Chancelloriida Walcott, 1920

Wrona, Ryszard, 2004, Cambrian microfossils from glacial erratics of King George Island, Antarctica, Acta Palaeontologica Polonica 49 (1), pp. 13-56 : 24

Order Chancelloriida Walcott, 1920

Family Chancelloriidae Walcott, 1920 Characterization and remarks.—Exclusively Cambrian, composite, mostly star−shaped sclerites which are very variable in shape, number and arrangement of rays (e.g., Sdzuy 1969; Fernández−Remolar 2001). The rays have their own individual calcareous (possibly aragonitic) wall, which separates the rays from each other, and an inner cavity which is open to the exterior through a basal foramen ( Sdzuy 1969; Bengtson et al. 1990; Bengtson and Hou 2001). This sclerite architecture is similar to that found in other sclerites of the Coeloscleritophora ( Bengtson and Missarzhevsky 1981; Bengtson et al. 1990). Extraordinarily preserved specimens of body fossils from the Lower Cambrian Chengijang biota in China, with articulated sclerites clearly showing details of the flexible integument and scleritome arrangement, indicate that soft skin of the body and sclerites were structurally, functionally and developmentally integrated in the chancelloriid integument ( Bengtson and Hou 2001). This as well as many previous records of sclerite arrays on body surfaces ( Walcott 1920; Sdzuy 1969; Mostler and Mosleh−Yazdi 1976; Rigby 1978) allow a reconstruction of these enigmatic organisms as having a spherical or saccular body armoured with star−shaped, spiny sclerites ( Bengtson and Hou 2001). Their marine, sedentary benthic mode of life as suspension feeding animals has been commonly accepted by most workers ( Bengtson et al. 1990; Wood at al. 1993; Mehl 1996; Demidenko 2000; Bengtson and Hou 2001). For detailed taxonomic discussion see Bengtson et al. 1990.