Learn more about the mass extermination event that occurred 66 million years ago, and see the evidence to support it.
A wealth of fossil bones, teeth, and trackways have shown that Earth was the domain of the dinosaurs at least 230,000,000 years ago. However, no trace of dinosaur remains has been found in rocks older than 66 million years. It seems that all non-avian dinosaurs disappeared suddenly at that point as the Cretaceous period gave way to the Paleogene.
Fearsome marine reptiles like the mosasaurs and ichthyosaurs were also introduced. Many areas of the planet seem to have seen ancient forests burn. While some birds, mammals, fish survived, and small reptiles the diversity of remaining life-forms declined precipitously. This mass extinction event caused the loss of three-quarters of Earth’s life forms. IF you want to discover what dinosaur has 500 teeth, then click on or article.
There were over a thousand species of dinosaurs that once roamed the Earth. Find out which dinosaurs were the largest and smallest, how they behaved and what they ate, and surprising facts about their eventual extinction.
It has taken a lot of effort to piece together the events. Theories for the death of the dinosaurs, as well as the of rest the Cretaceous inhabitants, have varied from the plausible and downright absurd. Two main ideas are currently being debated within the scientific community. Were dinosaurs’ victims of interplanetary violence or other Earthly woes?
Death from Above
The Alvarez hypothesis is one of the most popular theories about the death of dinosaurs. It was named after Luis Alvarez and Walter Alvarez, a father-son team. These two scientists suggested in 1980 that a meteor of the size and shape of a mountain crashed into Earth 66.6 million years ago. This would have caused a massive change to the climate.
Their main piece of evidence is an unusually high concentration of the metal iridium in the K-Pg, layer— Cretaceous-Paleogene, the geologic border zone that seems to cap all known rock strata bearing dinosaur fossils. Iridium is a rare metal in Earth’s crust, but it is abundant in stony meteorites. This led to the Alvarezs concluding that the mass extinction was caused by extraterrestrial objects. Scientists were able to link the extinction event with a large impact crater off the Yucatan Peninsula in Mexico. This theory gained more momentum. The Chicxulub Crater is approximately 93 miles in width and has the right age and size to explain the dino death.
In 2016, scientists dug a rock core in Chicxulub’s underwater section. They found a sample that was deep under the seabed. The rare glimpse into the interior of the crater revealed that the impact was powerful enough to release deadly amounts of vaporized rocks and gases into the atmosphere. These effects would have continued for many years. In 2019, North Dakota paleontologists discovered a treasure chest of fossils very close to the K–Pg boundary. This essentially captured the remains of an entire ecosystem that existed just before the mass extinction. The fossil-bearing layers are rich in tiny glass pieces called tektites, which are likely to be blobs made of melted rock that was impacted and then rained down on Earth. For more education topics that wonder you, click on our website snm-education.com.
Other scientists, however, believe that evidence for a large meteor impact event is not conclusive and that Earth may be the culprit.
The Deccan Traps, an ancient lava flow in India, seem to be in sync with the end of the Cretaceous. They are characterized by the massive outpouring of lava that erupted between 60 and 65 million years ago. The volcanic rock that resulted in covers almost 200,000 miles and is in layers that are more than 6,000 feet thick. This massive eruptive eruption would have clogged the sky with carbon dioxide and other gases, which would have drastically changed Earth’s climate.
This theory is supported by multiple clues that indicate volcanism is a better match. One is that studies have shown that Earth’s temperature was rising even before the impact event. Another study has shown evidence of mass die-offs earlier than 66,000,000 years ago. There are also signs that dinosaurs were in slow decline during the late Cretaceous. It is also possible that volcanic activity on the planet is responsible for other ancient extinctions. However, giant meteor strikes are far more uncommon. All this makes sense, supporters claim that continuing volcanic eruptions were to blame for the global K-Pg extinctions.
Why not both?
Scientists trying to solve this mystery of prehistoric life are increasingly open to considering a combination. The possibility exists that the unfortunate recipients of a geologic were the dinosaurs. Volcanism has weakened ecosystems enough to make them more vulnerable to an incoming meteor.
This notion is dependent on the precise dating of the Deccan Traps as well as the Chicxulub Crater. Two independent studies were conducted in 2019 to examine geochemical clues found in Deccan Traps lava. One paper suggested that the volcanoes played an important role in the demise of the dinosaurs by causing pre-impact decays. The other said that the eruptions occurred after the impact event, but may have only played a minor role in their final days.
As scientists discover new clues and create new methods to understand the past, this debate could continue for many years. It doesn’t matter if space invaders are to blame or loads of lava, scientists who study the last gasp of the dinosaurs are learning vital lessons about the impacts of climate change on Earth’s inhabitants. For more interesting information about dinosaurs click on our website articledirectorynews.com.
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