Two hundred million years ago, the land that became southern Sweden was covered in lush vegetation where crocodiles and dinosaurs roamed, an era paleontologist Vivi Vajda and her team have set out to reconstruct.
In a wing of the Museum of Natural History in Stockholm, the researcher recently welcomed AFP to her office, scattered with books and fossil samples.
Sitting behind her microscope, Vajda examined specimens collected in Sweden’s southern Skane province, projecting them onto the wall with an overhead projector.
“This is a pollen sample that I collected in the field,” she said, pointing to what looks like brown and yellow spots, round and rectangular in shape.
Most of the Jurassic-era fossils found in Sweden have been discovered in Skane, preserved thanks to deep cracks in the ground that protected them from the many ice ages that erased traces in the rest of Sweden.
“I’m interested in what forests there were during the Jurassic period, so when I see a pollen grain, I actually see the tree. I can see the tree and the ecosystem in front of me,” she said.
The idea of showing the general public what appeared in her mind whenever she saw a rock or a fossil gradually took shape over the course of her fieldwork.
“I really felt that we lacked a book with illustrations that actually shows scientifically, with a very strong scientific base, what it looked like in Sweden 200 to 100 million years ago during the Jurassic period for example,” Vajda explained.
‘Snapshot’
With her team, she set herself the task of reconstructing entire ecosystems from that period. The illustrations were published in a book in October 2025.
Starting from each fossil fragment -- such as a footprint, a tooth, or a leaf imprinted in rock, all carefully preserved in the museum archives -- the researchers identified the animal and plant species to which they belonged, then pieced them together with the help of an illustrator to recreate a local Jurassic ecosystem.
“I was myself surprised about the biodiversity, because it was the first time we actually put all the animals and plants that we had in these rocks together in one ecosystem,” she said.
The result very likely reflects what life looked like on the ground, “because we find them in the same area, within a few hundred metres of rock.”
“It was kind of surprising to see that it was such lush vegetation,” she noted.
The dense greenery was made up of ferns, primitive conifers and marsh plants -- a far cry from today’s Scandinavian landscapes.
The clues provided by the fossils provide “only a snapshot of one time interval, a short time ... where we have a window into the past.”
“But then we have older and younger (fossils) and we can compare how climate change and biodiversity changed over time,” she said.
“It’s always nice to see what it actually looked like and make the plants and animals come to life.”
