Scientists believe sperm whales secrete ambergris - a fatty, waxy-looking substance - inside their digestive tracts to protect themselves from sharp objects, like giant squid beaks and fish bones and teeth.
Also, contrary to urban legend, ambergris is actually whale poo, not vomit and is a sought after item by perfume makers.
While scientists have discovered fossilised feces, called coprolites, from dinosaurs, ichthyosaurs, mammoths and sharks, an ancient ambergris find has not been reported.
"These structures, derived from the original fossil ambergris masses, represent the first recovery on a global scale, since nothing like [it] has been described before in the scientific literature," lead study author Angela Baldanza, a sedimentary geologist at the University of Perugia in Italy, told LiveScience's OurAmazingPlanet.
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Trekking across the badlands, the scientists noticed mineralised lumps sticking out of the 1.75-million-year-old rocks.
They found 25 of the rounded structures over an area of about 0.3 acres (1,200 square meters). Each was about 23 to 47 inches (60 to 120 centimetres) wide and 12 to 23 inches (30 to 60 cm) long. The mounds were circular or tapered.
Several clues led the researchers to conclude they had found fossil whale poo. The trace fossils were striated with concentric rings, like modern ambergris, and their rounded and tapered shapes matched the appearance of ambergris found in sperm whales killed on ships in the 1950s.
"Unfortunately, chemical analyses are not conclusive, but preliminary results support the hypothesis," Baldanza said.