Paleozoic origins of cheilostome bryozoans and their parental care inferred by a new genome-skimmed phylogeny
11 pages, 3 figures, 1 table, supplementary material https://doi.org/10.1126/sciadv.abm7452.-- Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper, the Supplementary Materials, Dryad, and Zenodo ; Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic ; This project is funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 724324 to L.H.L.). Extra funding for specific sampling expeditions were provided by the National Science Centre of Poland (grant PANIC/2016/23/B/ST10/01936 to P.K.), the ASSEMBLE Plus (Horizon 2020), the Leverhulme Trust (Research Project Award RPG-2016-429 to A.W.), the Russian Science Foundation (grant 18-14-00086 to A.N.O.), Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil [PQ-CNPq 308768/2018-3], Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil [FAPESP 19/17721-9] and the DISTANTCOM project (CTM2013-42667/ANT to C. Avila). B.F. was supported by Beatriu de Pinós (2019-BP-00183), funded by the AGAUR (Government of Catalonia) and by the Horizon 2020 programme under the Marie Skłodowska-Curie grant (no. 801370). The CAML-CEAMARC cruise of RV Aurora Australis (IPY project no. 53) were supported by the Australian Antarctic Division, the Japanese Science Foundation, the French Polar Institute IPEV, and the Muséum national d'Histoire naturelle, led by voyage leader, M. Riddle ; With the institutional support of the 'Severo Ochoa Centre of Excellence' accreditation (CEX2019-000928-S) ; Peer reviewed
