The extinct fossil whelk, Neptunea angulata coils to the left, while most other Neptunea coil to the right. It was formerly known as Neptunea contraria, but that turned out to be the name of a living species. This specimen bemoans the change of name:
I’m a sinistral lefty, contraria, me.
I coil to the left, which feels right;
But that is the name of a living whelk, too,
So my name had to change overnight.
The namers of fossils, they thought long and hard,
Then came up with this: ‘angulata’.
But I am a lefty – contraria, me –
And I’m pretty rare in the strata
If you’re lucky, you’ll find me from the late Pliocene
In my sediment tomb, anchored fast;
So look out for me on your fossiling trips:
A left-coiling whelk of the past.