A Guide to Pennsylvanian (Carboniferous) Age Plant Fossils of Southwest Virginia

A Guide to Pennsylvanian (Carboniferous) Age Plant Fossils of Southwest Virginia

by Thomas F. McLoughlin

Product Details

ISBN-13: 9781490775036
Publisher: Trafford Publishing
Publication date: 11/11/2016
Pages: 142
Sales rank: 690,874
Product dimensions: 8.50(w) x 11.00(h) x 0.39(d)

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A Guide to Pennsylvanian (Carboniferous) Age Plant Fossils of Southwest Virginia

By Thomas F. McLoughlin

Trafford Publishing

Copyright © 2016 Thomas F. McLoughlin
All rights reserved.
ISBN: 978-1-4907-7503-6

CHAPTER 1

ABORESCENT LYCOPODS (CLUB MOSSES, SCALE TREES)

Lepidodendron


Lepidodendron---- This plant is some times referred to as a "scale tree" because of the distinctive tear drop or diamond shape pattern of the bark of this lycopod. It is often mistaken as the scales of a reptile or snake's skin. Each scale-like feature is accented by a small depression that looks like an eye. The modern relative of this plant is the "ground pine", "running cedar" and "club moss" or Lycopodium (Figure 4a). As a result Lepidodendron has been described as a giant "club moss". Note, neither Lepidodendron or Lycopoium are a pine, a cedar or a moss. The scar morphology of the branches appears as a miniature version of scars found the main stem. They appear as oval shaped depressions that can be from one to two inches in size. Others appear as nearly circular dome shaped features recessed into the bark. There are referred to as Ulodendron (See Plate I-Ulodendron). It is also thought by some scientist that these shallow tear drop shaped features may represent the points of attachment of reproductive cones or pods. These plants generally stood as much as 98 feet and where common during the Carboniferous.

Ground Pine and Club Moss are the common names for a small terrestrial evergreen that looks like a miniature pine tree with small scaly leaves that grows in patches (See Figure 4). The genus Lycpodium and other members of the Lycophyta (club mosses) have their origins in the Carboniferous as giant trees (e.g. Lepidodendron) (Figure 4).

Before the anatomy of Lepidodendron (i.e. microscopic examination of the tissue cells) was understood, generic names for the plant stems were based on the various appearances of the same plant form resulting from preservation at different stages of decortications, or states of decay. The generic terms which included Knorria, Bergeria, and Aspidiaria have been retained for descriptive purposes only (Figure 5). These forms of stem casts are more fully discussed by Seward, (1898). Two (2) of these are illustrated in Plate I (Lepidodendron numbers 2,3, and 4).

Species of Lepidodendron are based on the pattern and morphology of the leaf cushions on the surface (bark). Sigillaria and Lepidodendron are differentiated by the arrangement of the leaf cushions and scars. Silliaria leaves were formed in vertical columns in contrast to Lepidodendron, which were spirally disbursed along the stems. The distinguishing feature of a well preserved leaf-cushion of the genus Lepidodendron is a rhomboidal or fusiform cushion that is elongated longitudinally, somewhat reminiscent of scales found on fish and reptiles. Thus, the term "scale tree" has been associated with Lepidodendron. The leaf-scar or place of attachment of the base of the leaf is in turn a clearly defined smooth area located in the middle portion of the leaf-cushion. The anatomical characteristics for naming Lepidodendron species are presented in Plate II (Lepidodendron) numbers 1, 6 and 6a and Plate III (Lepidodendron) numbers 2a and 3a.

Not all of the species of Lepediodendron have been found in the southwestern Virginia coalfields as of the date of this publication. However, all coal seam horizons in Virginia have not been visited. Future studies may unearth additional forms of Lepidodendron, as well as other Paleozoic flora.

Plate I-- 1. Lepidodendron acuieatum preserved in sandstone. Collected from the strata directly overlying the Kennedy coal seam along Alt. State Route 58 North approximately 1.5 miles East of Coeburn, Wise County, Virginia.

2. Lepidodendron veltheimianum in the Aspidiaria stage of decortication preserved in shale.

3. Lepidodendron veltheimianum Aspidiaria stage. 4. Collected from the roof strata of a mine in the Parsons coal seam along Mud Lick Creek North of Roda, Wise County, Virginia.

4. Lepidodendron veltheimianum in the Knorria stage of decortication preserved in shale. Specimen collected from coal mine roof rock of the Parsons coal seam near Roda, Wise County, Virginia on Mud Lick Creek. Collected from the roof strata of a mine in the Upper Banner coal seam near Bucu, Dickenson County, Virginia.

5. Lepidodendron veltheimianum preserved in shale. Collected from the roof strata of a mine in the Lower Banner/Splashdam coal seam(s) northwest of Coeburn, Wise County, Virginia.

6a. Lepidodendron obovatum preserved in shale. Collected from the roof strata of a mine in the Taggart Marker coal seam Stonega, Wise County, Virginia

7. Lepidodendron halonia. 7a Reverse side. Collected from the roof strata of a mine in the Parsons coal seam along Mud Lick Creek North of Roda, Wise County, Virginia.


Plate II--1. Bothrodendron cf. B. punctatum inside blue box. 1a. Enlarged view of morphology below outer layer of area enclosed by the red box. Collected from the roof strata in the Parsons coal seam along Mud Lick Creek North of Roda, Wise County, Virginia.

2. Lepidodendron obovatum. Enlarged view of surface morphology. Collected from the roof strata in a mine in the Splashdam coal seam along Abners Fork (St. Rt. 670) near Hurley Shortt Gap, Buchanan County, Virginia.

3. Lepidodendron obovatum. 3a. Enlarged view of surface morphology. Collected from the roof strata in a mine in the Tiller coal seam West of St. Rt. 460 North near Shortt Gap, Buchanan County, Virginia.

4. Lepidodendron obovatum . 4a. Enlarged view of surface morphology. Collected from the roof strata in a mine in the Pocahontas No. 3 coal seam at the head of Cucumber Creek, 7.7 miles northeast of Squire, McDowell County, West Virginia. Plate III — 1, 1a, 1b. Lepidodendron obovatum in a gray clay shale. Collected from an outcrop of the Upper Banner coal seam in a road cut located along I-80 North near Hasysi, Dickenson County, Virginia.

2. Lepidodendron aculeatum in a medium grained sandstone enlarged view of surface morphology. Collected from above the Aily coal seam approximately 50 feet right off the West bound lane of Alt. St. Route 58 1.5 miles from Coeburn Wise Virginia


Plate I---- 1. Ulodendron preserved in shale displaying two well defined branch scars. 1a. Enlarged portion of branch scar displaying the attachment point of the structure which is believed to have delivered nutrients to the branch. 1b. A portion of outer layer greatly magnified to illustrate the characteristic honeycomb-like pattern. Specimen collected from the roof rocks in a mine developed in the Taggart coal seam Appalachia, Wise County, Virginia. 2. The shale mold of an Ulodendron branch scar.

Plate I---- Lepidodendron and Sigillaria Reproductive organs--- 1. Lepidophlois sp in shale. Collected from immediately above the Blair coal seam? In the Wise Formation along Alternate State Rt. 58 approximately 0.5 miles from the Appalachia High School, Appalachia, Wise County, Virginia.

2. Lepidophyiiumsp. in shale. Collected from the roof strata of the Parsons coal seam along Mud Lick Creek 2.4 miles northeast of Roda, Wise County, Virginia.

3. Lepidostrobussp in shale. Collected from the roof strata of a mine in the Lowsplint coal seam located 2.4 miles North of Stonega on Stonega Road, State Rt. 78, Wise County, Virginia.

4. A pair of Lepidostrobus sp. in shale. Collected from the roof strata of the Parsons coal seam along Mud Lick Creek 2.4 miles northeast of Roda, Wise County, Virginia.

5. Lepidostrobus sp. cast. 6. Lepidostrobus sp. mold. Both preserved in shale. Collected from the roof strata of a mine in the Splashdam coal seam located along Smith Branch (State Rt. 701) 0.7 miles north off Slate Creek (State Rt. 83), 8 miles East of Grundy, Buchanan County, Virginia.

7. Sigillariastrobus Schimper Feistmante in shale. Reproductive cone of Sigillaria. Unlike those of Lepidodendron Sigiiariastrobus grew in clusters and were attached farther back on the branches and not the very tips. Collected from the roof strata of a mine in the Lowsplint coal seam 2.4 miles North of Stonega on Stonega Road (State Rt. 78), Wise County, Virginia.


Plate I---- Lepidodendron Branches — 1. Dicranophyllum Domini preserved in shale. Collected from the roof strata of a mine in the Splashdam coal seam located along Abners Fork (State Rt. 670) southeast off State Rt. 645 near Hurley, Buchanan County, Virginia.

2, 2a. Dicranophyllum sp. preserved in shale. The grass like foliage is still attached to the tree branch. 3,3b. Lepidodendron Sternbergii . The arrows point to the leaf scars (green) and the linear leaves (dashed red). 3a. Drawing of leave cushions with linear leaves attached after Seward, A.C., 1898, Vol II, figure 141, p. 97. Collected from the roof strata of a mine in the Lowsplint coal seam located 2.4 miles North of Stonega on Stonega Road, State Rt. 78, Wise County, Virginia.

4,5. Lepidophylloides preserved in carbonaceous shale. Red arrows point to the leaves attached to the stems (branches). These specimens illustrate the basis for referring to Leidodendron as the "Scale" tree. Specimens collected from roof strata of a mine in the Parsons coal seam located along Mud Lick Creek 2.4 miles northeast of Roda, Wise County, Virginia


Plate I--- Lepidodendron Foliage --- 1. Lepidodendron cf wortheni in a sandy shale. Collected from a outcrop of the Blair coal seam? In the Wise Formation along Alternate Rt. 58 approximately 0.5 miles East of the Appalachia High School, Appalachia, Wise County, Virginia

2. Lepidophylloides sp. in siltstone. Collected from the roof strata of a mine in the Splashdam coal seam located along Abners Fork (State Rt. 670) southeast off State Rt. 645 near Hurley, Buchanan County, Virginia.

3,3a. Lepidophylloides in shale. 4. Lepidophylloides in shale. Collected from the roof strata of a mine in the Parsons coal seam located along Mud Lick Creek 2.4 miles North of Roda, Wise County, Virginia.


Plate II--- Lepidodendron Foliage --- 1, 1b. Lepidodendron twigs with attached Lepidophylloides in shale.1a Modern club moss branch for comparison. Collected from the roof strata of a mine in the Splashdam coal seam located along Abners Fork (State Rt. 670) southeast off State Rt. 645 near Hurley, Buchanan County, Virginia.

2. Lepidostrobophyllum lancifolius Lesquereux, 1870. 3. Lepidostrobophyllum lanceolatus Lindley and Hutton, 1831. Specimens collected from the Kennedy coal seam in an outcrop of a road cut located 0.1 mile East of the Jct. Alt. Rt. 58 and Boaright Hollow Road Coeburn, Wise County, Virginia

CHAPTER 2

ABORESCENT LYCOPODS (CLUB MOSSES)

Sigillarla


Another Clubmoss tree, Sigillaria (Figure 6), along with its relative Lepidodendron were among the most common and most wide spread floras of Europe and North America. Both clubmosses genera belong to lycopods. These trees dominated the Carboniferous up to the Middle-Late Pennsylvanian boundary. Progressively smaller forms existed through the Mesozoic with the last surviving member of the group is considered to be the modern quillwort (Isoetes).

Sigillaria and Lepidodendron are differentiated by the pattern and morphology of the leaf cushions and scars. The circular scars of Sigillaria are arranged in vertical columns in contrast to Lepidodendron, which were spirally disbursed along the stems.

The leaves of Sigillaria were long and grass-like forming circular scars/cushions as they were shed. The scars are arranged in vertical columns. Many species are identified on the basis of the shapes of the scars and the patterns of the scars. The impression of the bark of this plant is identified by broad linear ridges which are much wider than that of Caiamites and there is no segmentation. The ridges vary in design from plain to ornamented with tiny circular depressions resembling a "bulls- eye". Its leaves and roots are very similar to Lepidodendron, but lacks the scale- pattern on the trunk.

Like Lepidodendron it grew about 100 feet in height. This is truly remarkable considering the trunk of the tree consisted mostly of a spongy, weak tissue encased by a thin layer of a vesicular skin or woody bark.


Plate I--- Sigillaria--- 1. Sigillaria rugosa Brongn. 1a. Enlarged view showing the detail of the outer surface morphology. Specimen preserved in shale and was collected from a coal mine in the Lowsplint coal seam 2.4 miles North of Stonega on Stonage Road (State Rt. 78), Wise County, Virginia.

2. Sigillaria, Mesolobus depressus Stevens. 3. Sigillaria sp. 4. Sigillaria mammilaris showing the original outer surface (bark) and the underlying traces of the vascular bundles (parichnos) revealed as a result of decortication. These are the sites of foliage attachment (leaf scars) which are retained as the plant grew and dropped its leaves. 2 and 3 are preserved in carbonaceous shale and 4 in dark gray shale. Specimens collected from a coal mine in the Parson coal seam along Mud Lick Creek 2.4 miles northeast of Roda, Wise County, Virginia

5. Asolanus comptotaenia Wood. Possibly a decorticated Sigillaria brardii. Collected from the roof strata of a coal mine in the Splashdam coal seam located off State Rt. 610 near Conaway, Buchanan County, Virginia.

Plate II --- 1. Sigillaria sp. preserved in fine grained sandstone. Collected from the seatrock immediately below the Hagy coal seam at an underground coal mine located along Grant Branch Road off State Rt. 619 (Leemaster Drive) southwest of Vansant, Buchanan County, Virginia.

2. Sigillaria boblayi. 2a. Sigillaria elegans. This is the riverside of Sigillaria 2. These are examples of the Subgenus Eusigillaria, group Favularia. The specimen, preserved in a dark gray shale was collected from the roof strata of a coal mine in the Pocahontas No. 3 coal seam along Dog Fork Creek 4 miles northeast of Cucumber, McDowell County near the Virginia and West Virginia state line.

Plate III --- 1., 1a Sigillaria sp. preserved in medium grained sandstone. Collected above the Aily coal seam approximately 50 feet right off the West bound lane of Alt. State Route 58 1.5 miles from Coeburn, Wise County, Virginia.

CHAPTER 3

CORDAITES: EARLY GYMNOSPERMS

Ancient Mangrove-Like Plant


The Cordaites were trees that reproduced from seeds and spores borne by cone- like s tructures considered by some to be an "early conifer" or gymnosperm (Figure 7). They first appeared in the Upper Mississippian then disappeared after the Triassic period. There are no extant descendants of cordaites. Initially the name Cordaites was applied only to the narrow, strap like compression leaf remains but has come to be applied to the entire plant. It is believed that one variety of the plant lived on dry land growing to heights of as much as 98 feet. While the shrub- like counter part lived in marine to brackish water conditions on stilt-like root systems much like the modern Mangrove (Figure 7). Specimens of Cordaites have only been found at three (3) stratagraphic horizons in the study area.


Plate I - Cordaites — 1. Cordaites stem in transition between the stages of decortication: Artisia horizontalis with pronounced longitudinal ribs (pith cast) and Artisia transversa with wrinkled surface. 1a and 1b. Enlarged views of specimen

1c. Artisia horizontalis cast 1d. Artisia horizontalis mold. 2. Artisia transversa. Note the thin surface layer of bark which has been carbonized. Collected from the Norton Formation immediately above an "Unnamed Coal Seam" on West Alt. State Rt. 58 along the railroad tracks in Appalachia, Wise County, Virginia

Plate I - Cordaites Foliage. 1. Cordaites borassifolius preserved carbonaceous in shale. 1a. Enlarged view of specimen 1 revealing the detail of the outer surface morphology. Several Cordaites borassifolius superimposed on each other in shale. 2a. Enlarged view of 2 showing detail of morphology. All specimens collected from the Upper Banner coal seam near Bucu, Dickenson County, Virginia.


(Continues...)
Excerpted from A Guide to Pennsylvanian (Carboniferous) Age Plant Fossils of Southwest Virginia by Thomas F. McLoughlin. Copyright © 2016 Thomas F. McLoughlin. Excerpted by permission of Trafford Publishing.
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Table of Contents

Contents

ACKNOWLEDGEMENT, iii,
FOREWORD, v,
INTRODUCTION, vii,
COLLECTING PLANT FOSSILS, xi,
CHAPTER 1 ABORESCENT LYCOPODS (CLUB MOSSES, SCALE TREES) Lepidodendron, 1,
CHAPTER 2 ABORESCENT LYCOPODS (CLUB MOSSES) Sigillaria, 6,
CHAPTER 3 CORDAITES: EARLY GYMNOSPERMS Ancient Mangrove-Like Plant, 22,
CHAPTER 4 KETTLEBOTTOMS Ancient Tree Trunks, 28,
CHAPTER 5 STIGMARIA Ancient Root Systems, 32,
CHAPTER 6 CALAMITES Ancient Relative of the "Horsetall", 38,
CHAPTER 7 SPHENOPHYLLUM, 62,
CHAPTER 8 FERNS, 67,
CHAPTER 9 SEEDS, 111,
CHAPTER 10 MARINE FOSSIL FAUNA FOUND WITH PLANT FOSSIL FLORA, 115,
REFERENCES:, 121,
APPENDIX A, 123,

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