fbpx

KidsKonnect

Dinosaur Extinction Facts & Worksheets

The extinction of the dinosaurs is one of the most significant events in Earth's history and occurred around 66 million years ago at the end of the Cretaceous Period.

Search for Worksheets

Worksheets /Science /Dinosaur Extinction Facts & Worksheets

Premium
Not ready to purchase a subscription? Click to download the free sample version   Download sample

The extinction of the dinosaurs is one of the most significant events in Earth’s history and occurred around 66 million years ago at the end of the Cretaceous Period. There are several theories about the cause of dinosaur extinction, with the leading and most widely accepted hypothesis being the impact hypothesis.

See the fact file below for more information about the Dinosaur Extinction, or you can download our 28-page Dinosaur Extinction worksheet pack to utilize within the classroom or home environment.

Key Facts & Information

THE DINOSAURS

  • Dinosaurs were a diverse group of reptiles that dominated Earth for over 160 million years, from the Late Triassic Period (about 230 million years ago) until the end of the Cretaceous Period (about 66 million years ago). 
  • These fascinating creatures came in various shapes and sizes, ranging from small, bird-like dinosaurs to colossal giants like the long-necked sauropods and the fearsome Tyrannosaurus rex.
  • Dinosaurs belonged to two main groups: the Saurischia, which included the theropods (predatory dinosaurs like T. rex) and sauropodomorphs (long-necked herbivores), and the Ornithischia, which comprised diverse herbivores such as Triceratops and Stegosaurus. They walked on either two or four legs, and their stance and locomotion varied widely.
  • Dinosaurs exhibited remarkable adaptations, including specialized teeth for different diets, unique crests or frills, and elaborate displays for communication. Some were covered in feathers, suggesting a close evolutionary connection to modern birds.
  • The extinction event at the end of the Cretaceous, possibly triggered by an asteroid impact, led to the demise of most dinosaurs. 
  • However, birds, which evolved from small, feathered dinosaurs, survived and are considered the only living descendants of these incredible creatures. 
  • The study of dinosaurs continues to captivate scientists and enthusiasts alike, providing insights into Earth’s ancient ecosystems and the evolutionary history of life on our planet.

EXTINCTION THEORIES

  • The extinction of the dinosaurs, an event that occurred around 66 million years ago, is a fascinating mystery that scientists have been trying to unravel for decades. 
  • Several theories have been proposed to explain why dinosaurs, along with many other species, disappeared from the Earth. 
  • IMPACT HYPOTHESIS One widely accepted theory is the impact hypothesis, which suggests that a massive asteroid or comet collision played a crucial role.
  • The impact hypothesis posits that a celestial body, about 10 kilometers (6 miles) in diameter, collided with Earth near the present-day Yucatán Peninsula in Mexico. 
  • This catastrophic event created the Chicxulub crater, over 150 kilometers (93 miles) in diameter.
  • The impact would have caused widespread devastation, including fires, tsunamis, and the release of enormous amounts of energy.
  • The aftermath of the impact would have led to a “nuclear winter” effect. Debris and dust ejected into the atmosphere blocked sunlight, causing a significant drop in temperature worldwide.
  • The evidence supporting this theory includes the discovery of the Chicxulub crater and the identification of a layer of sediment, known as the Cretaceous-Paleogene (K-Pg) boundary, with high concentrations of iridium, a metal rare on Earth but common in asteroids and comets.
  • VOLCANIC ACTIVITY Another theory suggests that volcanic activity played a role in the mass extinction. 
  • The Deccan Traps, a large volcanic region in present-day India, experienced intense eruptions around the same time as the dinosaur extinction.
  • These eruptions released vast amounts of lava and gases into the atmosphere, potentially causing climate changes and environmental disruptions. 
  • The combination of volcanic activity and the impact event may have had a synergistic effect, amplifying the environmental stress that contributed to the extinction.
  • CLIMATE CHANGES Additionally, some scientists propose that gradual changes in sea levels and climate may have played a part in the extinction. 
  • These changes could have resulted from factors such as continental drift, where landmasses shifted over time, affecting ocean currents and global climate patterns.
  • SYNERGISTIC EFFECTS It is important to note that these theories are not mutually exclusive.
  • The combination of an asteroid impact, volcanic activity, and gradual environmental changes may have had synergistic effects, contributing to the mass extinction event.
  • The complexity of the extinction suggests that multiple factors may have acted in concert to create the challenging conditions for many species, including the dinosaurs.
  • Understanding the extinction of dinosaurs is like solving a puzzle with many pieces, and scientists continue to investigate and refine these theories. 
  • The study of dinosaur extinction not only deepens our knowledge of Earth’s history but also highlights the interconnectedness of geological and biological processes in shaping the evolution of life on our planet.

EVIDENCE OF EXTINCTION

CHICXULUB CRATER

  • The discovery of the Chicxulub crater in the Yucatán Peninsula provides strong evidence for an impact event. 
  • The crater is over 150 kilometers (93 miles) in diameter and is associated with the timing of the dinosaur extinction.

IRIDIUM LAYER 

  • The identification of a distinct layer of sediment known as the Cretaceous-Paleogene (K-Pg) boundary is crucial. This layer, found in rocks around the world, contains elevated levels of iridium, a rare metal on Earth but common in asteroids and comets.

FOSSIL RECORD

  • The fossil record reveals a sudden and dramatic decline in the diversity and abundance of dinosaur species at the K-Pg boundary. Many dinosaur fossils are found below this boundary, but few are above it.

MICROSCOPIC SPHERULES

  • Microscopic glass beads, called spherules, have been found in sediment layers associated with the K-Pg boundary. These spherules are thought to have formed during the impact event and are distributed globally.

SHOCKED QUARTZ CRYSTALS

  • Shocked quartz crystals, which exhibit distinctive microscopic features caused by the intense pressure from an impact, have been identified in sediments around the K-Pg boundary.

TSUNAMI DEPOSITS

  • Sediment layers associated with the extinction event contain evidence of tsunamis, consistent with a massive asteroid impact causing extensive ocean disturbances.

FOSSILIZED PLANT AND ANIMAL REMAINS

  • Fossilized remains of plants and marine organisms also show changes around the K-Pg boundary, indicating disruptions in the ecosystem.

DECCAN TRAPS ERUPTIONS

  • The timing of the massive volcanic eruptions at the Deccan Traps in India correlates with the dinosaur extinction. The release of lava and gases from these eruptions may have contributed to environmental stress.

CLIMATE CHANGE INDICATORS

  • Evidence of abrupt climate changes, including shifts in temperature and sea level, is found in sediment layers around the time of the extinction.

FOSSILIZED FOOTPRINTS AND NESTS

  • Some fossilized dinosaur footprints and nests suggest abrupt abandonment of nesting sites, indicating a rapid and catastrophic event.
  • These lines of evidence collectively support the idea that a combination of an asteroid impact and volcanic activity, possibly along with other contributing factors, led to the mass extinction of dinosaurs and many other species at the end of the Cretaceous Period. The interdisciplinary nature of the evidence underscores the complexity of the extinction event.

Dinosaur Extinction Worksheets

This fantastic bundle includes everything you need to know about Dinosaur Extinction across 28 in-depth pages. These ready-to-use worksheets are perfect for teaching kids about Dinosaur Extinction. There are several theories about the cause of dinosaur extinction, with the leading and most widely accepted hypothesis being the impact hypothesis.

Complete List of Included Worksheets

Below is a list of all the worksheets included in this document.

  1. Dinosaur Extinction Facts
  2. Major Extinctions
  3. Dino Timeline
  4. Dino World
  5. Extinctions Illustrated
  6. Post-Extinction Match
  7. World with Dinos
  8. Walking with Dinosaurs?
  9. Dino Essay
  10. Extinction Quiz
  11. My Favorite Dinosaur

Frequently Asked Questions

What caused the extinction of dinosaurs?

The most widely accepted theory is that a large asteroid impact occurred around 66 million years ago. This impact, known as the Chicxulub impact, created the Chicxulub crater in present-day Mexico. The resulting environmental effects, including massive wildfires and a “nuclear winter” scenario caused by dust and debris in the atmosphere, are believed to have led to the extinction of dinosaurs.

Were dinosaurs already in decline before the asteroid impact?

There is evidence to suggest that some dinosaur species were experiencing changes in population dynamics and diversity leading up to the asteroid impact. Climate changes and volcanic activity may have played a role in altering ecosystems, but the impact event is considered the primary cause of the sudden and widespread extinction.

Did all dinosaurs go extinct at the same time?

No, not all dinosaurs went extinct at the same time. While the large, non-avian dinosaurs (such as Tyrannosaurus rex and Triceratops) disappeared, some smaller dinosaur species that evolved into birds survived. Birds are considered modern-day dinosaurs, and their lineage can be traced back to the prehistoric era.

How did the asteroid impact cause such widespread devastation?

The impact of the asteroid released an immense amount of energy, causing fires, earthquakes, and a massive tsunami. The most significant impact, however, came from the debris ejected into the atmosphere, blocking sunlight. This led to a dramatic drop in temperatures (nuclear winter), disrupting ecosystems and food chains. Photosynthesis was severely impacted, affecting both plant and animal life.

Did any other factors contribute to the extinction event?

In addition to the asteroid impact, volcanic activity during the late Cretaceous period (such as the Deccan Traps in present-day India) is believed to have contributed to environmental stress. The combined effects of volcanic activity and the asteroid impact likely intensified the ecological disruptions, making it challenging for many species, including dinosaurs, to survive.

Link/cite this page

If you reference any of the content on this page on your own website, please use the code below to cite this page as the original source.

Link will appear as Dinosaur Extinction Facts & Worksheets: https://kidskonnect.com - KidsKonnect, February 8, 2024

Use With Any Curriculum

These worksheets have been specifically designed for use with any international curriculum. You can use these worksheets as-is, or edit them using Google Slides to make them more specific to your own student ability levels and curriculum standards.

Related Resources