NEW ANTS AND TRUE BUGS FROM CANADIAN CRETACEOUS AMBER AND THEIR PALEOBIOLOGICAL IMPLICATIONS

Late Cretaceous (Campanian) amber originating from the Foremost Formation in southern Alberta contains one of the world’s most diverse Mesozoic insect assemblages. Ongoing work upon the systematics of the Grassy Lake amber assemblage has yielded a number of new species and genera, with implications for the palaeobiogeography, palaeodiversity and temporal ranges of higher taxa. Newly-described ants indicate that the formicid subfamily Dolichoderinae was present nearly 10 Ma before the most recent molecular divergence estimates, and that the dolichoderine tribe Leptomyrmecini likely existed 30 Ma earlier than predicted. Meanwhile, a bizarre trap-jawed ant belonging to Haidomyrmecini (Sphecomyrminae) indicates that this extinct tribe persisted 20 Ma longer than previous amber studies have suggested, extending to reach near the end of the Cretaceous. A new leptosaldine bug (Hemiptera: Leptopodidae) provides the first Mesozoic record of the family, roughly 26 Ma earlier than previously reported. Many of these new discoveries alter more than just our understanding of temporal ranges—they are often the first records for higher taxonomic units within Laurentia (shaping paleobiogeographic schemes), and they provide character combinations that call into question existing taxonomic divisions. Ultimately, these discoveries contribute to our understanding of the paleo-forest and its diversity, while providing tantalizing glimpses of behaviors and faunal associations in a Cretaceous ecosystem.