Geology topics

W.H. Gillespie

Publications and source records attributed to W.H. Gillespie.

4 recordsLinked to original sources

USGS2000

Charbeckia macrophylla gen. et sp. nov. from the Lower Mississippian Price (Pocono) Formation of southeastern West Virginia

A fossil plant discovery from the Price (Pocono) Formation of southeastern West Virginia provides new information on the poorly known compression floras of the Lower Mississippian of North America. The new plant described herein consists of long tapering bipinnate fronds with imbricate basal pinnae, planate apical pinnae, and unlobed, elliptical to obovate pinnules with open dichotomous venation. Veins concentrated in the medial region of the pinnule curve toward the lateral margin, suggestive of an early stage in the evolution of a midrib. Pinnules exhibit a distinctly revolute or otherwise reinforced margin. The exceptional length of some fronds (over 1 m) and pinnule size (some over 3 cm by 2 cm) strongly contrast with the generally diffusely branched fronds and small or highly dissected pinnule morphology that typify Early Mississippian leaf taxa. A new generic assignment, Charbeckia macrophylla , is thereby justified. The rigid appearance of the tapering rachis, the imbricate pinnae that appear to have resisted compression, and the reinforced pinnule margins imply thick evergreen leaves, perhaps adapted for drought tolerance. A possible Calamopityalean affinity is indicated by the size of the fronds and the stout petioles, which fall within the expected size range of the Kalymma -type petiole bases described from the nearby New Albany Shale of Tournaisian age.

Review of Palaeobotany and Palynology↗

USGS1986

Taeniopterid lamina on Phasmatocycas megasporophylls (Cycadales) from the Lower Permian of Kansas, U.S.A.

New specimens of Phasmatocycas and Taeniopteris from the original Lower Permian locality in Kansas demonstrate organic attachment of the two and corroborate Mamay's hypothesis that Phasmatocycas and Taeniopteris were parts of the same plant. These forms also suggest that cycads evolved from taxa with entire leaves; i.e. Taeniopteris, rather than from pteridosperms with compound leaves. ?? 1986.

Review of Palaeobotany and Palynology↗

USGS1985

Significance of the Goniatite Bilinguites eliasi and Associated Biotas, Parkwood Formation and Bangor Limestone, Northwestern Alabama

The Bangor Limestone contains conodonts, smaller calcareous foraminifers, and a sparse marine macrofauna dating it as late or latest Chesterian (Late Mississippian). The Parkwood Formation, a paralic sequence disconformably overlying the Bangor, has yielded a fauna containing the reticuloceratid ammonoid Bilinguites eliasi Manger and Saunders which permits correlation of the Parkwood Formation in north-western Alabama to the upper part of the Prairie Grove Member of the Hale Formation in the type Morrowan sequence. The macrofauna occurring with the ammonoid, supports this correlation. Bilinguites eliasi also alows correlation with the lower part of the Yeadonian Stage (lowest Namurian 'C') of Europe. Florules collected just below and above the goniatite occurrence in Frankling County correlate with those in the lower two-thirds of the New River Formation, southern West Virgina, and with the upper Namurian of western Europe. -from Authors

Journal of Paleontology↗

USGS1981

The earliest seeds

Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

Nature↗