Collembola (Arthropoda, Hexapoda) from the mid Cretaceous of Myanmar (Burma)

A prior study involved 78 Collembola specimens preserved in Upper Cretaceous (Campanian) amber from Canada. This work deals with 109 specimens from the mid Cretaceous (Cenomanian or possibly slightly lower) of Myanmar, 37 of which have been identified to the generic level; 14 new species are described. Two species of the family Isotomidae are placed in previously described genera. One is placed in the Late Cretaceous genus Protoisotoma (burma), and one in the extant genus Proisotoma (s.l.) pettersoni. The remaining specimens are placed in 11 newly erected genera or as “Incertae sedis” taxa in the broadly construed families Sminthuridae, Isotomidae, and Neanuridae. The new genera are Sminthuridae (s.l.): Grinnellia, Sminthuricinus, Mucrovirga, and Sminthurconus; Isotomidae: Villusisotoma (two species, V. brevis and V. longa), Burmisotoma, Propachyotoma, and Protodesoria; Neanuridae (s.l.) Protodontella. Two new genera (Praentomobrya and Cretacentomobrya) are placed in a new family (Praentombryidae), which is similar to the modern family Entomobryidae. Most of the extinct genera are very similar to modern genera. This similarity, along with the occurrence of an extant genus, suggests that a greater proportion of the Collembola of Myanmar (Burma) survived the end-Cretaceous than did taxa in Canada, even though the former are approximately 30 Ma older.