Filling the Fossil Record with Mushrooms – The Lumberjack

Madison Lalica opens up 400 million year old fossils

Madison Lalica is a junior botany student studying ancient fungi in fossilized plants over 400 million years old. She fills gaps in the fossil record of fungi with her unique research.

“Given their importance in current ecosystems, I support [that fungi] must have played such a fundamental role in ancient ecosystems,” Lalica said. “And that’s what I’m trying to prove with fossil research.”

Lalica said she had the privilege of working with a huge box of rocks on loan from the Smithsonian Museum filled with fossilized plants. The fossils arrived at Humboldt State University via the Smithsonian, but were collected in the 1960s by a paleo botanist named Francis Huber from a rock formation called Battery Point in Canada.

“We’re looking at a bunch of plant fossils that are 400 million years old,” Lalica said. “They are very well preserved and you can see all their anatomical features.”

Certified botanist Megan Nibbellink works alongside Lalica. It focuses on the anatomy and relationships of host plants, called zosterophylls. The Battery Point fossils are preserved in a unique geological formation which serves to make very good fossils.

“It’s a river deposit,” Nibbellink said. “It was a bunch of chunks of fragments taken from fine sediment at the end of a river. The reason I like these fossils is that you can see the individual cells. And that’s also why Maddy is able to do what she does.

When host plants were buried by fine river sediments millennia ago, their shape was preserved as the sediments solidified over millions of years. The fine particles, however, essentially imprinted the high-resolution fossils in such detail that Lalica found what she was looking for: ancient fungi.

Lalica scans and studies these plant fossils for any evidence of fungal material. Spores, fungal tendrils called hyphae, and fungal infection scars are some of the indicators she found. More specifically, Lalica is working on the identification of glomeromycota fungi, a fungal group intimately symbiotic with today’s plants. She wants to know how similar ancient mushrooms are to modern mushrooms.

“Why do you want to know more about extinct life, then, one might ask. And to be honest, it’s a pretty philosophical quest, I guess. In the most direct sense, learning about extinct life forms helps us understand how the living life forms we see around today evolved.

Alexandru “Mihai” Tomescu

“The plant and animal fossil record is really well understood,” Lalica said. “Like they have a pretty clear timeline of ‘this happened and then this happened’, but for mushrooms it’s so sparse and incomplete that they have no idea what’s going on. come before what.”

Lalica’s educational advisor, Alexandru “Mihai” Tomescu, has made it his mission to figure out what precedes what. Tomescu explained that exploring the fossil record is important because fossils offer us the only way to directly examine life in the past.

Tomescu was Lalica’s botany teacher before she changed majors, but she said she fell in love with the world of paleobotany after her teaching. Interested in the subject, Lalica took the opportunity to begin her own research as soon as Tomescu offered her the opportunity.

“Why do you want to know more about extinct life, then, one might ask,” Tomescu said. “And to be honest, it’s a pretty philosophical quest, I guess. In the most direct sense, learning about extinct life forms helps us understand how the living life forms we see around today today have evolved.

The 400-million-year-old specimens are interesting to Tomescu and his team of researchers because the plants themselves represent the first wave of vascular plants, or plants that move water through special tissues, that evolved on Earth. Vascular plants make up almost all modern land plants, so these ancestors are important. Mushrooms, too, are important to life on Earth and may have been part of its foundation.

“Mushrooms are probably, almost certainly I think, older than actual plants,” Tomescu said. “The mushrooms are much older. But because they are just hyphae, since they are fragile, their fossil record is not so good.

Tomescu recruited undergraduate students to search for these fossils in his laboratory. Tomescu explained that HSU hosts a botany program that attracts a lot of students, but also that students are enthusiastic about participating in research. He said HSU has students who are interested in gray areas. Lalica was one of these students.

In the future, Tomescu and Lalica are preparing to publish an article about his year-long investigation of fossils. This summer, she is presenting her research at the annual conference of the Botanical Society of America.

“It seems like in Humboldt, the opportunities are like if you talk to the right person or become friends with the right person, it kind of happens,” Lalica said, “And I just happened to fall into the world of paleobotany.”