NEW YORK — A controversial United Nations report released this week concluded that the U.S. Marine Corps has officially entered a new stage of cognitive development after multiple independent observers documented Marines intentionally creating fire and using primitive tools.

U.N. Secretary-General António Guterres called the findings "a reality-altering development" and urged world leaders to remain calm.

"For decades we believed the technological ceiling for Homo marinus erectus was opening Meals, Ready-to-Eat with rocks," Guterres said. "We now know they are capable of combining sticks to produce controlled combustion."

Researchers say Marines diverged from the evolutionary path of Homo sapiens roughly two million years ago and have long been recognized within the scientific community as a distinct branch of humanity.

Retired Marine Gen. James Mattis, who has spent years advocating for the preservation of Marine habitats, described the discovery as "the greatest leap forward in Marine history."

"For generations we knew they were different," Mattis said. "Now they’re stacking sticks together and intentionally making fire. I don’t think we’ll ever stop them from eating crayons, but today proves they’re capable of learning."

The report also documented early evidence of cultural development after one Marine used charcoal from the fire to draw what experts believe was either a map of the area or...