The weird and wonderful of the Pre-Cambrian (Part 1): Gunflint stromatolites – microbial life in an oxygen-shifting world

Jon Trevelyan (UK) This is the first of my series of short articles on fossils of the Pre-Cambrian. The Gunflint stromatolites, preserved in the 1.88-billion-year-old Gunflint Iron Formation of Ontario and Minnesota, offer one of the clearest windows into early complex microbial ecosystems. Formed by thriving mats of cyanobacteria long … Read More

Geological anomalies: Chalcedony breccia in a cinnabar matrix and the disappearance of Michigan’s geology professor

Steven Wade Veatch (USA) Hidden among geological marvels at a mineral show was a cinnabar-bearing chalcedony breccia-specimen (Fig. 1). The term “breccia” refers to a rock composed of angular fragments, while “chalcedony” describes a type of cryptocrystalline quartz. Adding “cinnabar” specifies the presence of mercury sulphide, which creates a distinctive … Read More

Does the ground sloth, Mylodon darwinii, still survive in South America?

Dr Ross Barnett and Simon Sylvester In Zoology, nothing is more exciting than the rediscovery of an animal previously thought long extinct. The coelacanth (Latimera chalumnae) and the ivory-bill woodpecker (Campephilus principalis) are two famous recent examples of ‘Lazarus’ taxa. Well-publicised rediscoveries like these promote the idea that refugia containing … Read More