The dinosaurs died out when the climate radically changed, becoming colder due to the onset of the ice ages.
The Facts Are .....
Two dilemmas in evolutionary theory which haven't been answered yet are:- (i) How did dinosaurs lose their 'dominance' to mammals; and (ii) How did dinosaurs achieve their success in the first place?
Recent theoretical studies by Mike Benton (Queen's University, Belfast, Ireland) suggest that competition had nothing to do with it. The puzzle of how dinosaurs gained their dominance, and how they died out, still remains. New Scientist, September 3, 1987 p:28
There are approximately 60 theories proposed as an explanation for the sudden extinction of the dinosaurs. Not one of these can be called a fact. Sydney Morning Herald, 2/5/88
Meteor collision is one of the theories presented to explain the rapid extinction of the dinosaurs.
The analysis of fossilized dinosaur manure has led some researchers to develop another theory that it was their flatulence that was responsible. The theory proposes that the methane produced by their intestinal microbes, combined with methane gas, plus extensive volcanic eruptions, contributed to ancient climatic warming and the demise of the dinosaurs. This latter theory is not based on factual evidence, and would require the analysis of atmospheric samples taken at the time of the dinosaur’s extinction to prove it. Lafayette Journal and Courier, October 23, 1991
A study by the US Geological Survey Team showed that a rash of micro tektites in sediments indicates that there is no apparent connection with the extinction of life forms on earth. These micro tektites are thought to be produced by large meteorite collisions, and their study has suggested that large impacts occur without significant destruction of life forms. New Scientist, August 4, 1983
Another theory has been developed to explain the extinction of the dinosaurs, indicating that the truth is currently unknown. The latest hypothesis suggests that magnesium deficiency was the culprit.
An examination of dinosaur eggs in China has revealed that they are abnormally low in the element.
Magnesium is vital for egg-laying animals, with large deficiencies producing heart attack. Newcastle Morning Herald, February 7, 1991
Another hypothesis put forward in 1987 said that acid rain was the cause. The hypothesis stated that sulfur from volcanic activity eroded the ozone layer, turned into acid rain, cooled the climate and wiped out the dinosaurs. The West Australian, June 13-14, 1987 p:24
In 1983 Dr Allan Charig (Natural History Museum, London) and Dr Beverley Halstaed (Geological Department, Reading University) successfully debunked almost every one of the 40
theories on the extinction of the dinosaurs. The Times (London), August 27, 1983