oh I will do this without even being in a museum
some quick fun facts for you!
whales originally evolved from a kind of wolf with hooves called Pakicetus
their closest living relatives are even-toed ungulates such as hippos (unsurprising) and cows (very surprising)
baleen whales (the ones with giant hairbrush mouths) are called 'mysticeti' which translates to 'moustache whales'
the latin name for the blue whale, the largest creature to have ever lived on earth, bigger than all dinosaurs, is 'balaenoptera musculus' which translates literally to 'little mouse whale'
Southern right whales are so friendly they are surprisingly dangerous to dive with. They can't properly hug so they say hi by gently swimming by and rubbing their side against the side of their new friend. Unfortunately they are the size of a truck and 'gentle' for them is 'equivalent to being kicked by a horse' for you
the humpback whale has the longest limb on earth - its pectoral flippers can be 5 metres (16 feet) in length. The edges of these flippers are covered in sharp barnacles, essentially giving them knives for arms. You sometimes see predatory ocean-going dolphins (orca, false killer whales, pilot whales) with scars as a result of getting slashed by a humpback
humpback whales don't just use their knife-arms to defend themselves! They've been observed protecting other whale species, seals, and even people!
sperm whales are the largest toothed predators on the planet however they do not use their teeth to eat - they feed on squid by suction! the teeth are for mating rights duels and it's relatively common to see male sperm whales with broken or deformed lower jaws
whales still have hip bones! they are tiny and undeveloped and not connected to the rest of the skeleton
the bowhead whale lives in and around the arctic. its blubber (insulating fat in place of fur) can be 50cms thick and it has a special organ in its mouth to prevent this insanely thick blubber from causing it hypothermia! the organ is very sensitive to temperature, so when it opens its mouth to feed the cold arctic water flows over the organ and allows cooled-down blood to travel around the whale's body
sperm whales can control their buoyancy! they have this big ol' contraption in their huge heads called the spermaceti organ (it's white and liquid. early whalers thought it was a weird giant head testicle. this is where the name comes from) that is a very flammable wax, and blood washing over it makes it liquid while restricting blood turns it solid! this is what allows them to dive to depths of nearly two kilometres. they can hold their breath for an hour and a half
they are very cool and weird and I love them ever so much but sadly most whale species are endangered :( many of them were hunted to near-extinction for their oil, and as they reproduce similarly to humans (long pregnancies producing one baby every two-to-ten years) their population recovery rate is very slow :(
many die from getting tangled in fishing equipment, many more from ship strikes, some are starving because they're accidentally eating plastic waste that's wound up in the ocean, and most recently, human presence in the oceans is causing all sorts of noise that confuses, distresses, and even deafens them! some deep-diving whales have been found dead from the Bends, the same condition we see in human divers who surface too quickly without adjusting to the water pressure. It's painful and scary :(
you can help! buy certified dolphin-safe fish, dispose of your rubbish safely, and check out your local conservation societies! a lot of them are working to trace whale migration routes so we can reroute our shipping away from them, and others are protesting against Navy SONAR tests in the ocean
whales do a lot of work in keeping the air breathable by spreading nutrients that feed the plankton that absorbs carbon dioxide. we need to protect these weird and wonderful beasts for our own good as much as theirs!