PHOBERODON PHOBERODON ARCTIROSTRIS WHEN 23 to 15 97 million years ago WHERE Modern Patagonia Argentina LENGTH 10 1 4 feet 3 meters LOOK FOR Sharklike teeth and a small dorsal fin PREHISTORIC PROFILE Look out a shark Or well shark toothed dolphin Unlike modern day dolphins with their conical teeth Phoberodon arctirostris had ridged teeth similar to modern sharks and were part of a family of ancient cetaceans called Squalodontidae First discovered in 1840 Phoberodon was not largely studied until more than 100 years later Although most modern dolphins are not directly related to Phoberodon they provide an important link to help scientists better understand how different cetaceans evolved to adapt to their environment GIANT TOOTHED SPERM WHALE LIVYATAN MELVILLEI WHEN About 13 to 12 million years ago WHERE Modern Peru LENGTH Estimated 42 1 2 to 52 1 2 feet 13 to 16 meters LOOK FOR An incredibly long skull with large piercing teeth PREHISTORIC PROFILE When this species was first discovered scientists wanted to name it Leviathan because the ancient whale had a massive skull and jaw but that name was already taken by a species of mastodon Instead they named it Livyatan This ancient sperm whale likely lived during the Miocene era and fossils found in Peru suggest it lived in the Pacific Ocean Much like modern sperm whales see page 64 Livyatan had a large bulge on its skull that was likely a spermaceti organ The second part of this whale’s name melvillei is actually a reference to the writer Herman Melville who created the famous sperm whale Moby Dick Livyatan teeth are truly massive and they measure about 14 inches 35 1 2 centimeters long and 4 or 5 inches 10 to 13 centimeters wide with sharp tips For comparison Tyrannosaurus rex teeth were about 6 to 12 inches 15 to 30 centimeters long 14
WHALERUS SKIMMING PORPOISE ODOBENOCETOPS LEPTODON SEMIROSTRUM CERUTTII WHEN About 7 to 5 million years ago WHERE Modern Peru and Chile AVERAGE TUSK SIZE 3 feet 1 meter on the right side and 10 inches 25 centimeters on the left LOOK FOR A wide head similar to modern day walruses with one long tusk PREHISTORIC PROFILE What do you get when you cross a whale and a walrus A whalerus This extinct form of a toothed whale had a face similar in shape to a walrus and large tusklike teeth Because this whale had a walrus like head and tusks it was nicknamed the whalerus or walrus whale Their two tusks were not the same size which makes them different from any modern marine mammals although they are somewhat similar to modern narwhals WHEN About 5 to 1 6 million years ago WHERE Modern California JAW LENGTH About 2 3 4 foot 85-centimeter jaw LOOK FOR A long lower jaw with a comparatively short triangular upper jaw PREHISTORIC PROFILE Imagine what it would feel like if your bottom jaw was twice as long as your upper jaw The skimming porpoise a prehistoric porpoise that may be related to modern porpoises had a very interesting mouth with a lower jaw that extended out far beyond the upper jaw Scientists think they may have used this jaw to help them skim food from the seafloor 15
Mysterious Mysticetes The mysticetes group of whales also known as baleen whales are toothless Instead of teeth this type of whale has special filters in its mouth called baleen plates To eat baleen whales find an area of water with a big group of prey available usually small sea crustaceans called krill Then they take in a huge mouthful of water pulling in both water and prey Then they use the baleen to filter the water out of their mouth leaving just the prey behind for the whale to swallow Baleen whales are incredibly large but despite their size they’re able to move around well and are even known for being able to jump entirely out of the water 16
PYGMY RIGHT WHALE CAPEREA MARGINATA WHERE Southern Hemisphere surrounding Antarctica LENGTH 19 3 4 feet 6 meters LOOK FOR A dark and light gray whale with lighter patches behind the eyes WHALE WATCH Pygmy right whales earned their nickname by being the smallest of the baleen whales These whales are distinguished from other right whales because they have a dorsal fin These petite whales are only found in a small area near Antarctica where the water is very cold Because they only live in this area they’re not often spotted at sea In fact there have only ever been about 20 recorded sightings of groups of pygmy right whales at sea which is why we know relatively little about what they’re like Some scientists even speculate they are the last living members of an ancient type of baleen whale known as cetotheres meaning they might not be part of the right whale family at all 17
