Zivkovicia compressa – drawing by Ferry Siemensma
Genus Zivkovicia Ogden, 1987
Diagnosis: Shell pyriform, often with a distinct constriction of the neck region, either circular or compressed in transverse-section, composed mainly of agglutinate mineral particles bound by an organic cement matrix; aperture terminal, usually circular; internally the shell is partitioned into two parts by an extension of the shell wall to form a diaphragm which is bisected by two circular openings.
Type species: Zivkovicia compressa (Carter, 1864)
Other species:
- Zivkovicia spectabilis (Penard, 1902)
- Zivkovicia flexa (Cash & Hopkinson, 1909)
- Zivkovicia spiralis
Remarks: For the species described by Penard, look here.
Zivkovicia spec. with three openings
Z. spiralis – drawing Ferry Siemensma
Z. spectabilis