Fruits of Anacardiaceae from the early Oligocene of Baraval Quercy locality, southwestern France

The Anacardiaceae are widely distributed across tropical and subtropical regions today and are divided into two major subfamilies, Anacardioideae and Spondioideae. According to the fossil record, this family underwent significant diversification during the Paleogene. The Spondioideae are particularly well represented in the fossil record, characterized by fibrous, usually multilocular endocarps that germinate through pores, sometimes with opercula. In this study, we identified and classified new fossil fruits from the Oligocene Baraval site in the Quercy region of Lot, France. These phosphatized fossils are exceptionally well-preserved, with clearly observable three-dimensional morphology and cellular structure. Twenty-six endocarps were examined, and their anatomy was studied using micro-CT-scan analyses and physical sections. Two new genera and one new species are described: Palaeochoerospondias sheppeyensis gen. and comb. nov. has fruit with 4–6 symmetrical locules, apical recessed bilabiate germination mechanism, alternating with whale-tail shaped lacunae, a central vascular system composed of 5–6 bundles, and locular envelopes becoming progressively thicker toward the distal side. Baravalosphaera operculata gen. et sp. nov. has 5–7 symmetrical locules, simple, apical opercula, alternating with triangular lacunae; a central vascular system composed of 5–7 bundles, and homogeneous locular envelopes. Altogether, the data suggest that the climate of southwestern France during the Rupelian (33.9–27.3 Ma) was likely warm and humid, of a subtropical type, and consistent with regional palynological and macrofossil analyses. This work shows extinct morphological diversity within the Spondioideae and contributes to a better understanding of the floristic changes that marked the Eocene–Oligocene transition in Western Europe.