Non-aculeate hymenoptera in the Cretaceous ambers of the world

Abstract

A review of non-aculeate hymenoptera recorded in the world's Cretaceous amber assemblages is provided herein. Recorded are 287 species (265 named) representing 47 families in 17 amber assemblages. The richest in family number is the Burmese (Kachin) amber (35), followed by Canadian (19), Spanish (15), Kheta (12), Raritan (11), Charentese (10), Agapa (9) and Levantine (7) ones; hymenopterans in other ambers are less well documented. In the eight mentioned amber faunas, the share of extinct families decreases from 50/53 to 21 percent in a good correlation with their putative age, therefore suggesting a contiguous character of the studied world fauna. This inference is confirmed by the fact that endemic families are not recorded, with the only but prominent exception of the insular Burmese (Kachin) fauna with its 8 endemic families (23% of known hymenopteran families there). The rate of gradual loss of extinct families in succeeding amber assemblages shows that the main transformation took place during the first half of the Late Cretaceous, and not the Cretaceous-Paleogene boundary. As taxonomic revisions, two species are placed in different families than originally ascribed to, namely, Albiogonalys elongatus Nel, Perrichot & Néraudeau, 2003, is transferred to Praeaulacidae, and Phoriostephanus exilis Engel & Huang, 2017, is transferred from Stephanidae to Roproniidae.