Plant, or Animal?

[Recusant]

A pair of enigmatic fossils that had previously been identified as a leaves have been reanalysed and their actual identities revealed.

"Turtwig" fossil
Image Credit: Fabiany Herrera and Héctor Palma-Castro

"It turns out, this fossil plant is really a fossil baby turtle" | EurekAlert!

From the 1950s to the 1970s, a Colombian priest named Padre Gustavo Huertas collected rocks and fossils near a town called Villa de Levya. Two of the specimens he found were small, round rocks patterned with lines that looked like leaves; he classified them as a type of fossil plant. But in a new study, published in the journal Palaeontologia Electronica, researchers re-examined these "plant" fossils and found that they weren't plants at all: they were the fossilized remains of baby turtles.

[. . .]

The plants in question had been described by Huertas in 2003 as Sphenophyllum colombianum. The fossils come from Early Cretaceous rocks, between 132 and 113 million years ago, during the dinosaurs' era. Fossils of Sphenophyllum colombianum were surprising at this time and place— the other known members of the genus Sphenophyllum died out more than 100 million years prior. The plants' age and locality piqued the interest of Fabiany Herrera, the Negaunee assistant curator of fossil plants at the Field Museum in Chicago, and his student, Palma-Castro.

"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 Herrera, who has been collecting Early Cretaceous plants from northwestern South America, an area of the world with little paleobotanical work.

At first glance, the fossils, about 2 inches in diameter, looked like rounded nodules containing the preserved leaves of the plant Sphenophyllum. But Herrera and Palma-Castro noticed key features that weren't quite right.

"We spent days searching through wooden cabinets for fossil plants. When we finally found this fossil, deciphering the shape and margin of the leaf proved challenging," says Palma-Castro.

"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. So he reached out to an old colleague of his, Edwin-Alberto Cadena.


"They sent me the photos, and I said, "This definitely looks like a carapace'— the bony upper shell of a turtle," says Cadena, a paleontologist who focuses on turtles and other vertebrates at the Universidad del Rosario in Bogotá. When he saw the scale of the photos, Cadena recalls, "I said, 'Well, this is remarkable, because this is not only a turtle, but it's also a hatchling specimen, it's very, very small."


[Continues . . .]

The paper is open access:

"An Early Cretaceous Sphenophyllum or a hatchling turtle?" | Palaeontologia Electronica

Abstract:

Correctly identifying fossil specimens from parautochtonous deposits where marine and terrestrial organisms co-occur can be challenging due to the abundance of rare and obscure specimens with unclear morphologies.

In this study, we reviewed fossils from the Lower Cretaceous La Paja Formation (Ricaurte Alto, Villa de Leyva, Colombia) that were originally described as the plant "Sphenophyllum colombianum" based on an apparent resemblance to the upper Paleozoic genus.

We determined that the type specimen corresponds to the carapace of a hatchling turtle. In addition, a second specimen of "S. colombianum" although less well-preserved, also exhibits similar features of a hatchling turtle. The two fossil specimens are significant as they represent the first report of hatchling marine turtles from the Aptian of northwestern South America and provide evidence of the exceptional preservation of the Marine Reptile Lagerstätte of Ricaurte Alto.

[Asmodean]

It's neither plant nor animal. It's a prehistoric Asmo, it is.

Actually, this reminds me of them fractal Charnwood (Correct me if I got it wrong and it is, in fact, outer Mongolia, which... Is possible) creatures that... Are not animals, plants, fungi or anything we have today.

[Icarus]

It's neither plant nor animal. It's a prehistoric Asmo, it is.

Not prehistoric....Mid historic maybe... from the ninth century there is a viking turd on display at Jorvic Viking Center in Merry olde England. It is said to be held in high esteem by paleontologists and the like. A perfectly formed and neatly fossilized bit of poop.

[Asmodean]

...It is said to be held in high esteem by paleontologists and the like. A perfectly formed and neatly fossilized bit of poop.

Signs and wonders, my friend. Signs and wonders.