Paleontologists discovered Extraordinary fossils on the Grand Canyon that reveal new details about the Complex life emergence for half a billion years.
The recent traces of fauna in the region suggest that it offered Ideal conditions for flowering and the diversification of lifein a median habitable zone between the severe extremes of other regions. This evolutionary opportunity produced a multitude of primitive animals, including eccentric individuals with peculiar adaptations for survivalaccording to a new research.
During the Cambrian explosion, which occurred in the coastal waters of the Earth oceans about 540 million years ago, most of the types of animal bodies that exist today, scientists believe.
At that time, the Grand Canyon was closer to Ecuador, and the region was covered by a warm, growing sea, full of growing life-a water-like water-like water creatures and modern slugs-all-all
Researchers resorted to the Grand Canyon sedimentary rock layers to unravel the secrets of this crucial moment in the history of life, excavating the scale and clay shale of Bright Angel formation, where most canyon’s Cambrian fossils were found.
The study team expected to recover mainly fossilized remnants of hard shell invertebrates typical of the region. Instead, the team dug something unusual: rocks containing well -preserved tiny fragments soft body mollusks, crustaceans e priapulídeosalso known as .
“With these types of fossils, we can better study your morphology, your appearance and your lifestyle with a much larger resolution, which is not possible with the concosi parts,” said Giovanni Mussini, the first author of the study published on Wednesday “is a new window for Cambrian life in Grand Canyon.”
Using high power microscopes, the team was able to investigate innovations such as miniature jails of mollusks of rock scrapers and hairy crustacean limbs and molars who feed on filtration, providing a rare view of the biologically complex forms in which Cambrian animals have adapted to capture and eat prey.
Strange adaptations of Cambrian animals
Although some of the feeding mechanisms discovered in the Grand Canyon fossils still exist today, others are much stranger.
Among the most bizarre: Felic -shaped worms that turned their mouths inside out, revealing a throat covered with hairy teeth. See an illustration of what the animal would be like:
These worms, also known as Cactus worms, are practically extinct today, but were common during Cambrian. The fossilized worm found on the Grand Canyon represents a hitherto unknown species.
Due to its relatively large size – about 10 centimeters – and the distinct teeth, it was called Kraytdraco Spectatus, in honor of the Dragon Krayt Fictitious from the Star Wars universe, Mussini said. This particular worm in particular seems to have had a gradient of hundreds of branched teeth used to sweep the food into an extensible mouth.
“It’s a little difficult to understand exactly how he fed,” said Mussini. “But he probably fed on debris at the bottom of the sea, scraping them with some of the most robust teeth he had, and then using other delicate teeth to filter them and retain them inside that long, tubular mouth.”
Rows of tiny molars, sternal parts and limbs similar to combs that belonged to crustaceans were also among the discoveries, all dated 507 million to 502 million years ago.
Similar to current saltwater shrimp, crustaceans used these thin hair limbs to capture floating foods in the water and take them to the mouth, where the molars crushed the particles, Mussini explained. Nestled among the molars, the researchers even found some unlucky plankton.
Other creatures similar to those included slug -like mollusks. The fossils revealed tooth chains that probably helped them shave algae or bacteria from the seabed.
“For each of these animals, there are different components, but most of what we find is directly related to the way these animals processed their foods, which is one of the most interesting parts, because it tells us a lot about their lifestyle and, consequently, their ecological implications,” said Mussini.
The perfect zone for innovation
For most of the simplicity, it reigned. Unicellular microbes remained stationary at the bottom of the ocean, feeding on chemical compounds such as carbon dioxide and sulfur molecules to decompose food.
What has changed?
Scientists still debate what motivated the Cambrian explosion, but the most popular theory is that oxygen in the earth atmosphere began to increase slowly, said Erik Sperling, an associate professor of Earth and Planetary Sciences at Stanford University.
Oxygen provided a much more efficient way to metabolize food, giving animals more energy to mobilize and hunt prey, Sperling suggested, who was not involved in the new study.
“The (emergence of) started these growing arms races, and then we had basically an explosion in different ways to do business,” said Sperling.
During the Cambrian, the shallow sea that covers the Grand Canyon was especially oxygen rich thanks to its perfect depth, a habitable zone, Mussini said, a doctoral student in Earth Sciences at Cambridge University in the United Kingdom.
Various from 40 to 50 meters deep, the ecosystem was not disturbed by the constant waves of the coast that moved around the sediments, and sunlight could still reach photosynthetic plants at the bottom of the sea, which could provide oxygen.
The abundance of food and favorable environmental conditions made animals could take on more evolutionary risks to stay ahead of the competition, Mussini said.
“In an environment with more resource shortages, animals cannot afford to make this type of physiological investment,” Mussini said in a press release at Cambridge University. “There are certain parallels with the economy: investing and taking risks in times of abundance; save and conservative in times of scarcity.”
Many soft -bodied fossil discoveries before they came from regions with hostile environments, such as the formation of Burgess Shale, Canada, and Maotianshan Shales, China, Susannah Porter, a teacher of Earth Sciences at the University of California in Santa Barbara, who was not involved in the study.
“It is not unlikely that paleontologists, in the distant future, have great fossil records of Antarctica, where cold and rigorous environments forced people to adapt.… But then they find great human fossils in New York City, where people prospered,” Porter explained. “We have the opportunity to see different types of evolutionary pressures that are not where it is very cold, very hot, there is not much water.”
