whale hunt
DESCRIPTION
a powerpoint for teacher led presentation of the SENSI becoming whales lesson planTRANSCRIPT
Whale Hunt
Searching for whale fossils
Primitive whales
• Durodon• 25-45 mya• Different to modern whales– Distinctive teeth
Carl Buell
The search for the land relative• A group called Mesonychids had the same
kind of distinctive teeth as primitive whales
• They also had hooves, suggesting that whales may be related to cow, horse, deer, pigs
• Interesting but not convincing!
• Notice that you have a very big gap between the Durodon and the mesonychids.
• In 1983, a skull was found that had the same teeth as Durodon, as well as some other whale like features including whale-like ear bones.
• Found in Eocene deposits in Pakistan
Pakicetus• 50mya• Although Pakicetus has a land animals body, it’s head
is a distinctive whale shape with whale-like earbones• Had hooves• Probably lived near river and fed on fish
Carl Buell
Basilosaurus• The next piece of the puzzle was found by in Eygypt in
1990• The tiny hind limb of Basilosaurus• Basilosaurus had been known since 1830’s but the
hindlimb had never been found• It is thought to be the first fully marine whale, living in
deep oceans, around 37mya
Hind limbs
• The Basilosaurus hindlimb was too small to carry the animal on land, but was still functional
• It provides good evidence of a transition from land to water
Basilosaurus
Modern whale
• In 1994 in Pakistan another 4-legged fossil was found that was more recent than Pakicetus
• It had shorter legs, whale-like ear bones, and the nostril had moved to between the eyes and tip of snout
Pakicetus Rodhocetus Modern whale
Rodhocetus
• 46mya• Had small but functional legs. Still had tiny
hooves on its toes
• Notice now that you have a gap between Pakicetus and Rodhocetus where a large change has occured.
• Talk with your group about what an intermediate between these two animals might look like.
• Make a sketch.
• In late 1994 an almost complete skeleton of “the walking whale” was found
• It is about the size of a sea lion and probably swam like an otter.
• It had whale-like ears and little hooves on its toes.
Ambulocetus
Carl Buell
Whale valley - Egypt