• NEET
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • Class 6-10
      • Class 6th
      • Class 7th
      • Class 8th
      • Class 9th
      • Class 10th
    • View All Options
      • Online Courses
      • Offline Courses
      • Distance Learning
      • Hindi Medium Courses
    • NEET
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE (Main+Advanced)
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE Main
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • CUET
      • Class 12th
  • NEW
    • JEE MAIN 2025
    • NEET
      • 2024
      • 2023
      • 2022
    • Class 6-10
    • JEE Main
      • Previous Year Papers
      • Sample Papers
      • Result
      • Analysis
      • Syllabus
      • Exam Date
    • JEE Advanced
      • Previous Year Papers
      • Sample Papers
      • Mock Test
      • Result
      • Analysis
      • Syllabus
      • Exam Date
    • NEET
      • Previous Year Papers
      • Sample Papers
      • Mock Test
      • Result
      • Analysis
      • Syllabus
      • Exam Date
    • NCERT Solutions
      • Class 6
      • Class 7
      • Class 8
      • Class 9
      • Class 10
      • Class 11
      • Class 12
    • CBSE
      • Notes
      • Sample Papers
      • Question Papers
    • Olympiad
      • NSO
      • IMO
      • NMTC
    • ALLEN e-Store
    • AOSAT
    • ALLEN for Schools
    • About ALLEN
    • Blogs
    • News
    • Careers
    • Request a call back
    • Book home demo
NCERT SolutionsCBSE NotesCBSE Exam
Home
Science
Fossils

Fossils

Fossils are remains or impressions of the hard parts of the extinct organism preserved in the sedimentary rock or other media.

Archaeopteryx

• Archaeopteryx is the connecting link between reptiles and Aves.

• Fossils are useful in search of oil and minerals.

Note: Paleontology is the study of fossils and the person who is involved in the study of fossils is a paleontologist.

Let us start from 100 million years ago

Some invertebrates on the sea bed died, and they were buried in the sand. More sand accumulated and sandstone formed under pressure.

More sand accumulated and sandstone formed under pressure.

Millions of years later, dinosaurs living in the area died, and their bodies, too, were buried in mud. This mud was also compressed into rock, above the rock containing the earlier invertebrate fossils.

Millions of years later, dinosaurs living in the area died, and their bodies, too, were buried in mud.

Again, millions of years later, the bodies of horse-like creatures dying in the area were fossilized in rocks above these earlier rocks.

Again, millions of years later, the bodies of horse-like creatures dying in the area were fossilized in rocks above these earlier rocks.

Much later erosion by sun, water flow, wears away some of the rock and exposes the horse like fossils. As we dig deeper, we will find older and older fossils.

Much later erosion by sun, water flow, wears away some of the rock and exposes the horse like fossils. As we dig deeper, we will find older and older fossils.

1.0Living Fossils

The animals which underwent little change during long geological periods.

Fossil of dinosaur skull



Fossil of fish & invertebrate

2.0Determination of the Age of Fossil

There are two ways of determining age of fossils.

Relative Method

If we dig into the earth and start finding fossils it is reasonable to suppose that the fossils we find closer to the surface are more recent than the fossils we find in deeper layers.

Using Radioactive Elements

Rocks contain some radioactive elements that decay and convert into their more stable form. This decay takes place at a constant rate for each radioactive element. e.g., Carbon dating.

Carbon dating: Carbon dioxide of air contains a small proportion of radioactive carbon (C14). CO2 is used during photosynthesis and there is an equal proportion of C14 among carbon atoms of all organisms. The radioactivity of C14 is lost at a precise rate. Half-life of C14 is about 5730 years.

If a fossil shows radioactivity if it is one fourth of that found in the living organisms, then the organisms died about 11,460 years ago (Two half-lives).

3.0Also Read

Evolution By Stages

Gaseous Exchange in Animals and Plants

What is a leaf and its type

Photosynthesis Pigments

Gaseous Exchange In Human Beings

The Flower: Parts and Functions

Nutrition and Life Processes

Mechanism of breathing and its regulation in humans

Diversity in Living Organisms

Table of Contents


  • 0.1Let us start from 100 million years ago
  • 1.0Living Fossils
  • 2.0Determination of the Age of Fossil
  • 2.1Relative Method
  • 2.2Using Radioactive Elements
  • 3.0Also Read

Frequently Asked Questions

Fossils provide invaluable evidence about how the earth has changed over time. The type of fossil found in a particular location tells us what kind of environment existed when the fossil was formed.

(i) Fossil record helps in building the broad historical sequence of biological evolution. (ii) Phylogeny, then evolutionary history can be reconstructed from fossils. (iii) The habits and behaviors of extinct organisms can be inferred from well preserved fossils.

Join ALLEN!

(Session 2025 - 26)


Choose class
Choose your goal
Preferred Mode
Choose State
  • About
    • About us
    • Blog
    • News
    • MyExam EduBlogs
    • Privacy policy
    • Public notice
    • Careers
    • Dhoni Inspires NEET Aspirants
    • Dhoni Inspires JEE Aspirants
  • Help & Support
    • Refund policy
    • Transfer policy
    • Terms & Conditions
    • Contact us
  • Popular goals
    • NEET Coaching
    • JEE Coaching
    • 6th to 10th
  • Courses
    • Online Courses
    • Distance Learning
    • Online Test Series
    • NEET Test Series
    • JEE Test Series
    • JEE Main Test Series
    • CUET Test Series
  • Centers
    • Kota
    • Bangalore
    • Indore
    • Delhi
    • More centres
  • Exam information
    • JEE Main
    • JEE Advanced
    • NEET UG
    • CBSE
    • NCERT Solutions
    • NEET Mock Test
    • CUET
    • Olympiad
    • JEE Main 2 Solved Papers

ALLEN Career Institute Pvt. Ltd. © All Rights Reserved.

ISO