Eocyathispongia

Eocyathispongia is the genus of sponge-like creatures living in the Ediacaran period about 60 million years before the Cambrian.^[1] The current fossil record has found this genus in only one location, the Doushantuo Formation in Guizhou, China.^[2] It lived in shallow seas as a filter feeder.

Description[]

As of yet, only one fossil of the genus has been found, but it was excellently preserved. The specific attributes for this genus have yet to be confirmed until more specimens are found.

Eocyathispongia qiania[]

Eocyathispongia qiania is the only species in the Eocyathispongia genus. It is an epifaunal filter feeder that consists of three tubes, with two smaller side tubes that likely filtered in water, and a large, twisting, center tube that likely filtered water out. The cells inside the tubes are flat and porous, as would be expected in a filter feeder. The cells on the bottom of the fossil are less porous to keep the animal grounded, and the calls on the outside of the tube differ from those on the inside. The creature is asymmetrical. The fossil found was only about 1.1 millimeters tall and 1.2 millimeters wide,^[1] so it can be assumed that the species as a whole would be about the same size since there is no evidence indicating the fossil found was not a fully grown specimen.

Modern resemblance[]

The specimen found is surprisingly similar to sponges alive today. The cellular structure is almost identical to some modern-day sponges, and the less porous basal side is also consistent with modern sponges. However, it does not resemble any one species of sponge, so it is possibly a crown group.^[1]

Etymology[]

The genus name consists of a combination of the Greek word for dawn, eo, and the greek word for cup-shaped, cyathifer, to describe what the creature looks like. “Spongia” was added to the end to indicate that the genus is that of a sponge.^[1]

Significance[]

This genus is significant mostly for the time period it was alive is in. Until the discovery of this creature, the existence of sponges, like this one, in the Ediacaran was only theoretical.^[3] The specimen found also somewhat disproves a theory about early sponges because it was believed that the sponge crown-group would have choanocytes (a specific type of cell on the inner wall of sponges), but there is no significant evidence to show that the specimen had any. However, more specimens would have to be found and examined before any definitive conclusions can be made.

Doushantuo Formation[]

This is the location where the specimen was discovered. This formation consists of the shallow waters of the Edacarain and the rocks are made up of six layers of phosphorite and dolomite. The fossil was found in phosphorite rock near the lower layer of the rock formation.^[1] The specimen was fossilized through lithification.^[2]

References[]