Siboglinidae Caullery, 1914

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 : 297

?Family Siboglinidae Caullery, 1914 (?vestimentiferan)

‘Canyon River tubes’

( Fig. 6 )

2000 vestimentiferan worm tubes Goedert, Peckmann, & Reitner: 995, fig. 3.

Material. WA-CR LACMIP 16957, several large, straight tubes preserved in the same orientation. JLG 473, tubes embedded in carbonate matrix, thin sections of tubes only. Donated by J. L. Goedert.

Occurrence. Canyon River, south-west Washington State, USA (47 º 18.18 ' N, 123 º 30.52 ' W). Seep carbonate within siltstone, Lincoln Creek Formation, lower Oligocene ( Goedert et al. 2000; Peckmann et al. 2002).

Description. Carbonate tubes from this locality were originally described by Goedert et al. (2000). They measure 1.1–7.0 mm in diameter, and are non-branching, non-agglutinated and not attached to other tubes ( Fig. 6A–C ). Tubes taper slightly, and the walls of the majority of the tubes are smooth and lack ornamentation ( Fig. 6A, B ), while longitudinal wrinkles are present in one small-diameter tube ( Fig. 6C ). Tube walls are thick and multi-layered, and at times delaminated ( Fig. 6D ), suggesting an originally organic composition. The tubes appear to have originally been rigid as walls are generally not compressed, both in hand specimen ( Fig. 6A–C ) and thin section ( Fig. 6E ), and fluorescence during CLSM analysis of the tube walls further suggests that the tubes were originally organic ( Fig. 6F ).

Remarks. These tubes were suggested to have been made by vestimentiferans by Goedert et al. (2000), resembling tubes made by the genus Escarpia . Despite the tubes being largely unresolved in the cladistic and cluster analyses ( Figs 22 , 24 ), they closely resemble those of vestimentiferans owing to their smooth walls and columnar morphology. The diameter range of the tubes, as well as the hard, organic, mostly thick and multi-layered nature of the tube walls, are typical of most vestimentiferans. We therefore suggest that vestimentiferans are the most likely builders of these tubes, but this assignment is tentative due to the poor resolution of these tubes in the cladistic analysis.

Figures

Figure 6. ‘Canyon River tubes’, Oligocene, Washington State, USA. A–C, WA-CR LACMIP 16957; A, large-diameter tubes in hand specimen; B, smooth small-diameter tubes; C, small-diameter tube with longitudinal wrinkles. D–F, JLG 473; D, delaminated tube wall with a fragment of preserved multi-layered tube wall (white arrow); E, uncompressed transverse section of a small diameter tube; F, detail of tube wall showing fluorescent bands that likely indicate the presence of preserved organic matter from the tube wall, imaged using confocal laser scanning microscopy (see online for colour version). Scale bars: A = 20 mm; B = 5 mm; C = 3 mm; D = 150 µm; E = 300 µm; F = 30 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).