Question

Fossils which preserved both external and internal structure is

Answer 1

This is ur answer mate.....

Answer 2

Fossils which preserved both external and internal structure is Petrification.

Petrification definition:

"Petrification is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals"

Process of petrification:

• All organisms can undergo the process of petrification, in which the harder elements of the specimen like the bone, hard tissue, shell, etc are spared when compared to the softer parts of the specimen.
• The process of petrification can occur through two similar mechanisms- permineralization and replacement. These methods produces exact replica of the organism upto the microscopic level.
• Permineralization is the process in which the pores and the cavities of the specimen gets filled with minerals from the groundwater like silica (silicification), sulphur (pyritization) and many other minerals.
• Replacement is the process in which the tissues or the components of the organism gets destroyed and replaced by different minerals. This type of fossils preserves much more details.

The final stage of the fossil where it all solidifies is called lithification in which the fossil of the specimen loses all the water. Petrified woods are used in several ornamental purposes like tabletop, bowls, jewellery, etc.