Question about fossils. I understand that the skin and organs rot and decay. But why doesn't the teeth and bones decay?

The main reason for this, is because bones are hard to digest for bacteria. This is why shark skeletons are a lot rarer than normal skeletons (their bones are made of cartilage, which decays easier). For example, while skin and flesh of a human usually decay after a few months, a year or two tops, bones usually take atleast a decade before they start to decay. The reason fossils are found back at all is because in the time it takes for the skeleton to decay, it's covered in dirt and stones where no new bacteria can reach them. If the bacteria on the skeleton then die off, the skeleton will be safe from decomposition. Eventually (usually with dinosaurs) the soil they are buried in will become stone due to a lack of humidity and pressure from soil and dirt getting on top of it.

Dinosaurs fossils have been found on all continents. But bear in mind that 230 million years ago when the dinosaurs began there was only one continent, Pangaea. See

https://www.theguardian.com/science/2009/feb/07/pa...

Sort of like asking why wood burns but rock does not. I know that sounds like not an answer, but the bones and teeth are mineral but flesh is not. Bacteria eat flesh, flesh oxidizes easily. Minerals are stable (they are not open to oxidation). Minerals can dissolve, and can react with other minerals, but they don't provide any energy for bacteria or other consumer life forms. Also, flesh is mostly water whereas bones and teeth are mostly NOT water. Flesh dries out and changes shape but teeth and bones (mineral materials making up the skeleton) keep their shape when they dry out (water content is small).

Some fossils are entirely or partly the original mineral material that made up the skeleton, but lots of times that original material has been slowly dissolved and replaced by similar minerals, so the form of the fossil is the same but not the actual material.

The basic problem is that flesh is made from organic carbon compounds and skeletons are made from inorganic compounds. the two things have completely different chemical behavior.

The teeth and bones are made up mostly of calcium and phosphorous -- BOTH are mineral commonly found in rocks!

There is really not that much differnece between rocksd and bones!

Bones and teeth sure do decay, just a bit slower than flesh, allowing them to get buried if the geological conditions are right.

The fossilized remains are not bones - they are chemically entirely different from bones, although sometimes some compounds remain preserved.

The bones slowly rot and are replaced with mineral deposits which get turned to rock under extreme pressures. The thing with living bones is that they are hollow and light. These minerals enter the structure and make it super resistant to crushing so it is basically like rock in the shape of what was previously bone.

Also tectonic plates are constantly in motion, but we puny humans don't notice it. Over the humongous periods of time dinosaurs ruled, the Earth changed drastically and continents were not in their present form. Generally dinosaurs existed everywhere, but digging in some areas will be more fruitful.

Previous forest regions, for example, are not really fruitful because everything rots sooner than it is buried.

The bones and teeth that are found are not really the bones and teeth. They are a mold of the originals. Most dinosaur bones are permineralized. Permineralization is a type of fossilization involving deposits of minerals within the cells of organisms. Water from the ground, lakes, or oceans seeps into the pores of organic tissue and forms a crystal cast with deposited minerals. Crystals begin to form in the porous cell walls. This process continues on the inner surface of the walls until the central cavity of the cell, the lumen, is completely filled. The cell walls themselves remain intact surrounding the crystals.