Isolated conifer female reproductive structures are common fossil elements from Cenomanian (ca 99–94 Ma) charcoal- and resin-rich beds of theTupuangi Formation, Chatham Islands, southwest Pacific Ocean. Recent findings have proposed that these are the oldest fossil evidence of serotiny,a highly successful fire-adaptive reproductive strategy common among tree species living in fire-prone areas today. Herein, we systematicallydescribe the external morphological and anatomical features of these fossils, by employing a combination of manual extraction and neutron tomographytechniques. We propose a new species of conifer, Protodammara reimatamoriori, and a re-examination of fossil material of the Protodammaratype species facilitated an emendation of the genus. Protodammara shares numerous features with extant Cunninghamia, Taiwania, Athrotaxis, andseveral extinct taxa of Cupressaceae, and is interpreted as an extinct lineage of the early-divergent ‘taxodioid Cupressaceae’ stem group.