Aldebaran shellmouth

Leonard Fitzmurdle's personal log

November 30, 2116

One noteworthy encounter was with a species we’ve named the shellmouth. I discovered our first specimen inadvertently. In pursuit of a mud leech, I mistook the shellmouth’s unusual oral protuberance as a stepping stone. The creature moved under me, and I was thus privileged to see it up close moments later.
 

Octavio Briswald's field notes

November 30, 2116.

Lo! Our hero downward splashed,
Into the bog--all hopes seemed dashed!

 
 
 

Leonard Fitzmurdle's personal log

November 30, 2116

The shellmouth has powerful legs and a spring-like tail, which we assume enables it to propel out of the water when catching prey. Though obviously not a gastropod, the best way to describe its mouth is as an operculum: a calcareous trapdoor that we found ourselves unable to open, even with the help of a Capellan crowbar.
 

Octavio Briswald's field notes

November 30, 2116

They hammered, blasted, pried, and knocked,
But all for naught. The mouth stayed locked.
 

Leonard Fitzmurdle's personal log

November 30, 2116

We located several other shellmouths in our time in the swamp, but all of them appeared to be in a deep hibernation. 

This may prove a clue to some of the more unusual adaptations we’ve encountered on this planet. Our current hypothesis is that the planet has seasons that last multiple years. Thus, the habitat is essentially a time share, with half the fauna lying dormant at all times, waiting for the turn of the seasons to change guards. It would be most beneficial to return to this planet in the winter years, to see the shellmouth in action.
 

Octavio Briswald's field notes

November 30, 2116

Cryptic cuticular, opaque operculum;
Despair’s murky depths you’ve made us plumb.
A shame that can’t be captured in mere prose:
Defeated by a monster in repose!

--

Other mentions: McCoy accused Spock of being as tight-lipped as an Aldebaran shellmouth (TOS), and Phlox provided mud leeches as a cure for insomnia (ENT).