A symbiosis between two marine specimens has recently been discovered on the ocean floor. The discovery is enormous, as it marks the transition from a formerly known fossil to an alive life form, according to Sciencealert.
The researchers discovered non-skeletal corals growing on the stalks of marine animals called crinoids (also known as sea lilies).
They appear to be thriving on the Pacific Ocean floor, near the coasts of Honshu and Shikoku in Japan.
The scientists who discovered the symbiosis wrote:
“These specimens represent the first detailed records and examinations of a recent syn vivo association of a crinoid (host) and a hexacoral (epibiont), and therefore analyses of these associations can shed new light on our understanding of these common Paleozoic associations.”
In the Paleozoic era, crinoids and corals appear to have lived along very conveniently.
The seabed fossil record can confirm that, presenting numerous cases of corals overgrowing crinoid stems to rise above the seafloor into the water column. That would help them gain access to strong ocean currents that would allow for filter-feeding.
The two beings vanished from the fossil record some 273 million years ago, after the crinoids and corals went extinct.
However, at depths of more than 100 meters (330 feet) under the ocean’s surface, researchers discovered two fascinating species of coral – hexacorals known as the Abyssoanthus, which are very rare, plus Metridiodidea – a sea anemone, arising from the pedice of living Japanese sea lilies.
Under the guidance of palaeontologist Mikołaj Zapalski, the team of researchers initially used stereoscopic microscopy to analyze and photograph the specimens.
They discovered that the corals probably didn’t compete with their hosts for food. As they are non-skeletal, they also didn’t affect the crinoid stalks’ flexibility, which led to the convenient symbiosis.