Dinosaurs – Artfully Wild

Fossils are the remains of animals which have died millions of years ago. They occur when animal remains are preserved under layers of earth and water over millennia. The pressure and temperature of the soil need to be just right in order for the remains to become fossilised. Fossils are normally found in the sedimentary layer of the soil, when clay, mud and rocks accumulate on the top and compress the soil in the bottom.
There are 3 types of fossils on the planet – Body fossils which include the hard parts of an animals body such as teeth, nails, scales, shells, feathers and fur; Trace fossils which are physical signs that an animal was living/present in a particular place, for example footprints, prints of nest, faeces, egg shells and tracks; Plant fossils which are fossilised remains of plants and which include seeds, flowers, leaves, roots and shoots.
The oldest fossils on Earth are approximately 3.7 billion years old. They are fossils of stromatolites – which are mounds or sheets of mud that preserve cyanobacteria – the earliest bacteria that developed on Planet Earth. Apart from the bacteria themselves, the stromatolites also contain chemical by-products produced by the bacteria too. This gives us a glimpse into how the Earth was geographically and chemically billions of years ago.
Fossil fuels aren’t made from actual fossilised dinosaurs or plants. Fossil fuels like oil, coal and natural gas were formed when microscopic algae-like creatures called diatoms died in massive numbers and which over time were fossilised. The intense soil pressure on these fossil remains converted the carbon inside the diatom remains into fuels.
Scientists determine the age of fossils using two processes. The first is called the “carbon-14 dating” which involves studying the time it takes for the carbon present in the animals’ bodies to decay over time. The other process is called the “molecular genetic clock” which involves comparing the DNA and physiology of fossilised remains to animals that are alive today.

Bonus

Sometimes, when animals and plants get trapped inside tree sap or resin, over time, they fossilise completely intact – feathers, fur, bones, teeth, bodily fluids, roots etc. – to form a product called “amber“. The fossils preserved in amber are the most significant finds for any scientist or paleontologist, since these fully-intact fossils offer researchers a look at how animals really looked like millions of years ago and whether these species have changed over time or not. Take a look at this article to see the 10 strangest things to fossilise in amber.