Three new lithobiomorphan centipede specimens from mid-Cretaceous Myanmar amber, a clue on the geological record of Lithobiomorpha

Chilopoda, part of Myriapoda, is a species-rich group of ~3300 formally described species. Yet, the phylogenetic relationship of centipedes is not fully clear, and the scarceness of their fossil record, compared to the closely related Diplopoda, is a major challenge for understanding their evolutionary history. Within Chilopoda, Lithobiomorpha is one of the most problematic concerning its fossil record, so far restricted to the Cenozoic (~40 mya) and with a single lithobiomorphan-like specimen from Kachin amber (~100 mya). Here, we report three new exceptionally well-preserved lithobiomorphan specimens from Myanmar amber (~100 mya). These represent the first report of oldest representatives of Henicopidae from the Cretaceous, and with this the oldest definite record of Lithobiomorpha. Two specimens have ten pairs of walking legs (stage IV), and one has a fully developed trunk. These specimens are similar in many aspects to the extant group of Henicopidae and, more precisely, to Lamyctes Meinert, 1868. The specimens seemingly lack ocelli, exhibit ~14 (stage IV) and 24 antenna articles, have 2+2 coxosternite teeth, and present tooth-like setae on their coxosternite margins (=porodont). The fully developed specimen possesses a tibial spinose projection on each tibia of legs 1–11, a blunt projection on the tibia of leg 12, and undivided tarsi on their legs 1–12. With the finding of these specimens, we expand the fossil record of Lithobiomorpha significantly.