Fifty-million-year-old fossil beetles that fed only on palm seeds are giving Simon Fraser University biologists Bruce Archibald and Rolf Mathewes new information about ancient climates.
According to their research, published online this week in The Proceedings of the National Academy of Sciences, these fossil beetles indicate that during a period of global warming in the geological past, there were mild, frost-free winters extended even in the uplands of ancient western North America.
Working with co-authors Geoffrey Morse of the University of San Diego, California, and David Greenwood of Manitoba’s Brandon University, researchers used fossil beetles to determine winter temperatures where they couldn’t place a thermometer—in the 50-million-year-old uplands of British Columbia and Washington.
The key to their study was finding a particular group of beetles that only feed on palms.
"The natural distribution of palms is limited today to regions without significant frost days, which their seeds and seedlings can’t survive," Archibald explains. "A cooler upland with palms indicates a specific climate type, where a temperate average yearly temperature—rather like Vancouver today—had warmer winters where palms can complete their lifecycles."
But since detecting palm fossils is difficult, the research duo developed a new technique—they used the beetle fossils to test for the palms’ presence. Read More.
The newly-discovered polar dinosaur Nanuqsaurus, from fossil deposits in Alaska, seen here in scale with a modern-day Inuit girl. Nanuqsaurus was a small-sized relative of the famous Tyrannosaurus rex.
Picture: The mesocyon, the earliest tracked achestor of the wolves
ORIGIN OF THE WOLF
The earliest fossil carnivores that are certain to be the anchestor of today’s canids are the Eocene Miacids that lived 38-56 million years ago. There were two lines that evolved from the miacids – the feloidea (lions, cats, caracals) and the canoidea (wolves, dogs, foxes). The canoid line evolved from the Mesocyon that lived approximately 35 million years ago. It was the same size as today’s coyotes, and is believed to have lived in packs just like wolves do today. The line evolved further with (among others) the fox-like Leptocyon and the wolf-like Eukyon that wandered North America some 10 million years ago.