"The Cambrian Explosion," or the rapid diversification of Earth's animal species on Earth 520 million years, was likely caused by intertwining events rather than one fundamental cause, according to a press release.

Authored by Oxford University's Paul Smith and Durham University's David Harper, a new study presents a "holistic approach" to uncover the reasons behind the Cambrian Explosion. Previous theories have stated it was a standalone event, being geological, geochemical or biological.

"The Cambrian Explosion is one of the most important events in the history of life on our planet, establishing animals as the most visible part of the planet's marine ecosystems," Harper said. "It would be naïve to think that any one cause ignited this phenomenal explosion of animal life. Rather, a chain reaction involving a number of biological and geological drivers kicked into gear, escalating the planet's diversity during a relatively short interval of deep time."

After the Cambrian Explosion, animal diversity sped up, modern ecosystems originated and the first instances of burrowing and swimming took place.

For the study, Harper, Smith and a team of scientists traveled to a location called Siriuspasset, in northernmost Greenland just 500 miles from the North Pole. While the location was daunting to travel to, it lured the team because of the high-quality fossils it posses.

"This is a period of time that has attracted a lot of attention because it is when animals appear very abruptly in the fossil record, and in great diversity," Smith said. "Out of this event came nearly all of the major groups of animals that we recognize today."

The research was published in the journal Science's latest edition.

Harper and Smith said a "cascade of events" led to the Cambrian Explosion, but it was likely started by a rise in sea level. They said this would have made for a larger habitable area on the seafloor and encouraged animal diversity. Those early events then led to an intricate mix of geological, biological and geochemical events.

"Work at the Siriuspasset site in north Greenland has cemented our thinking that it wasn't a matter of saying one hypothesis is right and one is wrong," Smith said. "Rather than focusing on one single cause, we should be looking at the interaction of a number of different mechanisms."