Uchman et al.—New vermetid attachment trace from a Miocene rocky coast
polydioryx Beuck, López Correa, and Freiwald, 2008, and produced by parasitic foraminifers. However, these borings are much smaller than Spirolites n. igen. and occur on skeletal substrates (Spirolites n. igen. occurs on boulders), may display branched canals, which can be extended deeply into the substrate, and have more or less the same width (Beuck et al., 2008). Renichnus Mayoral, 1987 can display some similarities referred to trochospiral shape of the pro- ducing vermetid gastropods, but it is composed basically of crescent depressions arranged in rows (Mayoral, 1987; Taddei Ruggiero, 1999; Jagt, 2003; Hoşgör and Okan, 2010).
Spirolites radwanskii new ichnospecies Figures 2–4, 5.2–5.5, 6.1, 6.3, 6.4
Holotype.—The specimen INGUJ214P/SZG1a is the holotype.
Paratypes and other material.—The specimens in boulders INGUJ214P/SZG1 and INGUJ214P/SZG2 and pebbles INGUJ214P/SZG3 and INGUJ214P/SZG4 are paratypes. Two bored boulders of Jurassic limestones with chert nodules (INGUJ214P/SZG1 contain at least 17 specimens, INGUJ214P/ SZG2 contains at least 10 specimens), two small pebbles (INGUJ214P/SZG3 and INGUJ214P/SZG4) with three speci- mens and two silicone casts of the borings in parts of INGUJ214P/SZG1 and INGUJ214P/SZG2. The particular spe- cimens of Spirolites radwanskii n. igen. n. isp. are indicated by small letters as INGUJ214P/SZG1a–t, INGUJ214P/SZG2a–j, INGUJ214P/SZG3, and INGUJ214P/SZG4a, b.
Diagnosis.—Depression in form of an involute spiral, with perpendicular annulation of the first and second order. It shows an increase in width outward with the spiral and steep margin from the wider side.
Type locality.—Inactive quarry at Zajęcza Góra near Skotniki, central Poland (50°25'49.8"N, 20°48'15.3"E).
Type stratum.—Pińczów Formation (Langhian—equivalent of the lower Badenian in the Paratethys divisions).
Description.—Deep, trochospiral depression (trench), more or less tightly coiled. Its maximum width ranges in different specimens from 2–16mm; usually its depth is slightly larger than wide. The coil is 12–43mm wide. The completeness of coils differs among specimens, from 0.3 whorl in the smallest specimens (Figs. 2, 3.1) to 1.3 whorls in larger specimens (Figs. 3.1, 4.2). The direction of coiling in actual specimens is sinistral. The complete coil is circular to elliptical in outline.Width of the depression (trench) changes gradually along course of the coil. The narrowest (initial or proximal) and the widest (apertural or distal) parts are directed upward and located close to the surface of the substrate. Commonly, the apertural part is more steeply inclined than the initial, narrower part. The middle part of the coil is the deepest part of the boring. Locally, the trench is partly roofed by the substrate (Fig. 2.1, 2.5). The widest part (aper- tural) may surround or cut the initial part in some specimens (Fig. 4.2, 5.2–5.7). Cross section of the depression is in form of a half or incomplete circle (the latter resembles inverted Ω). Margins of the trench are annulated, with distinct, wider, and
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deeper annuli of the first order, 8–12 in number in most of specimens, within which distinct, narrower, and shallower, 5–10 second-order annuli can be present in some specimens. The first-order annulation is more distinct in larger specimens. The first-order annuli are straight or slightly curved, narrow crests (furrows on the casts) that are perpendicular to the trench. Individual annuli of the first order are 1–16mm wide. The segments between annuli are convex outward, and become inwardly narrower. They form a series of wedges dividing the cast perpendicularly. The trench around the bounding furrows is slightly constricted. The last annuli (i.e., those in the distal [apertural] part) are usually distinct and show hemispherical surface. The second-order annuli are straight, indistinct ridges and furrows, <1mm wide. Beside well-preserved specimens, shallower and less crisply preserved specimens of Spirolites are present (e.g., S1g–i in Fig. 4.1). The first-order annuli are poorly visible in them and their surface is slightly corrugated. Morphometric parameters of separate specimens are shown
in Table 1. Spirolites radwanskii n. igen. n. isp. occurs foremost in
patches on the upper surface of large boulders, which are at least 32cm wide and ~30cm high. Isolated specimens of Spirolites are more rare. Some specimens touch each other, or the less- distinct, shallower specimens are slightly truncated by deeper, sharply defined specimens (Fig. 2.5). The associated Gastro- chaenolites cross cuts some specimens of Spirolites n. igen. on the edge of the coil or in the middle (Figs. 3.2, 4.1).
Etymology.—To honor Professor Andrzej Radwański (1935– 2016), who studied borings of the Polish Miocene for several years and brought them to international attention through his seminal publications.
Remarks.—Spirolites n. igen. falls into the category “Spiral Borings” of Buatois et al. (2017). The smallest specimen of Spirolites n. igen., intermediate, and large ones (Fig. 4.1) are considered as a series related to ontogenetic development of the trace maker. Apart from size differences, the development is expressed by increasing completeness of coils. The less-distinct, shallower specimens represent earlier stages of colonization of the substrate.
Ichnogenus Gastrochaenolites Leymerie, 1842
Gastrochaenolites torpedo Kelly and Bromley, 1984 Figures 2, 3.2, 6.1, 6.2
Description.—Date-shaped boring, 15–30mm long, with smooth surface. The main chamber is 8–12mm wide. The neck is absent, aperture is 6–10mm wide. Both the basal and aper- tural parts are rounded to oval in transverse section. In some specimens, a cast commissure is visible as a straight, long- itudinal shallow furrow.
Remarks.—According to Radwański (1964, 1969), this boring was formed by Lithophaga, but Gastrochaena also can be a producer of this ichnospecies (Kelly and Bromley, 1984).
Gastrochaenolites lapidicus Kelly and Bromley, 1984 Figures 3.1, 6.2
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