Palaeophragmodictya is a Precambrian

Precambrian

The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...

 sponge-grade organism from the Ediacaran Period

Ediacaran

The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...

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Originally interpreted as a hexactinellid

Hexactinellid

Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges...

 sponge, the organism also bears some coelomate characteristics, including bilateral symmetry.

Morphology

The organisms take the form of a round bag, 7–68 mm in diameter, with an uneven margin. Radial grooves define sac-like compartments within the bag. The radial pattern has an element of bilateral symmetry. A stalk emerges from the central point of some specimens, at the top of the organism; in life, it probably extended into the water column. Ray-like filaments radiate outwards from the edge of the bag. Some structures in the organism have been interpreted as spicules.

Ecology

The organisms have been interpreted as tall suspension feeders, reaching 10 cm or more up into the sea water above them.

Original description

The genus was originally considered to be a member of the Dictyospongiidae family (hexactinellia), and was among the first Precambrian sponges to be described.

Distribution

First found in the Pound group of Australia, fossils have also been recovered from the White Sea

White Sea

The White Sea is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of...

region of Russia.