Here is a picture of one of my female ornate uros full of eggs, she's probably a couple weeks from laying.

Uromastyx can be pretty obvious when they are gravid, especially when close to laying. Females become very full and wide looking with the eggs visible as bulges as they move around. Since uros often balloon with air when they are handled it is hard to feel for the eggs by palpation. If a female is relaxed in your hand and not ballooning then you should be able to feel the eggs no problem a week or two before egg-laying.

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