Originally posted by Gonjo
Maybe you could tell us o mighty one, _if_ dinosaurs were actually killed by a massive chunk falling on the earth why did it only kill of the
dinosaurs and nothing else?
Um, no offense, but what are you talking about?
The asteroid that wiped out the dinosaurs wiped out most of the life on the planet,
in fact with out looking it up I think it was something like 90% of the species on the
planet went extinct.
The only things that survived were animals and plants that lived in the deep sea and
those land animals that were capable of burrowing, which were generally small rodentesque
creatures and smaller lizards.
Also theres some proof that birds today are what remains of the dinosaurs. So what the birds were not killed cause they made a deal with the chunk?
Yes, dinosaurs are the modern day descendants of dinosaurs, just as we are descendants
of early rodent-simians, the birds evolved from the very few dinosaur species and early
proto-birds that existed at the time.
I also find it funny that theres no proof anywhere of this supposed rock. One might think such a thing would leave a big crater in the planet.
Something like the ones on Mars.
There's plenty of proof, the Iridium layer for one, apart from that we know where it hit,
because we have identified it, the Chicxulub impact crater
The reason you don't see big crater all over the planet like on Mars is because the Earth
is geologically, climatologically and biologically active, volcanoes, earthquakes and
general shifting of the crust collapse and fill in craters, the climate weathers the craters away
and biology overgrows what is left of it.
Now, as to the hypothesis of a planet once being made from the Asteroid belt.
While a dwarf planet, something like Pluto could have existed if the entirety of it
were at one time a single object, however there is not enough material to make an Earth
or even Mars sized object in the Asteroid belt.
The Kuiper belt is an area that starts at Neptunian orbit and extends about 50AU,
and is made up of relatively small objects.
If indeed some catastrophic collision had occurred detonating a planet producing the
debris of the Asteroid belt and Kuiper belt, we should see at least several other belts
between the asteroid belt and the Kuiper belt, or a semi-even distribution of debris between them.
The Asteroid belt and Kuiper belts are primarily composed of the excess matter that never
made it into planet formation, dwarf planets and comets.
[edit on 5/28/2007 by iori_komei]