A group of scientists in Canada have discovered the oldest animals on our planet through recent research. A team of researchers collected samples from Mackenzie Mountains in north-western Canada, and dated them to be as old as 890 million years, making them the oldest known animals on the planet. The study was published in the Nature journal on Wednesday.
The research was led by Elizabeth Turner who is a professor of geology at Laurentian University in Ontario. Turner collected samples from the 890 million-year-old ancient reef which is known as Little Dal and brought them back to her lab to study them. For the research the scientist cut the rock into incredibly thin slices and looked at it under a microscope. As she examined the rock samples, it was revealed that its structure consisted of tubules about half the width of a human hair that branched and reconnected to form 3D structures that bear resemblance to those seen in fossils of bath sponges.
The study mentions that the compositional and textural homogeneity of the microspar groundmass supports the theory of an origin through permineralization of a pre-existing biological substance, rather than a steady accumulation of particles of rock eroded from the mechanical breakdown of preexisting rocks or microbial carbonate that passively incorporated with microfossils. Although modern reefs are built by corals and algae, our planet’s ancient past was geographically different. The planet consisted of one supercontinent Rodinia and present-day North America was in the center of that huge land mass. During that time the Little Dal reef system was present as it was submerged under shallow ocean water. Residing in them, the photosynthetic cyanobacteria created a giant carbonate reef that measured many kilometres wide and hundreds of metres thick.
Turner’s study further mentioned that the Little Dal vermiform microstructure is most likely what should be expected of the earliest metazoan body fossils. They exhibit the quality of preservation through post-mortem calcification of sponge-grade soft tissue in the decaying bodies of small, shapeless, sessile, epibenthic and cryptic animals that are closely affiliated with keratose sponges.