50 million year old, Eocene-Era fossil prawn comes from one of the
world's famous Laggerstatten, the Green River Formation in Wyoming.
A small portion of the fossils from Green River exhibits such fine
preservation. Most fossils offered are various fish, but other fossils
are also found, albeit much more rarely. Indeed, members of this
species are found only on the order of frequency of the highly-prized
prawn has wonderful details present, and represents the finest degree
of preservation. Notice that even the annulation of the antennae
is evident. Decaopds have a spotty fossil record beyond 30 million
years, but Bechleja from the Green River Formation is an exception.
There are 3 other members of the genus, all from the Oligocene,
found in Germany and Brazil. Pleocyematans are united by a number
of characteristics, most notably that the fertilized eggs are incubated
by the female, and remain stuck to the pleopods (swimming legs)
until they are ready to hatch.