I thought this was worth sharing with anyone who hasn't yet seen it:
It's from The Optimistic Painting Blog, via Prerogative of Harlots.
Forams with Teeth
7 hours ago in Catalogue of Organisms
A patient is being given some test results by a doctor. The doctor looks at his notes and says, "I'm sorry to tell you this, but your lungs appear to be infested with Mesozoic mammals". Aghast, the patient asks hesistantly, "You don't mean...?" "I'm afraid so", replies the doctor. "You have multituberculosis".