<span>These organisms are called autotrophs. Autotrophs are also called 'self-feeders,' and they are able to produce energy from sunlight and carbon dioxide and are therefore known as 'producers.' The only autotrophs that we know of are plants and some types of algae. This makes all other organisms heterotrophs</span>
Answer: Index fossils are used to identify layers of rocks. The layers will form an arrangement that relates to their age. In simpler terms, a layer that contains fossils are unique to that certain layer.
Index fossils are fossils that are mostly used by scientists due to it being easily found anywhere around the world and in abundant amounts. It can also be easily identified since they are fossils of widely varied organisms that lived during one short time period.
