Identification of fossil worm tubes from Phanerozoic hydrothermal vents and cold seeps Author Georgieva, Magdalena N. Department of Life Sciences, Natural History Museum, London, United Kingdom; & School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Author Little, Crispin T. S. School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Author Watson, Jonathan S. Department of Earth Science and Engineering, Imperial College London, London, United Kingdom; Author Sephton, Mark A. Department of Earth Science and Engineering, Imperial College London, London, United Kingdom; Author Ball, Alexander D. Core Research Laboratories, Natural History Museum, London, United Kingdom Author Glover, Adrian G. Department of Life Sciences, Natural History Museum, London, United Kingdom; text Journal of Systematic Palaeontology 2019 2017-12-28 17 4 287 329 http://dx.doi.org/10.1080/14772019.2017.1412362 journal article 10.1080/14772019.2017.1412362 1478-0941 10883381 ?Family Siboglinidae Caullery, 1914 ‘West Fork Satsop River tubes’ ( Fig. 4 ) Material. JLG459C, WFSR-3B, several wavy tubes. WFSR-3A-1, several tubes observed in thin section. Donated by J. L. Goedert. Occurrence. West Fork Satsop River, Grays Harbor County, Washington State , USA ( ~ 47 º 16 ' N, 123 º 33 ' W). Float seep limestone blocks. Lincoln Creek Formation, Oligocene ( Campbell & Bottjer 1993 ; Kiel & Amano 2013 ). Description. Carbonate tubes up to 2.4 mm in diameter, somewhat sinuous, non-branching, and not appearing to have been agglutinated or to taper in the observed fragments ( Fig. 4A, B ). Tubes appear inflexible and unattached, and the tube walls are free of ornamentation. In thin section, the tube walls are brown, of variable thickness but finely multi-layered ( Fig. 4C, D ). An originally organic composition of the tube walls is also supported by confocal microscopy ( Fig. 25 ), and breaks in the tube wall can be observed showing potential frayed fibre endings ( Fig. 4D ). Figure 4. ‘West Fork Satsop River tubes’, Oligocene, Washington State, USA. A, B, WFSR-3B and WFSR JLG 459C, respectively, tubes in hand specimen showing wavy nature and smooth tube walls. C, D, WFSR 3A-1; C , transverse section of tube showing multilayered brown walls of varying thickness; D , detail of tube wall where a potential preserved fibrous tear occurs, revealing frayed fibre endings (white arrow). Scale bars: A = 10 mm; B = 5 mm; C = 300 µ m; D = 100 µ m. Figure 5. ‘Murdock Creek tubes’, WA-MC LACMIP loc. 6295, Early Oligocene, Washington State, USA. A, a single tube in hand specimen possibly bearing longitudinal wrinkles. B, detail of tube wall in transverse section with thick, multi-layered and delaminated tube wall. C, transverse section of tube which appears to have originally been flexible. D, detail of tube wall where a preserved tear occurs, revealing fibre endings (grey arrow). Scale bars: A = 5 mm; B = 150 µ m; C = 100 µ m; D = 50 µ m. Remarks. These tubes were resolved only within the cladistic analysis that allowed for more homoplasy ( Fig. 23B ), in which they fall among siboglinids. The fibrous organic composition and concentrically multi-layered walls are, however, also consistent with the tubes of chaetopterids, although the smooth walls and sinuosity of these tubes suggest that they are possibly more likely to have been made by siboglinids. We therefore tentatively suggest a siboglinid affinity.