- Fossils of Dresbachian and Franconian (Cambrian) Age from the Subsurface of West-Central Indiana
By ALLISON R. PALMER
DEPARTMENT OF NATURAL RESOURCES GEOLOGICAL SURVEY SPECIAL REPORT 29
PRINTED BY AUTHORITY OF THE STATE OF INDIANA BLOOMINGTON, INDIANA: 1982 STATE OF INDIANA r Robert D. Orr, Governor DEPARTMENT OF NATURAL RESOURCES James M. Ridenour, Director GEOLOGICAL SURVEY John B. Patton, State Geologist
For sale by Geological Survey, Bloomington, Ind. 47405 Price $2.50 Contents Page r Abstract .... .1 Introduction .. .1 Acknowledgments .1 Stratigraphy ... .2 Paleontology . . . .3 Faunas of Franconian age .3 Faunas of Dresbachian age .7 Literature cited 11 Illustrations [Plates follow Literature Cited] Page Plate 1 Trilobites of Franconian age 2 Trilobites and gastropods of Dresbachian age Figure 1 Map of the eastern midcontinent region showing the general position of the lllinois Basin, subsurface datum points, and depositional facies of beds of the Crepicephalus Zone (middle Dresbachian age) ...... 2 2 Stratigraphic column showing the locations of paleontologic control (F) and the suggested stratigraphic nomenclature for the fossiliferous Cambrian part of Vermillion County well FMC No. WD-1 ...... 3 - Fossils of Dresbachian and Franconian (Cambrian) Age from the Subsurface of West-Central Indiana
By ALLISON R. PALMER
Abstract additional specimens not noted in my earlier Three fossiliferous levels in FMC No. WD-1, a report for Becker. Then publication of well in Vermillion County, Ind., have yielded descriptions of Franconian trilobites from Cambrian fossils. The highest level, in the southeastern Missouri (Kurtz, 1975) provided Davis Formation between depths of 4,497 a basis for reidentification of the trilobites and 4,546 feet, contains 17 distinct layers from the Davis Formation in the Vermillion with trilobites of the Elvinia Zone of early County well. The faunal identifications Franconian age. A single horizon, in an upper presented here reflect the new discoveries and oolite member of the Eau Claire Formation at the updating of identifications made since a depth of 4,698 feet, contains trilobites, completion of the 1970 report. gastropods, and other ·fossils of the Crepi Identifiable fossils, mostly trilobites, are cephalus Zone of middle Dresbachian age. present at three distinct levels in the Two lower horizons, in green shales of the Vermillion County well (fig. 2). The richest Eau Claire Formation at depths of 5,061 and interval is within the Davis Formation 5,083 feet, contain trilobites of the Cedaria between 4,497 and 4,546 feet. Seventeen silty Zone of early Dresbachian age. Characteristic to fine-sandy limestone layers in this 49-foot trilobites and gastropods are illustrated and interval yielded trilobites characteristic of the discussed. early Franconian Elvinia Zone (pI. 1). A single The upper oolite member is considered to collection from oolitic limestone at a depth of be a possible extension of part of the 4,698 feet yielded trilobites and other fossils Bonneterre Formation of Missouri. If this is (pI. 2, figs. 1-16) that represent the correct, the paleogeography of this interval in Crepicephalus Zone of middle Dresbachian the eastern midcontinent region suggests an age. Green to red micaceous shales at depths early presence of, or precursory conditions of 5,061 and 5,083 feet yielded trilobites (pI. for, the Illinois Basin. 2, figs. 17, 18) that represent a fauna of the Cedaria Zone of early Dresbachian age. Introduction This report confirms the record of fossils of Acknowledgments Dresbachian and early Franconian (Cambrian) Leroy E. Becker, then of the Indiana age from a deep well (FMC No. WD-l in the Geological Survey, and Alan S. Horowitz, NW1.4 sec. 9, T. 16 N., R. 9 W.) in Vermillion curator of paleontology, Department of County, west-central Indiana (figs. 1 and 2) Geology, Indiana University, sorted through (Becker and others, 1978). Fossils were first the Cambrian cores from Indiana and selected noted in cores 41,4 inches in diameter from the fossiliferous samples that were studied for this well by Becker in 1970 and were sent to this report. The photography was done by me for identification. Those preliminary Robert Eby, using facilities of the Depart identifications, made in August 1970, were ment of Earth and Space Sciences, State published in Becker and others (1978). In the University of New York, Stony Brook, N.Y. summer of 1977, I was asked to reexamine Partial funding was provided by NSF grant the faunas from this well and to prepare this EAR7825074. Final typing of the manuscript report. Permission was given for processing was done by Jean Davis of the Geological the samples for whatever could be recovered. Society of America. This resulted in the discovery of some 1 2 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AG
- o 200 Miles I I I o 300 Km
-----~- MO. EAU CLAIRE \ -.. ~I~ ) FORMATION I I
~r I .J WO-I l:weltfM9 I I . .( uppel: \ \ >()oH.te l i ILLINOIS·;memner ~j
-- -- T~~N.- - -
Figure 1. Map of the eastern midcontinent region showing the general position of the minois Basin, subsurfac datum points, and depositional facies of beds of the Crepicephalus Zone (middle Dresbachian age). Well FM No. WD-l yielded the fossils described in this report.
Stratigraphy most part of the Bonneterre Formation i The description of the lithologic succession several areas includes an oolitic interval ( that was assigned to the Eau Claire Formation comparable thickness (Howe and other in the Vermillion County well by Becker and 1972, pI. 1; Kurtz and others, 1975, pI. 1 others (1978) suggests that perhaps an that has also yielded faunas of the Crep alternative stratigraphic nomenclature might cephalu8 Zone (Lochman, 1968). Thereforl be appropriate for this interval. The upper the upper oolitic member of the Eau Claire i 18S-foot unit of the Eau Claire Formation is Indiana is considered to correlate with, an the upper of two distinct oolitic limestone perhaps to be an extension of, the UpPE members within the predominantly shaly and Bonneterre of Missouri. silty dolomitic Eau Claire Formation, and it is Buschbach (1964) described the Lombar this member that yields the faunas of the Dolomite Member of the Eau Claire Forml Crepicephalus Zone. In Missouri, the upper tion in northeastern lliinois as a sand PALEONTOLOGY 3 is no precise faunal control on the age of these rocks, the Lombard Dolomite Member D~EpLiH STRATIGRAPHIC FAUNAL DATA AND AGE (FT) NOMENCLATURE INTERPRETATION may also be a tongue of the upper part of the Bonneterre Formation. As better control on the ages and lithologic correlations of r KNOX DOLOMITE Z 4400-+------1 subsurface units in the eastern midcontinent 4900 OJ suggests that tectonic conditions controlling sedimentation patterns in Cambrian time were EAU CLAIRE en perhaps precursors to the formation of the w illinois Basin. c::: Some comments on the biostratigraphic 5000 o and biogeographic significance of the fossils found in the Vermillion County well are FORMATION F Cedaria presented below. 5100 F Zone Paleontology FAUNAS OF FRANCONIAN AGE A 51-foot interval within the Davis Forma Figure 2. Stratigraphic column showing the locations tion, between depths of 4,497 and 4,546 feet of paleontologic control (F) and the suggested stra in the Vermillion County well, includes a tigraphic nomenclature for the fossiliferous Cam· brian part of Vermillion County well FMC No. fauna dominated by disarticulated remains of WD-l. Datum is 5 feet above ground level and 647 trilobites, with rare fragments of linguloid feet above sea level. brachiopods. Thirteen species of trilobites, representing 10 genera, are present. Almost all of them represent genera characteristic of the dolomite with rare limestone interbeds. This Elvinia Zone of early Franconian age. The member ranges from 100 to 150 feet in definitive species for biostratigraphic dating thickness, which is not too much less than the are Eluinia roemeri (Shumard), Eluinia granu thickness of the Bonneterre equivalent (upper lata Resser, Pterocephalia sanctisabae Roe oolite member) in the Vermillion County mer, Bynumina caelata Resser, and Calo well. Although Buschbach included other cephalites cf. C. vulgaris Kurtz. The abun clastics above this dolomite in the Eau Claire dance of specimens of Calocephalites and the Formation of northeastern Illinois and there presence of Bynumina caeiata, both previous 4 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AG ly known only from the Davis Formation of material will be required to adequatel: Missouri (Kurtz, 1975), suggest similar condi characterize the new taxa that they rna: tions of deposition for the Davis Formation in represent. - Indiana and Missouri and emphasize the general faunal similarity of the two regions. Occurrence: Vermillion County well FMC N( Most other elements in the fauna are found in WD-1 at depths of 4,518, 4,518.5, 4,52( the Elvinia Zone throughout the central and 4,520.8, 4,530, 4,531, 4,531.5, 4,533, an, western United States. All but two species 4,546 feet. (represented by material too fragmentary for illustration) in the Vermillion County well are Figured specimens: IU16254 (pI. 1, fig. 14: illustrated on plate 1 and are commented on 4,518 feet; IU16256 (pI. 1, fig. 16), 4,53 briefly below. feet; and IU16255 (pI. 1, fig. 15) an IU16257 (pI. 1, fig. 17), both from 4,531. Genus APHELOTOXON Palmer feet. Aphelotoxon Palmer, 1965, p. 78. Genus BYNUMINA Resser Aphelotoxon? spp. Bynumina Resser, 1942, p. 58. (See Kurtz, 1975, I 1031, for most recent synonymy and discussion Plate 1, figures 14-17 Bynumina caelata Resser Remarks: Several small cranidia are character ized by narrow fixed cheeks, palpebral lobes Plate 1, figures 21, 22 anterior to the glabellar midlength, broad posterior limbs, an anteriorly tapered glabella Bynumina caelata Resser, 1942 (part), p. 58, pI. l( with distinct, short, lateral glabellar furrows, fig. 22 only; Kurtz, 1975, p. 1032, pI. 2, figs. 1·4 and a short frontal area that is strongly arched Bynumina missouriensis Resser, 1942, p. 59, pI. l( transversely. Differences between specimens figs. 23-26. in details of development of the frontal area and in strength of the glabellar furrows Remarks: Small cranidia from three interval suggest that more than one species may be in the Vermillion County well agree in al present. The specimen illustrated in figure 15 observable characteristics with cranidia aE may represent the same taxon as the specimen signed by Kurtz and Resser to B. caelata, figured from the Elvinia Zone of southeastern species previously known only from th, Missouri by Kurtz (1975, pl. 4, fig. 5) as Elvinia Zone in southeastern Missouri. Th "Genus and species undet. 1." Kurtz's two specimens illustrated here show th specimen is distorted, but both show a contrast in expression of the glabellar outUn well-defmed glabella, several glabellar furrows, and glabellar furrows between the externa and a border posteriorly expanded along the surface (pI. 1, fig. 21) and the internal mole sagittal line, so that it nearly touches the (pI. 1, fig. 22) of this species. The smal front of the glabella. Pygidia that are palpebral lobes anterior to the glabella associated with the cranidia (pI. 1, fig. 17) are midlength, the poor development of externa characterized by a long, prominent, well furrows, the broad and bluntly rounde( furrowed axis, and triangular, downsloping, posterior limbs, and the strongly curve( more weakly furrowed pleural regions. posterior pair of glabellar furrows on thl The combined characters of cranidia and internal mold serve to characterize thi pygidia are most similar to those of species of species. Aphelotoxon, a genus previously known only from the slightly older Dunderbergia Zone of Occurrence: Vermillion County well FMC No the Great Basin (Palmer, 1965). None of the WD-l at depths of 4,503, 4,518, and 4,52C Indiana specimens seem to represent any of feet. the described species of Aphelotoxon. More PALEONTOLOGY 5 Figured specimens: IU16261 (pI. 1, fig. 21), 4,503, 4,618, 4,518.5, 4,520, 4,620.8, 4,530, 4,603 feet; IU16262 (pI. 1, fig. 22), 4,520 4,531, 4,533, 4,534, 4,642, and 4,646 feet. feet. Figured specimens: IU16247 (pI. 1, fig. 7), Genus CALOCEPHALITES Kurtz 4,631 feet; IU16248 (pI. 1, fig. 8) and IU16249 (pI. 1, fig. 9), both from 4,531.5 Calocepholites Kurtz, 1975, p. 1022. feet. Calocephalites cf. C. vulgaris Kurtz Genus CHEILOCEPHALUS Berkey Plate 1, figs. 7-9 Cheilocephalus Berkey, 1898, p. 289. (See Palmer, 1968, p. 57, for complete synonymy.) CalocepluJlites vulgaris Kurtz, 1975, p. 1025, pl. 3, figs. 7·9. Cheilocephalus sp. Remarks: Numerous cranidia and a few Plate 1, figure 19 associated free cheeks and pygidia represent a species close to, if not conspecific with, C. Remarks: A single fragmentary pygidium has vulgaris Kurtz. Kurtz's illustrated specimens the distally expanded frontal band of the first have a slightly more inflated glabellar outline, pleural segment and generally broad, concave but otherwise they are similar to the Indiana border of uniform width characteristic of all specimens. species of Cheilocephalus. It is further Free cheeks and pygidia assignable to characterized by a well-developed external Calocephalites have not previously been ornamentation of fine granules on all parts. described. The free cheek is characterized by Two species of Cheilocephalus from the a narrow border well defined by a lateral Elvinia Zone have a granular ornamentation: border furrow that terminates before reaching C. brachyops Palmer (1965, p. 30) from the the posterior border furrow. The posterior Great Basin region and C. buttsi Resser (1942, border furrow continues laterally to the base p. 36) from Pennsylvania. But the pygidium of a moderately short, slender genal spine. of C. brachyops lacks granular ornamentation The pygidium is characterized by a broad, on the border, and there is no information prominent axis with two clear ring furrows about the pygidium of C. buttsi. Without posterior to the articulating furrow and by further material, the specimen is not identi downsloping, triangular pleural regions fiable to species. crossed by pleural and interpleural furrows. The pleural furrows of the second and third Occurrence: Vermillion County well FMC No. pleural segments converge axially with the WD-1 at a depth of 4,503 feet. interpleural furrow at the posterior margin of the preceding segment. A poorly defined, Figured specimen: IU16259. narrow, flat border is present. The structure of the border furrows on the Genus DELLEA Wilson free cheek is characteristic of several species of different genera within the family Elvini Dellea Wilson, 1949, p. 34. (See Grant, 1965, p. 128, idae. The pleural structure of the pygidium is for most recent synonymy.) different from pleural structures so far illustrated for other genera of the Elviniidae, Dellea spp. where the anteriorly converging pleural furrows have not been noted. Perhaps this is Plate 1, figures 10·12 distinctive for Calocephalites. Remarks: At least three species of simple Occurrence: Vermillion County well FMC ptychoparioid trilobites represented by only a WD-1 at depths of 4,497, 4,499.5, 4,501, few cranidia that are characterized by a 6 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AI narrow border, a well-defined and broad Genus ELVINIA Walcott preglabellar field, narrow fixed cheeks, and a glabella with at least two distinct pairs of Elvinia Walcott, 1924, p. 56. (See Palmer, 1965, glabellar furrows are present in faunas of the 43, for complete synonymy.) - Elvinia Zone in the Vermillion County well. They can all be accommodated within the Elvinia roemeri (Shumard) generalized genus Dellea, but without more material, specific identification is not pos Plate 1, figures 1, 4, 5 sible. This genus is widespread in the Elvinia Zone throughtout the United States, and no Dikelocephalus roemeri Shumard, 1861, p. 220. (S regional affinities are indicated by the Kurtz, 1975, p. 1032, for a guide to complE specimens illustrated here. synonymy.) Occurrence: Vermillion County well FMC No. Remarks: Most specimens assignable ~ WD-1 at depths of 4,503, 4,518, and 4,520.8 Elvinia from the Vermillion County wellla( feet. any exoskeletal ornamentation and represel the widespread and common species , Figured specimens: IU16250 (pI. 1, fig. 10), roemeri. The strong transglabellar furrow. 4,520.8 feet; IU16251 (pI. 1, fig. 11), 4,518 front of the occipital furrow, the anterior] feet; IU16252 (pI. 1, fig. 12),4,503 feet. tapered and truncated glabella, and tl narrow, well-defined border are distinctb Genus DRABIA Wilson features of cranidia of this nominal genus ( the early Franconian Elvinia Zone, which Drabia Wilson, 1951, p. 640. represented here by two distinct species, 1 roemeri (Shumard) and E. granulata (Resser Drabia? sp. Occurrence: Vermillion County well FMC N( Plate 1, figure 13 WD-l at depths of 4,501, 4,503, ?4,525. (pygidium only), 4,530, 4,531, 4,531.l Remarks: A single small cranidium has a 4,533, and 4,534 feet. glabella that is bluntly truncated anteriorly and bears two pairs of distinct, short glabellar Figured specimens: IU16241 (pl. 1, fig. 1 furrows. Among trilobites of the Elvinia 4,534 feet; IU16242 (pI. 1, fig. 4), 4,503 fee Zone, the glabellar shape is most similar to IU16243 (pI. 1, fig. 5),4,531 feet. that of specimens assigned by Wilson (1951) to Drabia. But most of Wilson's species have Elvinia granulata Resser broader fixed cheeks, an occipital spine, or strong granular ornamentation. The glabellar Plate 1, figures 2, 3 characters are also suggestive of the older genus Glaphyraspis, but the preglabeUar field Elvinia granulata Resser, 1942, p. 96, pI. 18, figs. 1: on the Indiana specimen is much longer than 12; Palmer, 1960, p. 71, pI. 6, fig. 4; Palmer, 196! on any species assigned to Glaphyraspis. The p. 44, pI. 3, fig. 12. specimen clearly represents another species in Elvinia ruedemanni Resser, 1942, p. 95, pI. 18, fig the fauna, but even its generic identity is not 7·10; Fisher and Hanson, 1951, pI. 1, figs. 1, 2. clear. ?Parairvingella hamburgensis Resser, 1942, p. 27, p 4, figs. 23, 24. Occurrence: Vermillion County well FMC No. WD-l at a depth of 4,497 feet. Remarks: This distinctive species of Elvini£ the only one with a granular ornamentatior Figured specimen: IU16253. is rare but widespread in the Elvinia Zone c PALEONTOLOGY 7 the United States. The specimens illustrated bellar median furrow of this genus is present here are typical and add no new morphologic in one collection from the Vermillion County information about the species. well. Without an associated pygidium, its - species assignment cannot be determined. Occurrence: Vermillion County well FMC No. WD-1 at depths of 4,520 and 4,520.8 feet. Occurrence: Vermillion County well FMC No. WD-1 at a depth of 4,520 feet. Figured specimens: IU16244 (pI. 1, fig. 2), 4,520 feet; IU16245 (pl. 1, fig. 3), 4,520.8 Figured specimen: IU16258. feet. Genus PTEROCEPHALIA Roemer Genus KINDBLADIA Frederickson Pterocephalia Roemer, 1849, p. 421. (See Palmer, Kindbladia Frederickson, 1948, p. 802. (See Palmer, 1968, p. 72, for complete synonymy.) 1965, p. 37, for complete synonymy.) Pterocephalia sanctisabae Roemer Kindbladia? sp. Plate 1, figure 20 Plate 1, figure 6 Pterocephalia sanctisabae Roemer, 1849, p. 421. (See Remarks: A few fragmentary specimens from Kurtz, 1975, p. 1036, for a guide to complete several levels in the Vermillion County well synonymy.) resemble specimens of Calocephalites, but they have narrow, convex fixed cheeks. Remarks: A single incomplete pygidium is Because of this feature, they seem to be more characterized by a broad, poorly defined characteristic of the widespread genus Kind border, a multisegmented axis, and a strong bladia of the Elvinia Zone and are tentatively ornamentation of terrace lines. It agrees in all assigned to it. Without larger samples, the respects with pygidia of the characteristic possibility that these are variants of associated species of the Elvinia Zone, P. sanctisabae. species of Calocephalites cannot be excluded. Occurrence: Vermillion County well FMC No. Occurrence: Vermillion County Well FMC WD-1 at a depth of 4,520.8 feet. No. WD-1 at depths of 4,501, 4,503, and 4,518 feet. Figured specimen: IU16260. Figured specimen: IU16246, 4,518 feet. FAUNAS OF DRESBACHIAN AGE Two levels of the Vermillion County well Genus PSEUDAGNOSTUS Jaekel contain faunas of Dresbachian age. The highest level, represented by a single collec Pseudagnostus Jaekel, 1909, p. 400. (For full tion from a depth of 4,698 feet, contains an discussion and current synonymy of this genus, see assortment of at least four species of trilobites Shergold,1977.) and other fossils characteristic of the Crepicephalus Zone. The most unusual Pseudagnostus sp. feature of the fauna is the rare gastropod Cycloholcus nummus Knight, previously Plate 1, figure 18 known from only seven specimens from an uncertain locality in the Nolichucky Shale of Remarks: A single exfoliated cephalon with Dresbachian age in eastern Tennessee. The full the characteristic bilobed glabella and pregla faunal list for this sample consists of: 8 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) Am Trilobita A pygidium of Blountia-like aspect il Blountia? sp. present in the same sample. It has ~ Kingstonia spp. moderately well defined, slender, tapered axil Llanoaspis? sp. reaching to the inner edge of a poorly definec r Tricrepicephaius sp. border that broadens posteriorly and hal Gastropoda strongly downturned lateral margins. It alS( Cycloholcus nummus Knight has a distinct semiparabolic outline. Pelagiella sp. A somewhat similar cranidium, witt Hyolitha narrower fixed cheeks, was descrbied at Hyolithes sp. "Genus and species undertermined 1" b) Chancellorida Palmer (1954b) from the Coosella Local ZonE Chancelloria sp. in Texas. In an unpublished dissertation, Eb) The lower level, represented by trilobite (1981) recorded a conspecific cranidium frorr bearing shales between 5,061 and 5,083 feet, the lower part of the Crepicephalus Zone OJ contains two species of trilobites: Kormag the House Range, Utah, where it is associate( nostus sp. and Norwoodella sp. Norwoodella, with a Blountia-like pygidium with a semi a characteristic genus of the early Dresbachian parabolic outline. That pygidium, however Cedaria Zone, has been reported from the has its axis also poorly defined. basal part of the Bonneterre Formation in More material is needed to resolve thE Missouri (Lochman, 1940) and from the taxonomic significance of these observations Nolichucky Shale in Tennessee (Rasetti, Until a larger sample can provide assurancE 1965). that the cranidium and pygidium are correctl~ The Dresbachian trilobites and gastropods associated and can also provide somE are illustrated on plate 2 and are commented information about intraspecific variability on briefly below. The specimens of Hyolithes this species, although perhaps distinct, is left and Chancelloria are of little biostratigraphic in open nomenclature. value and are represented only by fragmen tary material. They are not discussed further. Occurrence: Vermillion County well FMC No WD-1 at a depth of 4,698 feet. Trilobita Figured specimens: IU16263 (pI. 2, fig. 1) Genus BLOUNTIA Walcott lU16264 (pI. 2, fig. 2). Blountia Walcott, 1916, p. 396; Palmer, 1965, p. 28 Genus KINGSTONIA Walcott (synonymy to date); Opik, 1967, p. 233. Kingstonia Walcott, 1924, p. 58. (See Palmer, 1962 Blountia? sp. p. 29, for complete synonymy.) Plate 2, figures 1, 2 Kingstonia spp. Remarks: A peculiar species questionably Plate 2, figures 4-10 related to Blountia is represented by cranidia and pygidia. The cranidium differs from all Remarks: Kingstonia is a genus of smal: described Blountia species by lacking a trilobites with most external features effaced distinct preglabellar field. In most other cranidia are moderately convex transversel~ respects, however, such as its generally and longitudinally; pygidia are semicircular tc smooth external surface, poor definition of subtriangular in outline and have a low axil the glabella, slight anterior placement of the that is generally recognizable, lateral margin! palpebral lobes, and the very narrow, that are strongly downturned, and no distinc1 depressed, laterally tapered occipital ring, it border. One type of cranidium and threE conforms to the characteristics of Blountia. different types of pygidia in the single small PALEONTOLOGY 9 sample studied provide inadequate informa Genus KORMAGNOSTUS Resser tion for specific identification in this complex genus. The cranidium has short, blunt Kormagnostus Resser, 1938, p. 49; Palmer, 19Ma, p. - posterior limbs and lacks any trace of the 59; Palmer, 19Mb, p. 718; Howell, 1959, p. 185. narrow bandlike border typical of most species of Kingstonia. All external furrows are Kormagnostus sp. effaced. The general form suggests that this belongs to the group of species similar to Plate 2, figure 17 Kingstonia walcotti Resser. Two of the three pygidial types are nearly Remarks: Among the mostly indeterminate indistinguishable in dorsal view (pl. 2, figs. 6, agnostid fragments from the lower part of the 9). They have an axis that is well defined Vermillion County well, one cephalon has a laterally, has very little posterior taper, and is slightly effaced anterior glabellar lobe and a not defined posteriorly. They differ in the subquadrate posterior glabellar lobe and lacks development of the posterior margin. One any indication of a preglabellar median shows the nearly vertical part of the margin furrow. This combination of characters is increasing in vertical breadth from anterior to typical of species of Kormagnostus. Lack of posterior (pI. 2, fig. 5), and in posterior view any recognizable associated pygidia prevents (pI. 2, fig. 7) the edge is bowed slightly further refinement in the identification of this downward. The other pygidium (pi. 2, fig. 10) species. Kormagnostus, however, is a charac is not so deep at the posterior margin, and teristic genus of early and middle Dresbachian there is a slight upward indentation in the age. posterior median edge. Both of these pygidia have the general morphology of species Occurrence: Vermillion County well FMC No. related to K. walcotti. WD-l at a depth of 5,063 feet. The third pygidium is quite different (pi. 2, fig. 8) and may even represent another genus. Figured specimen: IU16275. Its margins are not so strongly turned down as those of the forms related to K. waicotti, and Genus LLANOASPIS its axis is well defined, clearly tapered, and rounded at its posterior end. The faint knobs Llanoaspis Loehman, 1938, p. 80; Palmer, 19Mb, p. on the axis marking the axial rings resemble 734; Loehman, 1953, p. 891; Lochman, 1959, p. axial features of pygidia of members of the 301. Blountiidae. Although the pygidium has an outline and pleural regions seemingly more Llanoaspis? sp. like a Kingstonia, it might be an immature pygidium of a member of the Blountiidae. It Plate 2, figure 13 is comparable in size to mature Kingstonia pygidia, however, and is retained here with Remarks: A single incomplete pygidium has some uncertainty. pleural furrows that are distinctly geniculated Because of the small sample size and the posteriorly as they cross onto a poorly complex and confused taxonomy within defined, anteriorly expanded border area. Kingstonia, confident identifications of these This is a characteristic feature of the genus species are not possible. Llanoaspis, although the border is usually expanded even more anteriorly on most Occu1Tence: Vermillion County well FMC No. species. Despite the questionable generic WD-l at a depth of 4,698 feet. assignment of the specimen, this kind of pygidial morphology is found only on Figured specimens: IU16266 (pI. 2, fig. 4); trilobites in rocks of early and middle IU16267 (pI. 2, figs. 5-7); IU16268 (pl. 2, fig. Dresbachian age, so that, even in the absence 8); IU16269 (pI. 2, figs. 9, 10). of the associated specimens, this would have 10 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AGl been a useful bit of paleontologic evidence for diagnostic genus Tricrepicephalus of th, the age of the sample. Crepicephalus Zone. Without associated parts identification cannot be made at the specifil Occurrence: Vermillion County well FMC No. level. WD-1 at a depth of 4,698 feet. Occurrence: Vermillion County well FMC No Figured specimen: IU16272. WD-1 at a depth of 4,698 feet. Genus NORWOODELLA Resser Figured specimen: IU16265. Norwoodella Resser, 1938, p. 89; Lochman, 1959, p. Gastropoda 303. Genus CYCWHOLCUS Knight Norwoodella sp. Cycloholcus Knight, 1947, p. 5. Plate 2, figure 18 Cycloholcus nummus Knight Remarks: Several poorly preserved, fragmen tary, narrow cranidia in green shales have the Plate 2, figures 14-16 moderately well defined, anteriorly tapered glabella, anteriorly placed palpebral lobes, and Cycloholcus nummus Knight, 1947, p. 5, pI. 1, fig! elongate, undivided frontal area characteristic 3a·d; Knight and others, 1960, p. 172, fig. 89.1. of species of Norwoodella. None of the specimens have the distinctive large proparian Remarks: Two specimens of a planispirall: posterior limbs preserved. Except for the coiled gastropod with a roughly dumbbel gently curved anterior margin, this species is shaped transverse section to the WhOl most similar to Norwoodella halli Resser from conform in all observable aspects to th the Nolichucky Shale of Tennessee (Rasetti, specimens of C. nummus figured by Knigh 1965) and the basal Bonneterre Dolomite of (1947). No other Cambrian gastropod ha southeastern Missouri (Lochman, 1940). such a distinctive whorl profile. This specie Absence of posterior limbs and other seems to be a rare guide to rocks of middl, associated parts precludes a meaningful Dresbachian age. specific identification. Occurrence: Vermillion County well FMC No Occurrence: Vermillion County well FMC No. WD-1 at a depth of 4,698 feet. WD-1 at depths of 5,063 and 5,083 feet. Figured specimens: IU16273 (pI. 2, fig. 14) Figured specimen: IU16276, 5,083 feet. IU16274 (pI. 2, figs. 15, 16). Genus TRICREPICEPHALUS Kobayashi Genus PELAGIELLA Tricrepicephalus Kobayashi, 1935, p. 278. (See Pe/agiella Matthew, 1895, p. 131; Knight and others Lochman, 1959, p. 250, for complete synonymy.) 1960, p. 323 (see this for complete synonymy tl that date); Vostokova, 1962, p. 64; Rozanov anc Tricrepicephalus sp. Missarzhevskiy, 1966, p. 101; Matthews ane Missarzhevskiy, 1975, p. 295. Plate 2, figure 3 Pelagiella sp. Remarks: A single mold of a pygidium has the long, divergent posterolateral spines coupled Plate 2, figures 11, 12 with a short, blunt axis as wide as the pleural regions that typify the widespread and Remarks: Several small gastropods witt LITERATURE CITED 11 rapidly expanding whorls and different Howe, W. B., Kurtz, V. E., and Anderson, K. H. degrees of development of growth lines are 1972 - Correlation of Cambrian strata of the assignable to this generalized Cambrian genus. Ozark and upper Mississippi Valley The sample is too small to determine whether regions: Missouri Div. Geol. Survey r forms typified by those that are illustrated and Water Resources Rept. Inv. 52, represent variants within a species or repre 68p. sent different species. Howell, B. F. 1959 . in Harrington, H. J., and others, Treatise Occurrence: Vermillion County well FMC No. on invertebrate paleontology, pt. 0, WD-l at a depth of 4,698 feet. Arthropoda 1: New York and Law rence, Kans., Geol. Soc. America and Figured specimens: IU16270 (pI. 2, fig. 11); Kansas Univ. Press, 560 p. IU16271 (pI. 2, fig. 12). Jaekel, O. 1909 - Uber die Agnostiden: Deutsch. Geol. Literature Cited Gesell. Zeitschr., v. 16, p. 380-401. Becker, L. E., Hreha, A. J., and Dawson, T. A. Knight, J. B. 1978 - Pre-Knox (Cambrian) stratigraphy in 1947 - Some new Cambrian bellerophont gastro Indiana: Indiana Geol. Survey Bull. pods: Smithsonian Misc. Colin., v. 57,72 p. 106, no. 17, 11 p. Berkey, C. P. Knight, J. B., and others 1898 - Geology of the St. Croix Dalles: Am. 1960 . Part I, Mollusca 1, in Treatise on Geologist, v. 21, p. 270-294. invertebrate paleontology: New York Buschbach, T. C. and Lawrence, Kans., Geol. Soc. 1964 - Cambrian and Ordovician strata of north America and Kansas Univ. Press, eastern llIinois: Illinois Geol. Survey 351 p. Rept_ Inv. 218, 90 p. Kobayashi, Teiichi Ehy, R. G. 1935 - The Cambro-Ordovician formations and 1981 - Early Late Cambrian trilobite faunas of faunas of south Chosen: Paleontology the Big Horse Limestone and correla Pt. 3: Tokyo Univ. Fac. Sci. Jour., sec. tive units in central Utah and Nevada 2, v. 4, p. 49-344. [unpub. Ph. D. dissert.]: State Univ. Kurtz, V. E. of New York at Stony Brook. 1975 - Franconian (Upper Cambrian) trilobite Fisher, D. W., and Hanson, G. F. faunas from the Elvins Group of 1951 - Revisions in the geology of Saratoga southeast Missouri: Jour. Paleon Springs, New York, and vicinity: Am. tology, v. 49, p. 1009-1043. Jour. Sci., v. 249, p. 795-814. Kurtz, V. E., Thacker, J. L., Anderson, K. H., and Frederickson, E. A. Gerdemann, P. E. 1948 - Upper Cambrian trilobites from Okla 1975 . Traverse in Late Cambrian strata from the homa: Jour. Paleontology, v. 22, p. St. Francois Mountains, Missouri to 798-803. Delaware County, Oklahoma: Missouri Grant, R. E. Div. Geol. Survey and Water Resources 1965 - Faunas and stratigraphy of the Snowy Rept. Inv. 55, 112 p. Range Formation (Upper Cambrian) in Lochman, Christina southwestern Montana and northwes 1938 - Upper Cambrian faunas of the Cap tern Wyoming: Geol. Soc. America Mountain Formation of Texas: Jour. Mem. 96, 171 p. Paleontology, v. 12, p. 72·85. Grohskopf, J. G. 1940 - Fauna of the basal Bonneterre Dolomite 1955 - Subsurface geology of the Mississippi (Upper Cambrian) of southeastern Embayment of southeast Missouri: Missouri: Jour. Paleontology, v. 14, p. Missouri Div. Geol. Survey and Water 1·53. Resources [Rept.], v. 37, 2d ser., 1953 - Analysis and discussion of nine Cambrian 133p. trilobite families: Jour. Paleontology, v. 27, p. 889-896. ------...... --...... 12 FOSSILS OF DRESBACHIAN AND FRANCONIAN (CAMBRIAN) AGl Lochman, Christina Resser, C. E. 1959 - in Harrington, H. J., and others, Treatise 1938 - Cambrian System (restricted) of thl on invertebrate paleontology, pt. 0, southern Appalachians: Geol. Soc Arthropoda 1: New York and Law America Spec. Paper 15, 140 p. - rence, Kans., Geol. Soc. America and 1942 - New Upper Cambrian trilobites: Smith Kansas Univ. Press, 560 p. sonian Misc. Colln., v. 103, no. 5 1968 - Crepicephalus faunule from the Bonne 136p. terre Dolomite (Upper Cambrian) of Roemer, Ferdinand Missouri: Jour. Paleontology, v. 42, p. 1849 - Texas, mit besondered Riicksicht au 1153-1162. deutsche Auswanderung und die physi :Matthew, G. F. schen Verhaltnisse des Landes: Bonn 1895 - The Protolenus fauna: New York Acad. 464 p. Sci. Trans., v. 14, p. 101-153. Rozanov, A. Yu. and Missarzhevskiy, V. V. :Matthews, S. C., and Missarzhevskiy, V. V. 1966 - Biostratigraphy and faunas of the lowe 1975 . Small shelly fossils of late Precambrian horizons of the Cambrian: Akad. Naul and Early Cambrian age: a review of SSSR Geo!. Inst. Trudy, v. 148, P recent work: Geo!. Soc. London 5-119 [in Russian]. Quart. Jour., v. 131, p. 289-304. Shergold, J. H. Opik, A. A. 1977 - Classification of the trilobite Pseudag 1967 - The Mindyallan fauna of north-western nostus: Paleontology, v. 20, p. 69·100 Queensland: Australia Bur. Mineral Shumard, B. F. Resources Geology and Geophysics 1861 . The primordial zone of Texas, witt Bull. 74, 404 p. descriptions of new fossils: Am. Jour Palmer, A. R. Sci., 2d scr., v. 32, p. 213-221. 1954a - An appraisal of the Great Basin Middle Vostokova, V. A. Cambrian trilobites described before 1962 - Cambrian gastropods of the Siberiar I 1900: U.S. Geol. Survey Prof. Paper Platform and Taimyr: Sbornik Statei 264-D, p. 55-86. po Paleontologii i biostratigrafii, v. 28 19Mb - The faunas of the Riley Formation in p. 53-74 [in Russian]. central Texas: Jour. Paleontology, v. Walcott, C. D. 28, p. 709-786. 1916 - Cambrian trilobites: Smithsonian Misc 1960 . Trilobites of the Upper Cambrian Dunder Colin., v. 64, no. 5, p. 303-456. berg Shale in the Eureka district, 1924 - Cambrian and lower Ozarkian trilobites Nevada: U.S. Geol. Survey Prof. Paper pt. 5, no. 2, of Cambrian geology and 3M-C, p. 53-109. paleontology: Smithsonian Mise 1962 - Glyptagnostus and associated trilobites in Colin., v. 75, no. 2, p. 53-60. the United States: U.s. Geot. Survey Wilson, J. L. Prof. Paper 374-F, p. Fl-F49. 1949 - The trilobite fauna of the Elvinia Zone in 1965 - Trilobites of the Late Cambrian Ptero the basal Wilberns limestone of Texas: cephaliid biomere in the Great Basin, Jour. Paleontology, v. 23, p. 25-44. United States: U.S. Geol. Survey Prof. 1951 - Franconian trilobites of the central Paper 493, 105 p. Appalachians: Jour. Paleontology, v, 1968 - Cambrian trilobites of east-central Alaska: 25, p. 617 -654. U.S. Geol. Survey Prof. Paper 559-B. p. B1-B115. Rasetti, Franco 1965 - Upper Cambrian trilobite faunas of northeastern Tennessee: Smithsonian Misc. Colin., v. 148, no. 3. 127 p. r Plates 1-2 - PLATE 1 Elvinia Zone 1,4, 5 Elvinia roemeri (Shumard) 1. Latex cast of cranidium, X2, IU16241, 4,534 feet. 4. Cranidium, X3, IU16242, 4,503 feet. 5. Pygidium, X2, IU16243, 4,531 feet. 2, 3 Elvinia granulata Resser 2. Cranidium, X3, IU16244, 4,520 feet. 3. Cranidium, X3, IU16245, 4,520.8 feet. 6 Kindbladia? sp. Cranidium, X6, IU16246, 4,518 feet. 7-9 Calocephalites cf. C. vulgaris Kurtz 7. Latex cast of cranidia, X3, IU16247, 4,531 feet. 8. Latex cast of free cheek, X3, IU16248, 4,531.5 feet. 9. Pygidium, X3, IU16249, 4,531.5 feet. 10-12 Dellea spp. 10. Cranidium, X4, IU16250, 4,520.8 feet. 11. Cranidium, X5, IU16251, 4,518 feet. 12. Cranidium, X10, IU16252, 4,503 feet. 13 Drabia? sp. Cranidium, X15, IU16253, 4,497 feet. 14-17 Aphelotoxon? spp. 14. Cranidium, X8, IU16254, 4,518 feet. 15. Cranidium, X8, IU16255, 4,531.5 feet. 16. Latex cast of cranidium, X8, IU16256, 4,531 feet. 17. Pygidium, X6, IU16257, 4,531.5 feet. 18 Pseudagnostus sp. Cephalon, X5, IU16258, 4,520 feet. 19 Cheilocephalus sp. Pygidium, X5, IU16259, 4,503 feet. 20 Pterocephalia sanctisabae Roemer Pygidium, X2, IU16260, 4,520.8 feet. 21,22 Bynumina caelata Resser 21. Cranidium with external surface preserved, X10, IU16261, 4,503 feet. 22. Exfoliated cranidium, X10, IU16262, 4,520 feet. All specimens illustrated here are deposited in the collections of the Indiana Geological Survey and bear the indicated IU catalog numbers. ------...... -~--...... --.~.-...... ----- DEPT. "'AT. RESOURCES, GEOL. SURVEY SPECIAL REPORT 29 PLATE I r 2 3 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 TRILOBITES OF FRANCONIA." AGE - PLATE 2 Crepicephalus Zone 1, 2 Blountia? sp. 1. Cranidium, X10, IU16263, 4,698 feet. 2. Pygidium, X8, IU16264, 4,698 feet. 3 Tricrepicephalus sp. Latex cast of a pygidium, X3, IU16265, 4,698 feet. 4-10 Kingstonia spp. 4. Cranidium, XI0, IU16266, 4,698 feet. 5,6,7. Left lateral, X15, top and posterior views, X8, of pygidium, IU16267, 4,698 feet. 8. Latex cast of pygidium, X8, IU16268, 4,698 feet. 9,10. Top and posterior views of pygidium, X8, IU16269, 4,698 feet. 11, 12 Pelagiella sp. 11. Side view, X10, IU16270, 4,698 feet. 12. Side view, X10, IU16271, 4,698 fet. 13 Llanoaspis? sp. Pygidium, X10, IU16272, 4,698 feet. 14·16 Cyciohoicus nummus Knight 14. Side view, X3, IU16273, 4,698 feet. 15,16. Side and posterior olbique views, X3, IU16274, 4,698 feet. Cedaria Zone 17 Kormagnostus sp. Cephalon, X8, IU16275, 5,063 feet. 18 Norwoodella sp. Cranidium, X 5, IU16276, 5,083 feet. All specimens illustrated here are deposited in the collections of the Indiana Geological Survey and bear the indicated IU catalog numbers. DEPT. NAT. RESOURCES, GEOL. SURVEY SPECIAL REPORT 29 PLATE 2 r 2 3 6 4 7 8 9 10 II 12 13 17 14 15 16 18 TRILOBITES AND GASTROPODS OF DRESBACHIAN AGE