Using sequence analysis, they found that the underground mycelia of one individual fungal colony covered , weighing over , with an estimated age of 1,500 years. The analysis examined genetic samples collected in the forest from fruit bodies and rhizomorphs. Samples from the 15-hectare area had identical mating type alleles and mitochondrial DNA fragments. This showed the samples were all from a single genetic individual, or clone, which reached its size through vegetative growth. The authors noted: "This is the first report estimating the minimum size, mass, and age of an unambiguously defined fungal individual. Although the number of observations for plants and animals is much greater, members of the fungal kingdom should now be recognized as among the oldest and largest organisms on earth". After the "Nature" paper was published, media outlets from around the world visited the site where the specimens were found. As a result of this publicity, the individual acquired the common name "humongous fungus". There was afterward some scholarly debate as to whether the fungus qualified to be considered in the same category as other large organisms such as the blue whale or the giant redwood.