Abstract: Gryllidae Laicharting, 1781, the most speciose family within Grylloidea, has a rich fossil record; yet, the phylogenetic relationships among these fossil taxa remain poorly resolved. Integration of fossil and extant lineages into a systematic framework has been impeded by sexual dimorphism and the fragmentary preservation typical of compression fossils, thereby confounding homology assessment and topological stability. Here, we describe Elongatitarsus falcatus gen. & sp. nov., represented by a male and a female specimen from mid-Cretaceous Kachin amber, which serves as a morphological bridge linking Cretaceous and extant cricket diversity. To evaluate the phylogenetic signal and homoplasy of different morphological character partitions across fossil and extant Gryllidae, we conducted maximum parsimony analyses using three distinct matrices: a comprehensive morphological matrix, a wing venation-only matrix, and a matrix excluding venation-only fossils. The venation-only matrix yielded poorly resolved topologies with low nodal support; in contrast, the comprehensive morphological matrix recovered a phylogeny partially congruent with recent molecular hypotheses at the subfamilial level, and placed E. falcatus gen. & sp. nov. within Gryllinae. Our results underscore that integrative morphological data sets are essential for reliable placement of fossil taxa. This approach provides a framework for testing the reliability of isolated wings in phylogenetic inferences, offering broader implications for evaluating fragmentary fossil records in deep-time systematics.

Key words: fossil insects, morphological evolution, phylogeny, wing venation