The ryömäläinen (Terroreptilis crapulacorne) is a bottom-dwelling scavenger common to the fast-flowing streams of Eurasia.  Although, like all ammonoids, a ryömäläinen ammonitella is a planktonic predator of the open ocean, their adult for is quite different.  A mature ryömäläinen rarely uses jet-propulsion or buoyancy to swim, but instead rely on their powerful tentacles for locomotion.  The shell is tightly coiled and almost helical, like a snail, which allows water to rush past the animal without upsetting its grip.

    Because of their ability to crawl against the pull of a current, ryömäläinen are also able to climb against the pull of gravity, and so are often seen crawling though the soggy grass, on the way from one river to another.  The animals' four gills, safely buried deep within its shell, can remain moist for hours at a time, allowing ryömäläinen to crawl for great distances, and some have even been seen in trees (see The Salmonite Run)
 

(Text by Daniel Bensen)

• The Salmonite Run