We present a chromosome-length genome assembly and annotation of the Black Petaltail dragonfly (Tanypteryx hageni). This habitat specialist diverged from its sister species over 70 million years ago, and separated from the most closely related Odonata with a reference genome 150 million years ago. Using PacBio HiFi reads and Hi-C data for scaffolding we produce one of the most high quality Odonata genomes to date. A scaffold N50 of 206.6 Mb and a single copy BUSCO score of 96.2% indicate high contiguity and completeness.

Using recently published chromosome-length genome assemblies of damselfly species Ischnura elegans and Platycnemis pennipes and dragonfly species Pantala flavescens and Tanypteryx hageni, we demonstrate that the autosomes of Odonata show a high level of conservation, despite 250 million years of separation. In the four genomes discussed here, our results show that all autosomes have a clear homolog to the ancestral karyotype. Despite clear synteny, we demonstrate that different factors, including concentration of repeat dynamics, GC content, and the relative proportion of coding sequence all influence the amount of synteny across chromosomes, and that the influence of these factors differ among species. Micro- and sex chromosomes in Odonata do not share the same level of synteny as autosomes. Of the four species sampled, the genome of the Black Petaltail, which diverged from its sister species 70 million years ago, is a clear outlier, showing similarities to other long-lived lineages.

We present a chromosome-length genome assembly and annotation of the Black Petaltail dragonfly (Tanypteryx hageni). This habitat specialist diverged from its sister species over 70 million years ago, and separated from the most closely related Odonata with a reference genome 150 million years ago. Using PacBio HiFi reads and Hi-C data for scaffolding we produce one of the most high quality Odonata genomes to date. A scaffold N50 of 206.6 Mb and a BUSCO score of 96.8% indicate high contiguity and completeness.SignificanceWe provide a chromosome-length assembly of the Black Petaltail dragonfly (Tanypteryx hageni), the first genome assembly for any non-libelluloid dragonfly. The Black Petaltail diverged from its sister species over 70 million years ago.T. hageni, like its confamilials, occupies fen habitats in its nymphal stage, a life history uncommon in the vast majority of dragonflies. We hope that the availability of this assembly will facilitate research onT. hageniand other petaltail species, to better understand their ecology and support conservation efforts.