New evidence has emerged that is sparking scientific interest and debate about the early evolution of animal life on Earth.

Laurentian University geology professor Dr. Elizabeth C. Turner has discovered what appear to be 890-million-year-old sponge fossils, collected from the site of ancient reefs in the Mackenzie Mountains, located in Northwest Territories, Canada.

The fossils are about 300 million years older than any undisputed animal fossil on record.

Turner published her findings in the prestigious scientific journal Nature, in an open-access paper titled “Possible poriferan body fossils in early Neoproterozoic microbial reefs.”

In it, she shows the similarities between sponge body fossil structures found in 890-million-year-old reef rock and compares them to microstructures in much younger sponge body fossils.

The study’s approach uses optical petrography, a fundamental geological method that has been learned by all undergraduate geology students for over a hundred years.

Describing the ancient sponge fossil body structure, or “mesh skeleton,” Turner says “the microstructure consists of fibres that branch and rejoin in a complicated three-dimensional way that is not seen in any of the other known types of branching microorganisms.”

Although Turner’s initial discovery of the material was several decades ago, it was not until early 2021 that other papers were published that provided a foundation for comparison. She took another look at her 890-million-year-old samples, and determined the mesh structure to be a close match with a specific group of sponges both in the rock record and in the modern world.

Dr. Douglas Tinkham, Director of the Harquail School of Earth Sciences at Laurentian University, said Turner’s publication marks another major contribution to her field. “Dr. Turner’s most recent publication in Nature is generating strong global media interest in Earth Science, questions from students and members of the general public, and vigorous debate in the scientific community,” Tinkham said.

If Turner’s animal fossil interpretation is ultimately accepted by the scientific community, it will mean that the evolutionary appearance of the earliest animals took place prior to two major Earth-system events previously understood as necessary preconditions for the existence and diversification of animal life.

Turner added that further research is required because “it’s possible that these are not sponges, but an organism type that we haven’t yet identified.”

Tinkham said Turner’s latest publication is important because “it’s research like this that encourages further inquiry and curiosity about ‘what we think we know.’ This new evidence could change how we understand the evolution of animal life on Earth, and that’s an inspiring and significant contribution by Dr. Turner.”

Turner is also co-author of a 2019 paper in Nature describing the earliest fossil fungi, and the 2020 winner of the Geological Association of Canada’s Howard Street Robinson medal.

She is known by students and peers as an inspiring professor and a relentless researcher.

This latest paper is further evidence that Laurentian University and the Harquail School of Earth Sciences are global leaders in Precambrian and economic geology research and teaching.

Dr. Turner is a geologist and a professor of Carbonate Sedimentology and Invertebrate Paleontology at Laurentian University’s Harquail School of Earth Sciences.

She has been teaching and supervising geology students since 2005, leading the next generation of researchers and geoscientists.

Story is from Laurentian University