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 : 303-304

Family Siboglinidae Caullery, 1914 (vestimentiferan)

‘Troodos wrinkled tubes’

( Fig. 10D, E )

1999a vestimentiferan worm tubes Little, Cann, Herrington, & Morisseau: 1028, fig. 2e.

Material. Kambia 4051, 4061, 6061, t3; Kapedhes 204b, 2101, worm tubes with walls ornamented by transverse and longitudinal wrinkles. Collected by C. T. S. Little.

Occurrence. Massive sulphide deposits. Troodos Ophiolite, Cyprus. Turonian, Late Cretaceous ( Oudin & Constantinou 1984; Little et al. 1999a).

Description. Generally straight or slightly curving pyritic tubes 1.2–4.5 mm in diameter, which do not show signs of having been flexible and are not attached to other tubes ( Fig. 10D, E ). Whether tubes taper cannot be assessed with certainty due to the short length of preserved fragments. Tubes do not have collars, and instead possess fine transverse and longitudinal wrinkles on their surfaces, with the transverse wrinkles often being more pronounced and fairly regular ( Fig. 10D ). Longitudinal wrinkles are fine and occasionally bifurcating ( Fig. 10E ). One tube specimen has a smaller tube preserved within it.

Remarks. These tubes are resolved among siboglinids by both cladistic and cluster analyses ( Figs 22–24 ), as a result of the fine, bifurcating longitudinal wrinkles as well as the fine transverse wrinkles which they possess. The features above are not observed on serpulid tubes, which sometimes possess coarse longitudinal wrinkles. The longitudinal wrinkles of chaetopterid tubes are often coarser ( Kiel & Dando 2009), and have not been observed to be crosscut by fine transverse wrinkles. We therefore suggest that the most likely builders of these tubes are vestimentiferans, which do exhibit such ornamentation patterns (cf. Ridgeia piscesae tubes, Fig. 15G ).

Figures

Figure 10. Tubes from the Turonian of Cyprus. A–C, ‘Troodos collared tubes’; A, B, Kambia 4061 and Memi 212b2, respectively, sinuous worm tubes with collars; C, Kambia 401b, worm tube with collar attached at an oblique angle. D, E, ‘Troodos wrinkled tubes’, Kapedhes 2101 and 204b, respectively, worm tubes bearing longitudinal and transverse wrinkles. F, G, ‘Troodos attached tubes’, Memi 2021 and Kinousa 2023, respectively, sinuous tubes that appear attached to a surface, tubes in F bearing fine parallel transverse wrinkles. Scale bars: A–D, F, G = 1 mm; E = 0. 5 mm.

Figure 15. A–F, H, I, ‘Figueroa tubes’, Pliensbachian, California, USA; A–C, tubes in hand specimen; A, FFC-12, straight, tapering tube with fine longitudinal wrinkles; B, FFC-00-21, tube fragment bearing longitudinal wrinkles and collars; C, FFC-18B, tube with longitudinal wrinkles and a fine, obliquely positioned collar; D, FFC-18, longitudinal section of tube exhibiting long, flaring collars; E, FFC-12, scanning electron microscopy (SEM) image showing details of tube wall ornamentation; F, FFC-12, greater detail of same tube; H, FFC-19, detail of tube transverse section showing preservation of tube walls; I, FFC-19, detail of tube wall in transverse section. G, Ridgeia piscesae (Siboglinidae) tube, JdF317, showing detail of the ornamentation. Scale bars: A, C = 2 mm; B, D, G, H = 1 mm; E = 500 µm; F = 100 µm; I = 300 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 23. Strict consensus cladograms constructed using a total of 64 modern and fossil annelid taxa and 48 mostly morphological tube characters. Analyses were performed using implied character weighting, with the concavity constant set as default (k = 3; A), and also set to downweight homoplastic characters less (k = 4; B). Numbers on nodes represent groups present/contradicted support values. Modern taxa are coloured according to taxonomic groups; fossil taxa are in grey. A, consensus of 271 most parsimonious trees (best score = 15.387, consistency index = 0.195, retention index = 0.264); B, consensus of 60 most parsimonious trees (best score = 13.568, consistency index = 0.232, retention index = 0.569). 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).