40 New Dinosaur King Rears Its Head

Tyrannosaurus rex slipped further in the ranks of terribleness with the enthronement of a bigger, badder king of the dinosaurs: Spinosaurus aegyptiacus, a gigantic predator that stalked Africa around 100 million years ago and whose head alone was almost six feet long.


Courtesy of Museo di Storia Naturale di Milano
After examining skull fragments of Spinosaurus, paleontologist Cristiano Dal Sasso of the Civic Natural History Museum in Milan, Italy, and his colleagues estimated that the whole animal would have measured between 52 and 59 feet from tip to tail, as much as a dozen feet longer than the largest known T. rex and bigger than the previous record holder among carnivorous dinosaurs, Giganotosaurus; a full-grown adult might have stood 20 feet tall and weighed as much as nine tons. In addition to its astonishing bulk, Spinosaurus had a fearsome ridge, or sail, down its back, a croc-like jaw, and strong, taloned arms to catch its prey. "We were astonished when we calculated its overall size," says Dal Sasso. "We realized that we were studying the largest predator of all times."

Richard Hollingham

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59 Fossilized Frog Marrow Found


Courtesy of Museo de Geologia del Seminari
In August researchers examining fossils in the National Museum of Natural Sciences in Madrid reported the first example of fossilized bone marrow, found in
10-million-year-old remains of frogs and salamanders. Because of the way the slabs containing the bones were fractured during preparation, they revealed a clean cross section of bone, in which the red of the bone marrow and the yellow of the fatty marrow were clearly visible. Paleobiologist Maria McNamara of University College Dublin theorizes that the bones provided a protective environment for the marrow, preventing microbes from infiltrating and destroying the soft tissue. Why has no one noticed this material—which may contain DNA and proteins—before? "We think one reason is that when well-preserved fossils with traces of other soft tissue, such as muscle, are studied, people focus on those and sample those," McNamara says. "But when I was doing the museum work in Spain, I was using a binocular microscope to study each specimen. If I'd been skimming through them, I don't think I would have found the marrow."

Nicholas Bakalar

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66 Hobbit Wars Heat Up

When small, humanlike bones were discovered in a cave on the Indonesian island of Flores in 2003, anthropologists knew they had found something exceedingly odd. But what? A new species of dwarf people? A colony of pygmy freaks? Half-joking, some researchers simply referred to the remains as "hobbits."


Courtesy of National Academy of Sciences
The evidence from 2006 has sharpened the speculation. In September Penn State evolutionary biologist Robert Eckhardt published a paper attacking the idea that Flores Man was a separate species of hominin, related to Homo erectus, that lived in isolation as recently as 13,000 years ago. That idea is championed by Peter Brown of the University of New England in Armidale, Australia, a codiscoverer of Flores Man.

Eckhardt argues that the bones share many features, such as rotated teeth and a receding chin, with the Rampasasa pygmies living today near the cave where the remains were found. He notes that the average Rampasasa is just a foot taller than Flores Man. "They may have been going through a temporary food shortage that made them small even for pygmies," he says. In addition, his team found that the most complete specimen of Flores Man was so misshapen that the individual likely suffered from some sort of developmental abnormality, which might explain why the brain was so small.

But when anatomists at Stony Brook University in New York examined the Flores specimens at the request of Brown's team, they supported that group's very different interpretation. They found that Flores Man's shoulders were hunched slightly more forward than in modern humans, and the extraordinarily short legs ended in long feet. Such features seem to tag the Flores people as a separate species, not pygmy versions of modern humans. In addition, some of the oldest Flores remains date back before modern humans were thought to be in the area, which suggests that Flores Man was a distinct species. These little remains could rewrite the story of modern human evolution, so don't expect the debate, or the tempers, to cool down anytime soon.

Jeffrey Winters

85 Dodo's Lost World Resurrected

While a few dodo bones and one skeleton remain in museums, they aren't enough to tell biologists exactly why or how the birds went extinct more than 300 years ago. So Dutch geologist Kenneth Rijsdijk was thrilled when he unearthed a cache of 3,000-year-old dodo bones on the island of Mauritius last December. By July he had more good news: The seven-acre site holds a near-complete fossilized ecosystem, including plants, bacteria, reptiles, mammals, and other birds. "There's a lot of potential to reconstruct their world," Rijsdijk says. "What did it look like, and what was the effect of man?"

Elise Kleeman

94 Tough Times for Tyrannosaur Teens

Life was rough for teen tyrannosaurs, according to Florida State University paleontologist Gregory Erickson. Analysis of a trove of North American dinosaur fossils shows a highly elevated death rate among tyrannosaurs who had recently reached sexual maturity, which occurred between the ages of 14 and 18. "Love may have been a dangerous game for these animals," Erickson says. Competition for mates and nesting sites probably took a toll: Only 2 percent of T. rex's relatives survived all the way to reach their maximum life span of about age 30.

Jennifer Barone