'systematically-preserved' is a compound formed from 'systematically' + 'preserved'. 'Systematic(ally)' ultimately comes from Greek 'systema' via Latin and Late Latin where 'systema' meant 'an organized whole'; 'preserve' originates from Latin 'praeservare', where 'prae-' meant 'before' and 'servare' meant 'to keep'.

'systema' (Greek) → Latin 'systema' → Old French/Medieval Latin forms → Middle English 'system' → adjective 'systematic' → adverb 'systematically'. 'Praeservare' (Latin) → Old French 'preserver' → Middle English 'preserven' → modern English 'preserve' and its past participle 'preserved'. The compound form 'systematically-preserved' is a modern English compound combining the adverbial form with the past participle.

Originally, 'systema' referred to an organized whole and 'praeservare' to 'keep beforehand' or 'protect'; combined in modern English the compound's sense has shifted to emphasize that preservation was carried out according to an organized, repeatable system rather than by chance.