“Living Fossil” Found by Accident May Reshape Tree of Life

It’s not unusual for a brand new species to be found amongst current collections; it’s uncommon that the brand new species continues to be alive, although. But that’s what a analysis group from Charles University within the Czech Republic discovered after they examined an previous tradition of marine microorganisms.

In the years-old pattern, bigger organisms had expired, however there was nonetheless one tiny, odd-looking creature left residing. It was a minuscule, one-celled protist—a catchall group that includes eukaryotic organisms that aren’t crops, animals, or fungi. With ray-like protrusions extending from a central mass, their new discover resembled a solar, so the group dubbed it Solarion arienae, publishing their findings in Nature.

The curious construction and resilience of the newfound species was exceptional, however a genetic evaluation revealed S. arienae was hiding much more gorgeous surprises. After sequencing the genome and cross-referencing it with current databases, the researchers decided this organism didn’t belong to any beforehand acknowledged lineages of eukaryotes. Instead, S. arienae, together with a handful of different mysterious protist relations, constituted a brand new supergroup, referred to as Disparia. A search of environmental DNA databases indicated S. arienae is (considerably paradoxically) each uncommon and widespread, residing a quiet life in marine sediments.

Even extra stunning was the DNA inside S. arienae’s mitochondria. Tucked in these organelles was the gene secA, a fraction of a protein translocation system inherited from the bacterial ancestor that gave rise to mitochondria, and a sequence that’s been misplaced in virtually all different eukaryotic species. According to the endosymbiotic idea, mitochondria had been as soon as free-living prokaryotic cells that had been engulfed by precursors to eukaryotic cells. After this intimate interplay, eukaryotic cells housed mitochondria, which supplied power to the partnership and resulted within the profusion of eukaryotes we see at the moment.

Read extra: “The Unique Merger That Made You (and Ewe, and Yew)”

In different phrases, S. arienae is actually a residing fossil, permitting researchers an unprecedented glimpse into the evolution of eukaryotic life.

“Solarion is a remarkable reminder of how little we still know about the diversity of microbial life,” examine authors Ivan Čepička and Marek Valt mentioned in a statement. “The discovery of such an evolutionarily deep lineage—essentially a living fossil—shows that key parts of the eukaryotic story remain hidden in places we rarely explore.”

Tree-of-life-changing scientific breakthroughs: Always within the final place you look.

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Lead picture: Charles University

• Jake Currie

  Posted on November 20, 2025

  Jake Currie is a author based mostly in Brooklyn, NY.