Plant fossil isn’t a plant, surprising Colombian scientists

An old fossil recovered from a small Colombian town more than 2100m above sea level has switched kingdoms – it’s not a plant, it’s an animal.

Specifically, the specimens embossed on the round rocks found more than half a century ago in Villa de Levya are baby turtles.

Originally described as the extinct plant species Sphenophyllum colombianum by their discoverer Padre Gustavo Huertas, a priest who lived in the region, a follow-up exam by palaeobotanists was, if nothing else, confusing.

Palaeobotanists study ancient and extinct plants that lived thousands or millions of years ago.

The rocks that supposedly contained c were from the Early Cretaceous period 113-132 million years ago, but on inspection it was clear the ‘veins’ of the plant didn’t match expectations.

“We went to the fossil collection at the Universidad Nacional de Colombia in Bogotá and started looking at the plants, and as soon as we photographed them, we thought, ‘this is weird,’” says Fabiany Herrera, an assistant curator of fossil plants at the Field Museum in Chicago, US.

Along with his student Héctor Palma-Castro from the National University of Colombia, Herrera was reviewing many fossilised plants as part of their study but was stumped by the specimens from Viila de Levya.

“When you look at it in detail, the lines seen on the fossils don’t look like the veins of a plant— I was positive that it was most likely bone,” says Herrera.

They handed it to another teacher-student pairing to see if they had any more luck.

“[It] definitely looks like a carapace – the bony upper shell of a turtle,” says Edwin-Alberto Cadena, a palaeontologist at Universidad del Rosario. “this is not only a turtle, but it’s also a hatchling specimen, it’s very, very small”.

“This is actually really rare to find hatchlings of fossil turtles in general. When the turtles are very young, the bones in their shells are very thin, so they can be easily destroyed.”

Specifically, the print shows the inside of the carapace, the baby turtle’s shell, likely only a few years old. What the priest mistook for the anatomy of ancient plants are actually modified ribs and vertebrae from the turtle shell. The students involved in revaluation, Palma-Castro and Diego Cómbita-Romero, have rechristened the specimens with a name inspired by a Pokemon.

“In the Pokémon universe, you encounter the concept of combining two or more elements, such as animals, machines, plants, so, when you have a fossil initially classified as a plant that turns out to be a baby turtle, a few Pokémon immediately come to mind. In this case, Turtwig, a baby turtle with a leaf attached to its head,” says Palma-Castro.

“In palaeontology, your imagination and capacity to be amazed are always put to the test. Discoveries like these are truly special because they not only expand our knowledge about the past but also open a window to the diverse possibilities of what we can uncover.”