Celebration that might follow discovery of a dinosaur's femur? (7)

I believe the answer is:

shindig

'celebration' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for shindig that I've seen before include "Large, lively party" , "Large and noisy party or quarrel" , "Lively party, knees-up" , "Noisy disturbance" , "Noisy knees-up" .)

I've seen this clue in The Guardian.

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