Serpulidae Rafinesque, 1815

Georgieva, Magdalena N., Little, Crispin T. S., Watson, Jonathan S., Sephton, Mark A., Ball, Alexander D. & Glover, Adrian G., 2019, Identification of fossil worm tubes from Phanerozoic hydrothermal vents and cold seeps, Journal of Systematic Palaeontology 17 (4), pp. 287-329 : 294

Family Serpulidae Rafinesque, 1815

‘Bexhaven tubes’

( Fig. 3 )

Material. BXG, many small-diameter tubes occurring clustered together ( Fig. 3A ). Collected by C. T. S. Little.

Occurrence. Bexhaven locality, northern Hawke’s Bay area, east coast of North Island, New Zealand (~ 38 º 3 ' S, 178 º 5 ' E). Seep carbonates occurring as isolated lenses in mudstone, Bexhaven Limestone Formation, Tolaga Group, Middle Miocene ( Campbell et al. 2008; Saether 2011).

Description. Carbonate tubes 0.5–1.9 mm in diameter, non-branching, somewhat sinuous (wavy) ( Fig. 3A ), and appearing to have been originally rigid as they demonstrate clean fractures ( Fig. 3E ). Tubes do not taper in the fragments observed. Tube wall surfaces exhibit numerous fine, parallel transverse wrinkles ( Fig. 3B ). Tubes are clearly attached to each other ( Fig. 3C, D ), and show chevron-like multi-layered tube wall structure ( Fig. 3E ), while in some cases the tube walls have been replaced ( Fig. 3D ). Tube walls do not appear to contain preserved organic matter ( Fig. 25 ).

Remarks. The attachment exhibited by the tubes and the chevron-like structure of their walls clearly point to the tubes having been made by Serpulidae Rafinesque, 1815 , and they are identified as such by both cluster and cladistic analyses ( Figs 22 , 24 ). The tube wall ornamentation of fine closely spaced transverse wrinkles is also seen in many members of this family (e.g. Serpula spp. ). Serpulids have also tentatively been suggested to occur at the Haunui and Ugly Hill localities ( Saether 2011).

Figures

Figure 3. Serpulidae sp., ‘Bexhaven’, BXG, Middle Miocene, New Zealand. A, tubes in hand specimen. B, detail of tubes in hand specimen showing fine parallel transverse wrinkles on tube surfaces. C, tubes in section. D, cluster of five attached tubes in transverse section. E, detail of partial transverse section of tube wall showing its chevron-like appearance. Scale bars: A = 20 mm; B = 3 mm; C = 2 mm; D, E = 500 µm.

Figure 22. Strict consensus cladogram of the three most parsimonious trees of tubes built by a total of 43 modern annelid taxa (best score = 14.344, consistency index = 0.308, retention index = 0.629). The analysis was based on the 48 mostly morphological tube characters and was performed using implied character weighting (k = 3). Numbers on nodes represent groups present/contradicted support values. Symbols/colours indicate taxonomic affinities.

Figure 24. Fourier transform infrared (FTIR) spectroscopy spectra of the organic tubes of vent and seep annelids. Spectra are offset on the absorbance axis, and key spectral absorbance peaks are labelled with the types of chemical bonds they represent: -NH, nitrogenhydrogen; -CH, carbon-hydrogen; -OH, oxygen-hydrogen. The regions of the tube analysed are as follows: Tevnia jerichonana (anterior, inner tube wall); Zenkevitchiana longissimi (middle, outer tube wall); Lamellibrachia anaximandri (posterior, outer tube wall); Sclerolinum contortum (anterior, outer tube wall); Alvinella sp. (middle); Spiochaetopterus izuensis (middle, outer tube wall).

Figure 25. Results of confocal laser-scanning microscopy (CLSM) of recently mineralized and ancient fossil annelid tubes (see online edition for colour version). Tubes are imaged in auto-fluorescence mode, where areas of fluorescence likely reflect the presence of organic matter. A, detail of mineralized Escarpia southwardae (Siboglinidae) tube transverse section. B, fossil tube from Upper Waiau River, New Zealand (UWT3-4), detail of transverse section. C, fossil tube from West Fork Satsop River, Washington State, USA (WFSR 1A), detail of transverse section. D, fossil tubes from Bexhaven, New Zealand (BXG), detail of two near-transverse sections. Scale bars: A = 100 µm; B–D = 200 µm.