Fossils turn out to be a rich source of information
|The rock has created a detailed mold of the beetle’s fragile legs and outer structure, |
thereby preserving them. Internal organs, for instance the genitalia, have also been
preserved in a mineral way [Credit: Achim Schwermann/
Thomas van de Kamp]
With the help of modern imaging methods, however, their internal structures could now be unlocked. The researchers analyzed the fossils in the Synchrotron Radiation Facility ANKA at the Karlsruhe Institute of Technology (KIT), using X-ray computed tomography. That allowed them to create a three-dimensional image of the insides of the opaque fossils. "The actual measurement process only took a few seconds," explains engineer Tomy dos Santos Rolo from the KIT in Karlsruhe. "During that time, the object is rotated in the path of the X-ray and imaged from various directions. After the measurement, we can digitally reconstruct the three-dimensional object."
Reconstruction allows for a modern description
This digital reconstruction of one beetle-specimen quickly showed that it was a male animal. "The genitals have been preserved, for the most part," says biologist Dr. Heiko Schmied from the University of Bonn. "That gives us an opportunity to describe the beetle as a representative sample according to modern standards."
"A diamond in the rough"
The scientists discovered that the outwardly unpromising beetle fossils had internal organs that were amazingly well preserved. The precise detail in the fossilized beetles goes well beyond what is normally seen in fossilized arthropods. "The unusually well-preserved soft tissue shows that the beetles must have become petrified within a very short amount of time, probably hours or days," explains Dr. Schwermann.
One beetle specimen that is partly embedded in the rock shows the outer structure of the carapace. The attached rock thus conveys what the beetle's outer shell originally looked like. "Surprisingly, the beetle that looks the least well preserved from the outside has the best level of preservation inside," says biologist Dr. Thomas van de Kamp from the KIT in Karlsruhe. The attached rock protected even its fragile extremities from being destroyed by external environmental influences.
Unexpected potential in old collections
While the fossilized arthropods from Quercy in France were considered less interesting during their initial study in the 1940s, this old collection turns out to be a rich source of information. "That makes us, as researchers, look at the old collections in museums and universities in a new way," says Dr. Schwermann. The research team now plans to study other similarly preserved fossils. The fact that the Quercy beetles had been largely ignored for 70 years highlights the unrecognized potential of old collections.
Source: University of Bonn [February 09, 2016]