activity during the KT. The Deccan traps of India and Pakistan- (covering 500,000 sq. km and up to 2 km thick) , southern Brazil , western U.S, etc which was more than enough to produce the iridium spikes. Plus the volcanic activity unlike a one shot asteroid lasted a long time so it could have been laying down iridium over 10,000-100,000 years. Koeberl (1989) also reports iridium concentrations up to 7.5 ppb in volcanic dust bands in blue ice fields from Antarctica.
5) Check out the distribution of iridium in the picture below
a) The concentration of iridium is spread randomly around the world, If it was caused by an Asteroid wouldn't there be more by where the Asteroid hit.
b) There is equal if not bigger iridium spikes in the Southern Hemisphere, Air doesn't mix well between the Hemispheres so if an Asteroid hit in the Northern Hemisphere there should be more there and only a little in the Southern Hemisphere. That is not what we find.
6) Iridium is missing from the Chicxulub crater itself!!!!!
How can an Asteroid or whatever (It's still not proven to be a meteror crater and it's looking like one less and less) that caused the Chicxulub crater produce a iridium spike around the world when it didn't contain iridium?
Side Note: In the link is an example of how scientist who buy into the Asteroid killed the Dinosaurs hypothesis will often deliberately ignore evidence to the contrary. The findings in that report clearly show that whatever happened at Chicxulub has nothing to do with the K-T yet the scientist(s) refuses to even consider the possiblity, They even say so in the paper, Quote from the conclusion "If we exclude the extremely implausible assumption that the K/T boundary is not related to the Chicxulub impact event". That is just poor science, You can't just exculde evidence you don't like.
Stuff like that unfortunately isn't uncommon, The Asteroid proponents have been very shady with evidence refuting their claims (More on this)
7) There is increasing evidence that the Chicxulub crater predates the end-Cretaceous mass extinction by about 300,000 years.
a) More info here and here.
b) Again not surprising since the Radiometric dating that was carried out only one out of the ten samples gave a perfect date of 64.7 million years ago with other results spread over an eight million years.
8) The so called "Fingerprint".
a) The ratios of platinum-group elements ruthenium, rhodium and iridium in the KT boundary are suppose to show meteoritic origin. Well those elements could also be coming from volcanos and the "Fingerprint" actually shows volcanic origin because along with those elements there are also high arsenic, antimony and selenium levels in the KT boundary which are very rare in meteroites but common in earthly volcanos.
9) The Soot.
It is often claimed that the soot in the K-T boundry shows a meteror caused a world wide forest fire but it's not true..
a) Again you have the same problem as you do with the Iridium layer in that how in the hell did the soot stay supsended in the atmosphere for thousands of years?
b) The nature of the soot doesn't show it was massive amounts of vegetation that burned at the time, In fact it shows the opposite. The soot contains very little charcoal which if a lot of vegetation was burned you would expect a lot of it and Abundant vitrinite (coalified plant tissue) is recorded. Plants can't turn to coal if they are burned!!!
c) In Danish sections the soot starts about 50,000 years earlier than the iridium anomaly.
10) Tektites/Basaltic spherules
The tektites/basaltic spherules found in the KT Boundary are often used to further the idea of a meteror strike
a) Same problem with the Iridium and soot in how were they able to stay up in the atmosphere for 1000s of years.
b) They could also be from Volcanic origin
c) There presence really doesn't prove anything because Tektites are actually quite common since small meteors are hitting the earth and/or Volcanoes are going off all the time (releatively speaking). On a "Feild trip" students at the university of Maryland were able to collect 40 pounds of them.
d) Like the Iridium, The Spherules age doesn't always match each other and in some places there are multiple layers.
From http://www-geol.unine.ch/MSA/mexico.html
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In the discussion (see "What happened 65 millions years ago"), we saw that the age and the origin of spherules remain controversial. This photo (From Monterrey, Mexico) shows you two distinct spherules layers separeted by marls, indicating a multi-event scenario near the KT boundary. (Note: The Maastrichtian was the last period of the Cretaceous)
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For another example of duel Spherule layers see section #12
e) The spread of the Spherules.
It is often said that the spread of the Spherules show a meteror hitting Chicxulub at a southeasternly direction with smaller spherules as you spread out. Yes it looks that way if you only include Western North America but if you include the rest of the world it doesn't.
Here is the worldwide spread map again.
Just connect the dots starting with Chicxulub and going NW to see how crazy that sounds. In order for the spread to be like that the cloud would start from Chicxulub the spread out to NW USA then head out into the North Pacific (OK so far so good) then make a 90° left (S) turn and head into the south Pacific stopping at Antarctica then make another left turn (E) and go through the Straights of Magellan then make another left turn (NE) and go up to Brazil and back to the Gulf of Mexico (depositing the second layer I guess) and continue onward to New Jersey and then finally cutting across the Atlantic to Europe and then from there working it's way to New Zealand and what ever is left over somehow gets back to Italy. Yeah, That sounds plausible.
11) stishovite
Stishovite is the best evidence favoring a meteor strike since it is only known to form in one, However
a) Stishovite is still simple SiO2 (Sand). While as of now it hasn't been known to be formed in Volcanoes that doesn't mean it's necessary impossible. In the late Cretaceous there was massive volcanism unseen today, Today's volcanoes might not be able to produce the pressures to create it but the massive volcanoes of the Cretaceous might have.
b) Stishovite has only been found in New Mexico and Montana. Which means it is possible that there could have been local smaller Barrington or Tunguska type strikes in that area that the traces have been lost.
c) I can't find any Stishovite at Chicxulub itself, Here is an inventory of cores taken at Chicxulub Stishovite isn't mentioned and a search on the Chicxulub Scientific Drilling Project home page for Stishovite turns up nothing which suggest scenario a or b above.
12) The Tsunami.
It is often claim that the Asteroid caused a Tsunami which left sediment around the Gulf of Mexico area that can be seen today. Well that's been debunked.
Quote right from the Geological society
In l992 the only glass spherule layer known in NE Mexico occurred at the base of a thick siliciclastic unit bearing the K/T boundary at its top. The glass spherule layer could only be causally linked to the K/T boundary impact by interpreting the intervening siliciclastic unit as an impact-generated tsunami deposit.
This hypothesis became very popular even though there was contrary evidence from the beginning – namely, bioturbation (churning caused by burrowing organisms), rate of sedimentation and the position of the K/T boundary and Ir anomaly. The tsunami hypothesis was challenged during the l994 LPI-sponsored field trip (led by the present authors) by trace fossil expert Toni Ekdale, who discovered bioturbation within the upper siliciclastic unit.
Although he was effectively booed for this observation, he later returned to Mexico to study many of the classic K/T localities and document several horizons of bioturbation. In El Penon, J-shaped burrows infilled with spherules were found near the base of the sandstone of layer (unit 2) and at the top of the sandy limestone layer that is within the underlying spherule layer (unit 1) in many sections. This indicates that the siliciclastic unit was deposited over a long time, during which the ocean floor was repeatedly colonised by invertebrates. It also suggests that the underlying spherule deposit does not represent the original fallout and that its re-deposition was interrupted by “normal” deposition - of a bioturbated limestone layer (Fig. 3).
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Figure 3. El Penon, Mexico. Impact spherule layer at base of siliciclastic deposit is separated by a 15-20 cm thick sandy limestone. J-shaped burrows infilled with spherules are present in the sandy limestone and sandstone unit above. This indicates that both the spherule and sandstone units were deposited over an extended time period that excludes tsunami deposition. |
What Lived and What didn't
This is the crux of the Dinosaur were killed by an Asteroid hypothesis. What would be expected to die out due to an asteroid induced global nuclear winter lived while what you would expect to survive didn't.
1) Southern Hemisphere species were equally devistated as the Northern Hemisphere ones. This makes absolutely no sense. An asteroid hitting in the Northern Hemisphere should cause more devistation in the Northern Hemisphere.
2) Freshwater Species including amphibians (100% survial rate) did quite well. One only has to come to upstate NY to see the damage done to freshwater species by acid rain, Some lakes are completely dead. If the releatively tiny amount of acid rain put out by midwestern plants can cause all that damage then the massive amounts of acid rain produced by a global nuclear winter would have had devistating effects all all freshwater species. That is not what we see.
3) Plankton
a) Diatoms. The K-T event did not much affect the diatoms. Harwood (1988), based on studies from Seymour Island, eastern Antarctic Peninsula, the first to record siliceous microfossil assemblages across a K-T boundary sequence, notes that diatom survivorship across the K-T boundary was above 90 percent. Resting spores increase from 7 percent below to 35 percent across the K-T boundary.
b) Dinoflagellates. Dinoflagellates also were little affected by the K-T event (Bujak and Williams, 1979). Brinkhuis and Zachariasse (1988) record no accelerated rates of extinction across the K-T boundary in Tunisia. Nor does Hultberg (1986) in Scandinavia. Danish dinoflagellates responded more by appearance of new species than by extinctions (Hansen, 1977), as did Seymour Island assemblages (Askin, 1988).
c) Yes other plankton did suffer massive extinctions but it wasn't because of the Asteroid or K-T event.
Marine calcareous microplankton, the coccolithophorids and planktonic foraminifera, were hit hardest of all by the K-T event. Thierstein (1981) proposes that the coccolithophorids extinctions were the most severe plankton extinction event in geologic history; via a "deconvolution" process, Thierstein (1981, 1982) reduced a Cretaceous-Tertiary "transition," in which Cretaceous assemblages were replaced by "new" Tertiary taxa, to an instantaneous catastrophe. Perch-Nielsen et al. (1982) note that the "catastrophic event"at the K-T boundary did not result in geologically instant extinction of the calcareous nannoplankton, and that most Cretaceous species survived the event. At DSDP Site 524, a sample above the K-T boundary contains 90 percent Cretaceous species. Isotopic analyses indicated that the Cretaceous species were not reworked specimens, but represented survivors of the K-T event that continued to reproduce in the earliest Tertiary oceans. The relict species became extinct some tens of thousands of years after K-T boundary time, probably via environmental stresses.
d) Antia and Cheng's (1970) work on survival times of phytoplankton species in complete darkness indicate that 1 month of complete blackout would produce 13 percent extinction, 3 months 68 percent extinction , and 6 months 81 percent. Thus, the 6 month to 1 year global blackout predicted by Wolbach et al. (1985) would have obliterated diatoms, dinoflagellate, and coccolithophorids precisely at the K-T boundary. A blackout event is not reflected in the algal record. The calcareous coccolithophorids and foraminifera were likely affected by pH change of the marine mixed layer via CO2 mantle degassing by the Deccan Traps volcanism.
So please tell me how did photoplankton who depend on sunlight for their very exsistance not only not die out but actually thrive during a global blackout??
e) Another interesting thing about plankton, Microfossils were actually found in the Chicxulub crater itself!!! and even though they are essentially at "Ground Zero" they show no ill effects.
4) Reptiles would have suffered greatly if an Asteroid struck however they seem to have cruised through the K-T with no problems.
a) Turtles "The Hell Creek and Tullock formations contain many turtles, and span the Cretaceous-Tertiary boundary. Over 3000 specimens were counted on a modified minimum number basis from 510 localities. At least 15 of about 19 Cretaceous genera and subgenera survive into the Paleocene. The magnitude of the change in diversity is less than or comparable to examples within the Tertiary. These data do not support a unique comprehensive extinction at the end of the Cretaceous as postulated on the basis of Iridiurn concentrations."
b) The four crocidilian families survived seemingly unaffected through the K-T boundary.
Most notable is the American Alligator whose ancestors were living at the time of Cretaceous right at ground zero
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This is the skull of an extinct animal closely related to living crocodylians (U.S. National Museum 22039). It comes from the middle Cretaceous (roughly 100 million years ago) of central Texas. It shows the occlusal pattern seen in the common ancestor of alligators and crocodiles. So they were there! |
Even forgetting about the implausibility of Alligators who are very cold sensitive surviving a nuclear winter, How did they survive the blast and the follow up tsunami an Asteroid would have caused?
5) Dinosaurs
a) Dinosaurs were living near the poles so they were capable of surviving cold temps, So if other animals could survive a global nuclear winter why couldn't they?
b) Dinosaurs were slowly going extinct before the K-T event and probably most of them were gone by it.
Sullivan (1987) For the 19 dinosaurian families (33 to 39 species) existing in the last 20 million years of the Cretaceous, most disappeared before K-T boundary time, and eight at the K-T boundary. The eight families are represented by 12 species in the final 3 million year of the Cretaceous, and most of the species by only a few specimens (two to 10, average 5.7).
c) Few dino fossils are found in the K-T boundary. Fossilization maybe a rare process mostly due to scavengers scattering the bones. However if an Asteroid strike instantly wiped out the dinosaurs than there would have been too many dead bodies for even the scavengers so there should be large amounts of Dinosaur fossils in the K-T boundary
d) Actually there is evidence that some dinosaurs made it into the Tertiary.
Tertiary Dinosaurs Here*, here and more Here
Quote from the 1st "here*" because it covers both b & d
http://www.eiu.edu/~scienced/3290/science/earth/rigby.html
In North America, dinosaurs reached their peak in the Middle Cretaceous period (about~l00 mya) when the Earth's climate was far warmer and more homogeneous than it is today, the result of a Cretaceous "greenhouse." Depending upon whose classification one uses, between 33 and 39 species of dinosaurs roamed the continent then. By the time of the catastrophe 65 mya, however, we found only 13 dinosaur species had survived. Dinosaur groups certainly were not dying of fright, waiting for the asteroid to hit; something else had to be forcing their extinction. By counting teeth in increasingly younger deposits, we could see that the remaining dinosaur species were declining rapidly. In Early Tertiary rocks we found only 11. Both the number of surviving species and the number of dinosaur fossils continued to drop in each successively younger deposit. Then in 1986, in a new locality named Doverzee, we hit pay dirt. In a stream deposit that lies completely above Cretaceous rocks, we found the world's youngest dinosaur remains to date.
This sediment contains a new group of mammal fossils very different from the older Cretaceous mammals. If the dinosaur remains were merely reworked fossils, we reasoned; then certainly the more abundant Cretaceous mammals would have gotten the same treatment and accompanied the dinosaur fossils during the process. After all, some of the Cretaceous mammal teeth were larger than the small dinosaur teeth that we were finding, so we hardly could have missed them. But after processing four-and-a-half tons of sediment at Doverzee, we never found a single Cretaceous mammal. Dinosaurs, it seemed, had outlived most of their Cretaceous mammal compatriots.
At Doverzee we found but five dinosaur species:
a ceratopsian (the horned and frilled dinosaurs); a hadrosaur (duck-billed dinosaurs); a questionable pachycephalosaurid (small, thick-bone-headed dinosaurs); and two small carnivorous dinosaurs (carnosaurs).
In rock samples deposited over a period of several tens of thousands of years the total number of dinosaur teeth recovered also dropped dramatically. Tooth abundance declined from about 200 teeth per ton of screened sediment well prior to the catastrophe to about 70 teeth per ton just before the asteroid hit to 40 teeth per ton just after the impact to teeth per ton at Doverzee.
This extinction process obviously took many thousands of times longer than the one-to-ten years the Alvarez team had suggested. We estimated that a minimum of 40,000 to a maximum of 240,000 years passed from the pronounced decline of dinosaurs just prior to the catastrophe to the last known occurrence of dinosaurs at Doverzee. The whole Pleistocene "ice age," including all four advances and retreats of major ice sheets, by comparison, lasted perhaps 250,000 years.
e) One group of Dinosaurs did make it and lives to this very day, We call them Birds.
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An Interesting read on the subject
Fascinating. Hope they show pictures of this soon!
