Megalodon was the largest shark ever to have lived, potentially growing up to around 60 feet in length.
Researchers have discovered the fossilized remains of at least 40 different species of ancient shark in Mammoth Cave in Kentucky, dating back to around 325 million years ago.
The predation event took place 99 million years ago in what is now Myanmar.
"Diagnosis of aggressive cancer like this in dinosaurs has been elusive," said researcher Mark Crowther.
The fossilized excrement could help to shed light on what the extinct animal once ate.
Researchers also found another news species of prehistoric shark in Georgia.
The reptile is an early member of the animal group Ornithodira to which both dinosaurs and pterosaurs belong.
Latest study supports the idea that the asteroid impact 66 million years ago was the main driver of dinosaur extinction, not intense volcanic activity as some have suggested.
Many giant dinosaur specimens are very incomplete, which makes it difficult to produce reliable body mass estimates.
The latest findings also help to shed new light on other sites in South Korea where scientists have previously found footprints that were originally thought to belong to giant flying reptiles.
"The finding of the actual preserved stomach contents from a dinosaur is extraordinarily rare," said researcher Jim Basinger.
The dinosaur is one of the largest and youngest megaraptors on the fossil record, say paleontologists.
Scientists describe the two-inch bone of a 110 million-year-old elaphrosaur found in Victoria, Australia, after it was misidentified as belonging to a pterosaur.
The shape of the structures resemble that of complex carbon molecules known as "fullerenes," which were one of the first nanoparticles discovered by scientists.
Bones from a fossil rich site at Tanque Loma in Ecuador offers clues to how a group of 22 plus giant sloths met their end 18,000 years ago.
A new Spinosaurus skeleton proves one of the largest dinosaur predators ever discovered lived a largely aquatic lifestyle, opening up a new understanding of dinosaur's place in the ancient world and overturning old dogmas.
Researchers reviewed a group of fossils from an area of the Moroccan Sahara, which includes a host of large dinosaurs, pterosaurs, crocodilians, and other animals.
A recently published paper describes some of the oldest plants and animals in Australia and Zealandia, aged between 40 and 230 million years old.
Scientists say the young Homo naledi was between 8-15 years old. Further research could determine whether the species was more ape-like or human-like in its maturation.
The extinct animal may reveal how modern birds survived the asteroid that wiped out large dinosaurs.
"[The discovery] shows that some of the big steps in evolution we thought were restricted to land animals actually first took place in fishes," said researcher John Long.
Researchers have found around 50 footprints at two sites on the island.
Information stored by a geologist's daughter contained data that helped determine the makers of a series of dinosaur tracks found on a cave ceiling in Australia.
The animal is one of the oldest tyrannosaur species ever discovered in North America.
"Thalattosaurs were among the first groups of land-dwelling reptiles to readapt to life in the ocean," Neil Kelley, an author of the study from Vanderbilt University, said in a statement.
The discovery provides new insights into hunting behavior of these 150 million-year-old flying reptiles
The shark was likely similar in size to great whites, which grow to an average of around 15 feet.
Computer simulations suggest Neanderthals were already on the brink of extinction and had been for hundreds of thousands of years when demographic fluctuations and inbreeding pushed them over the edge.
In theory, the ancient shark could have grown up to a staggering 22 feet in length, according to researchers.
New discoveries in Bavaria of an ape with "orangutan arms" but human-like legs has the science community excited about connecting the dots of evolution between great apes and humans.