Hadimopanella from the Lower Cambrian of North Greenland: structure and affinities

New records of minute phosphatic sclerites of Hadimopanella are described from the Aftenstjernes0 and Henson Gletscher Formations of western and central North Greenland in strata of Early Cambrian age. The new material illustrates the occurrence of mineralisation in the wall between individual sclerites and confirms earlier suggestions of the close relationship between Hadimopanella and Utahphospha. Both forms are compared with spicules produced by living and fossil compound ascidians of the genus Cystodytes and it is concluded that they may have been Early Palaeozoic representatives of the chordate Class Urochordata.