Fossil Record 24(2): 379-393, doi: 10.5194/fr-24-379-2021
Past ecosystems drive the evolution of the early diverged Symphyta (Hymenoptera: Xyelidae) since the earliest Eocene
expand article infoCorentin Jouault§, Arvid Aase|, André Nel
‡ Muséum national d’Histoire naturelle, Paris, France§ Univ. Rennes, Rennes, France| Fossil Butte National Monument, 864 Chicken Creek Road, Kemmerer, WY 83101, United States of America¶ Institut de Systématique, Évolution, Biodiversité (ISYEB) Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP50, 57 rue Cuvier, 75005 Paris, France
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Paleoxyela nearctica gen. et sp. nov., is described from the upper Eocene ofFlorissant Formation in Colorado. We placed Paleoxyela gen. nov. in the subfamilyMacroxyelinae and the tribe Macroxyelini based on the numerous wing venationcharacters visible on the specimen. Proxyelia pankowskii gen. et sp. nov. is described from thelower Eocene Fossil Lake deposits of the Green River Formation in Wyoming.We placed Proxyelia gen. nov. in the subfamily Macroxyelinae and the tribe Xyeleciinibased on the numerous wing venation characters visible on the specimen.These new records of the family Xyelidae are of particular importance tobetter understand the past diversity of the clade and propose hypothesesabout their diversification. Extant Xyelidae inhabit temperate NorthernHemisphere forests, and most of their larvae feed on conifers, which mayexplain why they are relatively poorly diversified compared to the othersymphytan families. We suggest that the global decline in conifers and thereduced diversity of extant host trees partly explain the diversity ofextant Xyelidae. We correlate the biome repartition during the Eocene tothat of the extant xyelid.