It took 8 million years to recover from the extinction of 66 million years ago

A team of researchers has tried to assess how long it took for life on Earth to recover from the mass extinction some 66 million years ago, believed to have been caused by an asteroid. The results show that it took at least 2 million years to restore the level of plankton, an essential element of the entire ocean ecosystem. After the impact of the asteroid, plankton, especially the smaller one, nanoplankton, was almost completely destroyed.

These creatures are important because once they die, they throw their calcium and carbon exoskeletons onto the seabed. At the bottom of the sea, they form rich organic deposits that thicken and become lime. And it is by analyzing the fossil layers of these deposits that researchers have obtained data on plankton.

Analyzing various other fossil data, the researchers found that it took at least another 8 million years for the number of species of living creatures to return to their previous levels, i.e., the level preceding the catastrophic event.

Researchers described their findings in an article in the Conversation (below).


Sources & Recommended Reading:

https://theconversation.com/ocean-ecosystems-take-two-million-years-to-recover-after-mass-extinction-new-research-124328

Why the tyrannosaurus skull wasn’t damaged when it broke the bones of its prey

A team of scientists from the University of Missouri-Colombia has studied the conformation of the skull of a tyrannosaurus, trying to solve what is considered one of the mysteries of paleontology.

Paleontologists, in fact, have always wondered how the tyrannosaurus managed to break the bones of its victim and therefore bite so hard, without damaging the bones of the skull. According to Caleb Sellers, a researcher at the University of Missouri, this dinosaur had a huge mouth, more than 1.8 meters long, with which it could bite with more than six tons of force.

According to the same researcher, all previous studies of the problem did not take into account all the connections within the skull, including those between ligaments and cartilage. Using new imaging techniques, the team analyzed the anatomy and structural conformation of the tyrannosaurus skull and observed how the mouth reacted to chewing stress.

They also used models of those who could be considered two relatives of a tyrannosaurus, a gecko and parrot. The researchers concluded that tyrannosaurus skulls should have been more rigid than ever before, similar to the skulls of hyenas, crocodiles and inflexible skulls, such as lizards and birds, of two animals that are still direct relatives of the same dinosaur.


Sources & Recommended Reading:

https://news.missouri.edu/2019/t-rex-used-a-stiff-skull-to-eat-its-prey/

https://anatomypubs.onlinelibrary.wiley.com/doi/abs/10.1002/ar.24219