An "extraordinary" species of fossil sponge dating back 315 million years has been discovered near the Cliffs of Moher in County Clare. 

The fossil sponge, named Cyathophycus balori, measures 50cm and is the largest known example of its kind anywhere in the world. 

The fossil sponge dates back to a time when County Clare was located close to the equator and was discovered in the rocks that make up the Cliffs of Moher

When it was alive, the vase-shaped sponge featured a circular opening at the top surrounded by a ring of eyelash-like structures and would have resembled the modern-day Venus Flower Basket sponge, which is found in the Pacific Ocean. 

Sponges are creatures with a very basic body plan. They do not have a nervous system or circulatory system, but they are very abundant and form an important part of the earth's biodiversity.

The fossil sponge is named after Balor, a giant from Irish mythology whose eye was said to have killed anyone it gazed upon when it was open. 

Dr. Eamon Doyle, geologist for the Burren and Cliffs of Moher UNESCO Global Geopark, discovered the fossil sponge near the Cliffs of Moher and noted that it is the first time that the species has been discovered in Ireland. 

"This is an exceptionally large example of a type of fossil sponge that was previously only known from much older rocks elsewhere in the world. It is the first record of this type of fossil sponge from Ireland and its excellent preservation is highly unusual," Dr. Doyle said. 

"The sponge was originally composed of a rectangular meshwork of tiny spicules made of silica, held together by a thin organic membrane.

"When they die, they usually fall apart quickly, and often only scattered remains of the spicules are preserved as fossils, so I was delighted to find these largely intact specimens." 

Dr. Doyle added that the fossil sponge dates back to a time when the Atlantic Ocean had not even started to form, adding that County Clare was part of an earlier sea located close to the equator. 

"Discoveries like this help us to promote awareness about the wonderful geological legacy we have on our doorstep here in County Clare and to encourage a new generation of paleontologists." 

The discovery has been published in the latest edition of the international geological journal Geobios.

International fossil sponge expert Dr. Joseph Botting, the lead author of the report, and co-author Dr. Lucy Muir both worked closely with Dr. Doyle during the recent discovery. 

Dr. Botting said he was "amazed" to see the size and "excellent state of preservation" of the fossil sponge. 

"This find offers important insights into the evolution of sponges and how some species can survive in niche environments where few other species can live. Finding such large and intact specimens is exceptional," Dr. Botting said. 

Dr. Lucy Muir described the discovery as "wonderful", adding that fossils help us understand the story of life on Earth.