The Earth averages slowing down two tens of a second per year If I take top and spin it as fast as I can with in a minute or two the top will stop spinning and topple over . The top stopped spinning because of friction and gravity . In the earth also subject to both friction and gravity. Earth spins in a atmosphere ( friction ) and the moon supplies the gravity . High tides happen because the moons gravity . How about 213,000 MPH . bet Dino got dizzy . Doing research on this like going to basket and robins and deciding which one of the 31 flavors you want. In this case it there are those who say the world was spinning the same speed it is now . Or those who try to stick with science and use there own brain regardless if the whole world says your wrong . Personally I cant make a top spin for a day little lone for millions of years . Seems perfectly logical that the earth was spinning allot faster millions of years ago. Here is a link that some of you might find interesting . How quickly was the Earth rotating 250 million years ago?