Cretaceous/Palaeogene Extinction Event – Unlucky Dinosaurs

A new research paper, published this week suggests that the mass extinction event at the end of the Cretaceous could have turned out very differently.  Analysis of vertebrate fossils from Upper Cretaceous sediments in North America suggests that if the comet/asteroid impact had occurred a few million years before or after it actually happened, our planet could look very different today.  The largely Anglo-American research team propose that dinosaurs could have survived into the Cenozoic, perhaps to the present day.  If these reptiles had survived the Cretaceous mass extinction event it would have had significant implications for the evolution of mammals including the primates and ultimately our own species - Homo sapiens.

New Study Suggests Unlucky Dinosaurs

Analysis of species diversity indicates the Dinosauria were vulnerable to extinction.

Analysis of species diversity indicates the Dinosauria were vulnerable to extinction.

Picture Credit: Everything Dinosaur

A large number of studies have been carried out before, but this new paper published in the academic journal “Biological Reviews” examined the number of dinosaur genera recorded as fossils in Upper Cretaceous strata.  The researchers wanted to estimate how well the Order Dinosauria was doing in terms of species diversity at the time of the impact event.  A lack of diversity within an ecosystem, or the dominance of one particular animal group can make such ecosystems vulnerable to extinction if the environment changes suddenly.

The research team, drawn from a number of American and British universities, concluded that prior to the extraterrestrial impact, planet Earth was going through a period of dramatic climate change.  Sea levels were changing, global temperatures altering and there was enormous amounts of volcanic activity.  The space rock collision provided the final “coup de grâce” that led to the demise of the dinosaurs, pterosaurs and marine reptiles.

To read a more detailed article about this new research: Dinosaur Extinction – A Perfect Storm

Extension Ideas and Activities

  • Look up recent reports and new stories about impact events or potential near misses, can the class identify where these objects are coming from?  Why are there such objects within our solar system?
  • Examine the moon and compare/contrast this to craters found on the Earth today, are there similarities?  Why do those craters on the moon persist?  What about other planets, have they suffered from extraterrestrial impact events?  What evidence is there for such events?
  • More capable learners can be challenged to find out about the Chicxulub impact and the evidence for the impact theory in regards to dinosaur extinction
  • If the Earth is vulnerable to such impacts, what steps could be taken?  What are the moral dimensions?
  • Consider what life on Earth might have been like if the dinosaurs had not become extinct – what implications for our own species?  Intelligent dinosaurs?
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