When Whales Walked: Journeys in Deep Time

Appearing to be basically unchanged since prehistoric times, crocodiles are blessed with armored scales, powerful jaws, and a low profile that enables them to surprise and attack prey. Actually, however, the crocodile has undergone constant evolution, just like birds, whales, and elephants. Filmmakers Chad Cohen and Graham Townsley’s PBS-aired documentary tries to solve the mystery of all of these creatures who have outlasted multiple extinction level events, the best known dating back 65 million years, when an asteroid hit the Earth, snuffing out most life forms. Like others, the croc was once embodied in many species, but is now whittled down to a mere few, benefiting from being a shoreline predator able to move on land and in water. Birds probably evolved from dinosaurs, with early feather-like claws that were used for killing, not flight. Shorebirds had an edge in survival, but their diversity is now threatened by human action, including pollution, pesticides, and habitat loss. Whales, who can live up to 200 years, moved from land to sea millions of years ago, becoming fully aquatic. Finally, elephants boast superior intelligence, memory, empathy and social communication skills, but have been reduced to only three species. Pairing fine scientific and natural history with a timely plea to preserve animals on the brink of a possible new extinction event, this is highly recommended. Aud: H, C, P. (S. Rees)