Hi! I understand that it is very common to work from fractions of skeletons to ID or define a new creature.

I understand this is about referring to the accrued knowledge of how bodies and bones work etc

I'd just like to know, is identification reliant on the expertise (internalised knowledge bordering on intuition) of the person, or are there other tools like databases, computer extrapolation models etc as well?

Thank you

Both of the things you mention play into the process of identifying extinct animals from their (sometimes very incomplete) fossil remains. The main computerised tool is called cladistics. It works by analysing a matrix of morphology, and figuring out the possible evolutionary trees that would require the fewest transitions to achieve those states. I wrote a fairly approachable overview many years ago: it's at http://www.miketaylor.org.uk/dino/faq/s-class/clad/

But in order to even know what parts of the morphology you want to put into your matrix, you need a familiarity with the group you're working on and the related animals. A layman looking at, say, a vertebra, would just see a mass of sheets and struts of bone; but to someone who knows the group well, individual struts can be very suggestive. "Ah", we might say, "this vertebra has a spinoparapophyseal lamini, something otherwise known only in a single vertebra of Giraffatitan brancai." And that would start us thinking about whether the vertebra we're looking at might be from that animals, or a close relative. We might start comparing details, and so discover interesting similarities and differences. Often (not always) part of the output of this kind of thought is that we expand the matrix that we use for cladistics, adding new morphological characters.