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The recent discovery of a 100
million year old tooth lodged in the spine of a fossilized flying reptile is changing scientists' perceptions of the spinosaurs' feeding habits.
The spinosaurus was a huge dinosaur, reaching up to 50 feet long and weighing 4 tons. It had six-foot sail-like spines on its back, and a snout that looked much like today's crocodiles.
The spinosaurus' teeth also resembled the cone-shaped teeth of crocodiles, which led many scientists to think that the dinosaur's diet was similar to crocodiles. Crocodiles eat a diet heavy on fish.
However, a fossil of a flying reptile called a pterosaur was found in Brazil with a spinosaur tooth stuck in its spine. There are now several theories about how the spinosaur's tooth came to reside in the pterosaur. One theory is that the spinosaur was a scavenger as well as a fish-eater, and that it came upon a dead pterosaur. Another is that the spinosaur regularly preyed on pterosaurs and other creatures.
For now, the answer remains a mystery.
Neanderthal Man
Meanwhile, scientists debate about the life of Neanderthal man, and teeth are at the center of the controversy.
Neanderthals first inhabited Europe and western Asia 200,000 years ago. The last Neanderthal disappeared about 30,000 years ago.
A study led by paleontologist Fernando V. Ramirez Rozzi, with the National Center for Scientific Research in Paris, suggested that Neanderthals reached adulthood by age 15. Rozzi reached his conclusions by studying growth patterns on the crowns of incisors and canines from several dozen Neanderthal skeletons. Tiny lines form on teeth every nine days or so. These lines mark the formation of tooth enamel. Rozzi used this method to estimate the Neanderthals' ages.
Neanderthals developed teeth about 15% faster than modern humans, says Rozzi. He also theorized that a Neanderthal's physical development must have also been faster, since tooth development typically coincides with physical development. The Neanderthals' rapid maturation may have had something to do with the harsh conditions in which they lived.
Not all scientists agree with Rozzi's findings, however, and believe more research must be done. Debbi Guatelli-Steinberg, an assistant professor of anthropology and evolution, ecology and organismal biology at Ohio State University, has spent the last decade comparing the teeth of Neanderthals with those of modern Inuit, or Eskimos. One tooth defect, called linear enamel hypoplasia, is a series horizontal grooves that form in tooth enamel during times when food is scarce. By comparing the teeth of the Inuit with those of Neanderthals, she concluded that, " Neanderthals were no worse off than the Inuit who lived in equally harsh conditions."
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