All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
28 07, 2014

Dinosaur Extinction – A Perfect Storm

By | July 28th, 2014|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Educational Activities, Teaching|2 Comments

Bad Luck and Bad Timing for the Dinosaurs

A new collaborative study looking at the dinosaur fossil record from the Upper Cretaceous of North America suggests that if the extraterrestrial impact event had occurred a few million years before or after it actually hit, life on Earth could be very different today.  Dinosaurs could well be still roaming around.  If the Dinosauria (with the exception of the birds), had not gone extinct, then it could be argued that many of the families of mammals so familiar to us today may not have evolved.  The evolution of the primates, and indeed, our own species, might not ever have happened.

Unlucky Dinosaurs Sixty-six Million Years Ago?

Cataclysmic impact event.

Cataclysmic impact event.

Picture credit: Don Davis (commissioned by NASA)

Similar studies into the extinction event that took place approximately 66 million years ago have been carried out before, however, this new research, published in the latest edition of the academic journal “Biological Reviews” and led by the University of Edinburgh, focused on examining an updated catalogue of North American dinosaur fossils, in a bid to understand how well the Order Dinosauria was doing in terms of species diversity at around the time of the impact event.

Previous studies, examining the number of different dinosaur species and genera preserved in Upper Cretaceous strata such as the Hell Creek Formation of the western United States, have showed that the number of different types of dinosaur fossils found declines in rocks that mark the time period towards the end of the Cretaceous.  A lack of diversity in an ecosystem, or the dominance of one particular type of creature, can make such ecosystems vulnerable to sudden and dramatic changes that ultimately lead to an extinction.  The research team, drawn from a number of universities and museums, conclude that prior to the impact event, our planet was experiencing dramatic environmental upheaval.  Changing sea levels, fluctuating global temperatures and enormous amounts of volcanic activity were all happening.  Many groups of animals and plants were under stress and the devastating impact from a six-mile-wide space rock provided the final “coup de grâce” that finished off the dinosaurs.

Soon to Become Extinct

Triceratops was one of the last dinosaurs to evolve.

Triceratops was one of the last dinosaurs to evolve.

Picture credit: Julius Csotonyi

The research team which includes scientists from Edinburgh University, Birmingham University, Imperial College (London), Oxford University, University College (London) and Baylor University (Waco, Texas) suggest that the dinosaurs’ food chain was threatened by a lack of diversity amongst large herbivorous dinosaurs.  The lack of diversity, much of North America was dominated by a handful of plant-eating types of ornithischian dinosaur, created a “perfect storm” and the vulnerable Dinosauria was unable to recover from the extraterrestrial strike and its aftermath.

Everything Dinosaur team members have provided a number of teaching resources to schools that help to explain extinction events.  To read an article specially prepared for use in schools at Key Stage 2 and 3 about the Cretaceous mass extinction event: Dinosaur Extinction Event – Providing Teaching Resources for Schools.

Environmental change, even dramatic global events such as an asteroid impact can in fact provide a stimulus to evolution.  Earlier extraterrestrial impacts which at first caused devastation may actually have acted as catalysts helping certain types of life to flourish.  It can be argued that once the dinosaurs became extinct, the Mammalia were able to rapidly diversify and exploit the niches left vacant by the demise of the Dinosauria, back in 2010, Everything Dinosaur reported on a scientific paper that suggested that earlier cataclysmic events and significantly benefited life on Earth.

To read this article: Extraterrestrial Impact Led to Palaeozoic Explosion of Life.

Dr Steve Brusatte (School of GeoSciences at Edinburgh University) commented:

“Five million years earlier dinosaur ecosystems were much stronger, they were more diverse, the base of the food chain was more robust and it was harder to knock out a lot of species.  If they had a few million years more to recover their diversity they would have had a better chance of surviving the asteroid impact.  Dinosaurs had been around for 160 million years, they had plenty of dips and troughs in their diversity but they always recovered.”

A number of mass extinction events have been identified in the fossil record.  Such mass extinctions ultimately led to a change in direction for life on Earth, permitting new types of organism to evolve.

A Table Showing the Major Extinction Events of the Phanerozoic Eon

Mass Extinction in Summary

Table credit: Everything Dinosaur

The research team hope to extend their study by taking into account vertebrate fossil data from Upper Cretaceous sediments that have been examined in China and Spain.  This will help the scientists to formulate a global picture.  Naturally, with such academic papers, there is always speculation as to whether or not the dinosaurs would have survived until the present day.  Some speculators go further and ask the question would the dinosaurs have evolved greater intelligence, perhaps evolving into the reptilian equivalents of primates and eventually into a form of humanoid dinosaur – a dinosauroid?

Could the Earth Have Been Dominated by “Intelligent Dinosaurs”?

What intelligent life on Earth might have looked like if the dinosaurs had not become extinct.

What intelligent life on Earth might have looked like if the dinosaurs had not become extinct.

Picture credit: Boxtree

Dr Brusatte speculates that the Dinosauria could well have survived and that non-avian dinosaurs could make up a significant proportion of the fauna today, whilst other scientists, including a number who worked on this study remain less sure.

For example, Dr Richard Butler (Birmingham University) stated:

“We can’t re-run the tape of life and see whether an impact at a different time would have led to total extinction.  But it [extraterrestrial impact event] did come at a particularly bad time.”
28 07, 2014

Dinosaur Extinction – Unlucky Dinosaurs

By | July 28th, 2014|Key Stage 3/4|Comments Off on Dinosaur Extinction – Unlucky Dinosaurs

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

Mammals benefited from the extinction of the non-avian dinosaurs.

The extinction of the non-avian dinosaurs permitted the Mammalia to diversify and become the dominate terrestrial fauna.  Were the dinosuars unluckly?

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?

To view the wide range of prehistoric animal and dinosaur themed toys and games available from Everything Dinosaur: Dinosaur Toys and Games.

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