Researchers have discovered the earliest Jurassic corals, the fossil record of the earliest North American coral species that reappeared after the mass extinction event of the Triassic-Jurassic ages.
The discovery was made in central Nevada's high desert, particularly in the New York Canyon that is covered with sedimentary rocks that represented the North American west coast during the Jurassic period.
Montana Hodges, a Ph.D. student, and George Stanley, a professor of geosciences, both from the University of Montana, investigated the coral reefs—typically badly hit by ocean temperature changes and acidity—in their study published this October in GSA Today, the Geological Society of America’s publication.
Coral reefs totally collapsed about 200 million years ago. The researchers found no proof of asteroidal or any other similar catastrophic event, but instead discovered evidence of severe climate change spread throughout the world during this specific extinction in history.
According to Hodges, warming climate was brought about by a mix of effects from the division of the supercontinent Pangaea, changes in sea level, and huge amounts of gas from cracks in the crust of the Earth reaching the atmosphere.
Coral reefs took over 20 million years to completely recover after the mass extinction event.
Experts have visited the Nevada site for nearly a century now to study rock deposits from the Triassic-Jurassic era. The mass extinction that took place left signs and clues through the fossils in the rocks yet, according to the researchers, it is only now that the importance of the corals in the area is noted.
Hodges deemed the Jurassic corals a representative of "a recovery of all species" after the said extinction. They are simple and solitary corals that resided in thick mud, something that probably assisted them in surviving during the turbulent period.
They may have migrated from the distant side of Pangea, too, added the scientist.
The important discovery made is believed to be the earliest basis for the corals that gradually rebuilt and evolved over millions of years. The study aims to help people better understand how they survived and recovered.