Whale Evolution Data Table Name Mesonychids e.g. The first specimen, found in Northern Pakistan in 1983, was a skull. Basilosaurus, unlike modern cetaceans, had various types of teeth–such as canines and molars–in its mouth (heterodonty), and it probably was able to chew its food in contrast to modern cetaceans which swallow their food whole. From the outside, they don't look much like whales at all. In other words, based on some details in its teeth and ear bones, some persons felt able to describe this quadrupedal, wolf-like land dweller as a ‘walking whale.’ Just one look at the reconstruction of Pakicetus by the evolutionist illustrator will reveal the absurdity in terming it a ‘walking whale.’ Even Gingerich himself admitted: •Its ear structure is more developed for hearing in the air rather than water. •In whales, the ear region of the skull is used for directional hearing underwater. The tiny brain leads scientists to believe today that the Basilosaurus lacked … From the teeth, it was learned that Pakicetus was likely an omnivore. Fossils show its ear shape and position to be of a type unique to whales. - Pakicetus inachus, A New Archaeocete (Mammalia, Cetacea) from the Early-Middle Eocene Kuldana Formation of Kohat (Pakistan) - Contributions from the Museum of Paleontology, The Museum of Michigan 25 (11): 235–246 - Philip D. Gingerich & Donald E. Russell - 1981. The Basilosaurus had a specialized ear region in its skull that allowed the animal to hear well underwater. However, the rest of Basilosaurus’ hearing adaptations indicate it was fully marine, and thus any retention of adaptations for hearing airborne sound was probably vestigial. The teeth also are quite distinct among among mammals in that they are especially primitive, mostly-unspecialized, triangular, shrew-like, almost reptilian teeth, just like those of some modern whales. How Did Whales Evolve? •It had a body of a land mammal but a long distinctive skull shape of a whale’s. Pakicetus lived in Pakistan about 50 million years ago. However, the skull revealed that this marine mammal had a small brain compared other whales. Unlike modern cetaceans, the skull of Basilosaurus has bony external ear canals, suggesting that it may have retained some form of highly reduced external ear. If you happened to stumble across the small, dog-sized Pakicetus 50 million years ago, you'd never have guessed that its descendants would one day include giant sperm whales and gray whales. No other mammal had teeth like this since the days of the dinosaurs. Once your tooth has been pulled out and you recover from the anesthetic administered by your dentist, you may feel the pain not only from the extraction site but from the teeth nearby and possibly around your ear 1 2. But … The Pakicetus skull shape is more like that of a whale, and the teeth of Pakicetus and of whales are very similar. Its skull shows adaptations for holding large, struggling prey underwater. Pachyaena Pakicetus Ambulocetus Rodhocetus Basilosaurus Zygorhiza Year reported Country where found Geological The features of the details discussed by National Geographic, “the arrangement of cups on the molar teeth, a folding in a bone of the middle ear, and the positioning of the ear bones within the skull” are no compelling evidence on which to base a link between Pakicetus and the whale:. To detect prey on land, they may have lowered their heads to the ground and felt for vibrations. Its ear bones also show that it did not have external ears but instead used the same method of hearing as modern whales - picking up vibrations through the jawbone. They had long skulls and large carnivorous teeth. Originally mistaken for dinosaur fossils, whale bones uncovered in recent years have told us much about the behemoth sea creatures This shows that it spend more time on land then in water. Although no post-cranial bones of Pakicetus were found, it seemed logical to assume, from the teeth and ear structure, that the animal spent a great deal of time in shallow water looking for food, but returned to the land to rest, somewhat like a modern sea lion. Basilosaurus may have been one of the first fully aquatic cetaceans (sometimes referred to as the pelagiceti). This puts the Pakicetus in the Cetacean class, the same class as whales, dolphins and porpoises, even though it lived on land. Primary stabbing headaches are caused by overactivity or problems with pain-sensitive structures in the head.