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When fossils are discovered
that are from no known species, they are described and often given a
name, even though their is not enough material to really identify
animal they came from. This is the case with Majungatholus. It was originally named for an isolated skull fragment thought to
belong to a pachycephalosaur, or dome-headed dinosaur. In 1998, paleontologist/anatomist Scott Sampson from the New York College of Osteopathic Medicine at the New York Institute of Technology discovered far more complete fossils on what is now the island of Madagascar Uncovered in separate pieces on the island of Madagascar (off the southeast coast of Africa), the skull of the dinosaur called Majungatholus is one of the best preserved dinosaur skulls ever found. The pieces literally fit together like a jigsaw puzzle! Speaking of his new discovery, Sampson said, "It's the kind of face that only a mother could love. It had textured, convoluted bone all over the surface of the skull which probably had skin tightly adhering to it. It had this horn-like structure on the top of the head between the eyes and another projection at the back of the skull as well." Sampson doesn't know for sure what the protrusions were for, but he does know one thing. It was damn ugly – and terrifying. "Although the brain is smaller than the size of a fist, this thing was definitely a predator…it's got a mouthful of razor-sharp teeth, walked on hind legs, and would have been pretty quick." Majungatholus atopus was a meat-eating dinosaur, a theropod. It was at the top of the food chain in its locale. It probably ate sauropods, long-necked plant-eaters and other large dinosaurs. The name Majungatholus is derived from "Majunga," a district of Madagascar and "tholus," which means dome in Latin. Majungatholus belongs to the group of dinosaurs called abelisaurids, which until now were only found in India and South America. While tyrannosaurs ruled the northern hemisphere, a group of dinosaurs called abelisaurs roamed the southern half of the world. Majungatholus is very similar to the horned dinosaur Carnotaurus, which is found in in Argentina. The discovery of this new species in Madagascar, so far from its relatives in India and South America, has implications for plate tectonics. In particular, the continent of Gondwanaland may have had a connecting land-bridge from South America through Antarctica to India-Madagascar for longer than believed, allowing animals like Majungatholus to slowly migrate to new, far flung habitats. "Dinosaurs lived at a time when all of the continents were connected, so we use them to test hypotheses about the timing of the break up of the Earth's continents," says Sampson. "Until now, people assumed that South America and Africa broke away as one unit." Like sharks, dinosaurs have replaceable teeth. So, although many isolated teeth of the dinosaur were found, it wasn't until Sampson's discovery that scientists now have an accurate picture of what Majungatholus looked like. Also discovered were several bones of another Majungatholus dinosaur that had teeth marks in it them that could have only been made by another Majungatholus dinosaur. There was one other discovery of what might have been another cannibal dinosaur; the Coelophysis bauri, a small Triassic theropod. This discovery however has not yet been proven and may be unconfirmed. The discovery of the Majungatholus however has what geologist Raymond Rogers calls the “smoking gun in the form of diagnostic tooth marks,” which are “a ‘snapshot’ of a day in the life-- and death—of Majungatholus." There is however no evidence to point to whether or not Majungatholus killed its meals or simply scavenged. Extensive research later proved that this dinosaur was a cannibal. In her 2003 press release for the National Science Foundation (NSF), Cheryl Dybas quoted the NSF program director Richard Lane, “this research greatly expands our understanding of how dinosaur species related to each other in the context of their environment, and also serves as a way of increasing public awareness of and appreciation for the earth sciences." Rogers says the evidence for the theory of cannibalism comes from twenty-one tooth marked elements which were a part of two different Majungatholus individuals found in two isolated locations on the island Madagascar. On these bones are distinct sets of tooth marks that point only to being from the jaws of a Majungatholus dinosaur; the marks not only match the size and spacing of the teeth found in the jaws of the Majungatholus, but they also have the same smaller grooves that match the sharp irregularities of this particular dinosaur. According to “measurements taken from the modified bones and the Majungatholus teeth are comparable.” The set of parallel tooth marks found on one of the bones matched up with the same approximate inter-tooth spacing as the jaw of the Majungatholus. This particular dinosaur also can display an even pattern of tooth eruption that is evident in several of the bones in the sample. Rogers and his colleagues still took no chances in trying to rule out any other potential dinosaurs or related individuals, which might have left similar tooth marks on the fossilized bones. In order to rule out this possibility concretely, examined the “jaws and teeth of other known meat-eaters in the Malagasy fauna, including a much smaller carnivorous dinosaur called Masiakasaurus knopfleri, and two large crocodiles.” The small size of the only other known theropod from the region, Masiakasaurus knofleri eliminates it from having been able to leave the tooth marks found on the bones, which were definitely from a larger dinosaur. The early forms of the crocodiles were also ruled out because, “their robust, conical teeth were too blunt, too irregularly spaced, too variable in height, too variable in orientation and too variably positioned” to be have caused the narrow U shaped grooves found in the bones. After all of this research and examination, Rogers and his associates concluded that only the Majungatholus had the jaws and teeth capable of inflicting the damage they saw on the fossilized bones they had discovered. This, along with the data from three separate bone-beds that points to Majungatholus regularly de-fleshing carcasses shows that this dinosaur is the closest researchers have come as of yet to finding cannibalism among dinosaurs. was quoted as saying, “despite the bad press that human cannibals receive, this discovery of cannibalism in a theropod dinosaur should come as no big surprise.”; Cannibalism is a natural tactic that is somewhat common among animals past and present.“ At least fourteen species of mammalian carnivores kill and eat members of their own species, and numerous reptilian and avian taxa also practice cannibalism.” What makes this discovery important is that previously there had been little to no concrete evidence that cannibalism existed among dinosaurs. |
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