Sentence:  Wavy lines , feather like patterns , rosettes of indefinitely floral nature , birds either singly or in stylized rows , animals in solemn frieze bands ( see Plates 11 - 12 ) - all these turned up in the more developed fabrics as <WSD>preliminary</WSD> signs that the potters were broadening their gaze . 
Meaning of the word marked with <WSD> tags:  denoting an action or event preceding or in preparation for something more important; designed to orient or acquaint with a situation before proceeding