A Much Earlier Start for Animals
Where did all the animals come from? … The problem with the earliest animals, from a paleontologist’s perspective, is that they lacked hard parts.
The answer lies in the unique molecules they left behind…. one such molecule [c]alled 24-IPC, … is only produced by Demospongiae, a class of animals that includes most modern sponges and is thought to constitute the roots of the animal family tree. The researchers acquired 30 pristine drill cores removed from underneath the southern Arabian Peninsula by the oil company Petroleum Development Oman. The cores ran through sedimentary layers and extended back beyond the Cambrian Explosion into the Cryogenian Period, about 635 million years ago near the end of a long, global ice age.
And what did they find? Read about it here.