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    Machaeridia (annelid) - Wikipedia

    • Machaeridia is an extinct group of armoured, segmented annelid worms, known from the Early Ordovician (Late Tremadoc) to Carboniferous. It consists of three distinct families: the plumulitids, turrilepadids and lepidocoleids. 展开

    Fossils

    Only the calcitic sclerites ("armour plates") of these worms tend to be preserved in the fossil record. These are tiny, and usually found disarticulated: articulated specimens reach about a centimeter in length, and are incredibly rare – … 展开

    Ecology

    Machaeridians are often found in association with stylophorans - the cornutes and mitrates. This suggests that they possessed a similar ecology. They probably fed on organic detritus, perhaps even the faeces of … 展开

    Taxonomic affinity

    Historically the group has been assigned to the echinoderms, barnacles, annelids and mollusks. Relationships to other Cambrian forms (such as the Halkieriids) have been proposed and discounted. In 2008, the discovery of a fo… 展开