Wright, Robert P. - pdfs.semanticscholar.org · All specimens were deposited in the Orton Museum at The Ohio State University in Columbus, Ohio and designated with OSU num-bers. SEM

The Ohio State University

1976-09

Occurrence, Stratigraphic Distribution, and

Abundance of Chitinozoa from the Middle

Devonian Columbus Limestone of Ohio

Wright, Robert P. The Ohio Journal of Science. v76, n5 (September, 1976), 214-224http://hdl.handle.net/1811/22397

Downloaded from the Knowledge Bank, The Ohio State University's institutional repository

Knowledge Bank kb.osu.edu

Ohio Journal of Science (Ohio Academy of Science) Ohio Journal of Science: Volume 76, Issue 5 (September, 1976)

http://kb.osu.edu

http://hdl.handle.net/1811/22397

OCCURRENCE, STRATIGRAPHIC DISTRIBUTION, ANDABUNDANCE OF CHITINOZOA FROM THE MIDDLEDEVONIAN COLUMBUS LIMESTONE OF OHIO1

ROBERT P. WRIGHT, The Department of Geology and Mineralogy, The Ohio State University,Marion, Ohio

Abstract. Chitinozoa from the Middle Devonian Columbus Limestone of centralOhio belong to eight species of the genera Alpenachitina, Ancyrochitina, Angochitina,Conochitina, Desmochitina, and Eisenackitina. Two new species, Ancyrochitinafrankeli and Eisenackitina robusta, are described. The Chitinozoa occur in carbonaterocks such as mudstone, grainstone and packstone that represent well circulated openmarine conditions. They are absent from dolomite which represents sediment de-posited at a shallow water depositional site characterized by restricted water cir-culation. Comparison of the Columbus Limestone Chitinozoa with faunas fromsimilar Middle Devonian strata in Iowa, Illinois, and Missouri indicates that theMiddle Devonian Wabash Platform, located in Indiana, effectively restricted the dis-tribution of chitinozoans in the Illinois and Appalachian Basins.

OHIO J. SCI. 76(5): 214, 1976

Chitinozoa were first described in the193()'s by the German scientist A.Eisenack (1930, 1931) from Silurian gla-cial erratics in the Baltic region ofEurope. Since that time interest in thisgroup of extinct organic-walled micro-organisms has grown in Europe and theAmericas as exemplified by the recentmonographic treatment of the group(Combaz et al, 1967; Taugourdeau et al,1967). The interest of North Americanpaleontologists in this group of fossilshas grown steadily since the 1950's.

The importance of Chitinozoa is two-fold. They are abundant and easily ex-tracted from strata of Ordovician throughDevonian age and, as some of the formsmay have been members of the lowerPaleozoic zooplankton (Chaiffetz, 1972),their biostratigraphic value is obvious.The presence of Chitinozoa in the Co-lumbus Limestone as well as faunas fromstrata of similar age elsewhere in theMidwest (Urban, 1972; Urban and New-port, 1973; Legault, 1973; Wood, 1974)suggest their potential importance for therefinement of the biostratigraphy of Mid-dle and Upper Devonian strata in North

xManuscript received January 28, 1976 and inrevised form May 18, 1976 (#76-11).

America. Second, Chitinozoa appear tobe useful bathymetric indicators (Wil-liams and Sarjeant, 1967; Gray et al,1974). Laufeld (1975) has noted, in theSilurian of Gotland, Chitinozoa diversityand abundance increase away fromreefoid detrital limestones in the directionof deeper water.

The dominant feature of the MiddleDevonian paleogeography of Indiana,Illinois, and Ohio is now recognized asconsisting of a broad shallow water car-bonate shelf (Droste et al, 1975). Thatshelf, called the Wabash Platform, con-trolled the sedimentology of adjacent ba-sins in Missouri, Iowa, Illinois, Michigan,and Ohio. It must have influenced thespatial and temporal distribution of themarine plankton and members of thebenthic fauna. In this regard, the de-scription of the Columbus LimestoneChitinozoa is the necessary first step inestablishing the degree of Chitinozoafaunal interchange in the Illinois, Michi-gan, and Appalachian Basins. The pur-pose of this paper is to describe the oc-currence, stratigraphic distribution, andabundance of Chitinozoa in the MiddleDevonian Columbus Limestone in north-central Ohio.

214

No. 5 COLUMBUS LIMESTONE CHITINOZOA 215

METHODS AND MATERIALSCollections for this study were obtained from

the Hamilton Brothers Quarry near Marion,Ohio. The Columbus Limestone is well ex-posed and stratigraphically complete at thislocality (tig. 1). The strata were examined indetail in order to determine the depositional

environments represented by the various car-bonate lithofacies and to attempt to identifythe environmental occurrence of the Chitinozoa.

Fresh samples were taken systematically attwo-foot vertical intervals or at every changein lithology. In all, 41 samples were treatedusing the following techniques. Fifty grams

Abundance of chitinozoansin 50 grams of rock

Legend

Bivalves £ > J Grainstone ^ J Ripple marks

Bone bed | ^ | Horn corals | @ | Sample number

Brachiopods 1 Mudstone J Shale

Bryozoans [—H Oil stain | ^ | Stromatoporoids

Chert \Mi Packstone \~~[ Stylolites

Dolomite | ^ | Pelmatozoans [<Hh] Colonial corals

[ ^ 1 Calcite-f i l ledvugs

FIGURE 1. Stratigraphic section of the Columbus Limestone exposed in the Hamilton BrothersQuarry. The section shows the vertical destribution of carbonate lithofacies andChitinozoa.

216 ROBERT P. WRIGHT Vol. 76

from each sample were placed in beakers andcovered with concentrated HC1. After the re-action ceased, the acid was diluted and sedi-ment washed by filling the beaker with tapwater and sieved according to a procedure de-scribed by Laufeld (1974). The sieving clothhad a mesh distance of 45 microns.

After sieving and washing, the residue waspoured into a beaker and treated with concen-trated HF, and allowed to stand for 24 hoursuntil the silica was digested. The acid wasthen diluted with water and the residue sieved,washed, and stored in small vials filled withdistilled water. Identification and counts ofeach taxon were made and recorded. The bestspecimens were removed from the beakers witha finely drawn glass pipette and prepared forscanning electron microscopy. Four to sixspecimens were mounted on a glass coverslipusing a graphite adhesive. The specimens werecoated with gold in a vacuum apparatus andstudied using a Cambridge S4 Stereoscan(SEM).

All specimens were deposited in the OrtonMuseum at The Ohio State University inColumbus, Ohio and designated with OSU num-bers. SEM stubs containing the specimens arecoded thusly: In 1-29, 1 = stub number, 29= fieldnumber.

GENERAL STRATIGRAPHY ANDDEPOSITIONAL FRAMEWORK

Columbus Limestone crops out in anarrow belt from the Columbus areanorth to Kelly's Island in Lake Erie.In central Ohio the formation consists ofa lower dolomite unit and an upper lime-stone unit. At the Hamilton Quarry thedolomite is less than 25 feet thick, rela-tively unfossiliferous and banded withhydrocarbons (fig. 1). The dolomite wasdeposited in shallow water with restrictedcirculation when submergence of the low-lying weathered craton took place duringEarly and Middle Devonian. The over-lying fossiliferous limestone was depositedin an open marine environment with good

water circulation. At the HamiltonQuarry, the so-called "coral-stromato-poroid zone" is well developed, andmarks the beginning of open marine con-ditions. The association of stromatopor-oid sponges, tabulate and rugose coralsthat characterizes this unit representsstabilization of the mud substrate bybottom dwelling "carpeting" organisms.

The skeletal-poor mudstone above thebiostrome is a low energy, below wave-base deposit (Chapel, 1975). The oc-currence of the mudstone above the bio-strome indicates deepening of the waterover the coral-stromatoporoid studdedshallow platform.

The fossiliferous packstone midwaythrough the section records regression orshallowing of the water. The abundanceof specimens of Brevispirifer gregarious aswell as the appearance of other species ofbrachiopods, corals, molluscs, bryozoans,and pelmatozoans indicate that circula-tion kept the bottom relatively free oflarge amounts of carbonate mud thatwould have smothered many of the filterand suspension feeders.

The cherty mudstones near the top ofthe stratigraphic section do not containlarge quantities of skeletal material, ex-cept Chitinozoa. The mudstones repre-sent a semi-restricted above wave-basedeposit, perhaps deposited in an environ-ment that was somewhat lagoonal. Thepeaks in abundance of the Chitinozoa inthe cherty mudstone indicate that therate of sedimentation at this time wasless than when the packstones and grain-stones were deposited.

The grainstone in the uppermost por-tion of the Columbus Limestone, with its

EXPLANATION OF FIGURE 2No. 1-6. Scanning electron micrographs of Ancyrochitina frankeli Wright, n. sp.

1. Paratypc, OSU 32159, X600, 4-32.2. Paratype, OSU 32158, X900, 4-32, high magnification showing the oral end of the

specimen.3. Paratype, OSU 32157, X450, 4-32.4. Paratype, OSU 32156, X525, 3-31, note the clavate basal spine.5. Holotype, OSU 32155, X525, 3-31, specimen shows the long neck in proportion to the

body chamber and the bifurcating neck and basal spines.6. Paratype, OSU 32154, X525, 3-31, note absence of neck spines.

No. 7-9. Scanning electron micrographs of Alpenachitina eisenacki Dunn and Miller, 1964.7. Note the small spines at the base, OSU 32153, X575, 2-35.8. Specimen showing the delicate branching of the vesicle spines, OSU 32152, X575,

2-40.9. Note the length of the neck in comparison to the body chamber, OSU 32151, X575,

1-29.


FIGURE 2


crinoidal debris, abraded ripples (Bates,1971), and bone beds representing lagconcentrations, abruptly changing tomudstone in the overlying DelawareLimestone indicates transgression andsubmergence.

CHITINOZOA

Representatives of six genera and eightspecies of Chitinozoa were collected fromthe Columbus Limestone. Their distri-bution is not random through the sectionas they are more abundant in the mud-stones than in the grainstones and pack-stones. Their small numbers in thecoarse-grained sediments do not appearto be a function of selective preservation,as well preserved specimens of forms withdelicate spines (e.g., Alpenachitina eisen-acki) are common in these deposits.

It is apparent that Chitinozoa are ab-sent in the dolomite below the coral-stromatoporoid layer. Their absence wasnot caused by vescile destruction duringdolomitization because the Chitinozoa arepresent and well preserved in the dolo-mitized mudstone immediately above thecoral-stromatoporoid interval. The ab-sence of Chitinozoa in the dolomite andfirst occurrence above the coral-stroma-toporoid interval is interpreted as atransition from a nearshore restrictedshallow water environment to an off-shore, deeper water area with well circu-lated water.

Ancyrochitina frankeli (fig. 2) domi-nates the chitinozoan fauna in the chertymudstone. The great abundance of A.frankeli, well over 1,000 specimens per 50grams of rock, stands out in comparison

to the relative abundance of the otherspecies throughout the rest of the section.Cramer (1970) has suggested that anenormous increase in the abundance ofChitinozoa within just a few inches ofrock may represent a planktic bloomsimilar to blooms in modern coastalwaters. An alternative, and probablycorrect, explanation is that the increasein numbers of specimens is a conse-quence of the relatively slower sedimen-tation rate of the mudstone in compari-son to the coarser-grained carbonates.The Columbus Limestone, by being de-posited in very shallow water, precludesplanktic blooms from being recorded.

The regional distribution pattern ofChitinozoa suggests that the WabashPlatform influenced their geographic dis-tribution. Ancyrochitina frankeli, Cono-chitina inflata, and Eisenackitina robustaappear to be unique to Middle Devonianstrata in Ohio and Ontario in so far asthese species are not part of the chiti-nozoan faunas of the Cedar Valley For-mation and Wapsipinicon Formation ofIowa and northwestern Illinois or theCedar City Formation in Missouri.

Ancyrochitina frankeli and Conochitinainflata are known from the Silica Forma-tion (Wood, 1974) in northeastern Ohio,the Dundee Limestone (Hill, 1975) nearSt. Mary's, Ontario and the ColumbusLimestone as reported here. Specimensreferred to as Eisenackitina robusta havenot been reported from Middle Devoniansediments, other than the ColumbusLimestone.

In spite of the apparent effectiveness ofthe broad shallow platform in acting as a

EXPLANATION OF FIGURE 3No. 1-5. Scanning electron micrographs of Desmochitina arunea Urban, 1972.

1. Specimen shows the slight bulge at the base of the chamber, OSU 32168, X500, 10-41.2. Note the ornamentation of short verrucae that is characteristic of this species when

the periderre is preserved, OSU 32167, X575, 9-41.3. Note the prominent membranous collar that is devoid of ornamentation, OSU 32166,

X575, 9-41.4. Shows the cylindro-oval shape which is typical for the species, OSU 32165, X575,

8-41.5. Specimen shows the basal callus, OSU 32164, X575, 7-41.

No. 6. Scanning electron micrograph of Ancyrochitina sp.6. Note the abnormally directed basal spines, OSU 32163, X500, 6-35.

No. 7-9. Scanning electron micrograph of Ancyrochitina cf. A . langei Sommer and van Boekel, 1964.7. An 4 . langei type, OSU 32162, X525, 3-31.8. Specimen shows how the spines are unbranched and curl in an oral direction, OSU

32161, X550, 4-29.9. Note the appendices are attached without any connection to the vesicle interior,

OSU 32160, X500, 5-29.

No. 5 COLUMBUS LIMESTONE CHITINOZOA

2

219

FIGURE 3


faunal barrier to some species in the Mid-west, geographic isolation between theeastern (Ohio, Ontario, Michigan) andwestern (Iowa, Illinois, Missouri) portionsof that platform was not complete.Desmochitina aranea, Alpenachitina eisen-acki, and Angochitina devonica are com-mon to Middle Devonian sediments de-posited along both sides of the WabashPlatform. Mapping the distribution ofchitinozoans from Middle Devonianstrata in Indiana and in Illinois will helpdetermine the degree of faunal inter-change between the areas east and westof the platform and permit comparisonwith Chitinozoa faunas from Middle De-vonian strata in Iowa, Missouri andOntario.

Most of the species of Chitinozoa inthe Columbus Limestone, except Eisen-ackitina robusta, occur in the Middle Dev-onian strata elsewhere in the Midwest.With my findings of Alpenachitina eisen-acki and Desmochitina aranea in the Co-lumbus Limestone, the stratigraphic rangeof these species is now extended to includethe entire Middle Devonian. Conochi-tina inflata and Ancyrochitina frankeliare now known to occur in the ColumbusLimestone, Dundee Limestone, and SilicaFormation, representing Eifelian andearly Givetian strata of the MiddleDevonian in North America.

SYSTEMATIC PALEONTOLOGYCHITINOZOA, Eisenack, 1931

Genus AlpenachitinaDunn and Miller, 1964

Type species:Alpenachitina eisenacki Dunn and

Miller, 1964

Alpenachitina eisenacki Dunn andMiller, 1964Fig. 2 (7-9)

Genus Ancyrochitina Eisenack, 1955Type species:

Conochitina ancyrea Eisenack, 1931Ancyrochitina frankeli n. sp.

Fig. 2 (1-6)

Ancyrochitina cf. A. ancyrea (Eisenack)(Wood, G., 1974, p. 135, pi. 7, figs. 1, 2).

FIGURE 4. Drawing of Angochilina devonicashowing the specimens profile andnearly circular, elevated spine at-tachment scars distributed ran-domly on the vesicle.

EXPLANATION GF FIGURE 5No. 1-2. Scanning electron micrographs of Conochitina inflata Wood, 1974.

1. Note the swollen shoulder, characteristic of the species, OSU 32177, X500, 6-17.2. Specimen shows the swollen base of the cylindrical vesicle, OSU 32176, X500, 12-17.

No. 3-9. Scanning electron micrograph of Eisenackitina robusta Wright, n. sp.3. Paratype, OSU 32175, X500, 12-17, heavily ornamented aboral portion of the vesicle

wall and the well defined collar.4. Paratype, OSU 32174, X600, 11-13, the surface of this specimen is relatively smooth

due to degradation of the ornamentation.5. Paratype, OSU 32173, X500, 10-13, note how the ornamentation is greatest on the

aborally inflated portion of the vesicle.6. Holotype, OSU 32172, X500, 10-13, note the expanded aboral portion of the chamber

and the coarsely verrucate ornamentation which characterizes this species.7. Paratype, OSU 32171, X575, 13-16.8. Paratype, OSU 32170, X575, 6-16, specimen shows the prominent basal callus.9. Paratype, OSU 32169, X450, 11-16, note the ornamentation.


FIGURE 5


Derivation of name: In honor of Dr.Larry Frankel, paleontologist at the Uni-versity of Connecticut.

Description: The vesicle is cylindro-conical to pyriform with a flat or slightlyconvex base. Vesicle collapse results ina convex base and a compressed neck andbody chamber. Ornamentation consistsof basal and neck spines, both of whichvary in number, size, and shape. Basalspines are in most cases 4 to 6 in number,but may be up to 8, are hollow, long, andcommonly delicately bifurcated at theirtips. Several specimens possess clavatespines. Spines may be thick or thin andboth types may occur on the same speci-men. The spines on the neck vary inshape from short, thick spikes to longdelicate simple or bifurcating ones. Acollar is often distinguishable. The sur-face of the vesicle is usually smooth,however some specimens have a finelyverrucate ornamentation.

Dimensions: Population from the typestratum in microns: length (excel.) 120-195 (holotype 140), width (exl.) 60-100(holotype 66), maximum length of basalspines 30 (holotype 30).

Types: Holotype OSU 32155, Para-types OSU 32154, 32156, 32157, 32158,32159.

Type stratum and locality: Cherty lime-stone (sample 31), forty feet above the"coral-stromatoporoid zone," the Co-lumbus Limestone, Hamilton BrothersLime and Stone Quarry, Marion, Ohio.

Discussion: Ancyrochitina frankeli isthe most abundant chitinozoan species inThe Columbus Limestone. More than3,000 specimens were examined. Al-though the vesicle morphology is some-what variable, the species is distinct inits pyriform to cylindro-conical shapewhich resembles that of Ancyrochitinaancyrea. A. ancyrea is reported to havea long stratigraphic range (Ordovicianthrough Devonian) and to be a cosmo-politan form. Laufeld (1974) has re-stricted the scope of the species and re-ports it as characteristic of the Silurian.Specimens of A. ancyrea reported fromthe Devonian may not be conspecificwith the A. ancyrea of the Silurian.Pichler's (1971) figured specimens of A.ancyrea from the Devonian of the EifelSynclinorium, West Germany, and those

reported by Taugourdeau (1965) fromFrance possess sharply conical bodychambers with a shorter neck than theSilurian forms from Gotland. Repre-sentatives of A. frankeli from the Eifelianand Givetian of North America exhibit adifferent silhouette than do the specimensillustrated by Pichler and Taugourdeauin that the body chamber is not as sharplyconical and the neck much longer in pro-portion to the body chamber. In addi-tion, the basal spines of A. frankelitypically bifrucate at their distal ends,whereas those of Pichler's specimens aremultibranched. Individuals of A. frankelihave broadly based and often clavatebasal spines and, when present, longdelicate neck spines which distinguishthem from the Gotland specimens (Lau-feld, 1974). A. frankeli, therefore, is adistinct species characteristic of the Mid-dle Devonian. The form has not beenreported from any other North Americanlocalities outside Ontario (Hill, 1975) andnorthern Ohio (Wood, 1974).

Ancyrochitina cf.A. langei Sommer and van Boekel, 1964

Fig. 3 (7-9)

Ancyrochitina sp.Fig. 3 (6)

Genus Angochitina Eisenack, 1931Type species:

Angochitina echinata Eisenack, 1931Angochitina devonica Eisenack, 1955

Fig. 4

Genus Conochitina Eisenack, 1931Type species:

Conochitina claviformis Eisenack, 1931Conochitina inflata Wood, 1974

Fig. 5 (1-2)

Genus Desmochitina Eisenack, 1931Type species:

Desmochitina nodosa Eisenack, 1931Desmochitina aranea Urban, 1972

Fig. 3 (1-5)

Genus Eisenackitina Jansonius, 1964Type species:

Eisenackitina castor Jansonius, 1964Eisenackitina robusta n. sp.

Fig. 5 (3-9)

Derivation of name: Latin robusta,


physically strong and powerful referringto the general appearance of the vesicle.

Description: Vesicle is subconical tosubcylindrical with sides that vary fromslightly to strongly convex. The shoulderis distinct; the neck is reduced to a narrowcollar that flares in oral direction. Theaboral portion of the chamber expandsprominently at the basal edge; the baseis convex and possesses a prominent basalcallus. The surface of the vesicle has averrucate ornamentation and in somespecimens the swollen basal edge is moreheavily verrucate than the remainingchamber wall. The fine verrucae on avery few specimens may be a result ofdegradation of the vesicle surface froma more verrucate condition.

Dimensions: Population from the typestrata in microns: length (excl.) 160-170(holotype 166), width (excl.) 110-132(holotype 110).

Types: Holotype OSU 32172, Para-types OSU 32169, 32170, 32171, 32173,32174, 32175.

Type stratum and locality: Dolomitizedmudstone (Sample 13), five feet abovethe "coral-stromatoporoid zone," theColumbus Limestone, Hamilton BrothersLime and Stone Quarry, Marion, Ohio.

Discussion: This species is tentativelyassigned to the genus Eisenackitina. Theelongate shape of the vesicle is typical ofEisenackitina and the distinct collar issimilar to that found in specimens of E.canadensis (Legault, 1973) and E. syl-vaniensis (Wood, 1974). Legault (1973,p. 91, pi. 8, figs. 3, 9) has noted bulgingat the basal edge in specimens which shehas referred to as Eisenackitina. Thenumber of characteristics of E. robustathat do fit well with the description ofthe genus justify the reference of thisspecies, at least tentatively, to Eisen-ackitina.

Acknowledgments. I wish to express mygratitude to James M. Schopf, who brought tomy attention and encouraged the investigationof Middle Devonian Chitinozoa. I am in-debted to Stig M. Bergstrom, James Chapel,Sven Laufeld, and James Urban for reading themanuscript and offering advice. Thanks arealso due to Robert Markley who operated theSEM, to Karen Tyler and Theodore Myers forpreparing the illustrations, and to Pat Kocsov-sky for typing several versions of this paper.

LITERATURE CITEDBates, R. L. 1971. Abraded ripple-marked

surfaces in Columbus Limestone, CentralOhio. Ohio J. Sci. 71: 233-240.

Chaiffetz, M. S". 1972. Functional interpreta-tion of the sacs of Ancyrochitina fragilisEisenack and the paleobiology of the ancyro-chitinids. J. Paleontol. 46: 499-502.

Chapel, J. 1975. Petrology and depositionalhistory of Devonian carbonates in Ohio.Unpub. Ph.D. Thesis, The Ohio StateUniversity.

Combaz, A., F. Calandra, J. Jansonius, P.Millepied, C. Poumot and F. H. Van Oyen.1967. Microfossiles organiqucs du Paleo-zoique 2, Les Chitinozoaires, Morphographie.Ed. Centre. Nat. Rech. Scient. (Paris): 1-47.

Cramer, F. H. 1970. Angochitina sinica, a newSiluro-Devonian Chitinozoan from YummanProvince, China. J. Paleontol. 44: 1122-1124.

Droste, J. B., R. H. Shaver and J. D. Lazor.1975. Middle Devonian paleogeography ofthe Wabash platform, Indiana, Illinois, andOhio. Geology 3: 269-272.

Dunn, D. L. and T. H. Miller. 1964. A dis-tinctive Chitinozoa from the Alpena Lime-stone (Middle Devonian) of Michigan. I.Paleontol. 38: 725-728.

Eisenack, A. 1930. Neue Mikrofossilien desbohemischen Silurs. Die Naturwissenschaf-ten, 18.

1931. Neue Mikrofossilien des baltis-chen Silurs. I. Paleontol. Zeitschr. 13: 74-118.

1955. Chitinozoen, Hystrichospharenund andere Mikrofossilien aus dem Beyrichia-Kalk. Senck. Leth. 36: 157-188.

Gray, J., S. Laufeld and A. Boucot. 1974.Silurian trilete spores and spore tetrads fromGotland: their implication for land plantevolution. Science 185: 260-263.

Hill, J. 1975. Some Chitinozoa of the Dun-dee Limestone, St. Mary's, Ontario. Unpub.B.S. Thesis, Univ. Western Ontario.

Jansonius, J. 1964. Morphology and classifi-cation of some Chitinozoa. Canad. Petrol.Geol. Bull. 12: 901-918.

Laufeld, S. 1974. Silurian Chitinozoa fromGotland. Fossils and Strata 5: 1-130.

1975. Paleoecology of Silurian poly-chaetes and chitinozoans in a reef controlledsedimentary regime. Geol. Soc. Amer.,Abstr. with Programs, 7: 804-805

Legault, J. A. 1973. Chitinozoa and Acri-tarcha of the Hamilton Formation (MiddleDevonian), southwestern Ontario. Geol.Surv. Canada, Bull. 221: 1-101.

Pichler, R. 1971. Mikrofossilien aus demDevon der sudlichen Eifeler Kalkmulden.Senck. Lethaea. 52: 315-357.

Sommer, F. W. and N. M. van Boekel. 1964.Quitinozoarios do Devoniano de Goias.Acad. Brasiliero Ciencias Anais. 36: 423-431.

Taugourdeau, P. 1965. Trois petites associa-tions de chitinozoaires du Frasnian duBoulonnais. Rev. Micropaleontol. 8.

, P. Bouche, A. Combaz, L. Magloire andP. Millepied. 1967. Microfossiles organi-


ques du Paleozoique. 1, Les Chitinqzoaires,Analyse bibliographique illustree. Ed. Cen-tre. Nat. Rech. Scient. (Paris), 1-97.

Urban, J. B. 1972. A reexamination of Chi-tinozoa from the Cedar Valley Formation ofIowa with observation on their morphologyand distribution. Bull. Amer. Paleontol. 63.

and R. L. Newport. 1973. Chitinozoaof the Wapsipinicon Formation (Middle De-vonian) of Iowa: Micropaleontology. 19:239-246.

Williams, D. B. and W. A. S. Sarjeant. 1967.Organic-walled microfossils as depth andshoreline indicators. Marine Geol. 5: 389-412.

Wood, G. D. 1974. Chitinozoa of the SilicaFormation (Middle Devonian, Ohio): vesicleornamentation and paleoecology. Mich. StateUniv. Paleontol. Museum Publ. Ser. 1: 127-162.

Documents

Wright, Robert P. - pdfs.semanticscholar.org · All specimens were deposited in the Orton Museum at The Ohio State University in Columbus, Ohio and designated with OSU num-bers. SEM