Forgotten fossil helps rewrite part of animal evolution

New research, to be published in BMC Biology at NOON GMT on 28 May, helps to fill in questions about the so-called “Furongian gap” from about 497 million to 485 million years ago, when palaeontologists previously thought there were far fewer fossils than periods before or after it.

“Palaeontologists have wondered whether this time of markedly less diversity of life could be linked to ocean chemistry, cooling climates or environmental instability,” says corresponding author Dr Russell Bicknell, from Flinders University’s College of Science and Engineering.

“But perhaps we haven’t been looking at the right sedimentary rocks or fossil-bearing deposits to get a clear picture of the kinds of soft-bodied organisms and early anthropods (animals with exoskeletons) which inhabited the planet at that time.”

An international team led by Flinders University research fellow Dr Bicknell and Dr Julien Kimmig from Germany’s Karlsruhe Institute of Technology (KIT) have described a new 500-million-old fossil anthropod related to the lineage which evolved into spiders and scorpions.

Named Magnicornaspis garwoodi, this enigmatic animal features broad head shields, segmented bodies and defensive spines that belong to the corcoraniids group.

Found near Québec in Canada and preserved within the Rivière-du-Loup Formation, the specimen was one of only a handful of species known from the Cambrian and Ordovician.

The researchers – who include Dr Aaron Goodman from the University of Illinois, Thomas Turner (Flinders University honours student and palaeoartist) and Dr Patrick Smith (Macquarie University) – say the fossil is important because it helps to fill blanks in fossil history. It joins a growing list of Furongian sites that challenge the notion of a barren late-Cambrian world.

Each new Furongian fossil discovery narrows this supposed gap and reveals increasingly sophisticated ecosystems thriving during the late Cambrian.

“Together, these discoveries increasingly suggest that Furongian ecosystems remained diverse and ecologically complex,” says ARC DECRA research fellow Dr Bicknell, who investigated the long-shelved museum specimen during his time at the American Museum of Natural History.

“Importantly, it comes from a geological setting not previously recognised for exceptional preservation.”  

Research co-author Dr Kimmig says the discovery fits within a broader pattern emerging over the past two decades.

“The Furongian may not represent a true collapse in biodiversity, but rather a gap where scientists have looked and what kinds of rocks have been studied,” says Dr Kimmig, from the KIT Institute of Applied Geosciences and Head of Palaeontology and Evolution at Staatliches Museum für Naturkunde Karlsruhe.

The new fossil is named after Russell Garwood, a Manchester University palaeontologist who has spent his career understanding chelicerate evolution. The specimen was originally collected in 1962 during geological mapping near Québec and comes from black shales within the Rivière-du-Loup Formation, a unit deposited in relatively deep marine slope environments during the late Cambrian.

The specimen has been stored as part of the Smithsonian collections in Washington DC for decades.

“This highlights one of the most important aspects of palaeontology: major discoveries do not always emerge directly from fieldwork,” adds Dr Kimmig.

“Museum collections contain enormous quantities of under-studied material collected during geological surveys and expeditions over the past century.

“Revisiting these collections with modern techniques can fundamentally reshape understanding of ancient ecosystems.”

The article – “New exceptionally preserved arthropod from the Furongian of Canada” (2026) by Russell DC Bicknell), Julien Kimmig, Aaron Goodman (University of Illinois, US), Thomas Turner (Flinders) and Patrick M Smith (Macquarie University) – is published in BMC Biology. https://doi.org/10.1186/s12915-026-02617-4