To the bone: A giant shark attack severely injured the owner of this rib fragment, a whale. Photo: Stephen Godfrey
Read More Imagine an ocean in modern-day North America three to four million years ago: a hungry giant shark approaches a whale, does it catch? many times bigger? Booty in a careless moment and hits his gigantic teeth in their side. Then, however, the tide seems to turn around: the shark only succeeds in tearing out a piece of meat from the flank of its victim before it can escape. But the luck is short-lived: The bite wound ignites, and not six weeks after the attack dies the marine mammal. The highlight of this story, which three US researchers have now reconstructed: The full details can be read on a single, only palm-sized bone fragment. The find is the remnant of a rib discovered in an open pit near the village of Aurora in the southeastern United States. It originally belonged to a whale from the geological era Pliocene, presumably an ancestor of today's blue or humpback whales, and has a peculiarity: at a distance of about six centimeters, three round imprints can be seen therein. In the scientists' opinion, do they have to come from giant teeth that are almost certainly associated with a very large shark species? possibly even Carcharocles megalodon, also called megalodon, the largest shark species that has ever existed. However, it seems to have been a rather small representative who was "only" four to eight feet long.

This animal has apparently bitten the marine mammal, and quite vigorously. Nevertheless, the attack can not be considered successful, because the whale has the bite? at least first of all? Survived: Almost everywhere on the rib fragment, a thin layer of so-called woven bone can be seen. This is a fairly soft, immature form of bone tissue that typically forms when there is an infection somewhere in the immediate vicinity of the bone. Although the bite wound obviously began to heal, it seems to have become inflamed, the researchers interpret this finding. This assumption is also supported by typical inflammatory features in the bone marrow.

Long has the whale not survived the injury? a maximum of two to six weeks, the scientists estimate. Had he lived longer, a reconstruction of the woven bone would have to use hard bone tissue. Whether the wound and the infection were indeed the cause of death can not be said today. It is quite possible that the whale has died for a completely different reason, so the researchers. However, it is remarkable how much the bones tell about the behavior of prehistoric animals. "Only a handful of fossils show this kind of interaction, " says Stephen Godfrey of the Calvert Marine Museum in Solomons, who discovered the rib fragment. Although there are many bite marks on fossils, most came from scavengers who would have gnawed at the bones after the death of the animal. "This fossil is one of very few examples with an injury that can be clearly attributed to another animal, but also clearly shows that the victim survived the event."

Robert Kallal (Calvert Marine Museum, Solomons) et al .: International Journal of Osteoarchaeology, online pre-publication, doi: 10.1002 / oa.1199 © wissenschaft.de? Ilka Lehnen-Beyel advertisement

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