Species

Circulichnis montanus Vialov, 1971

Taxon description

Fan, R. et al., 2021

Circular to elliptical ring-like structure. The tunnel is 1–2 mm wide, uniform in a single specimen, and the diameter of the entire structure is 23–45 mm. Short branches tangential to the circular tunnel are present locally.

Uchman & Rattazzi, 2019

Diagnosis. Horizontal, cylindrical burrow, which shows a course along a regular circle or ellipse.

Kim et al., 2003

Remarks: The ichnogenus Circulichnus (the orthography as Circulichnis was addressed by Keighley and Pickerill, 1997).

Buatois et al., 1996

Description Smooth, circular to slightly ellipsoidal traces. Burrow diameter 1.5-9 mm. Circle or ellipse diameter 43-53 mm. Preserved as positive hyporeliefs.

Remarks. Circulichnus is a monospecific facies-crossing ichnogenus that has been recorded not only in deep-marine faciès (e.g., McCann and Pickerill, 1988), but also in shallow-marine (e.g., Fillion and Pickerill, 1984) and nonmarine (Buatois and Mángano, 1993a) deposits. It ranges in age from the Ordovician (Fillion and Pickerill, 1984) to Paleocene (Ksiazkiewicz, 1977).

Buatois et al., 1998c

Circulichnis montanus is a feeding structure (Fodinichnia) probably produced by vermiform animals.

This ichnotaxon has been recorded from deep-marine (e.g.,Pickerill and Keppie, 1981; McCann and Pickerill, 1988; Buatois et al., 1996a), shallow-marine (e.g., Fedonkin, 1988), marginal marine (e.g., Fillion and Pickerill, 1990), and even nonmarine facies (Buatois and Mangano, 1993a). Therefore, Fillionand Pickerill (1984) regarded this form as a eurybathic ichnotaxon.

Pickerill & Fyffe, 1999

Description: Smooth, completely or incompletely preserved, elliptical traces preserved in positive hyporelief on the sole of
a 67 mm-thick slab of tool marked and current lineated mudstone/fine-grained sandstone interlayers. Geometry, orientation and ellipse size are variable, with a maximum (x) axis of 24 mm. Individual traces possess a fill of similar grain size to the lowermost preserving sandstone layer, are unlined, internally structureless and consistently 1.6 mm in observable diameter apart from areas where they have been partially exhumed by current activity. The possible smaller examples have been extensively eroded; as a result they cannot confidently be assigned to this ichnotaxon.

Synonymy list

975 Circulichnis montanus — Häntzschel , pp. W52, fig. fig. 31.4

1971 Circulichnis montanus Vialov, sp. n. — Vialov , pp. 91, fig. 1:1

1979 problematic structure, form of flattened ring — Palij et al. , fig. 63:4

1981 Circulichnis montanus Vialov, 1971 — Pickerill & Keppie , pp. 131, fig. fig.3a–d

1983 Circulichnis montanus Vialov, 1971 — Gureev , pp. 31, fig. fig. on p. 31

1984 Circulichnus montanus Vialov, 1971 — Fillon & Pickerill , pp. 9, fig. 7g

1984 Circulichnis montanus Vialov, 1971 — Pickerill et al. , fig. 5E

1986 Circulichnis montanus Vialov — Gureev , pp. 43, fig. fig. 3e (non fig. 3d)

1988 Circulichnis montanus Vialov, 1971 — MvCann & Pickerill , pp. 334, fig. fig. 3.4

1990 Circulichnis montanus — McCann , pp. 245, fig. 4b

Selection of related publications

Palij, V. M., Posti, E., Fedonkin, M. A. 1979. Soft-bodied Metazoa and trace fossils of Vendian and Lower Cambrian. Upper Precambrian and Cambrian Paleontology of East-European Platform, pp. 49-82. Nauka.

Classification

Organism group	Biota
Ichnofossil group	Ichnofossils
	Bioturbation trace fossils
Genus	Circulichnis
	sinensis
Species	ligusticus
	montanus
	spiralis

References based on distribution

Palij et al., 1979 Kunevich 4 borehole, Leningrad Oblast 328.2 - 0 Kotlin Stage