Dinosaur Killers

by Popoff, Alexander

  Some researchers claim that the hypothetical impact winter couldn’t kill off the dinosaurs because they were used to cold climate, as some of them were living far north and south. There were polar dinosaurs. These scholars claim that this adaptation of some species to cool climates invalidates hypotheses according to which dinosaur extinction was a result of long-term climatic cooling. This is a very naïve idea. Because there are now animals that live near the poles does not mean that if you take tropical animals and move them into the harsh polar conditions they will survive, just because there are some animals that can live in such conditions. The polar dinosaurs also would not have survived significant cooling because the harsh weather would become unbearable even for animals used to it.

  On the other hand, no animal, including humans, can get used to not eating food; the severe food shortage was the main problem in the Cretaceous catastrophe.

  Only small animals used to small amounts of food could survive. At the beginning of the catastrophe there was more than enough food for the carnivores and the omnivores because of the large amounts of dead plant eaters, but soon the corpses disintegrated. Catching small, agile animals was a very tough task, and the amount of flesh of the prey was not enough to feed the huge beasts. Imagine a lion feeding only on mice! One lion consumes about 5 to 60 kg of meat daily. Weights for adult lions range between 150–250 kg (330–550 lb) for males and 120–182 kg (264–400 lb) for females. What do lions eat? Practically any animal they can catch. But most of their victims weigh 50 to 300 kg. The average weight of a mouse is 20 to 40 grams. It’s impossible for a lion to catch hundreds of mice daily to survive. The lion would starve to death. The dinosaurs were in the same situation.

  After the K comet impacts the competition was between the small animals. The huge species couldn’t survive.

  Dr. Robert T. Bakker, a paleontologist at the University of Colorado, said to The New York Times in 1990, “It is as if nature aimed a smart bomb at the animal kingdom, designed to kill off only certain groups, particularly the large land animals.”

  “Why the small animals survived while the larger ones became extinct remains a riddle,” Bakker said in the interview.

  Researchers often ask the question of why some species died off while others survived. The most important factor was body size—only small species survived the harsh period of severely reduced energy. Small animals cope much better with low amounts of food and oxygen. Experiments also prove that small animals perform better in a low-oxygen environment.

  John Harrison, professor of biology at Arizona State University and graduate student Scott Kirkton tested the aerobic performance of grasshoppers given varying amounts of oxygen, and found that smaller grasshoppers can hop nonstop in atmospheric oxygen levels lower than that of our 21 percent. In fact, the smallest grasshoppers didn’t even have problems in oxygen as low as 5 percent.

  As for the larger grasshoppers? They were quite the contrast from their smaller brothers and sisters, as they tired out faster and their hopping rates rapidly dropped to zero. When extra doses of oxygen were given, however, they began jumping more, strongly suggesting an oxygen-stimulated boost, which increased their performance.

  The average body size of animals after the K-Pg events was between 2 and 5 kg. All species over 25 kg died off.

  The average surviving animals were as large as cats, chicken, and rabbits. The largest ones were as “huge” as dogs and goats.

  The smallest dinosaurs were mainly from the late Triassic and early Jurassic. Most of them perished before the end of the Cretaceous period. Dinosaurs got largest in the late Jurassic and Cretaceous periods.

  Most species extinctions, perhaps up to 95 percent, occurred as background extinctions, occurring throughout time. They were not caused by major catastrophes or drastic climactic changes. Most dinosaur species perished in background extinctions that occurred throughout the Mesozoic Era.

  All dinosaur species never lived together. Different dinosaur species lived during each of the Triassic, Jurassic, and Cretaceous periods.

  In the movies we see Stegosaurus and Tyrannosaurus side by side, but in fact the Jurassic dinosaur Stegosaurus had already been extinct for about 80 million years before the appearance of the Cretaceous dinosaur Tyrannosaurus.

  Large animals couldn’t squeeze through the K-Pg energy filter. They were too large. The typical dinosaur body mass was between one and ten tons. Far higher than the maximum “permitted weight” of 25 kg.

  Scientists have found that freshwater species largely survived, and they wonder why. Freshwater species generally are much smaller than the land and ocean animals, which helped most of them to survive. On the other hand, many of them were feeding on dead plants and corpses. The rains constantly added food from the land for the river and lake animals: dead and living plants, seeds, leaves, parts of corpses, etc.

  Many scientists suggest that the impact played some role in extinctions, but it was not decisive.

  However, without the K comet impact, the dinosaurs and many other species would have survived the Deccan volcanism, marine regression, etc. Volcanism and other disturbances were only contributing factors to the mass extinction, not the reason for it. There are also other contributing factors in the theories of various scholars I represent in the next chapter.

  If the K comet impact had not happened, there wouldn’t be the K-Pg boundary, the limit between two different worlds with different plants and animals.

  75 percent of the species died off in the mass extinction. However, the Cretaceous catastrophe boosted evolution on Earth.

  The comet impact events provided a specific, decisive blow to the ecosystem that was already under some stress, but it was far from critical. With the K comet impact, though, the ecosystem, the flora, and the fauna were changed forever.

  After the K comet hit, the Mesozoic world was over.

  THE Tunguska example

  The K-Pg events have some important specifics, which an adequate extinction theory should be able to explain properly.

  It should explain the loss of part of the terrestrial atmosphere. But how could we know that some of Earth’s air was lost? The animals who survived and the vegetation (food for herbivores) recovered very quickly, but they couldn’t become as large as before the catastrophic events due to the loss of atmosphere. The oxygen level and the air density in the post-catastrophic world were too low to restore the gigantism so common among the Mesozoic animals. In the present atmosphere, animals and the plants also don’t reach the gigantic size of the pre-catastrophic period, characterized by high levels of atmospheric oxygen and significant air density.

  Asteroid impact theory can’t explain in a satisfactory way many peculiarities of the K-Pg extinction, including the partial loss of the atmosphere. Comet intrusion gives a better picture of the extinction events, but we still can’t find out the precise mechanism of the loss of atmosphere.

  The analysis of the Tunguska meteorite explosion gives us important clues and a working hypothesis that could help us explain the mechanism of the loss of air.

  The Tunguska event is the largest meteorite explosion in recorded history and it happened only about 100 years ago, which makes it possible to have many relatively reliable reports from witnesses and have some firsthand authentic scientific research data from the year of the impact.

  The central part of the Tunguska event was an airburst of a celestial body, which occurred near the River Podkamennaya Tunguska in Siberia, Russia, at about 07:14 on June 30, 1908.

  At that day, the Taurid meteor shower, caused by the comet Encke, was at its peak. Most probably the Tunguska meteorite was a cometary fragment from Encke.

  Ľubor Kresák linked the Tunguska events to the comet 2P/Encke, the parent body of the annual meteor shower Beta Taurids, which peaks in intensity in the last days of June. He suggested that the orbital trajectory of the Tunguska meteorite would have matched a stray fragment from the meteor shower.

  The Tunguska events started
several days earlier. In Western Europe, large areas of the European part of Russia, and western Siberia, people observed high in the evening skies strange, silvery (noctilucent) clouds, brilliant twilights, green- and red-colored skies, and solar halos. Halos are an optical phenomenon produced by tiny ice crystals, which create colored or white arcs and spots in the sky. The crystals behave like prisms and mirrors.

  The optical phenomena high in the skies increased during the three days before the explosion.

  Noctilucent clouds are tenuous, cloudlike phenomena in the upper atmosphere, visible when the Sun is below the horizon. These clouds are high enough in the atmosphere that the Sun is still shining on them. This makes the clouds appear to glow in the dark against the darker sky. Noctilucent roughly means night-shining in Latin. Noctilucent clouds are composed of tiny crystals of water ice and are higher than any other clouds in Earth’s atmosphere.

  In the 1980s, Russian scientists observed that the space shuttle entering the atmosphere left specific silvery clouds in the wake of the aircraft. They linked the noctilucent clouds created by water vapor after the space shuttle and the noctilucent clouds before the Tunguska events, and suggested that the meteorite was a fragment of a comet, and that the coma and/or the tail, which consists of significant amounts of frozen water droplets, caused the strange, silvery clouds high in the skies.

  In 2009, the journal Geophysical Research Letters of the American Geophysical Union published a Cornell University research paper. Michael Kelley et al. observed noctilucent clouds days after the space shuttle Endeavour launched in 2007. Similar cloud formations had been observed following launches in 1997 and 2003.

  The Cornell University team also connected the two events and came to the same conclusion as their Russian colleagues that “The evidence is pretty strong that the Earth was hit by a comet in 1908.”

  The noctilucent clouds and the aurora borealis are often seen together, making an incredible night show high in the skies. The aurora is caused by charged particles from the Sun, or charged cometary dust and gases, entering the Earth’s magnetic field and stimulating molecules in the atmosphere.

  The silvery (noctilucent) clouds, solar halos, brilliant twilights, and green- and red-colored skies (i.e., the aurora borealis) are explained by the cometary dust, gases, and icy crystals from the coma hitting Earth’s atmosphere.

  As I described earlier, the coma is the nebulous envelope around the nucleus of a comet. It contains dust, gases, and microscopic water droplets. The neutral particles in the coma are excited by the solar wind, causing the particles to become ions. A continual stream of neutral particles is produced as long as the core of the comet is evaporating, and these neutral particles are continually converted to ions.

  Some researchers claim that the noctilucent clouds and the aurora couldn’t be caused by the Tunguska comet because it was too small, only 60 m to 190 m in diameter, and it was far away from Earth when this phenomena appeared in the skies. However, the Tunguska meteorite, along with the Taurids meteoric shower material, are fragments of the Encke comet, and they could be far apart and follow the same orbit. A comet, cometary fragments, dust, and particles travel along approximately the same orbit with dispersion, most of them lagging behind the comet. When the fragments, dust, and particles in orbit come too near some planets, which may nearly intersect that of the comet, the fragments, dust, and particles’ orbital velocities are perturbed.

  Comet Encke is still large enough, about 4.8 km in diameter, to be responsible for the silvery clouds and other phenomena. In 1908, it was even larger. Encke is a periodic comet and completes its orbit of the Sun once every 3.3 years. This is the shortest period of any known comet, and with every orbit it is losing matter. Since 1908, Encke has made 35 orbits about the Sun and lost lots of matter. Every year we can still enjoy the Taurids meteor shower, the matter of which is so generously provided by the comet Encke.

  The solar wind directs the cometary tail and to some extent the coma, too, so they can reach Earth several days before the bolide itself, depending on the position of the Earth, Sun, the comet, its fragments, the coma, and the tail.

  Ludwig Weber from Kiel University, Germany, reported that three days before the Tunguska explosion there were unusual geomagnetic effects. Several times he observed inexplicable, small, regular oscillations of Earth’s magnetic field lasting for many hours.

  The deviations of the compass needle began right after dusk and lasted well after midnight, coinciding with the light phenomena high in the night skies. The recordings looked like geomagnetic storms, usually associated with solar electrical activity.

  The noctilucent clouds, the aurora borealis, and geomagnetic disturbances were associated with the ionized coma and tail of comet Encke and its fragment, now known as the Tunguska meteorite.

  A geomagnetic storm is a temporary disturbance of the Earth’s magnetosphere caused by ionized particles (a solar wind or other sources of electric charged particles) that interacts with the Earth’s magnetic field. In this case, the disturbance was caused by the electrically charged cometary coma and tail.

  In March 1986, the Giotto spacecraft encountered comet Halley, approaching to within about 600 km of the nucleus. Results from this encounter have shown that the coma is negatively charged.

  In the article “Negative ions in the coma of comet Halley” by P. Chaizy and team, published in 1991 in Nature, the researchers reported that the coma of the comet Halley is negatively charged at a distance of about 2,300 km from the nucleus. The comet is about 11 km in diameter.

  In the bright, sunny morning of June 30, 1908, a fiery celestial body flew over central Siberia. It was described by witnesses as a spherical or cylindrical object; they saw its color as red, yellow, bluish, or white. The heavenly body moved downward for 10 minutes.

  But there were some strange events minutes before people observed the flying object.

  In 1926, I. M. Suslov recorded testimonies from local evenks, one of the indigenous peoples of the Russian North. A few individuals, sleeping in their chooms (huts usually made of animals skins or birch bark) some 30 km from the epicenter, reported that before they saw the bright object in the sky they were awakened by a strong wind, whistling and rustling sounds, sounds like numerous birds flying overhead, sounds of falling trees, and several claps of thunder; something invisible was hitting and pushing the huts and the people, knocking them off their feet, the ground was trembling, and something was thumping the ground. There were many reports that the chooms “were flying like a bird,” and people in their sleeping bags were tossed upward several times.

  The people observed strange “fire” on the tops of the trees. Some trees were burned from the top to the roots, including the roots of uprooted trees.

  The evenks said that trees were falling down. The pine needles, dry braches on the ground, and their reindeer were burning. It became very hot.

  Electrostatic effects can cause pushing, falling, flying (electrostatic levitation), St. Elmo’s fire, etc.

  Movement of objects were described by witnesses of other falling meteorites.

  When two objects in each other’s vicinity have different electrical charges, an electrostatic field exists between them. An electrostatic field also forms around any single object that is electrically charged with respect to its environment.

  Rubbing a glass rod with fur or cloth, or a comb through the hair, can build up static electricity. Static electricity from a plastic slide causes the child’s hair to stand on end. Static electricity is also generated by the friction of clothing against fabric in vehicles or furniture, and footwear against floor coverings. Most of these items consist of synthetic materials, all known to generate static charges. (Many are familiar with the spark or minishock produced by the discharge of static electricity when removing synthetic clothing.)

  The spark associated with static electricity is caused by electrostatic discharge, or simply static discharge, as excess charge is neutralized by a flow of charges fr
om or to the surroundings. Lightning is a dramatic natural example of static discharge.

  The Tunguska witnesses reported airborne objects like trees, chunks of upper layers of soil, chooms (huts), clothes, etc. Large waves appeared in the rivers against the current. Water suddenly disappeared from riverbeds. They saw St. Elmo’s fire: this is a weather phenomenon in which luminous plasma is created by a coronal discharge from a sharp or pointed object in a strong electric field in the atmosphere.

  Earth’s surface under storms becomes charged when the electric fields of the storm get strong enough. Grass, trees, animals, people, and everything start giving up a charge that flows up into the atmosphere; sometimes it can be seen as St. Elmo’s fire. The intrusion of a comet and its coma can cause effects of charging and discharging of the local environment.

  A variety of discharges happen all the time. At any given time there are about 2,000 thunderstorms around the globe, producing about 50 lightings per second.

  There are many factors influencing the charging and discharging of the ionosphere and the surface of the Earth.

  A safety tip for mariners says, “The glow on a masthead produced by an extreme buildup of electrical charge is known as St. Elmo’s Fire. Unprotected mariners should immediately move to shelter when this phenomenon occurs. Lightning may strike the mast within five minutes after it begins to glow.”

  To sum up, St. Elmo’s fire is a signal that there is a powerful buildup of static electrical energy. And that this electrical energy will discharge very soon.

  The electrostatic discharge sounds like the flapping of a ship’s sails, the noise of flying birds, muffled reports, the sweeping of sand, a distinct tearing, ripping sound as when thin muslin is ripped or torn apart, swishing or rustle, etc.

  This event happened before the witnesses saw the bright object in the sky.

  Possibly the events before the appearance of the burning bolide in the sky was caused by the ionized dense coma near the core of the comet fragment and the cometary dust and gases hitting the atmosphere at great speed. The density of the coma near the core of the comet depends how active it is and from the distance to the nucleus. The density of the coma increased significantly when it hit the atmosphere because it was pressed against the atmosphere. Large amounts of ionized cometary material from the coma were ejected at high speed into Earth’s atmosphere in a matter of minutes. The comets move at very high speed, about 25 to 60 km/s. The effects were electrical, mechanical, and thermal. The static electricity as a result of pumping of ionized particles from the coma caused also an atmospheric pulsing, wind, and tremble of the ground.