Written in stone: history of serpulid polychaetes through time

Abstract

Ippolitov, A.P., Vinn, O., Kupriyanova, E.K. and Jäger, M. 2014. Written in stone: history of serpulid polychaetes through time. Memoirs of Museum Victoria 71: 123-159.Although the fossil record of annelids in general is poor, calcareous tube-building Serpulidae are a notable exception. The "stumbling block" of understanding the serpulid fossil record is obtaining reliable taxonomic interpretations of fossil tubes based on morphology. Luckily, serpulid tubes demonstrate high variety of ultrastructures and nonuniform mineralogical composition, which can be used as new tools for decrypting the fossil record. Ancient Late Ediacaran (580-541 Ma) and Paleozoic (541-252 Ma) rocks contain diverse tubicolous fossils that have often been erroneously interpreted as annelids, and serpulids, in particular. Palaeozoic to Middle Jurassic coiled spirorbiform tubes, often referred to as Spirorbis, had been shown to be microconchids, a group of probable lophophorate affinity. The most ancient records of unequivocal serpulids date back to the Middle Triassic (~244 Ma) of the Mesozoic, and from the Earliest Jurassic (~200 Ma) fossil serpulids become common. From the latest Jurassic (~146 Ma) serpulids colonised hydrocarbon seep environments and possibly also penetrated the deep sea. Concerted efforts of paleontologists and zoologists are needed for further understanding of serpulid evolutionary history. The serpulid fossil record can become a valuable instrument for calibration of "molecular clocks" in polychaetes, which would allow dating not only divergence events in serpulids, but also in annelid groups that lack a representative fossil record.

Identification of fossil worm tubes from Phanerozoic hydrothermal vents and cold seeps

“…While there has been some confusion as to whether chaetopterid tubes contain chitin (Barnes 1964;Ippolitov et al 2014;Parry et al 2014), our FTIR (Fig. 24) and py-GC-MS (Supplementary File 1, Table S7) results from four chaetopterid genera suggest that they do not, as three major chitin marker pyrolysis products that were commonly observed in siboglinid tubes were absent from the tubes of chaetopterids.…”

“…As annelid dwelling tubes are not joined to the annelid body and the adaptive evolution of tubes is considered independent to that of soft tissues (Ippolitov et al 2014), tubes have generally been considered to have limited utility in taxonomy. However, there are recognized characters of fossil tubes, such as tube wall structure in fossil serpulid tubes from seeps (Vinn et al 2012), that can enable taxonomic designation.…”

“…sediment grains), and tubes comprised purely of an organic secretion. Calcareous tubes are almost exclusively confined to the family Serpulidae, but single extant sabellid and cirratulid genera also produce calcareous tubes (Ippolitov et al 2014). Calcareous tubes can be formed of either calcite or aragonite, or of both minerals, and may also exhibit distinct crystal microstructures (Vinn et al 2008).…”

“…However, the dwelling tubes that many annelids create are often more robust structures that have a greater likelihood of becoming preserved as fossils (Ippolitov et al 2014;Georgieva et al 2015a), and especially so within vents and seeps where rapid mineral precipitation often favours fossilization.…”

Notes on Additional Material Associated with the Type Specimens of Diphuicrinus ohioensis (Echinodermata: Crinoidea) from the Middle Pennsylvanian of Southeastern Ohio

“…These are superficially similar to those produced by serpulid (polychaete annelid) worms in modern marine environments. However, true serpulid structures are restricted to younger deposits (Vinn and Mutvei 2009;Ippolitov et al 2014). Crinoid ossicles vary from being relatively densely encrusted-close to 10% of surface area covered; Fig.…”