At the bottom of the sea, 540 million years ago, humanity’s oldest known ancestor lived between grains of sand and scavenged for food.
Researchers call this Cambrian aged creature the Saccorhytus, and believe it may be the most primitive example of a deuterostome on record. Deuterostomes were just step off from vertebrates in the evolutionary ladder, which would go on to evolve into the land mammals that roam our world today. The Saccorhytus is barely large enough to see with the naked eye, and would appear only as a speck of dirt, however, once held under a microscope it becomes a stunning find.
Researchers also noted that because it did not have an anus, that the Saccorhytus most likely defecated from its mouth. Yep, that definitely sounds like a human ancestor.
“To the naked eye, the fossils we studied look like tiny black grains, but under the microscope the level of detail was jaw-dropping,” said Prof Simon Conway Morris from the University of Cambridge in the UK. “We think that as an early deuterostome this may represent the primitive beginnings of a very diverse range of species, including ourselves. All deuterostomes had a common ancestor, and we think that is what we are looking at here.”
The fossils were found in the Shaanxi Province of central China by an international team of researchers, who were ecstatic to add good ol’ Sacco here to the list of our evolutionary record. Sacco isn’t the first recorded deuterostome, on the contrary, there are plenty of these pre-vertebrate creatures known to the scientific community, however, the records pre-existing the discovery of Sacco date only as far back as 520 million years ago. Sacco has a full 20 million years seniority over the next in line of succession!
Saccorhytus most definitely moved around the sea floor, scientist realized, when they detected features of skin that could be used for contracting and wiggling. Yep, this big mouth here would just wiggle its way through sandy sea beds until it found some food. A big mouth that sits around all day and wiggles for food. Sound human?