These dinosaurs ate through lots of teeth

Plant-eating dinosaurs had to chew lots of tough material to sustain their large bodies, causing them to frequently replace their teeth. But researchers discovered evidence that a carnivorous dinosaur — the only known cannibal — replaced its chompers even more frequently.

The research centered on several meat-eating dinosaurs, but Majungasaurus crenatissimus was the star of carnivorous dinosaur dentition. This 20-foot-long apex predator, which lived on what is now Madagascar about 70 million years ago, left behind a plentiful fossil record. Allosaurus and Ceratosaurus had rates of replacing teeth roughly 100 days. But Majungasaurus went through teeth every 56 days on average, the team found. “Their teeth were contacting bone a lot,” said vertebrate paleontologist Michael D. D’Emic.

Smelly fruit relies on bats for pollination

Known as the world’s smelliest fruit, durians command the highest unit price of any fruit in Indonesia, with an export value of more than $250 million in 2013.

Hoping to help improve the yield of small-scale farmers, researchers decided to figure out what pollinates the durians in Sulawesi, Indonesia. They reported in the journal Biotropica that they caught three species of bats in the act, including a cave nectar bat and two types of flying foxes.

The last two were a surprise, said Holly Ober, an associate professor at the University of Florida in Quincy. Flying foxes are often killed by farmers trying to protect their mango crop.

“This study really is trying to provide empirical evidence for why we as a community should do more for bats,” said Joseph Walston, senior vice president for global programs at the Wildlife Conservation Society.

How an icy moon of Saturn got its stripes

Of the strange and unexplained terrains in our solar system, the south pole of Saturn’s moon Enceladus is among the most perplexing.

Enceladus is an ocean world, with a vast and briny sea tucked beneath its icy crust. But unlike other frozen moons, Enceladus constantly erupts, blasting salty water into space through fissures that are roughly parallel and evenly spaced.

Now Doug Hemingway of the Carnegie Institution for Science and his colleagues think they know how the moon got its tiger stripes. The team thinks that some time after it formed, Enceladus began to cool. Some of its inner ocean froze, expanded and strained the moon’s icy crust, which was thinner at the poles.

Eventually, the swelling sea fractured the southern crust.

The first fissure to form was 80-mile-long Baghdad. As water began erupting through Baghdad, some of it snowed back to the surface, piling up near the fracture’s margins. The weight of that material strained the ice shell, and new cracks opened. The stripes’ even spacing is a result of the ice’s elasticity and its thickness, which is thinner at the poles and bulkier at the equator.

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