It was a soft-bodied invertebrate that lived in shallow tropical coastal waters of muddy estuaries (where the tide meets the stream) during the Pennsylvanian geological period, about 310 million years ago. Many exquisitely preserved specimens are found in the ironstone nodules that make up the deposits.
It is thought to be a filter-feeding organism that grew throughout its lifetime, achieving a maximum length of 4.3 inches.
|A little hard to see, but look at the darker "H" in the center of the fossil.|
The “Y Animal," Escumasia Roryi.
It is a puzzling creature. It has only found in the Peabody Coal Pit 11 of the Mazon Creek formation. The only species of the subfamily, it is Y-shaped, bilaterally symmetrical, soft-bodied and is about 6 inches in length.
Therefore, it is considered a separate group that may have broken off of the cnidarians and gone extinct as a failed evolutionary experiment. If it were to be classified as a coelenerate, the definition of coelenerate would have to be changed and a new class would have to be added.
Compiled by Neil Gale, Ph.D.