SCIENCE BOND

The common hippopotamus (Hippopotamus amphibius), or hippo, is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus (Choeropsis liberiensis orHexaprotodon liberiensis).  After the elephant and rhinoceros, the common hippopotamus is the third-largest type of land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago. The common ancestor of whales and hippos split from other even-toed ungulates around 60 million years ago. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around 16 million years ago.   Common hippos are recognizable by their barrel-shaped torsos, wide-opening mouths revealing large canine tusks, nearly hairless ...

Snail is a common name that is applied most often to land snails, terrestrial pulmonate gastropod molluscs. However, the common name "snail" is also applied to most of the members of the molluscan class Gastropoda that have a coiled shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also thousands of species of sea snails and freshwater snails. Occasionally a few other molluscs that are not actually gastropods, such as the Monoplacophora, which superficially resemble small limpets, may also informally be referred to as "snails". Snail-like animals that naturally lack a shell, or have only an internal shell, are usually called slugs, and land snails that have only a very small shell (that they cannot retract into) are often called semislugs.   Snails that respire using a lung belong to the group Pulmonata, while those with gills form a polyp...

  Kangaroos are the largest living marsupials from the family Macropodidae. There are four species commonly referred to as the kangaroo: the red kangaroo, the eastern grey kangaroo, the western grey kangaroo, and the antilopine kangaroo.Kangaroos are grazing herbivores, which means their diet consists mainly of grasses. They can survive long periods without water.Kangaroos are found in Australia and Tasmania, as well as on surrounding islands. Kangaroos live in varied habitats, from forests and woodland areas to grassy plains and savannas.   Kangaroos live and travel in organized groups or "mobs," dominated by the largest male. Male kangaroos are called boomers, bucks or jacks; females are does, flyers, or jills, and the young ones are joeys. The collective noun for kangaroos is a mob, troop or court. Kangaroos are the only large animals to use hopping as a means of locomotion. The comfortable hopping speed for a red kangaroo is about 20–25 km/h (13–16 mph), but speeds of u...

A U.S. astronaut and a Russian cosmonaut are headed for a year in outer space, the longest stay ever at the International Space Station.The two men and a second cosmonaut were aboard a Russian Soyuz rocket that blasted off Saturday from the Baikonur Cosmodrome in Kazakhstan, Russia's space launch facility. The rocket launched in the very early morning local time and docked at the space station about six hours later. NASA astronaut Scott Kelly and cosmonaut Mikhail Kornienko, both in their early 50s, will stay at the space station until next March. Scientists hope to study the physical and mental effects of living in space as the men surpass the usual six-month stay at the station.NASA will use the information learned from the mission to plan future expeditions to Mars that could last two to three years.Astronaut Kelly's identical twin is participating in the study on Earth. Retired astronaut Mark Kelly will undergo the same tests that his brother is subjected to in space, givin...

  The insects were identified as part of a project led by Emily Hartop of the Natural History Museum of Los Angeles County, where local volunteers took part by setting up 24-hour insect traps at 30 sites across the city. "For us, it seemed like a no-brainer," says volunteer Walter Renwick. "We have two young bug-crazy children, a bug-crazy dad, and a very patient mom in our household." Hartop then sifted through 10,000 fly specimens over a three-month period to identify the new species. Conveniently, each new member of the fly genusMegaselia could be matched to one of the backyards where it had been spotted, so researchers named each species after the corresponding citizen scientist.The finds reveal a surprising biodiversity in LA, one of the most smog-choked cities in the US.