liik

Planolites beverleyensis (Billings, 1862)

Taksoni kirjeldused

Stachacz, 2012b

Diagnosis. Relatively large, unlined, smooth, horizontal to undulant, straight to sinuous, cylindrical burrows. The filling typically
differs in colour from the surround ing sediment (Frey and Bromley, 1985).

Hofmann et al., 2012

Description.—Subcylindrical to cylindrical, horizontal vermiform structures with irregularly constricted surface, predominantly preserved as positive epirelief and hyporelief (Fig. 7.7). Width is 1 to 4 mm. Course is irregular, gently curved, or arcuate. Overlap among specimens is common. Fill is coarser-grained than the host rock.

Remarks.—The constrictions clearly point to an active infill. Deposit feeding was mostly constrained to an interfacial sand-mud boundary. Planolites beverleyensis differs from Planolites montanus in its curved to arcuate courses and more penetrative nature (Pemberton and Frey, 1982)

Mikuláš et al., 2013

Straight, moderately to conspicuously curved, smooth, exceptionally branching tunnels of circular outline, parallel to oblique to the bedding, preserved as full reliefs or convex hyporeliefs. Diameter of tunnels ranges usually from 2 to 6 mm; length of preserved sections may reach few decimetres. Tunnels present on one bed or bedding plane show usually a constant diameter.

Pemberton & Frey, 1982

Predominantly cylindrical, smooth-walled, rarely toirregulerly branched or unbranched burrows, typically oriented more or less parallel with bedding. Some specimens are terete, and may exhibit slight distentions; most are cylindrical and straight toarcuate over appreciable lenghts. Rare specimens display discontinuous, poorly developed annulations. Occurenses range from single, isolated specimens to crowded masses in which crossowers, interpenetrations, and reburrowed segments are commen. Burrow density and substrate characteristics may modify burrow configurations. Preserved as endichna, hypichnal ridges, and epichnal grooves.

Orłowski & Źylińska, 1996

Burrows cylindrical to flattened, with smooth walls, straight to slightly curved, very regular with insignificant variations in shape or diameter. They occur either isolated or densely cover bedding surfaces, overlapping each other. Their diameter ranges from 4 to 8 mm, length reaches up to 9 cm. Sometimes they occur within the sandstone bed being infilled with clay and differing in colour from the host rock; occasionally they remain empty. Convex epireliefs.

Sünonüümika
1861     Palaeophycus congregatus — Billings , lk. 3
1862     Palaeophycus beverleyensis — Billings , lk. 97, joon. text fig. 86
1975     Planolites beverleyensis (Billings, 1862) — Alpert , lk. 513
1975     non Planolites beverleyensis (Billings, 1862) — Alpert , lk. 517, joon. 1:15; 3:1,7,8
1982     Planolites beverleyensis (Billings, 1862) — Pemberton & Frey , lk. 866, joon. 1:7; 2:5,8,9; 3:1,2,7,8; 5:1,2
1984     Planolites beverleyensis (Billings, 1862) — Pickerill et al. , lk. 266, joon. 6c
1985     Planolites beverleyensis (Billings, 1862) — Frey & Howard , lk. 384, joon. 5.7, 10.11; 15; 16.9; 17
1985     Planolites beverleyensis — Crimes & Anderson , lk. 332, joon. 12.1
1985     Planolites beverleyensis (Billings, 1862) — Crimes & Anderson , lk. 331, joon. 12.1
1985     Planolites beverleyensis (Billings, 1862) — Frey & Bromley , lk. 811, joon. 13B
Valik taksonit käsitlevast teaduskirjandusest
Mikuláš, R., Meškis, S., Ivanov, A., Lukševičs, E., Zupinš, I., Stinkulis, G. 2013. A rich ichnofossil assemblage from the Frasnian (Upper Devonian) deposits at Andoma Hill, Onega Lake, Russia. Bulletin of Geosciences 88, 2, 389-400. DOI:10.3140/bull.geosci.1358
Landing, E., Peng, S., Babcock, L. E., Geyer, G., Moczydlowska-Vidal, M. 2007. Global standard names for the Lowermost Cambrian Series and Stage. Episodes 30, 4, 287-289. DOI:10.18814/epiiugs/2007/v30i4/004
Orłowski, S., Żylińska, A. 1996. Non-arthropod burrows from the Middle and Late Cambrian of the Holy Cross Mountains, Poland. Acta Palaeontologica Polonica 41, 4, 385-409.
Clausen, C. K., Vilhjálmsson, M. 1986. Substrate control of lower Cambrian trace fossils from Bornholm, Denmark. Palaeogeography, Palaeoclimatology, Palaeoecology 56, 1-2, 51-68. Elsevier BV. DOI:10.1016/0031-0182(86)90107-0
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