Our bond with dogs is etched in stone. In a new study, archaeologists exploring rock engravings in the Saudi desert have found what they say may be the earliest depictions of human-canine companionship. The ancient carvings date back about 8,000 to 9,000 years and depict hunters using dogs to overwhelm prey such as gazelles and ibex before they fired killing blows with bows and arrows. With their pricked ears, angled chests and curly tails, each dog in the rock art resembles the modern breed of Canaan dogs. In one scene there are two lines connecting the necks of two dogs to the hips of the humans. "This is the first imagery of a dog with a leash," said Michael Petraglia, an archaeologist and an author of the study. He said that because of where the lines were on the dog and human's anatomy, they most likely represented actual leashes and were not mere symbolic lines.

Lefties have an advantage in certain sports

Violins, cameras, school desks, computer mouses, can openers — these are just a few items that demonstrate how routinely disadvantaged left-handers are in this world. One notable exception may be sports. Some of the best athletes in history have been portsiders. But even in this realm, the southpaw advantage may vary, being more pronounced in sports where a player has less time to react to an opponent, like table tennis, according to Florian Loffing, a sports scientist at the University of Oldenburg in Germany and author of a study in Biology Letters. In such games, he found a higher proportion of lefties than in those with longer intervals between players' actions. Loffing chose to analyze baseball, cricket, table tennis, badminton, tennis and squash, because they lent themselves to a standardized measure of time pressure, he said. Comparing all six sports against one another, he found the proportion of southpaws increased as the time available for players to act decreased. Nine percent of the top players were left-dominant in the slowest contest, squash, while 30 percent of the best pitchers were lefties in the fastest, baseball.

25 million-year-old sea cow fossils found

Scientists say they've unearthed fossil remains of a sea cow that lived in the shallow waters off Southern California's Channel Islands some 25 million years ago. The fossil skull and rib cage were discovered this summer on Santa Rosa Island, about 50 miles northwest of Los Angeles, the National Park Service announced. Scientists say the remains may be from a previously unknown sea cow species, but they won't know for sure until the skull is analyzed by an expert. Some fossilized remnants from at least four other sea cows also were found nearby. Sea cows are torpedo-shaped plant-eaters that graze in shallow waters and can grow up to 13 feet long.

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