FOSIL stands for Framework Of Skills for Inquiry Learning, which it basically is.
However, The fact that it also sounds like fossil is deliberate. Firstly, the discipline of archaeology is a helpful way to think and talk about inquiry, especially with children. Secondly, it serves as a warning against complacency, because a framework, or progression, of inquiry skills must evolve in response to changes in the environment if it is to remain vital.*
This idea is reflected in the FOSIL logo/ head (see below), which is suggestive not only of an ammonite fossil, but also of inquiry as being an iterative process that, while centrally cognitive, unfolds to involve us fully as social human beings. Placing the FOSIL head/ inquirer at the centre of the FOSIL Inquiry Cycle is deliberate, then, and also makes it clear that reflection is central to and occurs throughout the dynamic inquiry process, and is not limited to the Reflect stage.