Three new species of the long-tailed wasp genus †Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber

†Megacoxa is a recently described extinct genus of Megalyridae Schletterer, 1889 from Kachin amber with three described species until now. Here, we investigate four new fossils and integrate them in a phylogenetic framework. We describe three additional species of †Megacoxa: †M. brazideci sp. nov., †M. gungner sp. nov. and †M. mjoelner sp. nov. Furthermore, we describe the previously unknown female of †M. synchrotron Brazidec et al., 2024. We provide an emended diagnosis of †Megacoxa and a key to all recognized species. The continued expansion of the known Cretaceous diversity of Megalyridae underlines the relictual nature of the Recent fauna.