To place a new fossil occurrence of Sacoglottis in a broader context, we surveyed the fruit morphology of all extant genera of the Humiriaceae, conducted a cladistic analysis, and critically reviewed the fossil record for this family. Living and fossil fruits of Humiriaceae are recognized by a woody endocarp, germination valves, and, in some genera, wall cavities. The phylogenetic analysis based on 40 morphological characters yielded two most parsimonious trees indicating Vantanea as sister taxon to all genera among Humiriaceae. Schistostemon is indistinguishable from Sacoglottis in fruit morphology and is recovered as sister to Sacoglottis in the topology; we recommend restoring Schistostemon to the rank of subgenus within Sacoglottis. A review of prior published reports of fossil fruits attributed to Humiriaceae led to the rejection and/or reattribution of some records but supports recognition of Vantanea, Humiria, Humiriastrum, and Sacoglottis. The available characters do not support recognition of multiple fossil species of Sacoglottis. We recognize the occurrence of Sacoglottis tertiaria Berry emend. Herrera from Peru, Ecuador, Colombia, and a newly collected Miocene site from Panama. The Cenozoic fossil record of Humiriaceae in South and Central America, together with discreditation of former reports from Europe, strongly supports a Neotropical origin for this family.
