The 180 million-year-old find consists of two three-meter-high slabs. One contains an almost complete skeleton of an ichthyosaur (an aquatic reptile resembling modern dolphins) of the genus Stenopterygius. The second is a fossilized colony of Seirocrinus daylilies, invertebrates that look like huge flowers. The plates were found at a unique paleontological site in Holzmaden, Germany, called Fossillagerstätte, or “fossil warehouse”. The remains from the Early Jurassic were brought to the Mineralogical Office of the Jagiellonian University in the 19th century, and this is how their turbulent history began.
In 1849 and 1851, i.e. over 170 years ago, the fossils were brought to the seat of the Mineralogical Office – Collegium Phisicum at ul. św. Anna 6. Little is known about their fate from the “early Krakow period”, but the slab with the daylilies was most likely cracked due to moisture.
“Crimsons are animals, distant cousins of starfish. You can imagine them as a starfish on a stick. They spend time filtering the water with this part that looks like a flower. Crinoids have a skeleton made of calcite (a component of limestone), but due to certain processes after the animal's death, it can be replaced by pyrite – a mineral called fool's gold, which is extremely susceptible to weathering. Upon contact with water, pyrite oxidizes and this process could have caused the slabs with daylilies to begin to fall apart at some point, says Dr. Bartłomiej Kajdas from the Jagiellonian University's Nature Education Center.
The decision was made to renovate. “Experts” of questionable quality came to the rescue (this may be explained by their ignorance, because the work was probably carried out in the 19th or early 20th century, when conservation techniques were far from contemporary). “Spece” glued the fragments of the daylily colony into one whole with the help of plaster. The effect exceeded our wildest expectations – the white filling against the background of the brown fossil made it impossible to recognize what it represented.
Confusion: what to do to make daylilies more visible? Someone came up with the idea of painting the slabs – black paint will unify the colors and hide the plaster, so the fossils should be more visible. Well, falling from expectations to harsh reality can be painful. As modern conservation works have shown, the “procedure” was repeated four more times.
The ichthyosaur plate did quite well, but it was different from the crinoid fossils. There was plenty of black paint, so the reptile skeleton and two plaster casts of a sea crocodile and a plesiosaur (bought together with the fossils) were also painted to match the crinoid plate – this is one hypothesis, there are others:
“Gypsum boards were often painted black, this is a typical procedure. However, we do not know why it was decided to paint the ichthyosaur fossil. Perhaps after the slab with the daylilies fell apart, they were trying to avoid a similar fate for the second slab? There is also a hypothesis that the black paint was a way to hide fossils from German troops during World War II – but these are just speculations, we have no evidence that would allow us to clearly answer the question of why the plate with the ichthyosaur skeleton was painted.
It is not known when the slabs were first painted, but already in the interwar period the layers of paint were so thick that the fossils, unique in Poland, were considered to be plaster casts – this is how they were described in the geological catalogs of the Jagiellonian University from that period. The barbaric renovation meant that the paleontological gold was considered tombac. Years passed, and the heir of the Mineralogical Cabinet, the Institute of Geological Sciences of the Jagiellonian University, had a new headquarters. In the mid-1970s, the slabs were moved to the Collegium Geologicum and painted black once again. Since then, the 180 million-year-old find has been hanging in the corridor of the building at Oleandry as a decoration.
In 2017, the Institute of Geology was moved to the Campus of the 600th Anniversary of the Renewal of the Jagiellonian University, and the collections of the Geological Museum were moved to a new unit – the Nature Education Center of the Jagiellonian University (CEP UJ). The curator of the geological collection, Dr. Bartłomiej Kajdas, started looking through 19th-century documents with collection inventories:
“Among other things, I found a publication from 1868 about the collections of the Jagiellonian University, where I found information that 'beautiful fossils of a prehistoric reptile' had been purchased for the Mineralogical Office. I began to wonder what happened to them. I studied at the Institute of Geological Sciences in Oleandry, so I remembered the plaster casts that decorated the staircase. Then it occurred to me that maybe not all of these exhibits were casts, maybe it was worth taking a closer look at them. It turned out that they were indeed originals, not plaster copies.
How to distinguish the original from the copy? Imperfections came to the rescue:
“During the inspection, we noticed various imperfections that are not present in the perfect plaster copies. “This was a significant indication that we had real fossils from 180 million years ago.”
The slabs with fossils were handed over to professionals (this time, real ones) who deal with the renovation of works of art on a daily basis. Using the methods used to preserve the sculpture, layers of paint were removed, the surface of the fossils was cleaned, plaster was added, all slabs were secured, stabilized and mounted in frames.
The work took almost two years, but was successful. Their effects can be seen by visiting the exhibition of the Jagiellonian University's Nature Education Center at 5 Gronostajowa Street. It is worth doing it, because the plates with a colony of daylilies and an ichthyosaur are unique (because the best and largest) specimens of this type in Poland.