Name of trunk-like objects What's the name of the black curved elements in the header/banner of https://www.flickr.com/groups/lego_arboretum/?

The full picture along with some others of the same diorama can be seen here:
https://www.flickr.com/photos/mark-of-falworth/sets/72157638713690815

In addition, does anyone know whether there is an instruction guide for these trees?
I think the piece you're referring to is Dinosaur Tail / Neck Middle Section with Pin.