Halkieria

Halkieria is a genus of halkieriid mollusc which has been found on almost every continent in Lower to Mid Cambrian deposits, forming a large component of the small shelly fossil assemblages. The best known species is Halkieria evangelista, from the North Greenland Sirius Passet Lagerstätte, in which complete specimens were collected on an expedition in 1989. The fossils were described by Simon Conway Morris and John Peel in a short paper in 1990 in the journal Nature. Later a more thorough description was undertaken in 1995 in the journal Philosophical Transactions of the Royal Society of London and wider evolutionary implications were posed.

==History of discovery== Armor plates called "sclerites" had long been known as elements of the small shelly fossils, and detailed analysis showed that some of these belonged to the same animal and how they fitted together. The first articulated specimens of Halkieria evangelista, with all their hard parts together, were collected in 1989 from the Sirius Passet lagerstätte in Greenland, and were described in 1990 by Simon Conway Morris and John S. Peel. H. evangelista is used as a model for identifying and reconstructing as halkieriids other similar shells and sclerites; its epithet evangelista reflects its power to explain the Lower Cambrian fossil record.