He did not know it at the time, but the tooth he uncovered once belonged in the mouth of a 25-million-year-old giant shark that was twice the size of a great white. As it was confirmed by Erich Fitzgerald, a senior curator of vertebrate paleontology, the seven-centimeter-long teeth belong to a long extinct species called the great jagged narrow-toothed shark (Carcharocles angustidens).
Fossil enthusiast Philip Mullaly holds a giant shark tooth-evidence that a shark almost twice the size of a great white once stalked Australia's ancient oceans-at the Melbourne Museum on August 9, 2018. A cousin of the famous megalodon, this enormous shark would have measured over 30 feet in length - aka, twice the length of a great white shark.
The citizen scientist ended up pulling a 2.7-inch-long (7 centimeters) out of the boulder and took it to Museums Victoria for authentication.
"By donating his discovery to Museums Victoria, Phil has ensured that these unique fossils are available for scientific research and education both now and for generations to come".
Secondly, these rare fossils are among a handful of ancient shark teeth to have been found as a set.
"These teeth are of global significance, as they represent one of just three associated groupings of Carcharocles angustidens teeth in the world", Fitzgerald explained.
This is because sharks, who have the ability to regrow teeth, lose up to a tooth a day and cartilage, the material a shark skeleton is made of, does not readily fossilise.
This makes the newfound fossils all the more extraordinary, as multiple shark teeth coming from the same specimen are notoriously hard to find.
Researchers believe those teeth were left behind as a result of getting lodged in the carcass of the Great Jagged Narrow-Toothed Shark as smaller sharks fed on it after the much larger animal died. When Fitzgerald and a team went to investigate, they found around 40 more teeth, including a few from a genus (Hexanchus) that is still alive today. According to Fitzgerald, the vast majority of shark dental remains consist of single fossilized teeth.
"I'm willing to bet there's more up there", he said.