There s a longstanding debate simmering among biologists who study porcupines. There are 16 porcupine species in Central and South America, but only one in the United States and Canada. DNA evidence suggests North America s sole porcupine belongs to a group that originated 10 million years ago, but fossils seem to tell a different story. Some paleontologists think they may have evolved just 2.5 million years ago, at the beginning of the ice ages.
An exceptionally rare fossilized porcupine skeleton discovered in Florida has allowed researchers to trace the evolutionary history for one of North America s rarest mammals.
In the evolution of walking, the hip bone connected to the rib bones sciencedaily.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from sciencedaily.com Daily Mail and Mail on Sunday newspapers.
Before the evolution of legs from fins, the axial skeleton -; including the bones of the head, neck, back and ribs -; was already going through changes that would eventually help our ancestors support their bodies to walk on land.
In the evolution of walking, the hip bone connected to the rib bones psu.edu - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from psu.edu Daily Mail and Mail on Sunday newspapers.