BERGAUERIA PRANTL (CAMBRIAN AND ORDOVICIAN), A PROBABLE ACTINIAN TRACE FOSSIL STEPHEN P. ALPERT Reprinted from JOURNAL OF PALEONTOLOGY Vol. 47, No. 5, September 1973 pp. 919-924 Made in United States of America JOURNAL OF PALEONTOLOGY, V. 47, NO. 5, P. 919-924, 1 PL., 3 TEXT-FIGS., SEPTEMBER 1973 BERGAUERIA PRANTL (CAMBRIAN AND ORDOVICIAN), A PROBABLE ACTINIAN TRACE FOSSIL STEPHEN P. ALPERT Department of Geology, University of California, Los Angeles ABSTRACT—New discoveries of Bergaueria Prantl, 1945, are reported from the Lower Cambrian Harkless and Poleta Formations of the White-Inyo Mountains and the Latham Shale of the Marble Mountains of California. A new species, Bergaueria radiata, is de- scribed from Cambrian rocks of Nevada and Lower Cambrian rocks of California. Burrows of Bergaueria have previously been reported from Cambrian and Ordovician rocks of Europe and North America. These trace fossils are probably casts of actinian (sea anemone) dwelling burrows. The genus is related to Conostichus, a trace fossil from the Pennsylvanian of the United States. INTRODUCTION place. As the bodies in the burrows decom- HE genus Bergaueria Prantl, 1945, was pro- posed, sand from the bed above slumped into T posed for cylindrical protuberances on the the burrows, leading to the formation of casts underside of Ordovician sandstone beds of on the bottom of the sandy bed (Prantl, 1946; central Bohemia (Prantl, 1945, 1946). These Radwanski and Roniewicz, 1963; Arai and Mc- structures were interpreted as casts of burrows Gugan, 1968). Evidence for this interpretation made by sedentary organisms, probably analo- is the slump structures that occur in the sandy • gous to the living anthozoans Cerianthus or laminae both within and above the burrow Edwardsia. Subsequent workers, describing- casts (PI. 1, fig. 9; Arai and McGugan, 1968, new specimens of Bergaueria or reviewing PI. 36, figs. 5, 8, 11). the genus, agree with Prantl's interpretation The casts are characterized by a cylindrical that the structures were made by coelenterates, shape with a flat to hemispherical base having owing to the radial symmetry, (Lessertisseur, a central indentation, radial ridges, and con- 1955), or, more specifically, by anthozoans centric impressions. Some are preserved as (Hantzschel, 1958; Howell and Hutchinson, hemispherical projections on the lower surface 1958), and most probably by actinians (Seil- of sandy beds. Known specimens of Bergaueria acher, 1956; Hantzschel, 1962, 1965; Rad- range between 15 and 45 mm in diameter, with wanski and Roniewicz, 1963; Arai and Mc- the length equal to or less than the diameter. Gugan, 1968). In comparison with the bur- Specimens occur singly and in clusters or rows made by living anthozoans (Frey, 1970), colonies. the fossils are similar to actinian burrows, and unlike the deep, vertical, cerianthid dwelling OCCURRENCES OF BERGAUERIA tubes. Specimens of Bergaueria have been found A possible body fossil of an actinian (Mac- in Lower Cambrian to Middle Ordovician rocks kenzia) is known from the Middle Cambrian of Europe and North America. Bergaueria Burgess Shale (Wells and Hill, 1956). Thus, perata Prantl has been described, reported, or the Lower Cambrian specimens of Bergaueria illustrated from the Middle Ordovician (Upper represent the earliest known occurrence of sea Llandeilian) of central Bohemia (Prantl, 1945, anemones in the fossil record. 1946), the Middle Cambrian of the Grand Bergaueria represents a permanent or semi- Canyon (McKee, 1945, PI. 8, fig. d; Seilacher, permanent dwelling burrow (Domichnia) of 1956), the lower Paleozoic of the State of a soft-bodied organism, by Seilacher's (1964) Washington (Howell and Hutchinson, 1958, ethological classification of trace fossils (for as B. magna), the Upper Cambrian of the a summary of the various classifications of Holy Cross Mountains in Poland, and the trace fossils, and other concepts in palichnology, Lower Cambrian of northern Spain (Rad- see Osgood, 1970, or Frey, 1971). Relatively wanski and Roniewicz, 1963), the Lower Cam- * rapid influx of sand on a normally quiet muddy brian of Alberta and western Newfoundland bottom in which the anemones lived probably (Arai and McGugan, 1968), and the Lower caused burial and death of the organisms in Ordovician (Lower Arenigian) rocks of Wales 919 920 STEPHEN P. ALPERT o > WmM—Paedeumias, Bonnia,Salterelia FE^R'".:; „J r NEVADA mm: )Bergauena Archaeocyathids Rusophycus, Cruziana -o WEST6ARD PASS •Archaeocyathids zrSkolifhos o ANDREWS MTN \Bergaueria? ' i i i ll II ^FromnnUniFremontia, PPaedeumias Fremontia, Ofeneiius —Nevadetia, Olenelfus, N . Heiicoplacus I NVrchaeocyathids yp ANGELES —Eocystites TEXT-FIG. 1—Map of California and Nevada. Berganeria has been found near Goldfield, West- gard Pass, Andrews Mountain, and Cadiz. (Crimes, 1970). Bergaueria sp. has been de- TEXT-FIG. 2—Columnar section of the Poleta For- scribed from Cambrian rocks near Goldfield, mation and lower half of the Harkless Formation, Nevada (Arai and McGugan, 1969). Lower Cambrian, White-Inyo Mountains, Cali- Bergaueria is reported here, for the first fornia (Expanded from Nelson and Durham, time, from the Lower Cambrian of the White- 1966, fig. 1). Inyo Mountains and Marble Mountains of California. The White-Inyo Mountains locali- Bergaueria has been included as a representa- ties are about 60 miles southwest of the Gold- tive member of the Cruziana or Skolithos trace field, Nevada area (Text-fig. 1). fossil assemblages (Crimes, 1970), both charac- In the White-Inyo Mountains, Bergaueria teristic of shallow waters. The Bergaueria of occurs in green shale, siltstone, and quartzite the Harkless Formation occurs in the same of the lower part of the Harkless Formation (Text-fig. 2) at several localities near the stratigraphic interval as trilobite traces (Ruso- Westgard Pass area in the Blanco Mountain phycus and Cruziana), but only rarely do they quadrangle, and also at a locality near An- occur adjacent to each other (PI. 1, fig. 11). drews Mountain in the Waucoba Mountain The questionable Bergaueria found in the quadrangle. Two poorly preserved hemi- Poleta Formation occurs in a quartzite unit spherical structures resembling Bergaueria (PI. that contains abundant Skolithos. The only 1, fig. 14) were found in the upper Poleta other trace fossils that are now known to occur Formation below the Harkless Formation near with Bergaueria on the underside of beds are Westgard Pass. The specimens measure 40 X Diplocraterion (Radwanski and Roniewicz, 47 mm across the base of the hemisphere, and 1963, PL 9, fig. 1), and among Harkless speci- are 16 mm high. All specimens collected were mens, small (1 to 5 mm wide), smooth, un- found as float on the outcrops, and most are branched burrows parallel to the bedding, poorly preserved. which are referrable to Planolites (PL 1, fig. In the Poleta and Harkless Formations, 10). Diplocraterion and Bergaueria are adja- Bergaueria is associated with other trace fos- cent on one of the Goldfield, Nevada speci- sils that suggest a shallow water environment. mens. TRACE FOSSIL BERGAUERIA 921 No trilobites are known to occur in the vironments (Bhargava, 1972), but their chances beds containing Bergaueria in the Poleta and of preservation are slim (Cameron and Estes, Harkless Formations. However, the occur- 1971). % rences of trilobites lower in the Poleta Forma- tion (Fremontia, Olenellus, Paedeumias) and SYSTEMATIC PALEONTOLOGY higher in the Harkless Formation (Paedeumias, Variation within the species of Bergaueria Bonnia) (Text-fig. 2) indicate that Bergaueria is due primarily to the final state of contraction is within the Bonnia-Olenellus Zone in the or dilation of muscles of the aboral end of the White-Inyo Mountains (Nelson and Durham, organism, which resulted in differences in the 1966; Fritz, 1972). pattern of radial and concentric impressions The specimen of Bergaueria from the Marble on the bottom of the burrow and subsequent Mountains (PI. 1, fig. 3) was collected along cast (Arai and McGugan, 1969), and second- with trilobites and trace fossils from the Lower arily to the mode and state of preservation. Cambrian Latham Shale, by Takeo Susuki. Commonly the lower ends of specimens of Bergaueria are poorly preserved, partially or COMPARISON WITH CONOSTICHUS completely broken off, or highly weathered, The trace fossil most closely similar to such that most or all of the details of the Bergaueria is Conostichus Lesquereux (PI. 1, central depression, radial ridges, and concentric figs. 12, 13), from Pennsylvanian rocks of the impressions are missing. United States, also believed to be the casts of actinian burrows (Chamberlain, 1971). Cono- Genus BERGAUERIA Prantl, 1945 stichus differs from Bergaueria in that Cono- Bergaueria Prantl, 1945; 1946, p. 50-52; Lesser- stichus is larger (average size about 65 mm tisseur, 1955, p. 68-69; Seilacher, 1956, p. 164, in height and 45 mm in diameter), more conical 165; Hantzschel, 1958, p. 85; 1962, p. W186; 1965, p. 15; Arai and McGugan, 1968, p. 205- than cylindrical or hemispherical in shape, and 209; 1969, p. 93-94. possesses more sculpturing (Branson, 1959, "Natural casts of small circular depressions," Mc- 1960, 1961, 1962; Chamberlain, 1971). Kee, 1945, PI. 8, fig. d. A recent experiment by Shinn (1968) demon- Type species.—Bergaueria perata Prantl, strated the burrowing activity of a living cone- 1945; 1946, p. 52-53, PI. 1, text-figures 1, 2. shaped anemone, and its ability to migrate Description.—Cylindrical to hemispherical upward through sediment after