CHANCELLORIIDAE Walcott 1920

Bengtson, S & Collins, D, 2015, Chancelloriids of the Cambrian Burgess Shale, Palaeontologia Electronica 10 (14), pp. 1-67 : 9-10

Family CHANCELLORIIDAE Walcott 1920

Genera Known from Scleritome Preservation. Chancelloria Walcott, 1920 , Allonnia Doré and Reid, 1965 , Archiasterella Sdzuy, 1969 .

Diagnosis. Sessile marine animals with radially symmetrical, baglike body, broadening upwards from attachment. Integument flexible, sometimes with fine, rectangularly or rhombically arranged platelets or spines, ~ 0.1 mm long, directed towards the apex. Armour consisting of spiny coelosclerites, which are usually composite, consisting of individual rays joined at base but having separate internal cavities and foramina; cross-section of rays nearly circular, except where bases are joined; foramen restricted. Sclerites rhombically or irregularly arranged; at the apex concentrated into an apical tuft consisting of modified spine-shaped sclerites surrounding a central apical orifice. (Modified after Bengtson et al., 1990.)

Spelling of Name. The spellings “ Chancelloridae ” and “ Chancelloriidae ” both occur in the modern literature (e.g., Janussen et al., 2002; Moore et al., 2010). Walcott (1920) based the family name Chancelloridae on the type and only genus Chancelloria . Following ICZN (32.5.3.1) a family-group name must be corrected if (before 1999) the stem of the generic name was not properly formed from its Latin suffix (ICZN 29.3.1). The stem of “ Chancelloria ” (genitive “Chancelloriae”) is “Chancellori-“, which combined with the family suffix “-idae” gives “ Chancelloriidae ”; thus the family should be referred to as Chancelloriidae Walcott, 1920 . In the 1955 Treatise on Invertebrate Paleontology, de Laubenfels (1955) erected a “Family Chancelloriidae de Laubenfels , nov.,” again with Chancelloria Walcott, 1920 , as the only genus. Chancelloriidae de Laubenfels, 1955 , is therefore both a junior homonym and a junior objective synonym of Chancellori[i]dae Walcott, 1920.