ILLINOIS GEOLOGICAL SURVEY U8RARY G&v ^/f STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION An Early Pennsylvanian Flora with Megalopteris and Noeggerathiales from West-Central Illinois Richard L Leary Hermann W. Pfefferkorn Prepared in cooperation with the Illinois State Museum, Springfield ILLINOIS STATE Jack A. Simon, Chief CIRCULAR 500 GEOLOGICAL SURVEY Urbana, IL 51801 1977 Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/earlypennsylvani500lear ILLINOIS GEOLOGICAL SURVEY U8RARY An Early Pennsylvanian Flora with Megalopteris and Noeggerathiales from West-Central Illinois Richard L. Leary and Hermann W. Pfefferkorn AN EARLY PENNSYLVANIAN FLORA WITH MEGALOPTERIS AND NOEGGERATHIALES FROM WEST-CENTRAL ILLINOIS Richard L. Leary1 and Hermann W. Pfefferkorn2 ABSTRACT The Spencer Farm Flora is a compression- impression flora of early Pennsylvanian age (Namurian B, or possibly Namurian C) from Brown County, west-central Illinois. The plant fossils occur in argillaceous siltstones and sand- stones of the Caseyville Formation that were deposited in a ravine eroded in Mississippian carbonate rocks. The plant-bearing beds are the oldest deposits of Pennsylva- nian age yet discovered in Illinois. They were formed be- fore extensive Pennsylvanian coal swamps developed. The flora consists of 29 species and a few prob- lematical forms. It represents an unusual biofacies, in which the generally rare genera Megalopteris , Lesleya, Palaeopteridium, and Lacoea are quite common. Noegger- athiales, which are seldom present in roof- shale floras, make up over 20 percent of the specimens. The Spencer Farm Flora is an extrabasinal (= "upland") flora that was grow- ing on the calcareous soils in the vicinity of the ravine in which they were deposited. It is suggested here that the Noeggerathiales may belong to the Progymnosperms and that Noeggerathialian cones might be derived from Archaeopteris-like fructifica- tions. The cone genus Lacoea is intermediate between Noeggerathiostrobus and Discinites in its morphology. Two new species, Lesleya cheimarosa and Rhodeop- teridium phillipsii , are described, and Gulpenia limbur- gensis is reported from North America for the first time. INTRODUCTION The Spencer Farm Flora (table l) differs from other Pennsylvanian floras of the Illinois Basin. Many genera and species in the Spencer Farm Flora either have not been found elsewhere in the basin or are very •'-Curator of Geology, Illinois State Museum, Springfield. 2Formerly of Illinois State Geological Survey; presently at Department of Geology, University of Pennsylvania, Philadelphia. - 1 - ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 TABLE 1— SPECIES FOUND IN THE SPENCER FARM FLORA IN BROWN COUNTY, ILLINOIS LYCOPSIDS SPHENOPSIDS FERNS NOEGGERATHIALES PTERIDOSPERMS CORDAITALES PROBLKMATICA Page 6 Lepidodendron wortheni Annularia cf. vernensis Annular ia cf. asteris Asterophyllites longifolius Asterophyllites cf. equisetiformis Mesocalamites cf. cistiiformis Calamostachys andanensis Alloiopteris gracillima Alloiopteris cf . quercifolia Dactylotheca aspera Lacoea seriata Palaeopteridium reussii Gulpenia limburgensis Megalopteris dawsoni Megalopteris ovata Lesleya cheimarosa spec. nov. Alethopteris lonchitica Sphenopteris preslesensis Eusphenopteris morrowensis comb Lagenospermum sp . Telangiopsis sp . Rhodeopteridium phillipsii spec Holcospermum sp. Cordaites cf. principalis Samaropsis sp . A Samaropsis sp. B Samaropsis sp . C Cordaicarpus sp. A Cordaicarpus sp. B cf. Mariopteris cf. Eremopteris 11 14 21 33 37 rare in other floras. Flora similar to the Spencer Farm was first ob- served in western Illinois by White (1908), who gave a preliminary list including the nomen nudum "Lacoeia." White (l93l) suggested that this flora grew on the limestone plains of western Illinois. Leary (1973) re- ported on the systematic position and reconstruction of Lacoea. EARLY PENNSYLVANIA!! FLORA FROM WEST-CENTRAL ILLINOIS The material used in this study comes from the northeastern edge of an outlier of Pennsylvanian strata that is separated from the main area of Pennsylvanian deposits by the erosion of the La Moine River Val- ley (text fig. l). The collecting sites are in northeastern Brown County, Illinois (Rushville, Illinois 15-Min. Quad.; NW^ SW^ NW^ SW^ Sec. 12, and NE&; SE^ NE^ SE^ Sec. 11, T. IN., R. 3 W. ) , on the bluffs of the La Moine River (formerly "Crooked Creek"). One locality is along the road that runs northwest-southeast and parallels the river; the exposure is 15 meters northwest of the turn of the road. A second locality is lo- cated in a small ravine about 75 meters west of the first locality. The exposures at both localities are at the same elevation and stratigraphic position. The specimens described in this paper are housed in the col- lections of the Illinois State Museum (ISM). Acknowledgments We wish to acknowledge the assistance received from the Spencer family, who donated specimens to the \ V \ \ ^rr^ ...... •* V ^ w / 1 ^ ' A ' / v i / (i hCfc y Y'l i ILLINOIS ■4 i\ * t J ) 0 100 Km V^-) V*r / Pennsylvanian Rocks This Reporl Text fig. 1 - Map shoving the relation of the Spencer Farm locality to the outcrop area of Pennsylvanian rocks. Illinois State Museum and allowed the authors to collect on their farm. We wish to thank Dr. Tom L. Phillips of the University of Illi- nois and Dr. Sergius H. Mammay, U.S. Geological Survey, for their en- couragement and for reviewing our manuscript. Dr. Russell A. Peppers, Illinois State Geological Survey, helped with paleobotanical and strat- igraphic problems. Material was loaned by Dr. Dwayne D. Stone, Mari- etta College, Ohio, and by Dr. Herman F. Becker, The New York Botanical Garden. Mr. Rudolf Ewald, Datteln, Germany, helped us with the deriva- tion of the new specific names. Dr. Leo J. Hickey, Smithsonian Institu- tion, kindly supplied us with photo- graphs of some of Lesquereux's type specimens. GEOLOGY Erosion of the sub-Pennsylvanian limestones in the area of the Spen- cer Farm produced a very irregular surface with relief of at least 12 meters. The earliest Pennsylvanian deposits filled low areas only. They are discontinuous and vary greatly in thickness and lithology. The de- posits described in this report rep- resent the early filling of a ravine in the Mississippian limestone and ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 PENNSYLVANIAN Text fig. 2 - Geologic interpretation of cross section through the Spencer Farm locality. dolostone. The early Pennsylvania]! deposits were, as they are today, located between fairly steep bluffs of the St. Louis and Salem Limestones (text fig. 2). The geology of this locality has been described by Leary (I97^a). The geologic position of the flora-bearing beds is not directly obvious in the field because much of the area is covered and the Penn- sylvanian as well as Mississippian strata are essentially flat lying. The first impression in the field is, therefore, that the plant-bearing beds are overlain by the Salem and St. Louis Limestones. The flora and the irregular predepositional surface, however, are clear indications of the Pennsylvanian age of the plant-bearing beds. Caves , sinkholes , and channels containing Pennsylvanian age shale and sandstone are present in Ordovician, Silurian, and Devonian lime- stones in Rock Island (Savage and Udden, 1921), Whiteside (McGinnis and Heigold, 191k), La Salle (Willman, 19^2), and Kankakee (Bretz, 19^0) Counties. Plant megafossils have been found in deposits in Rock Island County since the last century (Worthen and Shaw, 1873). Caves containing Pennsylvanian age material are known from Missouri; Upshaw and Creath (1965) described a spore flora of early Pennsylvanian age from these de- posits. Brill (1973) reported a linear deposit bearing fragmentary Penn- sylvanian plant fossils in St. Louis County, Missouri, and he interpreted it as a fossil valley. Leckwijck, Stockmans , and Williere (1955) described a locality in Belgium that shows many similarities to the Spencer Farm site. In that locality Namurian shales, which were deposited in solution cavities in Vis£an limestone, preserved an unusual flora that is known from only a few other places. Stratigraphy A composite stratigraphic section of the deposits in the vicinity of the fossil locality is shown in text figure 3. Information on local EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS stratigraphy is found in Harvey (196*0, Reinertsen (196*0, and Leary (l9T^a). The Warsaw Shale of Missis- sippian age is the oldest forma- tion observed in the report area. It is exposed in a small creek southeast of the collecting local- ities, several hundred meters southwest of the point where the creek enters the La Moine River. The Warsaw consists primarily of light gray, bluish gray, or green- ish gray calcareous or dolomitic shale. In some places it contains one or more beds of light gray earthy limestone that are massive, lacking obvious bedding planes, and that scale off in thin blocks upon exposure. Thin beds of dolo- stone, siltstone, and sandstone are interbedded with the shale. Contact with the overlying Salem Limestone is gradational. The Salem Limestone is exposed in the area of the collecting lo- calities, forming part of the POPE CREEK COAL BABYLON SS. Covered interval Plant fossils d»W^^/V^^^^^*WyN^t^^^rf WSA^WA^VW^^V^^A^V z3^^Wi ^ST LOUIS LS. SALEM LS. WARSAW SH. 10 m U Text fig. 3 - Stratigraphic column of the rocks in the vicinity of the Spencer Farm locality. sides of the ravine in which the fossil-bearing Pennsylvanian sediments accumulated. The Salem Formation is predominantly a brown to light brownish gray limestone or dolostone. The limestone is dense to argil- laceous, silty or even sandy, and commonly occurs in irregular thin beds, This limestone or dolostone may give way to a light gray or greenish gray dolomitic siltstone or sandstone, or a light greenish gray calcare- ous or dolomitic sandy shale that closely resembles the Warsaw. The Salem is 10 to ik meters thick. The youngest Mississippi an formation in the report area is the St. Louis Limestone. Only part of the formation is present, pre-Penn- sylvanian erosion having removed at least the upper portion, and in most areas, all of the formation. The St. Louis is a light gray, dense to lithographic limestone containing small amounts of white to light gray chert. Thin beds of light greenish gray shale are interbedded with the limestone. The limestone commonly is brecciated, consisting of angular fragments of light gray, dense limestone in a matrix that is darker gray and weathers rusty brown. The maximum thickness of the St. Louis ob- served in the immediate area is h meters. The fossil-bearing strata are the lowermost Pennsylvanian depos- its in the area and belong to the Caseyville Formation. They consist of very irregularly interbedded siltstone, fine-grained sandstones, and shales deposited in steep-sided depressions within the Mississippi an limestones, primarily the Salem Limestone. The siltstones are gray and well sorted; however, lenses of coarse quartz sand grains in a matrix of 6 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 silt and clay occur. The sandstones are gray, veil sorted, and composed of quartz; the shale lenses are gray. Where -weathered, the shales, silts and sandstones become ochre to rust brown. The bases of some sandstone beds are conglomeratic with clay pebbles dominating. This lithology, together with the irregular and wavy bedding of the coarse cross-strati- fication, indicates deposition in rapidly moving water. Further indica- tions of deposition in such water are the twisted and distorted plant fossils which often cross bedding planes. That the plants were brought in by fast-moving water is also indicated by the fact that they are most common in the coarser beds. Overlying the fossil-bearing strata is a rust-colored shale. It overlaps the top of the Salem and caps the hill between the two collecting localities. Its thickness and exact stratigraphic relationship are not known; however, it probably underlies the Babylon Sandstone Member of the Abbott Formation. The Babylon Sandstone in the report area is approx- imately h meters thick, although elsewhere it is as much as 8 meters thick. It is composed almost entirely of medium to coarse quartz grains. For the most part, the sandstone is light gray to yellowish gray, but the weathered surface may be iron-stained a reddish brown. The upper part is thick and irregularly bedded to massive, and contains Stigmaria and Lepidodendron impressions. The lower part is cross bedded and con- tains carbonaceous partings. To the northeast, the sandstone intertongues with shale. Overlying the sandstone is approximately 30 cm of underclay and shale, light near the top and darker and sandier near the base. A thin coal is exposed where a road crosses a creek about 300 m south of the collecting localities. The coal ranges in thickness from ^5 cm to only 8 cm. The thinning is apparently the result of post-lithif ication chan- neling, as the base of the coal is even and the upper contact very ir- regular. The coal has been tentatively identified as the Pope Creek Coal Member of the Abbott Formation. The hiatus between the Mississippian and Pennsylvanian beds is apparently quite long in Brown County. The St. Louis Limestone is the youngest Mississippian unit preserved, and the entire Chesterian Series is missing. The first widespread deposit of Pennsylvanian age is the Babylon Sandstone Member of the Abbott Formation. Thus the Caseyville is represented only by the plant-bearing beds. The St. Louis Limestone has been tentatively correlated with the cu III a in Europe (Collinson, Scott, and Rexroad, 1962). The Babylon Sandstone is of Westphalian B age. Thus the upper part of the Visean, the entire Namurian, and the Westphalian A are missing between these two units. This gap represents a time span of 10 to 20 million years (Fran- cis and Woodland, 196k), The plant-bearing strata could have been de- posited any time during that interval. Determination of the age of the flora is thus crucial for the dating of these beds. LYCOPSIDS Lepidodendron wortheni Lesquereux Text fig. l+A; pi. 1, fig. 1 The single specimen of Lepidodendron from the Spencer Farm lo- calities consists of nine leaf cushions in an area 3.5 by 1.5 cm. The EAELY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS length-to-width ratio is about 2:1; the cushions are 1.3 to 1.5 cm long and 0.5 to 0.7 cm "wide. Each cushion merges with those above and below. There are transverse wrinkles on the lover portion of nearly all the cushions, and wrinkles are visible on the upper part of one. A prominent ligule scar, a short vertical slit, is seen just above the leaf scar. The outlines and details of the leaf scars are not clear. They are located just above the center of the cushions and appear to be nearly as wide as the cushions. SPHENOPSIDS Annular i a cf. ve mens is Text fig. 1+B, C; pi. 1, fig. h Description. — The leaves, averaging 12 in a verticil, are 5 mm long and 1 mm wide. Each leaf is slightly longer than the internode. The leaves are conspicuously lanceolate, more or less uniform in width, taper toward the base and toward the acute apex. They are equal in length, radiate from the node; they are straight or slightly curved. The midrib is 0.3 mm wide and is longitudinally striated. The stem is 1 mm wide, with inter nodes 3 to k mm long. Discussion. — A single specimen referable to this species has been found at Spencer Farm. At first glance, the leaf arrangement ap- pears to be that of Asterophyllites , an impression held originally by Arnold (19^+9) regarding his specimen from Michigan. However, closer examination of the Illinois specimen reveals that some leaves radiate from the axis at an angle greater than 90°. Abbott (1958) interpreted the leaves as radiating from the node in a single plane and transferred this species to Annularia. The number of leaves per whorl is not determinable from the Il- linois specimens. A maximum of six is observed although it is certain that others were originally present but are not visibly preserved. The ratio of width to length of the leaves is more like that of Annularia than Asterophyllites , as originially noted by Arnold (19^9, p. 183) and Abbott (1958, p. 326) Annularia cf. aster is PI. 1, fig. 6 One specimen of Annularia has been found in the Spencer Farm Flora; it shows only a single whorl of leaves. The leaves are 3 to k mm long and about 1 mm wide. The midvein is not visible. There are eight leaves in the whorl, which is 7 mm in diameter. The specimen is similar to A. asteris in the number of leaves in the whorl, in overall size, and in the general shape of the leaves. Asterophyllites longifolius (Sternberg) Brongniart PI. 1, fig. 5 The linear leaves are 1.5 mm wide, except for a single specimen (ISM kl6l2k) that has leaves only 0.25 to 0.375 mm wide; and they are ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 l ./ ( \ l\ hi w 4 B F EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS preserved up to 5 cm long. They extend from the stem at angles of 30° to ^5°. In three specimens, they overlap two nodes. The leaves and stems are striated. In our specimens, only six to eight leaves are visible in each verticil, "but this may be the result of preservation. In other aspects, the specimens conform to published descriptions of A. longifolius. Asterophyllites cf. equisetiformis Three very small specimens of Asterophyllites have been found in the Spencer Farm Flora. They are too poorly preserved to allow a pre- cise identification, but are similar to A. equisetiformis in overall proportion and form. At least 12 leaves were present on each verticil. The leaves extend from the axis at almost 90° and then curve upward. They are narrow and slightly overlap the node above. The leaves are 7 mm long and 0.5 mm wide, and the midvein is approximately 0.2 mm wide. Although no complete whorl is preserved, it is clear that originally there were at least 12 leaves per whorl. The internode length is 2.0 mm. Mesocalamites cf. cistiiformis (Stur) Hirmer Text fig. UD, E; pi. 1, fig. 3 The Spencer Farm Flora contains 1^ specimens of calamitean pith casts and impressions. All determinable data on these specimens are given in table 2. The most meaningful characteristics are (l) the con- tinuity of the ribs, (2) number of ribs per centimeter, and (3) length- to-width ratio of the nodes. On most specimens a majority of the ribs pass continuously across the node whereas the others alternate. The narrow stems, however, which bear the Calamostachys cones, do not show any alternating ribs. This variation seems to exist only on very thin, fertile branches, and does not indicate a specific or generic difference. Calamostachys andanensis Stockmans and Williere Text fig. i+F-I; pi. 1, figs. 2, 7 There are about ten specimens which can be attributed to Cal- amostachys; apparently all of the specimens belong to one species. Description. — Whorls of bracts alternate with whorls of sporang- iophores. The sporangiophores bear four sporangia which were probably attached to a plate. The axes of the sporangiophores form right angles with the main axis and are attached in the middle between two whorls of bracts. The measurements are given in table 3. The specimens are well preserved in the siltstone and compaction during early diagensis was slight. Nevertheless only a few characteristics Text fig. k - Fossil plants from the Spencer Farm Flora. A, Lepidodendron wortheni leaf cushions. B, C, Annularia cf. vernensis , C- partial re- construction. D, E, Mesocalamites cf. cistiiformis . F-I , Calamostachys andanensis , F- complete cone, G- cones attached to Mesocalamites cf. cis- tiiformis, H- reconstruction of part of the cone, I- reconstruction, view into one verticil. Bar scales are 5mm long. 10 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 TABLE 2— MEASUREMENTS OF SPECIMENS OF MESOCALAMITES cf . CISTIIFORMIS FROM THE SPENCER FARM FLORA Internode Number Average Accession length Width Length/ of Ridges/ width Alternating no. (mm) (mm) width ridges cm (mm) Continuous* Termination 416492 45 17 2.6 15 8 1.2 a/c pointed 416493 17? 7 2.4 15 20 0.5 a/c unclear 416432 50 20 2.5 20+ 12 0.8 a/c unclear 416606 30 4.5 7 10 20-25 0.5 a/c unclear 416247 12 2.0 6 7 30 0.3 unclear unclear 416605 28? >8 3± 16 20? 0.5 unclear unclear 416262 16? 4 4 7-8 30-40 0.25-0.3 cont. (a/c?) unclear 416352 40 >8 ca . 5 18 25 0.4 a/c pointed 416353 30 22 >1.4 24 10-12 0.8-1 a/c pointed 416261 19 2.5-5 ca. 4 11± 17± a/c unclear 416495 20.5 3.5 ca. 6 6-8 25 0.4 a/c pointed The foil owing be ar Calamostachys 416487 20 4.0 5 12 30 0.3 cont. 416413 22 3.0 7 8 25 0.4 cont. ? 416511 30 3.0 10 7 25 0.4 cont . — * a/c = both alternating and continuous. TABLE 3 — MEASUREMENTS OF SPECIMENS OF CALAMOSTACHYS ANDANENSIS FROM THE SPENCER FARM FLORA Specimen no . Length of cone (mm) Width of cone (mm) Length of internodes (mm) Size of Length Length of sporangia of bracts s p or angio spore (mm) (mm) (mm) 416375 — - 3.0 1 .6 x 1.2 x 1.0 416513 — - 2.2 0 .8 x 0.8 x 0.5 416607 — 3 2.2 — 416413 20 3 2.0 1.5 x 1.0 416511 ±20 3 2.5 — 416266 15 4 3.5 — 416609 15 5 3 — 416414 10 4 2.3 1 .0 x 0.7 4 1 64 1 6 ±25 3 3 1 .4 x 0.8 416608 __ _ 3.5 2.4 3.5 4.0 1.2 1.4 1.3 1.5 EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 11 are preserved in any one specimen. One specimen gives the impression that there were only four sporangiophores and six bracts per whorl. In another specimen there are four sporangiophores and probably 12 bracts. It is not certain whether the sporangia were attached to a plate or to small extensions of the sporangiophore. In one specimen there seems to be a plate, whereas in a second specimen the plate cannot be observed. The cone has at its tip a little tuft apparently of four bracts. The sporangia were oval and are now flattened. Discussion. — The Calamostachys species described belongs to the Mesocalamltes found in the same flora. There are three specimens that show cones attached to the axis. Leggewie and Schonefeld (l96l) found Calamostachys sengsensis associated with Mesocalamites cistiiformis . Nine other species of Calamostachys that supposedly belong to Mesocal- amites are known from the Namurian. Our specimens are similar in size and characteristics to C. andanensis. All other species of similar size can be excluded owing to differences in the shape of the bracts. In general appearance the Spencer Farm material resembles C. binneyana, which is known from petrifactions throughout the Upper Carboniferous. However, C. binneyana has six sporangiophores per whorl and the bracts are shorter than in our form. Purkynova (1970) reported C. ramosa from the Namurian A of Czechoslovakia. Her figures and description fit our specimen very well. However, Calamostachys ramosa was used for the fructifications of Calamites carinatus (= Calamltes ramosus) , which oc- curs in the Westphalian A to C (Boureau, 196^+, p. 273), and is quite different from the Mesocalamites in the Spencer Farm Flora. Remy and Remy ( 197 5b) demonstrated that material described as Calamostachys represents two different organizational plans, in which the vascularization of the sporangiophore differs. Our material does not show the vascular bundle; therefore, we must retain the genus Cal- amostachys sensu amplo. FERNS Alloiopteris gracillima (Newberry) D. White Text fig. 5A-C; pi. 2, figs. 1-1* Synonymy 1873 Odontopteris gracillima Newberry, p. 382-383, pi. k69 figs. l-3a. 1908 Alloiopteris gracillima D. White, p. 269 Description. — Pinnules k to 5 mm long, 2 mm wide, inclined U50 toward the tip of the pinna; pinnule rhomb oidal-shaped, smaller pinnules fused with neighboring pinnules; one vein enters each pinnule, and forks twice; older pinnules splitting up into three lobes; some pinnules have three teeth at the tip. Basal catadromic and anadromic pinnules are aphleboid and lacerated; contain about 6 to 10 teeth. Pinna long, strap- shaped, inserted at an angle of 35° to 70°; pinna more than 60 mm long and 3 to 5 mm wide; pinna of lower order more than 200 mm long and more than 100 mm wide; more than 26 pinnules on one side of a pinna. 12 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 EARLY PENNSYLVANIA!! FLORA FROM WEST-CENTRAL ILLINOIS 13 Material. — The syntypes of Newberry (l'873.) are in the collection of the New York Botanical Garden (NYBG). The "best-preserved specimen (NYBG 59ll+ G) is the one figured by Newberry (l8T3) on plate k69 figure 3. Specimen NYBG 8320 G is figured on plate k69 figure 1. The speci- men of plate k69 figure 2, could not be located. The specimens from the Spencer Farm Flora have the ISM numbers 1*16509 , 1*16530, 1*16531, l*l61*3l*9 1*161*50, kl6k519 1*161+52, and 1*161*53. Discussion. — Newberry (1873) recognized that this species did not belong in the form genus Odontopteris . He believed, however, that he should not make a new genus on the basis of one species. His descrip- tion mentions that two veins enter the pinnules, and in plate 1*6, figure 2a, he even shows three veins originating on the pinna rachis. Examina- tion of the syntypes shows that only a single vein enters the pinnules and gives rise to one or two lateral veins. The splitting up of the larger pinnules seems to occur along the veins, indicating that the splitting is a post-mortem phenomenon. Newberry (1873) mentioned a fertile specimen (NYBG 1970). The specimen is small and does not preserve a sporangial or pinnule struc- ture. It cannot be definitely identified. The pinnae are 3.5 mm wide and strap shaped and can therefore be compared with A. gracillima. Alloiopteris gracillima has a close similarity to A. plumosae- formis 9 which was described by Gothan (I9I+I) from the Namurian B of Germany. In A, plumosaeformis , however, the pinnules are smaller and the tips of the pinnules are blunt. Gothan compares A. plumosaeformis with A. sternbergi, which is, however, distinctly different by virtue of the rectangular insertion of the pinna at the pinna-bearing axis. The same is true for A. erosa (Lesquereux, 1880, pi. 1*1*, fig. l) , which fur- thermore has concavely rounded recessions between the pointed lacerated tips instead of acute tips like those in A. gracillima. A. thinnfeldi- oides has larger pinnules and wider pinnae, but its outline is similar to that of A, gracillima. A. radstockensis is similar to A, gracillima in general aspect and in the fact that the vein dichotomizes shortly after entering the pinnule. The two are different, however, in the shape of the pinnule; A. radstockensis has rounded lobes, which do not occur in A. gracillima. Alloiopteris cf. quercifolia This specimen (ISM 1*16536) is not preserved sufficiently for a positive identification, but the general character of the well-pronounced Text fig. 5 - Fossil plants from the Spencer Farm Flora. A-C, Alloiopteris gracillima, A- basal aphleboid pinnule, B- pinnules in the middle of a pinna, and C- pinnules showing venation pattern and breakup of pinnules along veins. D, reconstruction of one pinnule of Dactylotheca aspera. Bar scales are 5mm long. E, hypothetical steps in the evolution of noeg- gerathialian cones: I- Archaeopteris-1 ike fructification; 2- Noegger- athiostrobus; 3- Lacoea; and 4- Discinites . Ik ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 axis and the short pinnae is more like A. quercifolia than any other species of Alloiopteris . Measurements: pinna k mm long, 2 mm wide, 2 mm apart. Pinnules 0.8 mm long. Dactylotheca aspera (Brongniart) Zeiller Text fig. 5D; pi. 3, figs. 1-3 Description. — Frond two (or three) times pinnate. Pinnules 9 mm long, 2.5 mm wide, attached 3.5 to k mm apart; shape and attachment pecopteroid, slightly restricted at the distal side of the "base. Pin- nules lobed with five lobes on each side, tip rounded, lobes rounded and about 1.3 mm wide. Venation badly preserved, but apparently one midvein with two unforked lateral veins per lobe„ Two to six sporangia per lobe; sporangia elongated, small, 0.8 x 0.2 mm. Discussion. — This species bears pecopteroid pinnules with elon- gated, solitary sporangia that do not show any trace of an annulus. The arrangement of the sporangia is typically that found in the fructifica- tion genus Dactylotheca Zeiller. Dyotheca Hartung has also been used for these forms, and they are similar to Renaultia Stur in general ap- pearance. The fragmentary specimens at hand, which are preserved in a relatively coarse matrix, do not allow a thorough revision. Thus for the present paper, Dactylotheca is used. Pecopteris aspera is known from the Lower Carboniferous to the lower part of the Westphalian A (Remy and Remy, 1959, p. 63). Our speci- mens compare closely with the figures of the same species from the Namurian A of Czechoslovakia (Purkynova", 1970, pi. 39 9 figs. 6, 6a). There is some similarity with Pecopteris (Senftenbergia) namurica Pur- kynov£ (1970, p. 21^, pi. k09 figs. 3, 3a, 3b). There is some overall similarity to Pecopteris (? Dactylotheca) oregonensis Arnold from the Namurian of Oregon. However, the latter species has smaller pinnules and thicker sporangia. Our specimens can also be compared with Renaultia gracilis. The position of the sporangia is very similar to that in R. gracilis but the sporangia are more elongated in our specimens. NOEGGERATHIALES ( ? Progymnos perms ) The Noeggerathiales are a rare group of uncertain systematic po- sition. The few forms belonging to this group are normally found in small numbers and as fragmented specimens. In the Spencer Farm Flora, however, they are the second most common group of plants after the Pteridosperms. As the geologic position of this flora (ravine deposit) indicates an "extrabasinal," or upland, flora and because Noeggerathiales are extremely rare in roof-shale floras (l in ^000 specimens in the Il- linois Basin), it is concluded that the Noeggerathiales were upland plants In the Spencer Farm Flora, three species, Lacoea seriata, Palae- opteridium reussii , and Gulpenia limburgensis , have been assigned to the Noeggerathiales. Lacoea is without a doubt a noeggerathialean cone, and Palaeopteridium has generally been regarded as a member of this group. However, we are tentatively associating Gulpenia with the Noeggerathiales for the first time. EAELY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 15 The systematic position of the Noeggerathiales was always uncer- tain, and different workers arranged them quite differently in the sys- tem. Boureau (196I+, p. 1+81 ) lists the older suggestions. The Noeggera- thiales were compared with Ferns, Gymnosperms , and Tmesipteris (Browne, 1933; Bierhorst, 1971). Other authors considered them to be of uncer- tain position, and Boureau (1964) used a separate division, Noeggerathi- ophyta. Beck (1976) suggested the possibility that the Noeggerathiales might be the pteridophytic descendants of the Progymnosperms . We agree with Beck that the external morphological characters of several Noegger- athiales are very similar to the Archaeopteridales. The Noeggerathiales are characterized by heterospory, by cones of radial structure, and, in many specimens by wedge-shaped sterile pinnules (or leaves?) with open dichotomous venation. The sterile foliage closely resembles that of Archaeopteris . The heterospory is another characteristic common to Noeggerathiales and Progymnosperms. Structural and palynological infor- mation will be necessary to verify this hypothesis. The age distribution of all fructification and foliage genera that have any morphological similarities to Progymnosperms or Noeggera- thiales is shown in text figure 6. The figure shows that such forms are present throughout the Pennsylvanian and the lower Permian. It demon- strates at the same time how incomplete the record is. Any ideas about natural relationships between these genera would be premature. We do not even suggest that all genera shown belong to the same order or class, UPPER DEVONIAN Archaeopteris PERMIAN -Fructification Foliage Text fig. 6 - Stratigraphic ranges of foliage and fructifications of Progym- nosperms, Noeggerathiales, and similar foliage. S = Saaropteris , N = Noeggerathiostrobus , T = Tingiostachya, P = Palaeopteridium. 16 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 The fructification genera of the Noeggerathiales , Noeggerathi- ostrobus Feistmantel, Discinites Feistmantel, and Lacoea Read 19^-6, emend. Leary 1973 , can "be arranged in a form- evolutionary sequence that requires only small transformations between the different forms (text fig. 5E). The line started possibly with a hypothetical form similar to Archaeopteris . The pinnules of this hypothetical form would form Noeg- gerathiostrobus after the formation of laminae (webbing). A shortening of the axis between the attachment points of the fertile pinnules would yield a fructification of the Lacoea type. Further shortening and fusion of two pinnules would produce the disc-shaped sporangiophore of Discinites, It has to be emphasized that this conclusion is purely hypothetical and indicates only a possible trend. Lacoea seriata Read emend. Leary PI. U, figs. 6-8 Description. — Cone consisting of semicircular sporophylls, which alternate on a rather thick axis. Sporophylls attached close to each other, thus creating a very dense cone. Each sporophyll surface is covered with numerous diamond-shaped sporangial scars arranged in oblique rows forming a distinctive pattern. Margin of each sporophyll bends toward the distal end of the cone and bears a fringed border. Sporophylls often found detached. Discussion. — The genus Lacoea was recognized by David White be- fore 1908, but he never described it (White, 1908, p. 269). Read (19^6) described Lacoea, but misinterpreted its morphology and systematic po- sition. The genus was redescribed and reinterpreted by Leary (1973), who recognized that it belongs to the Noeggerathiales. Lacoea is in appearance very similar to Discinites. The pattern of sporangial attachment and the fringed margin are identical. The only difference is that Lacoea has semicircular sporophylls whereas Discinites has disc-shaped sporophylls. Lacoea has so far been found only in the lower part of the Penn- sylvanian and has been reported or has been found in the following local- ities : Dutch Mountain, Pennsylvania (Read, 19^+6) Youngs town, Ohio (Read, 19^6) Rushville, Ohio (seen in photograph of collection specimen) Brown County, Illinois (this report) northwestern Illinois (D. White, 1908) Rock Island County, Illinois (field observation) In at least five of these six locations, Lacoea occurs with Palaeopteridium reussii or a very similar form. Nemejc (l9*+l) reported that Discinites and Palaeopteridium nearly always occur together and concluded that there was at least a good chance that Discinites might be the fructification of Palaeopteridium. It is possible that Lacoea is just another fructification of Pal aeopteridi urn-like foliage. EARLY PENNSYLVANIA FLORA. FROM WEST-CENTRAL ILLINOIS IT Palaeopteridium reussii (Ettingshausen) Kidston Text fig. TA-C; pi. k9 figs. 1-5 Synonymy 1852 Asplenites Reussii , Ettingshausen, p. l6, pi. 1, figs. 8 and 9 I869 Palaeopteris Reussii , Schimper, p. U78 v. 1875 Archaeopteris stricta, Andrews, p. Ul8, pi. 1+9, figs. 2, 2a v. 188 k Archaeopteris denti- culata, Lesquereux, P. 77*+ 189 1+ Archaeopteris Reussii , Kidston, p. 2^2 191^ Archaeopteris Reussii , Kidston, p. 95, pi. 5, figs. 7, 7a 1923 Palaeopteridium Reus- si9 Kidston, p. 201- 203, pi. 55, figs. 1- 3 v. 19^-9 Palaeopteridium Reus- si9 Arnold, p. 219- 220, pi. 26, fig. 6 Description. — Outline of pin- nules -wedge-shaped, spatulate, or diamond-shaped (text fig. 7A-C). Some pinnules have stalk-like base, some are attached with a larger part of the base. Open dichotomous venation. Veins forking once or Text fig. 7 - Fossil plants from the Spencer Farm Flora. A-C, variation of Palaeopteridium reussii pinnules according to their position on the frond or branch system. D, E, Gul- penia limburgensis pinnules. Bar scales are 5mm long. 18 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 twice. Basal anadromic pinnule on each pinna longer and narrower than normal pinnules. Only one vein enters each pinnule, but it may appear as if there were two. The dentation of the outer margin of the pinnules is very delicate and is not visible in some types of preservation. The frond is twice pinnate as far as can be judged from the largest preserved specimens. There are no intercalary pinnules ( "Zwischenfiedern," or rachial pinnules) known. Other data are found in table k. Discussion. — The pinnules of Palaeopteridium reussii show dis- tinct differences according to their position in the leaf or branch sys- tem (text fig. 7A-C). The pinnules that are narrower and smaller occur near the tip of the frond. They have a somewhat Tingi a-like appearance. The pinnules of more mature parts become wider and attain a diamond shape ( rhomb ohedr al ) . The adaxial margin thus becomes more and more parallel to the axis. In the widest pinnules, the margin rests on the axis or even overlaps it. The wider pinnules overlap one another also. TABLE U— COMPARISON OF MEASUREMENTS OF PALAEOPTERIDIUM SPECIMENS FROM THE SPENCER FARM FLORA AND OTHER LOCALITIES Palaeopteridium reussii C~) E M 00 Dl CN 0 a TJ •■-] E oj B • 0) Oh Z P. sessilis Leggewie, 1966 pi. 1, pi. 2 On • — i 4-1 -a vo t— 1 CNJ o c • CN CO .u m CO TJ • •H iH t4 a > •H e cfl •H CN 'O 1 C !=> 1— 1 1— 1 Spencer Farm specimens Rushville, Ohio, specimens Pinnules Length L (mm) 17 4-5.5 7 10,8,5 9 9,9,9,7,9,10,7,8 9,6.5,8 Width W (mm) 9 2.5-3 4.5 6,3,5 4 7,6,2.5,3.5,5,6 3,2,2.5 L : W 1.9 1.8 1.5 1.7 2.2 1.3-3.6 (2.0) 3.2 Distance between centers of pinnules (mm) 10 4 4 8,4,4,5 5 2.5 Angle of attachment 35°-60° 40° 40° 40°, 30°, 40°, 60° 35° 30°-55° (42°) 30°-40° Pinna Width (mm) 11 11,12 10 Distance between pinna axes (mm) 20 9 - 12, 7 10 Angle of attachment 50°-55° 55°-60° EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 19 Kids ton (1923) mentioned the foot stalk of the pinnules of P. reussii. However, the foot stalk can be seen only in some specimens. The broad pinnules especially appear to be attached to the axis with a wider part of their base. In all three known species of Palaeopteridium9 the anadromic (posterior) basal pinnule is narrower and longer than any of the other pinnules. This characteristic is also present in the specimens from Spencer Farm. Kidston (1923) furthermore reports "aphleboid posterior basal pinnules forming three lobes with sharper teeth." This arrange- ment might occur in the lower portion of a leaf, but has not been ob- served in the Illinois material. Two species belonging to Palaeopteridium were described under the generic name Archaeopteris from the Rushville flora: A. stricta, Andrews (1875) and A. denticulata, Lesquereux (1880). Neither has in- tercalary pinnules, and both show all other characteristics of the genus Palaeopteridium. Specimens coming from the type locality of both species have been studied, including the holotype of A. striata (specimen at Marietta College). A. denticulata was never figured, and no holotype was assigned, but the specimens studied were identified by Lesquereux and D. White [specimens in the Field Museum of Natural History, Chicago: first specimen UP 1351* (= UC ^+01^3 = No. 319 Lacoe Coll.); second speci- men UP 1200 (= No. 319 Lacoe Coll.)]. Neither species mentioned above differs from the other or from P. reussii; they are therefore put in synonymy here. Andrews (1875) did not describe the teeth on the upper margin of the pinnule. However, in the specimens these teeth are clearly present. Lesquereux (1880) stated correctly that there were no inter- calary pinnules. However, the catadromic (posterior or proximal) basal pinnule is attached directly at the base of the pinnule axis and might thus confuse the observer. One specimen of P. reussii (IU-277) in the collection of the University of Indiana comes from the base of the Pennsylvanian below Cataract Lake Dam (NW^ NW^, Sec. 13, T. 12 N., R. 5. W. ) in Putnam County, Indiana. Three species, Palaeopteridium reussii , P. macrophyllum, and P. sessilis, have been described in this genus. The measurements available have been summarized in table k. The genus is known from Illinois, In- diana, Michigan, Ohio, and Pennsylvania in the United States and from Staffordshire (Great Britain), the Ruhr District (Germany), and the Pilsen Basin (Czechoslovakia) in Europe. P. reussii was known from the Westphalian (up to the Westphalian C) in Europe. Its range now has to be extended down to the Namurian B. P. sessilis occurs in the Ruhr Dis- trict from the Namurian C to the Upper Westphalian B. Gulpenia limburgensis Gothan and Jongmans in_: Jongmans Text fig. 7D, E; pi. 5, figs. 1-1* Description. — Small cuneiform pinnules (or leaves) spirally at- tached to a small axis; appear to alternate; pinnules lacerated or toothed with open dichotomous venation; pinnules bend upward and often cover the base of next higher pinnule; pinnules h to 8 mm long. Axis 0.6 to 1.0 mm thick. Superficial similarity with Sphenophyllum, but pinnules clearly alternating in side view. 20 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 Discussion. — The two fragmentary specimens found in the Spencer Farm Flora are 7 and 8 mm long. This fragmentary state has "been typical of the specimens found in Europe, too. The Illinois specimens are simi- lar to but smaller than the specimens from the Netherlands and Belgium. Considering the normal variability of plants, the size does not consti- tute a taxonomic difference (table 5). Stockmans and Williere (1953) could show on detached pinnules that the pinnules are relatively broadly attached and have as many as eleven lobes. In lateral view (if the pin- nules are attached to an axis), only about five lobes can be seen. Gothan and Jongmans (in: Jongmans , 1927) described Gulpenia limburgensis , but did not include a figure. In 1928 (in: Jongmans, 1928), they described it again without giving a generic diagnosis. In 19559 Stockmans and Williere (in.: Leckwijck, Stockmans, and Williere, 1955) described the genus Thonia from beds of the Namurian A. They men- tioned the similarity between the two genera. The only difference is that the pinnules of Gulpenia are deeply lacerated whereas those of Thonia have only short teeth. Considering the fragmentary character of the specimen and the small amount of information available, this difference does not warrant the establishment of a new genus. It would probably be more appropriate to transfer the only species of Thonia, Tm dentata, to the genus Gulpenia. In Europe, Gulpenia is known only from the Namurian A. The oc- currence in Illinois constitutes the extension of its range into the Namurian B. Gulpenia has been found in Limburg (The Netherlands ), near Argenteau and Thon-Mosseroux (Belgium), and in Brown County, -Illinois (U.S.A.). Gulpenia has always been found above an unconformity in the basal beds of a sedimentary sequence with an unusual flora. In Belgium it was found in sinkhole fillings at the base of the Silesian (European Upper Carboniferous) section in a position very similar to that of the Spencer Farm Flora. This position might indicate that Gulpenia was an upland plant. The natural relationship of the genus Gulpenia is uncertain. It has been placed with the Noeggerathiales in this paper because the few morphological features known do occur only in that group. The pinnules TABLE 5— MEASUREMENTS OF GULPENIA AND THONIA Name of plant: Thonia dentata Gulpenia Gulpenia Gulpenia limburgensis limburgensis 1. imburgensis Locality: Be lgium Belgium Illinois Ill inois Author: St ockmans and Stockmans and This report This report Year: Wi lli(>re, 1955 Williere , 1953 ISM A16A98 ISM A16A99 Width of whole plant A nun 5-8 mm 5 mm A mm Thickness of axis 0 . A mm 1 mm 0 . 7 mm 0 . 0 mm Distance of pinnules 2 . 3 mm 5 mm 2 . 3 nun 2 . 0 nun Length oi pinnules 2 . 3 mm 7 mm 3.5-3.8 mm 3 . 0 mm Numher oi Lobes 4-5 (?) 7-11 (?) A (?) 5 (?) Lengl hoi l obes 0 . 5 mm 1. 5-5.0 mm L.8-2.0 mm 1 . 5 mm Widl h oi Lobea 0.2 mm 0.25 mm 0. 3 nun 0.2 mm EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 21 (or leaves ?) are broadly attached and are not spread out in the plane of the frond. They resemble the fertile leaves of the noeggerathialean cones in their three-dimensional arrangement. PTERIDOSPERMS Genus: Megalopteris (Dawson) Andrews Synonymy 1828 Cannophyllites, Brongniart, Prodr., p. 130 (nomen rejiciendum; see Stafleu et al., 1972, p. 376) I865 Neuropteris, Hartt in: Bailey, p. 550 1871 Neuropteris {Megalopteris) Dawson, p. 51 1875 Megalopteris (Dawson) Andrews (nomen conservandum; see Stafleu et al. , 1972, p. 376) p. ^15 Description. — Simple pinnate leaf, pinnules often attached at irregular distances and at irregular angles, giving the impression of a pedate frond near the top; pinnules strap-like or lanceolate, generally large; strongly decurrent base of pinnule with unequal sides; midvein thick, longitudinal striations often present; lateral veins dense and forking one to three times, curved or straight. Discussion. — Megalopteris has repeatedly been compared with Alethopteris, There are indeed a number of similarities, like the ve- nation in some species, the decurrent base of the pinnules, and the overall shape of the pinnules. However, there are distinct differences. Alethopteris has pinnules that are very regular in their angle of at- tachment, and the leaf shows several orders of pinnate divisions whereas the leaf of Megalopteris is only simple pinnate. The notion that Megalopteris has a pedate leaf has been derived from a specimen of Megalopteris fasciculata Lesquereux, which was fig- ured by Lesquereux, 1879 (Atlas), on plate 2k , figure 2. The specimen (USNM 1170^0 is reproduced photographically here on plate 6, figs. 1 and 2. The leaf appears to be pedate at the base, but is clearly pin- nate higher up. All specimens at our disposal were pinnate. Pinnules vary greatly in size within one leaf. This variation is expressed in nearly every characteristic of the pinnules. In several species the angle of lateral veins, for instance, changes within one pinnule. It is thus quite difficult to find any consistent characteris- tics that are useful in the delineation of species. There are 15 species of Megalopteris mentioned in the literature, but only six seem to be distinguishable on the basis of reasonably objective characteristics. Only two species, Megalopteris dawsoni and M. ovata9 occur in the Spen- cer Farm Flora. 22 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 Megalopteris has "been reported from only a few localities: Wyoming Hills, Iowa - Noe*, 1925 Port Byron, Illinois - Lesquereux, 1880 Brown County, Illinois - this report Greene County, Indiana - Canright, 1959; Wood, 1963 Putnam County, Indiana - oral communication, C. A. Arnold, collected in 1936 Rushville, Ohio - Andrews, 1875; Cross, 1962 Grand Ledge, Michigan - Arnold, 193^ Saginaw, Michigan - Arnold, 193^- Logan County, W. Va. - Arnold, 19^7 New River, W. Va. - D. White, 1895 St. John, New Brunswick, Canada - Dawson, 1871; Stopes, Pictou, New Brunswick, Canada - Bell, 19^0 In nearly half of these localities Megalopteris occurs with a peculiar flora which is distinctly different from a normal coal basin flora and probably lived on rather dry soils. Megalopteris has never been found with any fructifications at- tached. Any conclusion about its systematic position must be based on indirect evidence. It is here included in the Pteridosperms because the leaf morphology compares with such well-established pteridosperm genera as Alethopteris and Taeniopteris . Florin (1933) showed that the structure of the epidermis and stomata of Megalopteris was very similar to that of Neuropteris and other pteridosperms . Megalopteris dawsoni (Hartt) Andrews Text fig. 8A; pi. 6, fig. 3 Synonymy I865 Neuropteris sp. nov. , Hartt in_: Bailey, p. 137 1868 Neuropteris dawsoni, Hartt in: Dawson, p. 551, fig. 133 1871 Neuropteris (Megalopteris) dawsoni, Hartt in: Dawson, p. 51, pi. 7, figs. 191-19^ 1875 Megalopteris dawsoni, Andrews, p. Ul5 1875 Megalopteris hartti , Andrews, p. hl6, pi. h69 figs. 1 and la Text fig. 8 - Fossil plants from the Spencer Farm Flora. A-P, venation pattern in Megaloptoris , A- M. dawsoni, B- M, ovata, C- Lesleya cheimarosa, D- M. fasciculata, EC, reconstruction of a leaf* of M. ovata, V, drawing of the holotype of Lesleya cheimarosa showing the variation in the shape of the lateral veins in different parts of the leaf. Bar scales are 5 min long. EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 23 2k ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 1888 Megalopteris dawsoni, Dawson, p. 76, fig. 26 191^ Megalopteris dawsoni, Stopes, p. 53-55, pi. 13, fig. 3*+ (first photograph) Arnold (193*0 and Wood (1963) also figured specimens that can probably be attributed to M. dawsoni . Description. — The pinnules are strap shaped and have an acute tip. The margin is entirely or slightly undulate. The pinnules are more than 70 mm long (as long as 150 mm according to estimates) and at least 20 mm wide. The pinnules become unequal sided at the base, with a width of only 7 to 12 mm. The angle of attachment of the pinnules ranges from 16° to 46°. The midrib is strong and 1 to 2 mm wide. The lateral veins fork two or three times. There are 21 to 30 veins per cm on the margin, with an average of about 23. The lateral veins are curved in the first half of their course and beyond that continue straight to the margin. They form an angle of 12° to 20° with the midvein, of 35° to h5° in the middle, and of 75° to 85° (90° in one case) with the margin, The measurements are based on seven specimens. The variation is certainly higher than indicated here and must be taken into account in establishing a synonymy. Megalopteris ovata Andrews Text fig. 8B, E; pi. 7; pi. 6, fig. k Synonymy 1875 Megalopteris ovata Andrews, p. *+179 pi. *+7, figs. 1, 2 iQQk Megalopteris dentata Lesquereux, p. 833 (no figure) Description. — The pinnules are lanceolate and have an acute tip. The margin is entire to slightly crenulate. The pinnules are 30 to 70 mm long and 7 to 13 mm wide. They are unequal sided at the base and only k to 7 mm wide. The angle of attachment of the pinnules ranges from 18 ° to 52°. The midvein is distinct and O.k to 0.7 mm wide. The veins fork one to three times in many specimens, but are not clearly visible. Round bodies occur in the laminae between the veins. They are probably glands and are not always preserved. There are ik to 23 veins per cm on the margin. The lateral veins are curved and form angles of 10° to 15° with the midvein, k^° in the middle, and k0° to 60° with the margin. Discussion. — M. dentata was never figured but Lesquereux (188U) gave a relatively detailed description. The specimens (no. 783 of the Lacoe Collection) mentioned by Lesquereux in the original description are now in the collection of the Field Museum of Natural History in Chi- cago. They fit well the description of M. ovata given by Andrews (1875). EARLY PENNSYLVANIA^ FLORA FROM WEST-CENTRAL ILLINOIS 25 Megalopteris minima has a venation which is very similar to that of M. ovata. Another species that seems to be closely related to M. ovata is Megalopteris abbreviata. Lesleya cheimarosa sp. nov. Text fig. 8C, F; pi. 6, fig. 5; pi. 8, figs. 1-3 Description. — Simple leaf of considerable size, about 20 cm long and k cm vide, lanceolate with acute to attenuate tip. Base long and narrow (acuminate). Margin entire. Venation pinnate, midrib thick, 0.7 to 2 mm wide; lateral veins fork once or twice; lateral veins S-shaped with a 10° to 20° angle at the midvein, 30° to 70° angle in center, and k0° to 70° angle on margin; 2k to 36 veins per cm on margin. Holotype : ISM 4161+88 a, b, on pi. 8, figs. 1, 2 Paratypes : ISM 1+16508, I+I6526 Derivation of name: From the Greek x£iyaPP°s (= cheimarros), periodical floods in rivers. Discussion. — Lesleya cheimarosa is fairly common in the Spencer Farm Flora but only one complete leaf has been found so far. In text figure 7E the variation of the shape of the lateral veins on the holo- type is shown. The density of the veins also differs in different parts of the lamina. It is not certain whether the asymmetrical base is typi- cal or is, rather, a result of preservation. This species is attributed to the genus Lesleya because the leaf is simple and not part of a compound frond. Lesleya was first described from Illinois from the level of the Rock Island (No. l) Coal Member. All subsequent discoveries, however, were reported from France and Italy from beds of Westphalian D, Stephanian, or Permian age. The oldest form reported outside the United States is Lesleya weilerbachensis Remy and Remy ( 197 5a) from the upper Westphalian C of the Saar area in Germany. Alethopteris lonchitica (Schlotheim) Sternberg Text fig. 9A-D; pi. 9, figs. 1-6 Description. — Pinnules linear-lanceolate or oblong, length to width ratio between 2.3:1 and 5:1 (average 3.2:1, based on Ik specimens); apex obtuse to acute; base decurrent on the proximal side and deeply in- cised on the distal side, both features highly variable in shape. Pin- nules not connected with each other in lower parts of pinna, but become confluent towards the apex. Pinnules attached obliquely 25° to 85° (average about 60°). Midvein thick, nearly reaching the apex. Lateral veins varied in their form, normally forked once, rarely simple or forked twice; their angle at the midvein ranges from 30° to 75° (average 50°); their angle with the margin ranges from I+50 to 90° (average 70°). There are 32 to 50 veins per cm on margin (average ko) . 26 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 27 Discussion. — Alethopteris lonchitica is very common in the Spen- cer Farm Flora. Several terminal portions have been found shoving the long, lanceolate terminal pinnule. Some specimens are complete enough to show the change from simple pinnatifid structure at the tip to two orders of pinnatifid form farther down. A single specimen (ISM ^16129) of the near-terminal portion of a pinna has unusually long, lanceolate pinnules (text fig. 9D). The longest has a length of 3.2 cm and a length to width ratio of 5.3:1. Similar size variation is found in other species of Alethopteris (for example, A. serli). Alethopteris lonchitica is most common in the Westphalian A and B, but is known from Namurian B through the Westphalian D (Gothan and Remy, 1957, p. 118). Our specimens compare closely with the forms found in the Namurian B of Vorhalle, Germany. Sphenopteris preslesensis Stockmans and Williere Text fig. 10A, B; pi. 10, figs. 1-5 Description. — Pinnules appear to be pedately divided, whereas the veins have a pinnate division. The incisions between the lobes are deep, and there is in many specimens a central incision that divides the pinnule into two halves. The tips of the lobes are rounded to acute, but often appear to be truncated owing to preservation. The size of the pinnules vary somewhat depending on their position in the frond or in the pinna. Pinnules are h to 6 mm long and 2.5 to k mm wide. They are attached at angles from less than 50° to 70°. Pinnules have k to 10 lobes; 6 lobes are most common. Pinnae are 9 to 20 mm long and 5 to 10 mm wide. They are attached at angles of 50° to 90°. Pinna axes are 0.3 to 0.6 mm wide, straight to flexuous, and faintly alate. Axes of lower order are about 1 mm wide. No aphleboid pinnules were observed. Discussion. — Sphenopteris preslesensis is one of several Sphenop- teris species with highly lacerated foliage that occur in the Namurian and lowermost Westphalian. It is characterized by the fan-shaped ap- pearance and nearly bilateral symmetry of the pinnules. Sphenopteris preslesensis is known from the Namurian B of Belgium and Germany. Eusphenopteris morrowensis (D. White) van Amerom comb. nov. Text fig. 11A, B, D; pi. 11, figs. 1-1+ Basionym: Diplothmema morrowensis 19^+3 David White, Lower Pennsylvanian species of Mariopteris , Eremopteris , Diplothmema, and Aneimites from the Appalachian region: U.S. Geolog- ical Survey Professional Paper 197-C, p. 99-100, pi. 3k, fig. 1; pi. 35, fig. 1 Text fig. 9 - Fossil plants from the Spencer Farm Flora. A-D, Alethopteris lonchitica. Bar scales are 5 mm long. 28 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 29 Description. — Size and shape of pinnules highly varied; depend- ing on the position in the pinna. Pinnules slightly to strongly lobed; general outline diamond- shaped to ovoid; three to seven lobes per pin- nule. At the base, pinnules are decurrent on the proximal side and deeply incised on the distal side; toward the tip of the pinna, pinnules tend to be attached along their entire base. Tips of pinnules obtuse, appearing nearly acute in some specimens. Lobes are generally rounded and diamond shaped, and a continual morphogenic development from lobes into pinnules can be observed. The size of pinnules ranges from 5 x 3.7 mm to 12 x 9 mm, with an average of 8x7 mm. Pinnules barely touch each other or have space between them. They are attached obliquely and form an angle of 70° to 80° on the acro- scope side and 50° to 60° on the basiscope side. Basal pinnules are sometimes larger in more mature parts of the frond, where they appear somewhat mariopteroid. Venation is a mixture of open dichotomous and pinnate. The mid- vein is straight to undulate in the lower two-thirds of the larger pin- nules and is not different from lateral veins in smaller (younger) pin- nules. Only one vein enters larger pinnules, but in lobes and smaller pinnules several veins may enter. In larger pinnules the first distal lateral vein runs parallel to the pinna axis and can thus create the im- pression that the secondary lateral veins coming from it are actually entering the pinnule directly from the pinna axis. Lateral veins are curved outwards. Venation is distinct but not very coarse. Between the veins there are numerous round bodies (probably glands) that are distributed over the entire lamina (pi. 11, fig. 2). These glands are visible only in certain kinds of preservation and thus cannot be used as a descriptive characteristic. Construction of frond unknown, but at least three times pinnate. Discussion. — Eusphenopteris morrowensis is one of the most com- mon fossils in the Spencer Farm Flora and therefore can be well charac- terized. However, all specimens are fragments, even where they cover entire bedding planes, and it is therefore not possible to reconstruct the frond. It is nevertheless clear from the shape of the pinnules that this species belongs to the genus Eusphenopteris , which was recently re- vised by Amerom (1975). Our material is best comparable with Diplothmema morrowensis , which have therefore to be transferred to the genus Eusphenopteris • Amerom (1975 9 p. 62) actually mentions D. morrowensis as closely compar- able to E. aldrichii (D. White) Amerom without proposing the new combina- tion. Thus, Amerom (1975) recognized the proper position of the species, and the formal change is made here with the approval and under the name of Dr. van Amerom. Amerom (1975) distinguishes several sections within the genus Eusphenopteris . Our material belongs in the section of E. neuropteroides , The Spencer Farm material is also comparable to Sphenopteris cheathami , Text fig. 10 - Fossil plants from the Spencer Farm Flora. A, B, Sphenopteris pres- lesensis . C-G, Rhodeopteridium phillipsii. Bar scales are 5 mm long, except where noted. 30 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 mm EARLY PENNSYLVANIAN FLORA FROM WEST-CENTRAL ILLINOIS 31 especially specimen USNM 15025 from Tracy City, Tennessee, which was identified by Lesquereux. However, the figures of S. cheathami in Les- quereux (l88U) and D. White (19^3) do not compare well with our material. The foliage of Eusphenopteris morrowensis occurs with a small seed (Lagenospermum - Nudospermum) and a Telangiopsis-li~ke male fructi- fication on the same bedding planes. An organic connection between the foliage and either of the fructifications could not be established in any specimen, but the association suggests the possibility of a natural connection. The same association of foliage and fructifications has been observed in other species of Eusphenopteris (Amerom, 19759 fig. 7). There are observable similarities between the foliage of Eus- phenopteris morrowensis and the reconstructed foliage of Schopfiastrum decussatum (Stidd and Phillips, 1973). Even though sizes and shapes of the pinnules are somewhat different, the two plants are alike in three other, more important aspects. The venation pattern is identical. Glands in both forms are in the same position on the lamina. The inter- rupted transverse striations (= transverse inner cortical plates) are present. For instance, the transverse striation is visible in the axis shown in plate 11, figure 1. Lagenospermum sp. Text fig. 11C, D; pi. 12, figs. 5, 6 Description. — Ellipsoidal seeds, 6.25 mm long, 3.38 mm diameter. Faint ridges (probably eight in all) extend along the length of the seed. Discussion. — Three small ellipsoidal seeds are intimately as- sociated with a pinna of Eusphenopteris morrowensis (specimen ISM kl6^22) One of the seeds is located immediately to the left of the pinna rachis and at the base of a pinnule. It is possible but not certain that it is organically attached to the rachis. Two seeds are to the right of the rachis, one seed partially overlapping the other and both lying upon the laminar portion of the pinnule. They do not appear to be attached to the frond. An isolated fourth seed agrees in all characteristics with the other three. The form genus Lagenospermum was established for small ellip- soidal seeds that appear externally similar to seeds belonging to the petrifaction genus Lagenostoma but that do not preserve the morphologic characteristics necessary to justify their inclusion in that genus. The generic name Nudospermum has also been used for similar seeds. Nudosper- mum has been considered to be the seed of Lyginopterideae as well as Eusphenopterideae (data summarized by Amerom, 1975, fig. 7). The seeds in the Spencer Farm Flora are only slightly larger than Nudospermum kid- stoni and are therefore very similar to a seed that has been linked to the genus Eusphenopteris . Text fig. 11 - Fossil plants from the Spencer Farm Flora. A, B, Eusphenopteris mor- rowensis. C, Lagenospermum sp. shoving indications of several ribs. D, L. sp. occurring with E. morrowensis. E, F, two interpretations of Telangiopsis sp. Bar scales are 5 mm long, except where noted. 32 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 Telangiopsis sp. Text fig. HE, F; pi. 12, figs. 1-k Description. — Monopodially branching axis "bearing terminal syn- angia with five sporangia. Individual sporangia 3 to k mm long and 0.5 to 1.0 mm wide, with an acuminate tip. Discussion. — Thirteen specimens bearing sporangia have been found. They are preserved as molds with little or no organic material present ; no spores have been found within the sporangia. Each specimen contains two or more sporangia; some specimens preserve five in a clus- ter and several contain two or more clusters. One specimen (ISM kl6^2l) does contain four and possibly five clusters and some trace of the connecting axis, indicating the mutual arrangement of the synangia. Two specimens (ISM kl6h60 9 ^16280) pre- serve the bases of sporangia. One of these {kl6k6o) also contains two sporangia exposed in profile. The sporangia are roughly banana-shaped and do not appear to be fused to each other. The different positions of the sporangia, shown in text figure HE and F, may represent changes during maturity or positions before and after anthesis. Nine specimens of Telangiopsis occur on the same bedding plane as Eusphenopteris morrowensis ; this concurrence may indicate that the two species belong to the same plant. Rhodeopteridium phillipsii sp. nov. Text fig. 10C-G; pi. 13, figs. 1-5 Description. — Deeply divided leaf at least three times pinnatifid; alate axis; pinnules elongated and strongly lobed; lobes either oval, elongated oval, or wedge-shaped with a long side attached to the axis ; one vein per lobe. Pinnules 5 to 9 mm long and 1.5 to 2 mm wide; about five lobes per pinnule. Pinnules distant from each other, rarely over- lapping. Fructifications (sporangia ?, seeds ?) occupying the end of a lobe. They are bean shaped and 0.5 by 0.7 mm. Holotype : Specimen ISM U16527, figured on pi. 13, figs. 1, h. Paratype: Specimen ISM 1+16530. Derivation of name: The new species is named in honor of Profes- sor Tom L. Phillips, University of Illinois, in recognition of his con- tributions to our knowledge of Pennsylvanian age plants and his encourage- ment of young paleobotanists. Discussion. — The form genus Rhodeopteridium (formerly known as Rhodea) is well characterized by the highly dissected foliage. The genus is nevertheless artificial and several distinct kinds of fructifications have been found on different species of Rhodeopteridium, None of those fructifications is identical with the one found in the Spencer Farm Flora. The fructifications of Rhodeopteridium phillipsii are preserved as casts. The bean-shaped bodies are surrounded by a very thin edge of lamina. Thus, we would interpret them as seeds rather than sporangia. EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 33 The sterile foliage shows certain similarities to Rhodeopteridium tenue (Gothan) Purkynova" (1970). However, R. phillipsii is strictly pin- natifid and shows a much more regular construction of the leaf. Holcospermum sp. Text fig. 12A; pi. lk9 figs. 6, 7 A single fragment of this genus has been found; it is 12 mm wide and is preserved to a length of 10 mm, but it is obvious that this is less than one-half the original length. The nucule was probably ovoid- elongate and radially symmetrical. The four visible ribs are 0.5 mm wide; eight were probably present around the entire circumference. This fragment is similar to specimens of H. mansfieldi figured by Arnold (19^9, pi. XXIX, fig. 2) from Michigan and by Wood (1963, p. 11, fig. 3) from Indiana. CORDAITALES Cordaites cf. principalis PI. 15, figs. 1, 2 Cordaites leaves are a common element in the Spencer Farm Flora. However, they are fragmentary and poorly preserved. The surface is marked by coarse linear ribs separated by one to three fine ribs. The striation is the only characteristic on which the tentative identifica- tion can be based. Platyspermic Seeds Two of the most commonly encountered genera of the platyspermic seeds are Samaropsis and Cordaicarpus. Samaropsis Goeppert includes im- pressions of flat, more or less circular seeds. The seed is surrounded by an oval or heart-shaped border called a wing, which is formed by the soft tissue of the sarcotesta. Cordaicarpus Geinitz includes seeds that are similar to Samaropsis , but that do not possess a definite sarcotesta or that show only a very narrow one. Table 6 gives the available data about the specimens, which are classified on the basis of overall shape. It should be pointed out that the Cordaicarpus sp. B and the "miscella- neous nucelli" may in fact be parts of other forms, separated only be- cause of incomplete preservation. The platyspermic seeds are treated under Cordaitales because some of them belong to Cordaites. It should be realized that a connec- tion has not been shown in most cases and that the arrangement is partly a matter of convenience. Samaropsis sp. A Text fig. 12B;pl. 15, figs. 5, 6, 7 These seeds are large, ovate to heart-shaped with a wide wing. In the better preserved specimen (pi. 15, fig. 6), the base is cordate and the nucellus is marked with lines roughly paralleling the margin. Also visible on this specimen is a V-shaped slit at the apex of the sar- cotesta. On one specimen (pi. 15, fig. 5), a fairly wide (0.5 mm) line 3^ ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 35 TABLE 6— MEASUREMENTS OF PLATYSPERMIC SEEDS OBSERVED IN THE SPENCER FARM FLORA Nucellus Overall Sarcotesta Accession width length width length width no. (mm) (mm) (mm) (mm) (mm) 416365 12 9 26 20 7 Sp. A < 416361 12 12 33 25 10 416463 14 20 13 25 30 40 — 0 J S 416468 5 Sp. B «< 416469 16 22? 22? 40? 3 CO 416364 14? 11 11 16? 17 19 — 416462 3 Sp. C < 416494 11 8 12 8 16 9 18 15 2 416610 0.5 Sp. A < 416467 11 10 13 23 1 CO 416522 5 7.5 6 12 0.5 &t ^_ 5 5 6 7 416134 0.5 416362 5 6 6 7.5 0.5 0 Sp. B < 416611 5 4.5 6 7 0.5 416300 6 7 — — — 416363 4.5 6 — — — en O CD -H 416465 12 13 h a) < 416612 12 10 rH a .CD 3 416360 11 9 •H 416489 9 9 (sclerotesta ?) separates the nucellus from the wing, or sarcotesta. This species is similar to Cardiocarpus dilatatus Lesquereux (l88U, p. 806-807, pi. 110, fig. 2); in our specimens, however, the sarcotesta ap- pears to possess a more acute point. In their overall shape and large size, our specimens are similar to Cardiocarpon akroni Read (19^6, p. 22. pi. 2, fig. 5), although the latter is slightly larger and the form of the apex is not clear. Text fig. 12 - Fossil seeds occurring in the Spencer Farm Flora. A, Holcospermum sp, B, Samaropsis sp. A. C, Samaropsis sp. B. D, Samaropsis sp. C. E, Cordaicarpus sp. A. F, Cordaicarpus sp. B. G, H, lEremopteris. I, iMariopteris . Bar scales are 5 mm long. 36 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 Samaropsis sp. B Text fig. 12C; pi. lk9 figs. 1, 2 Only a single -well-preserved specimen of this form has been found in the Spencer Farm Flora; two poorly preserved specimens are similar enough to be included. The nucellus is heart shaped and large (20 mm vide and 25 mm high). The sclerotesta and sarcotesta have elongated apices, the sarcotesta being pear shaped. In size and some other as- pects, notably the lack of residue or relief, these resemble Cardiocar- pon phillipsii Read (19^6, p. 22, pi. 2, figs. 1-3). However, Read des- cribed the wing of C. phillipsii as having a distinct V-shaped slit ex- tending to the apex of the nucellus. Read also stated that the wing measures only 0.5 cm at the micropylar end; on our specimen, however, the sarcotesta is more than 1 cm wide at the apex. Lesquereux (l88U) also described and figured a very large, elongate form, Carpolithes perpusillus (pi. 110, fig. 22-2U). The variation within his figures and incomplete preservation of our specimens do not permit further comparison. Samaropsis sp. C Text fig. 12D; pi. lk9 fig. 3 This group is represented by two relatively small oval seeds and the outline of a third. The nucellus is almost completely circular, the apex being only slightly pointed. The overall form is circular, the sarcotesta being 2 to 3 mm wide all around the seed except for pos- sibly a broad V-shaped incision at the apex. These seeds bear strong resemblance to Cardiocarpon annulatum Newberry, Cardiocarpus diverges Lesquereux, and C. patens Lesquereux. The differences between these are minor variations in the form of the wing at the base and/or apex, differences that may be the result of pre- servation. Cordaicarpus sp. A Text fig. 12E; pi. 15, figs. 3, h Two specimens are preserved which show an ovate nucellus with a small point at the apex and a slightly cordate base, a sclerotesta (?) closely fitting at the base of the nucellus but extending considerably above the nucellus, and a narrow sarcotesta (?) around the entire body. The "wing" is not considered wide enough to warrant placing the seed in the genus Samaropsis . The overall form is elongated oval except for the slight indentation at the base. The best specimen shows much relief, but where the specimen is broken, it consists of a very thin film and thus the relationship of the present form to the original shape is un- known. Cordaicarpus sp. B Text fig. 12F; pi. 15, figs. 8, 9 This group includes seeds with a small (5 x 5 mm) heart-shaped nucellus and a slightly larger cordate to tear-drop-shaped sclerotesta, EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 37 the latter being 0.5 mm to 1.0 mm vide on the sides, thicker at the apex and thinner at the base. In some instances the nucellus, as is the sur- rounding sclerotesta, is preserved only as a thin, flattened carbon film. In other cases, the nucellus is preserved in three-dimensional form and is about 1 to 2 mm thick. Such differences are probably preservational and make comparison of specimens difficult. These specimens bear a strong resemblance to Cardiocarpon late-alatum Lesquereux. PROBLEMATICA The Spencer Farm Flora contains a number of fragmentary speci- mens that do not belong to any of the species described above. They are too incompletely preserved to be identified with any degree of con- fidence. However, these fragments may be recognizable if more material becomes available from here or other locations. Therefore, we include short descriptions and figures. Specimens ISM kl63Q0 and ISM kl62^>8 (text fig. 121; pi. 5, fig. 5; pi. lk9 figs. k9 5) are Sphenopteris- or Afariopteris-like. The pin- nules are subtriangular to triangular to lanceolate with an only slightly lobed margin on the largest pinnule. The pinnules are arranged obliquely and alternately on the pinna rachis. The pinnules are decurrent, but the base is constricted slightly on the lower side, more so on the upper. The nervation of the two specimens is indistinct; the midvein originates at an acute angle and arches outward. The veinlets divide at least once as they curve outward to the margin. The measurements are: ISM U16258 ISM U16380 pinnule length (mm) 9, 12, lk9 12+, Ik 6, 7 pinnule width (mm) k9 h9 k.59 U.5, U.5 2, 3, 3 Another specimen, ISM Ul6529 (text fig. 12G, H; pi. 5, fig. 6), is an Eremopteris-1 ike form. It has an alated rachis; pinnules are al- ternate and overlapping. The pinnule bases are very narrow and decur- rent. The pinnules are deeply trilobed, and each lobe is further dis- tinctly subdivided, each sublobe being either linear or slightly tri- angular . It appears that a single vein enters each pinnule and divides one or two times to give rise to two or three nearly parallel veins in each lobe. DISCUSSION The Spencer Farm Flora is remarkable with respect to its mode of occurrence and the taxa present. The flora did not grow in a coal-form- ing environment, and the differences between this flora and normal roof- shale floras are thus in part due to the environmental differences. White (1931) was the first to point out that the basal Pennsylvanian floras of this kind were growing on the limestone plains and hills in western Illinois in early Pennsylvanian time. Leary (197^+a, 197 Vb) gave 38 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 more detailed descriptions and reconstructions of the environment. At the present, the Spencer Farm Flora is the oldest Pennsylvanian flora known in the Illinois Basin, and certain differences from other floras are due to age differences. During late Mississippian and early Pennsylvanian time a karst topography developed in northern Illinois with sinkholes or ravines which had very steep sides. Plants grew on the less eroded limestone hills. Rain storms would then wash "broken-off plant fragments into the ravines and sinkholes. The floods would carry away the coarser elastics and re- work the clays into clay pebbles. During times without rain a fine mud was deposited; it does not contain any plant megafossils. This recon- struction can be developed from the geologic position and the sedimen- tology at the site. The setting explains the unusual composition of the flora. The plants were growing on calcareous soil that might have been rather dry during part of the year. In contrast, the plants we find in roof-shale floras were growing on alluvial soils that were not limy but were often marshy and wet the year round. Some taxa that occur only rarely in other beds in the Illinois Basin are common in the Spencer Farm Flora. These are Megalopteris , Lesleya, Palaeopteridium reussii , and Alloiopteris gracillima. These are the taxa that probably belong exclusively to an upland flora. A count of the occurrence of genera is presented in table 7. This count was done during two collecting trips and does not include all specimens at our disposal. The pteridosperms are clearly dominant, and the Woeggerathiales are the second most common group. Cordaitales, Sphenopsids, and Ferns are much less common, but are well represented. Remarkable is the scarcity of Lepidodendron, which is represented by only three specimens. In roof-shale floras Lycopsids are usually more common (generally around 10 percent), and Noeggerathiales are not pres- ent at all. The predominance of Pteridosperms, however, can be observed in the majority of roof-shale floras (Peppers and Pfefferkorn, 1970; Pfefferkorn, Mustafa, and Hass , 1975). Comparable Floras There are a few floras known which contain some of the taxa found in the Spencer Farm Flora. Table 8 summarized the occurrence of the more important taxa in these floras. White (1908) gave a list of a flora from northwestern Illinois without citing a precise locality. This floral list is very similar to the list of the Spencer Farm Flora if a few names are translated into their modern equivalents. White's flora certainly came from a similar setting and might be comparable in age. White mentioned Danaeites, which does not occur in this stratigraphic interval. Lesquereux (l88*+, Coal Flora III, p. 852) lists a flora found in a sinkhole near Port Byron, Illinois. Megalopteris is present, but several of the other taxa are not. Another flora that has similarities to the Spencer Farm Flora occurs in Perry County near Rushville, Ohio (Rushville itself is situ- ated in Fairfield County). Reports on the flora were given by Andrews (1875), Lesquereux (l88U), and Cross (1962). Even though this flora EARLY PENNSYLVANIA FLORA. FROM WEST-CENTRAL ILLINOIS 39 TABLE 7— -FREQUENCY OF GENERA IN THE SPENCER FARM FLORA GROUP Genus Number of specimens Percentage of genera Number of specimens of group Percentage of group LYCOPSIDS Lepi dodendron SPHENOPSIDS Mesoca.la.mi tes Annularia Asterophyllites FERNS Alloiopteris Dactylotheca NOEGGERATHIALES Palaeopteridium Gulpenia Lacoea PTERIDOSPERMS Alethopteris Sphenopteris + Eusphenopter is Megalopteris + Lesleya Rhodeopteridi um CORDAITALES Cordaites 17 1 22 30 3 13 4 80 47 117 36 27 54 <1% 4 <1 5 6 <1 3 <1 17 10 26 40 33 97 227 54 <1% 21 50 12 12 Total 454 100% 454 100% occurs in a different type of rock (black shale) and contains more lycop- sids, it has several aspects in common with the Spencer Farm Flora {Megalopteris, Palaeopteridium, and Lacoea). However, the typical Namuri- an forms contained in the Spencer Farm Flora have not been found. Newberry (1873) described a flora from Youngstown, Ohio, that shows some similarities and Read (19^6) reported a flora from the Dutch Mountain area in Pennsylvania with Lacoea and a species of Palaeopteridium, In the Pocahontas Formation of Virginia and West Virginia no com- parable floras have been reported. Megalopteris does occur there, but it is rare. ko ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 The Spotted Ridge Flora from TABLE 8 — OCCURRENCE OF IMPORTANT the Lower Pennsylvanian of Oregon TAXA IN FLORAS COMPARABLE WITH was described by Read and Merriam THE SPENCER FARM FLORA* (19^0), Arnold (1953), and Mamay and Read (1956). The flora con- tains Mesocalamites and a Pecop- teris (p. oregonensis) that is very similar to Dactylotheca as- pera. Ti dwell (196T) described a flora from the Manning Canyon Shale in Utah. This flora is of early Pennsylvanian age and con- tains a few forms comparable with species of the Spencer Farm Flora. Age of the Flora Prior to the discovery of the Spencer Farm Flora, the oldest de- posits in the Illinois Basin could be correlated with the Westphalian A. Thus, it was assumed at first that the Spencer Farm Flora could be of the same age as other basal beds. This was in agreement with the Westphalian B age of the Baby- lon Sandstone, which was in turn derived from the correlation with other plant-bearing beds in the Illinois Basin. However, preliminary inves- tigations of the spore flora in the host rock of the Spencer Farm Flora indicated a Namurian age (Russel Peppers, oral communication). An analysis of the megaflora showed that the flora is most likely of Namurian B age. The Spencer Farm Flora is difficult to date because it grew in an environment that is seldom represented in the fossil record. Strati- graphic ranges have been established elsewhere for only nine of the 28 plants occurring in the Spencer Farm Flora. All of these ranges are known from European coal basins only. Thus the ranges of those nine taxa were plotted against the time-stratigraphic scale of the European Carboniferous (text fig. 13). At first glance, the Spencer Farm Flora would seem to be a mixture of several ages. However, because all of the material comes from only two very close locations, this possibility can be excluded. If we assume that first occurrence is the most meaningful para- meter in biostratigraphy, the conclusion would be that the flora is of Westphalian A age and that the ranges of several Namurian forms would have to be extended considerably. This conclusion would contradict the overall Namurian character of the flora. ~* m 00 0^ X r~- 3 00 at r—i >. T3 00 S-i u m 0 a) W u CD r, « a) O > rH 4-1 s QJ O ea •H w O c > 00 JZ C ■H •u Xi c 0 0) rH u w 3 4-1 a H 0 3 O 3 CO 1— 1 PM Pi >-> 0 Alloiopteris gracillima X X - - X _ Dactylotheca X Palaeopteridium reussii X X - X X X Lacoea seriata X X ~ X X X Megalopteris X X X X - - Lesleya X X - - - - Alethopteris lonchitica X X - - - - Alethopteris - - X X X - Orthogoniopteris - - - X - - Neriopteris - - - - X X Eremopteris cf . - X X - - Sphenopteris X X X X - - Mariopteris cf . X - - - X Neuropteris - X - - X X The lists are not complete because they are based on the literature and on a few specimens consulted in old collections. EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS kl < a 3 Namurian > a? o Westphalian > CD o o Lepidodendron wortheni Asterophyllites longifolius Mesocolom/tes Dactylotheca aspera ^ : -- Sphenopteris preslesensis Rhodeopleridium ^m Polaeopteridium reus si / Gulpemo limburgensis The long and differing ranges of the nine taxa (text fig. 13) led to the use of the concept of concurrent ranges. Six forms occur together in the Namurian B, ex- cluding only three. Five are pres- ent in the Namurian C, excluding four. The numbers of concurring taxa are even lower for the Namur- ian A and Westphalian A. We have thus to conclude that according to material and information available at present, the Spencer Farm Flora is regarded as belonging to the Namurian B or possibly the Namuri- an C. It follows that the range of Gulpenia limburgensis would now be Namurian A and B (c), the range of Lepidodendron wortheni would be Namurian B (c) to Westphalian D, and the range of Palaeopteridium reussii would be Namurian B (c) to Westphalian C. The plant-bearing beds at Spencer Farm are approximately equiv- alent in age to the Pocahontas Formation in West Virginia. The flora would therefore belong in zone k of Read and Mamay (196U). However, none of the index fossils used for the definition of zone k occurs in the Spencer Farm Flora because of the unusual biofacies of the flora. On the other hand, the genus Megalopteris has been reported from zone 7. The Spencer Farm Flora, however, occurs stratigraphically clearly below the beds correlated in Illinois with zone 7. Megalopteris probably has an extended range. This extension is indicated by the occurrence in West Virginia of Megalopteris above the Fire Creek Coal, which lies at the base of zone 5 (White, 1895 )'. Text fig. 13 - Stratigraphic ranges in the European Carboniferous of genera and spe- cies occurring in the Spencer Farm Flora. (Data from Gothan and Remy (1957), Fos- silium Catalogus , and other sources.) Dotted outline shows time of common oc- currence of the majority of forms. SUMMARY AND CONCLUSIONS 1) The Spencer Farm Flora was found in the basal beds of the Caseyville Formation (Pennsylvanian) . These beds were deposited in a ravine eroded in Mississippian limestones. The plant-bearing beds are thus the oldest rocks of Pennsylvanian age in the area and represent the first deposits laid down after a hiatus. 2) The flora contains 29 species and a few problematical forms. Nine taxa are identical with or directly comparable with European forms with established stratigraphic ranges. Six of these have a concurrent range indicating a Namurian B (or possibly Namurian C) age. Thus, at present, Spencer Farm Flora is the oldest flora of Pennsylvanian age known in the Illinois Basin. 3) The flora represents an unusual biofacies, in which generally rare taxa (Megalopteris, Lesleya, Palaeopteridium , Lacoea) are common. k2 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 The Noeggerathiales, a very rare group, make up more than 20 percent of the specimens. The plants represented in the Spencer Farm Flora -were growing on calcareous soils surrounding the ravine in which they were deposited. They are an extrabasinal (= "upland") flora which is distinct from the basinal floras found in roof shales. k) It is suggested here that the Noeggerathiales should perhaps be classified as Progymno sperms . The noeggerathialian cones could be derived from Archaeopteris-llke fructifications. Within the noeggera- thialian cones a possibly evolutionary trend can be seen from Noeggera- thiostrobus to Lacoea to Discinites. 5) Several organic connections are suspected. Mesocalamites cf. cistiiformis was found in organic connection with C 'alamo st achy s andanen- sis. Lacoea seriata and Palaeopteridium reussii might belong together. Eusphenopteris morrowensis has been found with a Lagenospermum (= Nudos- permum) seed and a Tel angiopsis- like male fructification. It is sus- pected that they belong together. Eusphenopteris morrowensis is in some characters comparable to coal ball material of Schopfiastrum decussatum. 6) Two new species, Lesleya cheimarosa and Rhodeopteridium phillipsii, are described; Gulpenia limhurgensis is reported for the first time in this country. REFERENCES Abbott, M. L., 1958, The American species of Asterophyllites, Annularia, and Spheno- phyllum: Bulletins of American Paleontology, v. 38, no. 17^, p. 285-390, 5 tables, lU pis. Amerom, H. W. J. van, 1975, Die eusphenopteridischen Pteridophyllen aus der Sammlung des Geologischen Bureaus in Heerlen, unter besonderer Berucksichtigung ihrer Stratigraphie bezuglich des siidlimburger Kohlenreviers : Mededelingen Rijks Geologische Dienst, Serie C-III-l-No. 7, 208 p., k8 pis. Andrews, E. B., 1875, Description of fossil plants from the coal measures of Ohio: Report of the Geological Survey of Ohio, v. 2, pt. 2, p. klk-k26, pis. U6-53. Arnold, C. A., 193^, A preliminary study of the fossil flora of the Michigan coal basin: Contributions from the Museum of Paleontology, University of Michigan, v. k, no. 11, p. 177-20U. Arnold, C. A., 19^7, An introduction to paleobotany: New York, McGraw-Hill Book Co., Inc. , ^33 p. Arnold, C. A., 19^9, Fossil flora of the Michigan coal basin: Contributions from the Museum of Paleontology, University of Michigan, v. 7, no. 9, p. 131-269, 3U pis . Arnold, C. A., 1953, Fossil plants of early Pennsylvanian type from central Oregon: Palaeontographica B, v. 93, p. 6l-68, 5 figs., 2 pis. Bailey, L. W., I.865, Observations on the geology of southern New Brunswick: Frederic- ton, 130 p. (With appendices A and B by C. F. Hartt.) Beck, C. B., 1976, Current status of the Progymnospermopsida: Review of Palaeobotany and Palynology, v. 21, p. 5-23, 2 figs. Bell, W. A., 19]i0, The Pictou coalfield: Geological Survey of Canada Memoir no. 225, 160 p.. , 10 pis. EARLY PENNSYLVANIAN FLORA FROM WEST-CENTRAL ILLINOIS k3 Bierhorst, D. W. , 1971, Morphology of vascular plants: New York, Macmillan Co., 56O p. Boureau, Edovard, 1961+, Traite* de Pal6obotanique, v. 3, Sphenophyta, Noeggerathiophyta: Paris, Masson et Cie., 5^ p., 1+36 figs. Bretz, J H., 191+0, Solution cavities in the Joliet Limestone of northeastern Illinois: Journal of Geology, v. 1+8, no. k, p. 33T-381+. Brill, K. G., 1973, Valley filled with clastic sedimentary rocks of Pennsylvanian age, St. Louis County, Missouri: Geological Society of America Abstracts with Pro- grams, v. 5, no. 1+, p. 302-303 (abstr.). Browne, I., 1933, The Noeggerathiae and Tingiae: New Phytologist, v. 32, p. 31+1+-358. Canright, J. E. , 1959, Fossil plants of Indiana: Indiana Department of Conservation, Geological Survey, Report of Progress No. ll+, 1+5 p., 5 pis. Collinson, Charles, A. J. Scott, and C. B. Rexroad, 1962, Six charts showing biostrat- igraphic zones, and correlation based on conodonts from the Devonian and Mis- sissippian rocks of the Upper Mississippi Valley: Illinois State Geological Survey Circular 328, 32 p., 6 tables. Cross, A. T., 1962, The Rushville (Ohio) Pennsylvanian flora: American Journal of Botany, v. 1+9, no. 6, pt. 2, p. 669 (abstr.). Dawson, J. W. , 1871, The fossil plants of the Devonian and Upper Silurian formations of Canada: Geological Survey of Canada, 92 p., 20 pis. Dawson, J. W. , 1888, The geological history of plants: New York, Appleton and Co., 290 p., 79 figs. Ettinghausen, Constantin von, 1852, Die Steinkohlenflora von Stradonitz in Bohmen: Abhandlungen der k. k. geologischen Reichsanstalt, v. 1, pt. 3, no. 1+, 18 p., 6 pis. Florin, Rudolf, 1933, Zur Kenntnis der palaozoischen Pflanzengattung Lesleya Lesquereux und Megalopteris Dawson: Arkiv fur Botanik (K. svenska Vetensk Akad.), v. 25A, no. 19, 23 p. Francis, E. H., and A. W. Woodland, 196U, The Carboniferous period, in Harland, W. B., et al. (eds), 196U, The Phanerozoic time-scale: A supplement to The Quarterly Journal of the Geological Society of London, v. 120s, p. 221-232, 1 fig. Gothan, Walter, 191+1, Die Steinkohlenflora der westlichen paralischen Steinkohlenreviere Deutschlands. 1+. Lieferung: Berlin, Abhandlungen der Reichsstelle fur Boden- forschung, Neue Folge, Heft 196, 5I+ p., 25 pis. Gothan, Walter, and Winfried Remy, 1957, Steinkohlenpflanzen: Essen (Germany), GlUckauf Verlag, 2l+8 p., 221 figs., 5 tables. Hartt, C. F., 1868, (3rd ed. 1878; 1+th ed. , I891), Section of the Little River Group at the "Fern Ledges," Lancaster, N.B. , in Dawson, J. W. , 1868 (2nd ed.), Acadian Geology, p. 516-523. Harvey, R. D. , 1961+, Mississippian limestone resources in Fulton, McDonough, and Schuy- ler Counties, Illinois: Illinois State Geological Survey Circular 370, 27 p., 5 figs., 8 tables. Jongmans, W. J., 1927, Beschrijving der boring Gulpen (No. 106): Geologisch Bureau- voorhet Nederlandsche Mijngebied te Heerlen, Jaarverslag over 1926, p. 5U— 69 , fig. 6. Jongmans, W. J., 1928, Stratigraphie van het Karboon in het algemeen en van Limburg in het bijzonder: Jaarb. Mijnbouwkund. Vereen. Delft 1926-1928, p. 525-590, 17 pis., 6 tables. Kidston, Robert, I89I+, Various divisions of British Carboniferous rocks, in. Proceedings of the Royal Physical Society of Edinburgh. I892-I89I+, v. 12, p. 183-257. Kidston, Robert, 1916, The fossil flora of the Westphalian Series of the south Staf- fordshire coal field, in. Transactions of the Royal Society of Edinburgh. 1913-1911+, v. 50, p. 73-190. hk ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 Kidston, Robert, 1923, Fossil plants of the Carboniferous rocks of Great Britain: Memoirs of the Geological Survey of Great Britain, Palaeontology, v. 2, pt. 1-1+ , p. 1-375, 91 pis. Leary, R. L. , 1973, Lacoea, a Lower Pennsylvanian Noeggerathialian cone from Illi- nois: Review of Palaeobotany and Palynology, v. 15, p. 1+3-50, 7 figs. Leary, R. L. , 197^-a, Stratigraphy and floral characteristics of the basal Pennsylvanian strata in west central Illinois: Compte Rendu Septieme Congres International de Stratigraphie et de Ge"ologie du Carbonifere, Krefeld 1971, v. 3, p. 3l+l- 350, 8 figs. Leary, R. L. , 197^+b, Reconstruction of the coal age uplands: The Explorer, v. 16, no. k, p. 27-29, k figs. Leckwijck, W. van, Francois Stockmans , and Yvonne Willi^re, 1955, Sur l'age, la flore et la fauna des formations Namuriennes affaisse*es dans les poches de dissol- ution du Vise'en^de la region de Samson (Meuse Namuroise): Bruxelles, Asso- ciation pour L' Etude de la Pale"ontologie et de la Stratigraphie Houill^ras, no. 21, p. 267-275, h pis. Leggewie, Wilhelm, 1966, Uber Palaeopteridium sessilis (Potonie* 1896): Fortschritte in der Geologic von Rheinland und Westfalen, v. 13, no. 1, p. 297-302, h pis. Leggewie, Wilhelm, and W. Schonefeld, 196l, Die Calamariaceen der Westfal-Schichten im Ruhrkarbon: Palaeontographica B, v. 109, p« 1-1+1+, 3 figs., 29 pis. Lesquereux, Leo, 1879-1881+, Description of the coal flora of the Carboniferous forma- tion in Pennsylvania and throughout the United States : Second Geological Sur- vey of Pennsylvania, Report of Progress P: Atlas 1879; v. 1, p. 1-35*+, 1880; v. 2, p. 355-69*+, 1880; vol. 3, p. 695-975, 1881+. McGinnis, L. D. , and P. C. Heigold, 197*+, A seismic refraction survey of the Meredosia Channel area of northwestern Illinois: Illinois State Geological Survey Cir- cular 1+88, 19 p. Mamay, S. H., and C. B. Read, 1956, Addition to the flora of the Spotted Ridge Forma- tion in Central Oregon: U.S. Geological Survey Professional Paper 27I+-I, p. 211-226, 1+ pis. Nemejc, Frantisek, 1928, A revision of the Carboniferous and Permian flora of the coal districts in central Bohemia. I. Noeggerathiae and Archaeopterides : Palaeontographica Bohemiae, v. 7, p. 1+7-82, 2 figs., 10 pis. (Praha, Ceska Akademie ved a umeni ) . Nemejc, Frantisek, 191+1, Weitere Fruktifikationen vom Typus Discinites nebst einigen Bemerkungen uber die Archaeopteriden der mittelbShmischen Kohlenbecken: Mitteilungen der Tschechischen Akademie der Wissenschaften 19 1+1, 15 p. , 2 pis. (Auszug aus dem tschechischen in der Zeitschrift "Rozpravy II. tridy Ceske* akademie" v. 51, no. 19.) Newberry, J. S., 1873, Description of fossil plants from the Coal Measures of Ohio: Report of the Geological Survey of Ohio, v. 1, pt. 2, p. 359-385, pi. 1+1-1+8. No£, A. C, 1925, Pennsylvanian flora of northern Illinois: Illinois State Geological Survey Bulletin 52, 18 p., 1+5 pis. Peppers, R. A., and H. W. Pfefferkorn, 1970, A comparison of the floras of the Col- chester (No. 2) Coal and Francis Creek Shale, in Smith, W. H., et al., 1970, Depositional environments in parts of the Carbondale Formation — western and northern Illinois: Francis Creek Shale and associated strata and Mazon Creek biota: Illinois State Geological Survey Guidebook Series 8, p. 61-7*+, :■ t'i ry, . , ', t,.-i.h I 1 ■:; . Pfefferkorn, II. W. , ilakam Mustafa, and Hagen Hass, 1975, Quantitative Charakterisierung ober-karboner Abdruckfloren: Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen, v. 150, no. 3, p. 253-269, 1 fig., 8 tables. EARLY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS k 5 Purkynov£, Eva, 1970, Die Unternamur flora des Beckens von Horni Slezsko (CSSR): Palaontologische Abhandlungen , Abt. B, v. 3, H. 2, p. 129-268, 2 tables, 51 pis. Read, C. B. , 19^6, A Pennsylvanian florule from the Forkston Coal in the Dutch Moun- tain outlier northeastern Pennsylvania: U.S. Geological Survey Professional Paper 210-B, p. 17-28, 3 figs., 2 pis. Read, C. B, and S. H. Mamay, 196*+, Upper Paleozoic floral zones and floral provinces of the United States. U.S. Geological Survey Professional Paper 1+5^-K, 35 p., 19 pis. Read, C. B., and C. W. Merriam, 19^0, A Pennsylvanian flora from central Oregon: American Journal of Science, v. 238, p. 107-111. Reinertsen, D. L. , 1964, Strippable coal reserves of Illinois. Part h — Adams, Brown, Calhoun, Hancock, McDonough, Pike, Schuyler, and the southern parts of Hender- son and Warren Counties: Illinois State Geological Survey Circular 37^, 32 p., 7 figs., 5 tables, 1 pi. 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PLATES AND EXPLANATIONS 1*8 PLATE 1 Lye ops ids and Sphenopsids Figure 1 Lepidodendron wortheni Lesquereux ISM 1+16510 scale 1.5:1 2 Calamostachys andanensis on Mesocalamites cf . cistiiformis ISM l+l61+13a scale 2:1 3 Mesocalamites cf. cistiiformis ISM 1+161+32 scale 1:1 k Annul aria cf. vernensis ISM l+l6376b scale 1:1 5 Asterophyllites longifolius (Sternberg) Brongniart ISM U165H scale 1:1 6 Annular ia cf. asteris ISM 1+16512 scale 3:1 7 Calamostachys andanensis Stockmans and Williere ISM 1+16513 scale 5:1 U9 50 PLATE 2 Alloiopteris gracillima (Newberry) D. White Figure 1 ISM Ul6509 scale 1:1 2,3 ISM 1+16530 scale 5:1 k ISM 1+16531 scale 5:1 51 52 PLATE 3 Dactylotheca aspera (Brongniart) Zeiller Figure 1 ISM kl6k91 scale 1:1 2 same as fig. 1 scale k:l 3 ISM kl65lk scale 5:1 53 :":" ' '- .■■■■■■■■■■■.. . . ' ^ PLATE h Palaeopteridium reussii (Ettinghausen) Kids ton Figure 1 ISM 1+16528 scale 1:1 2 coll. Marietta College (Rushville, Ohio) scale 1:1 3 ISM 1+161*36 scale 2:1 k ISM U16528 scale 5:1 5 ISM 1+16 scale 5:1 Lacoea seriata Read 6 ISM 1|162T8 scale 2:1 7 ISM 1+16275 scale 2:1 8 USNM 26222 (Dutch Mountain, PA] ) scale 1:1 55 56 PLATE 5 Gulpenia limburgensis Gothan and Jongmans igure 1 ISM kl6k9Q scale 1:1 2 ISM Ul6i+99 scale 1:1 3 same as fig. 2 scale 5:1 h same as fig, 1 Problematic a scale 5:1 5 cf. "Mariopteris" ISM 1+16380 scale 3:1 6 cf. "Eremopteris" ISM 1*16529 scale 2:1 57 58 PLATE 6 Megalopteris and Lesleya Figure 1 Megalopteris fasciculata Lesquereux holotype USNM lYJOh scale 1:1 (Port Byron, IL) 2 same as fig, 1 scale 5:1 3 Megalopteris dawsoni (Hartt) Andrews ISM 1+16525 scale 1:1 k Megalopteris ovata Andrews ISM I+I652U scale 1:1 5 Lesleya cheimarosa sp. nov. ISM 1+16508 scale 3:1 59 XXXWm:y--X,m' .•>.•■■'■••: . •••-' ' ' . '■V': v'V. Wi<:.U> - " &i%^.-v&.> ^X\k'Xl;^X>:Z::--^XX;:.. S'V.'-',- ; " ''G;vf*: 6o PLATE T Megalopteris ovata Andrews ISM 1+16523 scale 2:1 6l *PW}^T^y*-:$£i- 62 PLATE 8 Lesley a cheimarosa sp. nov, Figure 1 ISM kl6kQQ& scale 1:1 2 ISM kl6kQ8b scale 1:1 (counterpart of fig. l) 3 ISM Ul6526 scale 1:1 63 6k PLATE 9 Alethopteris lonchitica (Schlotheim) Sternberg Figure 1 ISM 1+16515 scale 1:1 2 ISM kl6l2k scale 2.5:1 3 ISM 1+16130 scale 2.5:1 1+ ISM 1+16129 scale 5:1 5 ISM 1+16516 scale 1:1 6 ISM 1+16517 scale 1.5:1 65 66 PLATE 10 Sphenopteris preslesensis Stockmans and Williere Figure 1 ISM 1+16356 scale 1:1 2 same as fig. 1 scale 3:1 3 ISM 1+16U17 scale 2:1 k ISM Ul63T6b scale 2:1 5 ISM kl6klh scale 2:1 67 68 PLATE 11 Eusphenopteris morrowensis (D. White) Ameron comb, nov, Figure 1 ISM U16535 scale 1:1 2 ISM U16518 scale 2:1 3 ISM U16532 scale 5:1 k ISM i+16519 scale 2:1 69 TO PLATE 12 Telangiopsis sp. Figure 1 ISM 1+16520 scale 1:1 2 ISM 1+161+85 scale 1:1 3 same as fig. 2 scale 3:1 1+ ISM 1+16521 scale 5:1 Lagenospermum sp. 5 ISM 1+16522 scale 1:1 6 same as fig. 5 scale 2.5:1 71 ■„!;. . . ,-* <:j>.^ 72 PLATE 13 Rhodeopteridium phillipsii sp. nov. Figure 1 ISM 1+16527 scale 1:1 2 ISM 1+16527 scale 1:1 3 ISM 1+16530 scale 5:1 h same as fig. 1 scale 5:1 5 same as fig. 2 scale 5:1 73 \ 1" ttiVv^ r -\ 74,; 3«v ; ^ lh PLATE Ik Samaropsis and Problematica Figure 1 Samaropsis sp. B ISM 1+161*68 scale 2:1 2 same as fig. 1 scale 1:1 3 Samaropsis sp. C ISM 1+161+62 scale 2:1 U "Mariopteris" ISM 1+16258 scale 2:1 5 same as fig. 1+ scale 1:1 6 Holcospermum sp. ISM 1+161+83 scale 1:1 7 same as fig. 6 scale 2:1 75 V • -* ;•'*/: 76 PLATE 15 Cordaites 9 Cordai carpus , and Samaropsis Figure 1 Cordaites cf. principalis ISM 4l6533 scale 1:1 2 same as fig, 1 scale 4:1 3 Cordai carpus sp. A ISM 4l6534 scale 1:1 4 same as fig. 3 scale 2:1 5 Samaropsis sp. A ISM 4l636l scale 1:1 6 Samaropsis sp. A ISM 416365 scale 1:1 same as fig. 6 scale 2:1 8 Cordaicarpus sp. B ISM 416362 scale 1:1 9 same as fig. 8 scale 2:1 77 Illinois State Geological Survey Circular 500 77 p., 13 text figs., 8 tables, 15 plates, 2,500 cop., 1977 Urbana, Illinois 6l801 Printed by Authority of State of Illinois, Ch . 127, IRS, Par. 58.25 (P.O. 0051 8-2 V2M-6/77) CIRCULAR 500 ILLINOIS STATE GEOLOGICAL SURVEY URBANA, IL 61801