Spruceanum

Spruceanum is an extinct dipteran genus that lived during the late Cretaceous period, approximately 70 million years ago. The genus is known from a small number of exceptionally preserved amber inclusions found in the La Brea Tar Pits and earlier deposits in the Okanagan region of British Columbia. The diagnostic features of the genus include a distinctive filamentous proboscis, a robust thoracic musculature consistent with aerial maneuvering, and wing venation patterns that differ from modern Muscomorpha. Based on these traits, scientists classify Spruceanum within the order Diptera, suborder Brachycera, but its precise family placement remains unresolved; it is currently placed in the incertae sedis group pending further morphological study.

The genus name derives from the paleontologist Dr. Eleanor Spruce, who first described the initial specimen in 1939. The type species, Spruceanum elytrum, was named for the amber (“elytrum” meaning “wing” in Latin) that encased it. Additional species, though not formally described, have been tentatively identified in subsequent collections and are distinguished by wing span and antennal segment count.

Spruceanum provides insight into the diversity of mid-Cretaceous insects, particularly in relation to pollination networks that involved early flowering plants. Because the amber preserves fine detail, paleobiologists can study the morphological features of these flies in situ, allowing reconstruction of flight mechanics and feeding behavior. Future studies aim to extract ancient DNA from the amber inclusions to compare genetic markers with extant dipteran lineages, a technique that may help clarify the phylogenetic position of Spruceanum within the evolutionary history of Diptera.