†正筆石目 Graptoloidea Maletz, Carlucci and Mitchell 2009
参考
^Loduca, S. T.; Caron, J. B.; Schiffbauer, J. D.; Xiao, S.; Kramer, A. A reexamination of Yuknessia from the Cambrian of British Columbia and Utah. Journal of Paleontology. 2015, 89: 82–95. doi:10.1017/jpa.2014.7.
^Sato, A; Rickards RB, Holland PWH. The origins of graptolites and other pterobranchs: a journey from ‘Polyzoa’. Lethaia. 2008, 41: 303–316.引文使用过时参数coauthors (帮助)