Serpulids (Annelida, Polychaeta) at Cretaceous to modern hydrocarbon seeps: Ecological and evolutionary patterns

Six taxa of serpulid polychaetes are reported from early Cretaceous to Miocene seep communities and their ecologic and evolutionary implications are discussed. All studied tubeworms belong to Mesozoic to modern serpulid taxa and not to any of the problematic Paleozoic tube worm clades. They are thus not ‘relic taxa’ that found refuge in these environments. The seep serpulids are not confined to a specific taxonomic group within the serpulids, but belong to at least five different genera, Propomatoceros, Nogrobs?, Hyalopomatus, Protis (or Protula), and Spirorbis? These five genera belong to the two major serpulid clades, filogranins (including spirorbins) and serpulins. No conspicuous tube morphology was observed that could be associated with the adaptation to the life in seep environments. The three identifiable genera have colonized the seep environment recently (geologically) after their first appearance in the fossil record, a pattern seen also among other taxonomic groups of vent and seep inhabitants.