Mysterious plant fossil belongs to a family that no longer exists

Dec. 18 () –

A fossil plant preserved 47 million years ago It has such a strange variety of characteristics that scientists cannot find a family of plants, living or extinct, to which it may belong.

In 1969, fossilized leaves of the species were identified Othniophyton elongatum, which translates as “alien plant”, in eastern Utah. Initially, scientists theorized that the extinct species might have belonged to the ginseng family (Araliaceae). However, a once-closed case is now being reviewed. New fossil specimens show that Othniophyton elongatum is even stranger than scientists first thought.

Steven Manchester, curator of paleobotany at the Florida Museum of Natural History, has studied 47-million-year-old fossils from Utah for several years. While visiting the paleobotany collection at the University of California, Berkeley, he came across an unidentified and unusually well-preserved plant fossil collected from the same area as the leaves of Othniophyton elongatum.

Manchester is co-author of a new study published in the journal Annals of Botany in which he and his colleagues demonstrated that the leaves in question belonged to a unique plant, with unusual flowers and fruits. Close observation revealed that the 1969 fossils and those later studied by Manchester at the University of California at Berkeley belonged to the same plant species. But the leaves, fruits and flowers attached to the woody stem of the Berkeley fossils looked nothing like those of other plants in the ginseng family, to which that species had originally been assigned.

“This fossil is rare because it has the twig with fruits and leaves attached. They are usually found separately,” Manchester said. in a statement.

The authors exhaustively analyzed the physical characteristics of the new and old fossils and then methodically searched for any living plant families to which they might belong. There are over 400 diverse families of flowering plants alive today, but the authors were unable to compare the fossils’ strange variety of features with any of them.

Resisting the temptation to neatly group the obscure specimen with a living group, the team searched for extinct families to which it might have belonged, but once again came up empty-handed.

The authors say their results underscore what may be a widespread problem in paleobotany. In many cases, extinct plants that existed less than 65 million years ago are placed within modern families or genera: the taxonomic groups directly above the level of individual species. This can create a biased estimate of biodiversity in ancient ecosystems.

“There are a lot of things that we have good evidence for to fit into a modern family or genre, but you can’t always shoehorn these things in,” Manchester said.