For Abhidharma Pitka Wikipedia mentions (1) “Modern scholars generally believe that the canonical Abhidharma texts emerged after the time of the Buddha, in around the 3rd century BCE. Therefore, the canonical Abhidharma works are generally claimed by scholars not to represent the words of the Buddha himself, but those of later Buddhists. Peter Skilling describes the Abhidharma literature as "the end-product of several centuries of intellectual endeavour.” (2) “According to Frauwallner, the oldest Buddhist tradition has no Abhidharma Pitka but only mātṛkā (මාතෘකා) or topics. What this means is that besides the small number of fundamental doctrinal statements, the Buddha's sermons also contain a quantity of doctrinal concepts. The most suitable form for collecting and preserving these concepts would have been com-prehensive lists (developed in the first council). Lists of this kind were called mātṛkā, and it was from these lists that the Abhidharma later developed
