 |
| Icaroramus perisi Li, Kundrata & Cai in Li, Kundrata, Huang, Myint et Cai, 2026. Artwork by Ding-Hua Yang |
Abstract
The evolution of insect sensory and signalling systems has played a key role in arthropod diversification, yet direct fossil evidence illuminating their early history remains rare. Lampyroids, including fireflies and their relatives, are notable for their elaborately modified antennae and bioluminescence. These characteristics make them an exceptional model for understanding the coevolution of sensory and signalling modalities. Here we describe Icaroramus perisi gen. et sp. nov. from mid-Cretaceous Kachin amber, a lampyroid beetle tentatively placed within Cretophengodidae. Icaroramus is exceptional in possessing both extraordinarily elaborate antennae and a well-developed photic organ. Its 12-segmented quadriheteroramose antennae represent an antennal architecture unknown among extant and fossil beetles. Functionally, these antennae likely combined an expanded olfactory surface area with differentiated sensory fields, enhancing the detection of pheromonal cues. Mate location was therefore probably mediated primarily by pheromones, whereas bioluminescence may have retained its plesiomorphic role in aposematic defence. This discovery expands the known morphological and ecological diversity of Cretaceous lampyroids and provides new insight into the origins of complex signalling strategies in fireflies and their relatives.
Keywords: Cretophengodidae, Kachin amber, heteroramose antenna, mating strategy, bioluminescence
 |
| Icaroramus perisi, holotype, NIGP209038. (A, B) Habitus, dorsal and ventral views, under reflected illumination. (C) Schematic reconstruction of antenna (proportions approximate). Scale bars: 2 mm in (A,B). |
Systematic palaeontology
Order Coleoptera Linnaeus, 1758
Superfamily Elateroidea Leach, 1815
Family (?) Cretophengodidae Li et al., 2021
Genus Icaroramus Li, Kundrata & Cai gen. nov.
Diagnosis. Antennae 12-segmented; antennomeres 4–11 quadriheteroramose, each with two morphologically different pairs of rami (figures 1C, 2A–C) (antennomeres 4–11 biramose in Cretophengodes Li et al.). Pronotum with posterior angles acute and shortly produced posteriorly (figure 1A) (posterior pronotal angles obtuse in Cretophengodes). Prosternum in front of coxae longer than longitudinal diameter of procoxal cavity; prosternal process extending well beyond procoxae and fitting into mesoventral cavity (figure 2D). Mesoventral cavity well developed (figure 2E). Abdomen with six ventrites; ventrite 6 with entire surface luminous (figure 1B) (possible luminous organ present on medial portions of abdominal ventrites 1–3 in Cretophengodes).
Etymology. The generic name is formed from Icarus, the mythological figure who flew too close to the Sun and fell into the sea, and ramus, referring to the multiple long rami on each antennomere. It metaphorically evokes an evolutionary ‘overreach’, a unique antennal elaboration that was lost and not inherited by extant lineages. The name is masculine in gender.
Icaroramus perisi Li, Kundrata, Cai sp. nov.
Etymology. The species is named after the palaeoentomologist Dr David Peris.
 |
| Artistic reconstruction of Icaroramus perisi glowing in mid-Cretaceous forest. |
Yan-Da Li; Robin Kundrata; Diying Huang; Tin Aung Myint; Chenyang Cai. 2026. A Firefly Relative that Smelled and Glowed: Evidence for Complex Signalling Systems in Cretaceous lampyroids. Proc. R. Soc. B (2026) 293 (2075): 20260295. DOI: doi.org/10.1098/rspb.2026.0295 [29 Jul 2026]
Cretaceous Beetle Fossil Reveals Early Evolution of Firefly Sensory and Signaling Systems
https://english.cas.cn/newsroom/research-news/202607/t20260729_1179346.shtml