Yes it’s time for some more “stinkin’ mammals”, though in my defence I generally keep the place pretty synapsid-free. Anyway, one of the truly great transitional series in palaeontology is the origin of whales. It’s not a surprise really, they are relatively big and recent animals that hung around in water, all things that help fossilisation. Combined with their nicely diagnostic anatomy and the public’s general affection for cetaceans, this makes them a superb example of a major transition (here from land to water, obviously) as well as making the origin and radiation of an important clade. I’ve used it in my lectures and it seems to be a particularly popular subject with the students.
Among other things, the aquatic section of the ‘history of life’ room in Toyko houses a magnificent collection of casts of various stem whales. From Ambulocetus, Pakicetus and Basilosaurus (and indeed others) there is a lovely and clear pattern of the shape of the skull and teeth changing and the back elongates, and the hindlimbs atrophy. Put together, it’s a great series and I spent some time photographing as much of it as possible for my lecture notes. I’ll be able to make better use of this in the future thanks to such a great set-up.