The raw data and assembly of this submission are currently under a G10K-VGP publication embargo until removed from this description, following the G10K data use policy at the following URL: https://genome10k.soe.ucsc.edu/about/data_use_policy. The Razorbill is a colonical seabird and it is the closest living relative of the extinct great auk (Pinguinis impennis). The sample was provided by Copenhagen Zoological Museum and this reference assembly of has been produced as part of the G10K-VGP Project. Genome sequencing was conducted Olivier Fedrigo's group at the Rockefeller University Vertebrate Genome Lab. The genome assembly was conducted by the G10K-VGP group, by Arang Rhie and Sergey Koren of Adam Phillippy's lab at NIH. Manual curation of chromosomes and other genomic features was conducted by the gEVAL group led by Kerstin Howe at the Sanger Institute. The primary haplotype contains the longest contigs of the Pacbio FALCON unzip assembly, scaffolded with 10X linked reads, Bionano optical maps, and Arima HiC reads, with multiple tools to further separate out haplotypes. Funding was provided by the Maine Department of Inland Fisheries of Wildlife to Tom Gilbert, HHMI and Rockefeller start-up funds to Erich Jarvis, and individual grants and awards to the persons listed above.