From Flannery, T., Archer, M., Rich, T.H. and Jones, R. 1995. A new family of monotremes from the Cretaceous of Australia. Nature 377:418-420.
“Kollikodon ritchei was a platypus-sized montreme that fed on material that needed crushing but not shearing. Similar adaptations are evident in marine predators, such as sea otters, crabs and some fish that feed on hard-shelled animals.” p.420.
Wonderful train of thought here, and an excellent example of writing for a purpose (at least that’s what I get out of it; I don’t know what their intention was exactly). First, they extrapolate the size of the animal. Since it is known only from a single right dentary fragment, this is liable to be flexed up and down as need be in future papers–although nothing can be done about that, so I’m sure they made their best guess. The closest mammal in size they suggest as a platypus, first I am sure because platypi (platypusses?) are monotremes. This brings up a mental image of (obviously) a platypus. Where do platypusses (platypi?) live? In the water. So now you’ve been hit with a mental image of an aquatic monotreme right before they suggest the teeth could be used to eat hard-shelled things because they resemble the crushing mouth parts of other aquatic animals.
So now, you have an aquatic monotreme that eats mollusks. Isn’t this interesting from a single dentary fragment?