Paul Tasch

A Permian Trace Fossil from the Antarctic Ohio Range

A floodplain siltstone of the Permian Mt. Glossopteris Formation (Mercer Ridge, Ohio Range, Antarctica) contained a new vermiform trace fossil (trail). Cochlichnus antarcticus n. sp. is described and figured. This find establishes a second trace fossil zone that is higher in the formation than the basal invertebrate spoor fossils (trails, burrows) reported by Long.

Conchostracan Trails in Bottom Clay Muds and on Turbid Water Surfaces

The surface of the clay mud at the start of the experiment was free of any trails such as is shown in Plate 1. However, after several days, as the water level lowered, trails were found on the surface of the mud. At the end of, and slightly beyond one trail, the slit of the burrowed clam shrimp appeared at the sediment-water interface. Plate 1 illustrates the only conchostracan trail ever photographed. No mention of such trails occur in the biological or paleontological world literature on conchostracans. Its discovery came as a surprise, since prior to seeing it, the writer had no notion that conchostracans might make trails in bottom sediments.

Trace Fossils from the Permian Polarstar Formation Sentinel Mountains, Antarctica

During austral summer 1966-67, the writer spent several weeks engaged in geological exploration and collection of samples, in the Sentinel Mountain region of Antarctica. The original plan had been to search for ribbed fossil conchostracans (leaiids) in the Glossopteris beds of the Polarstar formation (Craddock et al., 1965). It was thought that, if present, such leaiids would permit correlation with the leaiid zone in the Ohio Range (Doumani and Tasch, 1965; Tasch, 1968). Preliminary and limited sampling, however, did not yield any leaiid or other conchostracan fossils. Bulk sampling that alone could prove conclusive, was found to be impossible without heliocopter support, due to terrain difficulties. Despite this, collections were made in other parts of the Polarstar Formation and at other exposures along the slopes of Polarstar Peak. At least one trace fossil (Cochlichnus) from these collections may have affinities with the species of the same genus found in the Ohio Range (Tasch, 1968). If so, the suspected correlation between the Sentinel Mountain and Ohio Range Permian beds would have this additional piece of evidence in its favor. Since Permian fossils (exclusive of the Glossopteris flora) from the Antarctic, are sparse, and Paleozoic trace fossils from Antarctica, though mentioned, (McElroy et al., 1967; Craddock, see next section; Webb, 1963; Allen, 1962) are rarely described, the present paper is written in an effort to begin to fill this gap. It is also the intention to indicate the potential value of Paleozoic trace fossils for regional correlation in the Antarctic.

A Scolecodont Natural Assemblage from the Kansas Permian

The literature on scolecodont natural assemblages in the fossil record is restricted. Such assemblages have been described by: Hinde (1896), Zebera [1935, 1962 (in Howell)], Eller (1936), Roger (1946), Lange (1947, 1949), Kozlowski (1956), Martinsson (1960), Kielan-Jaworowska (1961, 1962). While reviewing the large Permian scolecodont collections from the Fort Riley limestone of Kansas (Tasch and Stude, 1960; 1964), Stude discovered the natural assemblage that is described in this paper. Tasch had speculated that two Arabellites species in the Fort Riley collections were likely to belong to the same jaw apparatus. This speculation was based on three observations: first, the distance between denticles in both A. falciformis and A. comis followed the dental formula, n.(0.032); second, both of these species have been found together in the Devonian (Stauffer, 1939), Mississippian (Sylvester, 1959), and Permian beds (this paper, and Tasch and Stude, 1964); third, specimens of A. falciformis and A. comis that have been reported are Maxilla I and II respectively. These three observations taken together appeared to denote that the two species were part of a single jaw apparatus and hence, components of one species. Proof of the accuracy of this inference is given in this paper. The assemblage consists of three components: A. falciformis, A. comis, and Eunicites sp. However, other components not available to us may have been associated with this particular jaw assemblage.

Paleoecological Observations of the Wellington Salt (Hutchinson Member)

A study of shales interbedded with and trapped in salt of the Hutchinson member of the Wellington salt, exposed in the Carey mine at Hutchinson, Kansas (Figs. 1 and 2), affords a somewhat different concept than now prevalent of both the Permian evaporating basin involved and the surrounding land. Samples of shales interbedded with and trapped in the salt were collected and studied after dissolving the salt in boiling water, decanting, and examining the remaining residue of mineral content and objects under the binocular microscope.

PerInian Insect Bed Ohio Range, Antarctica

Ohto Range were further trimmed and fragmented. Such fragments reexamined after splintering yielded several insect fossils from a specific horizon described below. The present paper gives some details of microstratigraphy and paleoecology of the new insect horizon and indicates the signiScance of Russian/Asiatic afEnities of Antarctic fossil insects. Further, a brief description of the insect fragments is given by Dr. F. M. Carpenter.

Acetate Peel and Other Biotic Data from Selected Antarctic Permian Beds

Introduction Published data on fossil biotic elements from the Antarctic Paleotoic, particularly the Permian, are most sparse. Additions of any kind, for example, reports on spoor, fragmentary fossils artifacts among others, can help to expand available knowledge. The present study a spin-of3 of a larger research project, supplements previous reports on the same theme (Tasch, 1968a. 19685). Collections during austral summer 1966-67 included samples from fossiliferous and ncyn-fossiliferous l)eds. Of these, samples studied by the acetate peel technique incIuded in this report came from the following localities and beds: Ohio Range beds 0-17, 0^19 (for details see Tasch and Gaffordn 1968; Tasch, 1970); Sentinel Mts.-bed S-14 Whiteout Nunatak near the contact of the Polarstar Formation and the Whiteout Conglomerate. Standard acetate peel techniques were used (Stewart and Taylor, 1965) . In addition to acetate peel stlldies, an object attached to a leaiid conchostracan valve from the Ohio Range Levia Zone (Bed 0-21.8), not previously reported in the literature is figured and described.

MAGNETIC AND NONMAGNETIC FRACTIONS OF BEACH SEDI MENTS (GALAPAGOS IS LANDS) AND THEIR SIGNIFICANCE

Beach sediments collected from five of the Galapagos Islands (Narborough, James, Bartolomew, Tower and Hood} were partitioned by use of the Franz isodynamic magnetic separator into magnetic fraction (MF) and nonmagnetic Of carbonate fraction (NMS). The order of percent MF is given in the island list above (Narborough, greatest; Hood, least). Size distribution (phi units) of both fractions indicated sand-size grade dominant; Narborough being coarsest, and Tower most mature (medium sand). Orange color of sediments on Bartolomew is attributed to sidermelafine and palagonite tuff. The shell traction (NHIF) is chiefly molluscan-echinoderm. Data from the present study fit the paleomagneticlK-Ar dating by Cox (1975) for Narborough (Brunhes -0.6 m.y) and Hood (Matuyama- 2.41 to 0.6 m.y.) The Brunhes age for James and Bartolomew is however, put in question based on percent magnetic fraction and known record of two times of volcanism on each island, suggestive of a Matuyama age for the older event. The comparative greater maturny of Tower Island sediments (island not sampled by Cox), and closeness to Hood in percent MF, suggest an age somewhat older than that of Hood (i.e. older Matuyama). Bimodallty of Tower sediments likewise corresponds

Diversity Index and Informational Concepts

In a recent study of Silurian marine communities of invertebrates, Ziegler, et al., (1968) determined the diversity index using the following relationship: number of species/log of number of individuals. Odum, et al., (1960) and earlier Margalef (1958) noted that when plotted, such curves depict negentropy. Tasch (this issue) used a modified informational approach and found an important qualification of the above interpretation. The present paper delineates the nature of this qualification. Margalefs study determined bits of information residing in communities according to the information equation (and modifications of the same)

Valve Injury and Repair in Living and Fossil Conchostracans

A search of the world literature on living and fossil conchostracans failed to reveal any consideration, illustration, or treatment of valve injury and repair. The writer, while examining living specimens collected by a colleague, observed an example of shell injury and repair in Cyzicus mexicanus (Claus) (Fig. 1). Several additional damaged specimens of living forms were subsequently found. A deliberate search of fossil conchostracan collections from the