As I say on my page above (Dinosaurs, The Land Bridge, and Ancient Weather) I think the dinosaur extinction may have been caused by the submerged land bridge between antarctica and S.A. 85 million years ago; the mass of the water band around the southern ocean from then to now would have changed the precession and caused the seasons, weakening the (presumed to be) cold blooded dinosaurs. The comet would then have hit the tropics, killing the dinosaurs, and the birds mammals and flowering plants would have already had a large area N and S to live in already left by the dinosaurs. The crocodiles, alligators and snakes would perhaps have just been on the other side of the world, so they would have lived to better times.
Another possible way to explain the late Cretaceous has been devised by Donald L. Blanchard via changes in obliquity of the earth over geologic time. On THIS LINK the site author says the solar system may rotate around in cycles with the galaxies explaining the extinction of the "warm blooded dinosaurs as they are now believed to be by most" in cycles of about 190 million years. In this explanation the earth would remain stationary relative to the stars as it now does throughout the year to the N star, so when the solar system was at the maximum angle, the earth would then be with the N pole toward the sun and the S pole to the sun in each 6 month period. Before and after the late cretaceous maximum of 90 degrees, Blanchard says temperatures would have been cooler which would favor the warm blooded dinosaurs, but with more heat at the max, the dinosaurs being so large couldn't have stayed cool and might have baked in the heat.
One problem with this explanation is about Blanchard's conclusion that the current alignment of the ecliptic of the milky way with the plane of the solar system is not coincidence. If the rest of its period is just aligned one fourth of the time as the plane of the solar system pivots around, it would be aligned perhaps 40% of the time, so the chance that it's aligned may be more coincidence than not unless it's being held level to the plane by the gravity of the galaxy. While the moons of Jupiter and Saturn are considered to be a miniature solar system, they can't actually be used to prove if the Sun's gravity is causing them to go through cycles of obliquity just as the galaxy's gravity would cause the solar system itself to have these cycles, because all satellites in the solar system keep the same face to their parent planet due to unevenness of the mass of these moons. Even so the Sun, Mercury, the Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto would seem to precess like this in the obliquity and due to impacts with such as large impactors all of these bodies would presumably be at random in their cycles of this type of precession, with a 50% chance of obliquity because there are two poles and tropics twice in each cycle. Only one of these bodies, Neptune has much obliquity, one in 9 or just 11%, like flipping a coin 10 times and just the dime just with heads once or twice (if you used a great rich coin!). The larger the planet the less the obliquity seen by the Hubble and this could be because planets have more mass around the tropical zones and more mass attracts, aligning them with the central mass like the solar system is now with the center of the milky way. With the solar system never with its poles aligned with the center of the galaxy and usually flattened out nearer in, it might seem there could be precession of smaller planets like the Earth and Mars because they are smaller and so easier to move with the given force, they would give way by F=ma, smaller mass, more motion. This could seem to be be true even if the solar system is flattened out and would be how in a quantum well, with more pressure the fluid inside flows without much friction while the outside is more solid, and the particles precess. It seems more probable that while looser gravity like of Neptune allows the planet to be tilted if something hits it, the Earth would more probably just be aligned with Jupiter and the Sun. The sun has more influence on the Earth than the galaxy or inertia just as the moon has 600 times the attraction as the sun on the Earth, so like the disk that formed the solar system, it would mostly stay beveled where level.
If you have the earth at a 90 degree angle for half the year at the same time it's hot on the other side, the entire opposite realm has no light or heat whatsoever for months and this would be more complete than the most extreme winter now, not just the smaller area of our own far N and S winters causing the arctic and antarctic weather. Much more of the planet would be out of the heat leading no doubt to extreme high winds to adjust to the following hot weather months of the year, but the winds wouldn't be enough to moderate the heat. In our own time at random in the cycle a much larger part of the earth would be in extreme weather for more of the year. What you would see if the obliquity caused the dinosaur to go would be cycles of extreme heat at one of the poles, followed by much ice and darkness, disruptive to most life. The rocks at the poles would show lots of the most periodic shattering due to the extreme weather. And the high winds in many directions would cause great aeolian strata. This could be a way to prove or disprove the dinosaur demise via obliquity, except it may already be disproven because almost none of the earth had ice in the Jurrasic or Cretaceous.
The record of polar wandering of Mars has been found in the changes in the rocks like glacial strata on the earth. As the Martian poles moved they left proof in the rocks of where they were moving arouind the planet to many zones. The motion of the caps has been explained by just a shifting of the crust being somewhat loose. If obliquity were the cause, the motion of the crust would seem to be both a combination of the obliquity and the geotechonic processes that are common on the earth, so it would be more regular with a combination of both the more random wandering of the crust overlaid the more regular cycles of obliquity. and like on the earth there would be much more wind and windblown strata at the maximim obliquity of the earth's uniform heat.
If the large dinosaurs went extinct because they were warm blooded as via the obliquity, the small dinosaurs being like the mammals and able to cool off with smaller size wouldn't have had the same doom. A dinosaur is much like a crocodile or alligator, all reptiles for instance grow continually throughout their lives. Much of the same physiology is why dinosaurs were originally believed to be cold blooded like other reptiles, and there is no explanation of why the dinosaurs went extinct and not the snakes and other reptiles like alligators.
Another problem is about heredity being stored environment. We know that most of our ancient genes are a fused form of viral DNA, we got viruses, and their DNA is fused with us. If the weather changes drastically in long term cycles like 75 million years, it would be seen in the genome of all life in this time that has evolved before then, there is no evidence for this.
When the dinosaurs went extinct and not before is also disproven as I say in my site above by the rock called laterite, found only in monsoon rains when the seasonal temperature is changing, in the late cretaceous and after down to our own time. The even temperatures were before the dinosaur extinction not after (and not in long term cycles or natural history would be much changed) and gradually changing to more seasonal winds and rains before the dinosaur demise. The bevelled earth explanation would have there being presumably a gradual symmetrical peak of laterite at the end of the cretaceous, and with other regular peaks at the time of other extinction events. Instead, there are just three great layers of the strata, our is the tertiary, or third and higher layer, resting on the cretaceous chalk. There was thus a definite change in the weather of the late cretaceous, both about laterite and the chalk, and it's unsymmetrical. I think the change in the earth's angle caused by the land bridge and the tides might be the origin of the weather of 6 month cycles we now have via precession and laterite, and it seems to be evidence that the KT extinction was already part of the general change of the weather so the uniform temperatures in my causology were just caused by changes in the higher speed of precession, and this in turn would be caused by the more common gravity acting on the Southern water belt, and no outside cause may be necessary to explain the change.. the two extinctions of the dinosaurs in the precambrian Blanchard uses to fit in with the astronomical cycle may just be coincidence and this doesn't explain the 3 other great extinctions like the ones of the other creatures that the dinosaurs took the place of. Two samples are not enough to establish a link by the law of large numbers in probability. I agree with Blanchard about the disproofs of the other dinosaur extinction causologies others say are possible he disproves on his site, but the Land Bridge seems to be a better way for science as I say on the link, Dinosaurs, The Land Bridge.....
Site Link About This Possible Cause of The Extinction (bevelling earth).
