Murder Mystery!

After all these years of believing that an asteroid killed our lovely dinosaurs 65 million years ago, new findings have shown that it may not be entirely true. In 1978, when scientists discovered a huge, 112 mile wide crater, called the Chicxulub crater, they figured this was the perfect answer to the mass extinction.

When asteroids strike, they typically leave a layer of iridium behind, which is an element not commonly found on earth. While scientists were examining a site near the crater they noticed that above the iridium layer in the sediments, there was a 30 foot deep section that contained some of the same fossils as below the layer. If the dinosaurs were brutally killed by the impact and after effects of the asteroid then there shouldn't be the same fossils.

Geoscientists then analyzed the fossils they found. They examined 52 species that were below the layer and surprisingly found the same 52 above the layer. It wasn't until they examined the top of the 30 foot sample, dated 300,000 years after the impact, that they found species dying off. Some say that land bridges could attribute to this, allowing animals with different diseases to enter new territories and infect others. Also, the geoscientists agree that the scary prehistoric beasts could have perished from haze in the atmosphere, but they say it is more possible that it was from all the active volcanoes at the time.

In the end, something must have happened to kill off all those species, but these scientists are throwing out the asteroid that created the Chicxulub crater as the main cause.


Update:

When the ash cloud settles it leave behind that iridium layer. So finding fossils above that layer throughout shows that some species have survived that asteroid impact. It is possible that the immediate ones were killed and others moved in but from the old theory, it has been said that the impact killed all dinosaurs. These findings show that they dinosaurs as a whole did not go extinct from this one asteroid.

The idea of the volcanoes was that they spewed so much ash at the time that the atmosphere was too thick for the species to survive. So that volcanoes across the world could have helped the extinction and not just one single asteroid.

As for the scientists working on this, they say that they have many doubts of the asteroid killing all the dinosaurs. I don't think we need to necessarily throw out the whole idea, but definitely throw it as as the only cause of extinction. I think everything together caused the species to drop off. The asteroid definitely had to of killed the surrounding species, volcanoes, and other environmental changes pushed them closer to extinction.

-Katie Cyr [B/11]