At more than 50 cm (20 inches) in height, the remarkable new species Cyathophycus balori is the largest known member of its genus Cyathophycus, and one of the largest sponges in the order Reticulosa.
Cyathophycus balori. Image credit: Botting et al., doi: 10.1016/j.geobios.2023.07.004.
“Cyathophycus is one of the most widespread Ordovician and Silurian sponge genera, being recorded from across the Iapetus region, and tentatively also from Bohemia,” said senior author Dr. Eamon Doyle, a geologist for the Burren and Cliffs of Moher UNESCO Global Geopark, and colleagues.
“The genus was widely distributed in offshore marine environments from the Middle Ordovician to Middle Devonian, but has not previously been recorded in later rocks.”
Named Cyathophycus balori, the newly-identified species lived during the Carboniferous period, some 315 million years ago.
When it was alive the vase-shaped sponge featured a circular opening at the top surrounded by a ring of eyelash-like structures.
It would have resembled modern-day Venus’ flower basket sponges, which are found the Pacific Ocean and often feature on deep sea wildlife documentaries.
“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,” Dr. Doyle said.
“It is the first record of this type of fossil sponge from Ireland and its excellent preservation is highly unusual.”
The specimens of Cyathophycus balori were collected from the Kilkee Cyclothem of the Namurian Central Clare Group of County Clare, Ireland.
“The sponge was originally composed of a rectangular meshwork of tiny spicules made of silica, held together by a thin organic membrane,” Dr. Doyle said.
“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.”
“The excellently preserved fossil dates back to a time when the Atlantic Ocean had not even started to form and what we now call County Clare was part of an earlier sea, located near the equator.”
“Discoveries like this help us to promote awareness about the wonderful geological legacy we have on our doorstop here in County Clare and to encourage a new generation of paleontologists, that is, geologists that specialize in the study of fossils to visit and learn more about the unique geology of Ireland’s west coast.”
“I was amazed to see the size and excellent state of preservation of this fossil. This was totally unexpected,” said first author Dr. Joseph Botting, a researcher at the Amgueddfa Cymru-Museum Wales and the Nanjing Institute of Geology and Palaeontology.
“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.”
“This is a wonderful find and reminds us that there are still new and interesting fossils to be found which help us understand the story of Life on Earth,” said co-author Dr. Lucy Muir, a researcher at the Amgueddfa Cymru-Museum Wales.
The team’s paper was published in the October 2023 issue of the journal Geobios.
Joseph P. Botting et al. 2023. An oversized, late-surviving reticulosan sponge from the Carboniferous of Ireland. Geobios 80: 1-13; doi: 10.1016/j.geobios.2023.07.004
Source : Breaking Science News