Coast Guard: UTM paleontologist studies the world's first reefs

Invertebrate paleontologist Marc Laflamme is no stranger to the fieldwork. The assistant professor of chemical and physical sciences and head of the Laflamme Lab at U of T Mississauga has spent his career scouring alien terrains like the rocky interior of Namibia for fossil evidence of creatures that lived—and died—millions of years ago.

Laflamme’s ongoing research examines Ediacaran biota, unique creatures that died in a mass extinction 540 million years ago, however a new research project will bring him a little closer to modern day and a lot closer to home. In January, Laflamme was awarded funding from the 2018 UTM Office of the Vice-Principal, Research and Scholarly Activity Funds competition to study ancient creatures that built the world’s first underwater reefs on the southern coast of what is now Labrador, Canada.

This summer, Laflamme and two graduate students will travel to Forteau, a tiny town near the Quebec-Labrador border to study long-extinct sponges known as archaeocyathans embedded in the domed rocky remains of ancient reefs. The sponges appeared about 530 million years ago and lived for about 20 million years at the beginning of the Cambrian period. Their short-lived ocean reign contributed to the first reefs in the fossil record, and supported the evolution of development of early Cambrian organisms.

“For the longest time, we had no clue what they were,” Laflamme says. “Research in the 80s and 90s demonstrated they were most likely sponges, although they had a weird shape and construction. They built skeletons, as corals do today, but it consisted of calcified cones nested together like stacked ice cream cones, with lines of perforations that allowed water to move between the two layers.”

The creatures, which ranged in diameter from a few centimeters to the width of a softball, attached to rocks or to each other to build the first reefs in the fossil record and created a refuge for the burgeoning Cambrian ecosystem. “These biologically-produced mounds provided a protective barrier for everything living there,” Laflamme says. “This is the first time we see bona fide animals building skeletons that form reefs—the hard rigid framework that other organisms attached themselves to and depended upon for living.”

Similar outcroppings of calcified sponges can be found along the Nevada-California border in the United States, and in Australia where the modern day desert was once covered by ocean. In 1980, the late Erindale College professor of geological sciences David Kobluk published a study on the sponges in the Canadian Journal of Earth Sciences. “There’s nice UTM heritage that comes with that,” Laflamme says.

Laflamme will study the role these reefs played in the transition between the Ediacaran and Cambrian periods, and how the reefs may have led to the complex ecosystems we see today. “We’re investigating what happens when a mass extinction takes place and an ecosystem is destroyed,” he says. “I’m interested in the transition between systems that are not building reefs into the ones that do. Something starts these developments off, and that’s what we’re trying to understand. We’re interested in what took place and was driving the new complexities? How do you go from a worm to a beetle? How do you build big groups, or that first vertebrate or that first coral?”

For the Labrador study, Laflamme will work with graduate student Daniel Dick, who has created a breakthrough machine learning program to analyze field data and identify the similarities or differences between creatures within the same ecosystem.

“At some point, we had simplicity. Through evolution and interaction between organisms, we developed complexity, which builds upon itself. Something had to change or adapt or give way to make room for something else to change, and adapt and dominate. How do new organisms fill the blank slate?””