Cretomerobius

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Cretomerobius is an extinct genus of lacewings in the family Hemerobiidae, known from fossil insects found in Asia. The genus currently has one known species, C. disjunctus, dating to the Aptian stage of the Early Cretaceous.

History and classification
- The holotype of C. disjunctus comes from the Aptian Bon–Tsagan site in Mongolia. It was described by Alexandr G. Ponomarenko in 1992, originally under the name C. distinctus, which was later corrected to disjunctus.
- A second species, C. wehri, was described from a single forewing fossil from the Ypresian Klondike Mountain Formation near Republic, Washington, in 2003. The type specimen is housed at the Burke Museum in Seattle. In 2016, C. wehri was moved to the genus Proneuronema.
- When first described, placing Cretomerobius within Hemerobiidae was uncertain due to its wing venation. It was thought to be an early offshoot near groups like Drepanacrinae, Megalominae, and Drepanepteryginae, but its exact position remains unresolved.

Description
- The wings of Cretomerobius show a distinctive pattern where the radial vein splits into three main branches: ORB1, ORB2, and ORB3. ORB1 has a series of forked branches; the CuP vein forks deeply; the median vein also forks proximally.
- The forewing of C. wehri is mostly preserved but missing some margins and is estimated to be about 9 mm long and 4 mm wide.
- The two species differ in wing venation: in C. disjunctus the radial and subcostal veins fuse near the wing tip to form a single vein; in C. wehri they stay separate along the entire wing, supporting them as separate species. The two fossils come from different places and times, which also supports their distinction.

Taxonomy
- Genus: Cretomerobius (extinct)
- Family: Hemerobiidae
- Subfamily: incertae sedis
- Current species: C. disjunctus (Aptian, Mongolia)