Proceedings of the Iowa Academy of Science

Volume 84 Number Article 7

1977

A New Species of Bothriocidaris (Echinoidea) from the Cincinnatian Maquoketa Group of Iowa

Dennis R. Kolata University of Iowa

Harrell L. Strimple University of Iowa

Calvin O. Levorson University of Iowa

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Recommended Citation Kolata, Dennis R.; Strimple, Harrell L.; and Levorson, Calvin O. (1977) "A New Species of Bothriocidaris (Echinoidea) from the Cincinnatian Maquoketa Group of Iowa," Proceedings of the Iowa Academy of Science, 84(4), 146-149. Available at: https://scholarworks.uni.edu/pias/vol84/iss4/7

This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. Kolata et al.: A New Species of Bothriocidaris (Echinoidea) from the Cincinnatia

A New Species of Bothriocidaris (Echinoidea) from the Cincinnatian Maquoketa Group of Iowa

1 2 3 DENNIS R. KOLATA , HARRELL L. STRIMPLE , and CAL VIN 0. LEVORS0N

K OLATA, D .R ., STRIMPLE, H.L. and C.0. L EVORSON . A new two widely spaced primary perforate tubercles on opposite sides of the peripodia species of Bothriocidaris (Echinoidea) from the Cincinnati an Maquoketa Group and by numerous paired interambulacral plates. This occurrence extends the of Iowa, Proc. Iowa Acad, Sci . 84(4): 146- 149, 1977. geographic and stratigraphic range of Bothriocidaris in North America. A new species of echinoid , Bothriocidaris maquoketensis, has been disco­ INDEX DESCRIPTORS: Echinoidea, Bothriocidaris maquoketensis, vered in the Cincinnatian (Upper Ordovician) Fort Atkinson Formation, Maquoketa Group, Upper Ordovician , Iowa. Maquoketa Group, of northeastern Iowa. The new species is characterized by

The bothriocidarid echinoids are a primitive family of sea urchins from most other Paleozoic species which have numerous pl ates either known only from Ordovician rocks of Europe and North America. At arranged in several columns or irregul arly arranged. It is evident from present the family consists of three distinctive genera - Bot­ the material described here, however, that the interambulacral columns hriocidaris, Neobothriocidaris, and a new genus to be described by in Bothriocidaris may consist in part of paired plates . Although the Ki er (in press) from the Bromide Formation of Oklahoma. The three paired plates are suggestive of double-columned interambulacra , the genera are similar in that they are characterized by a small , rigid test lack of interradial genital plates and the position of orig in of the that is composed of thick, nonimbricated plates. In addition, they all interambulacra suggest that B. maquoketensis n. sp. is nothing more possess podial pores th at open externall y in distinct peripodia sur­ than a divergent species of Bothriocidaris. rounded by a rim on which one or more perforate spine tubercles are Bothriocidaris maquoketensis developed. They differ markedl y with respect to the position of the Pl. I , fi g . 1-8; text fig . I radi al water vessels (intern al or within the ambulacral plates) , arrange­ ment of ambulacra, position and shape of podial pores, and the de­ Diagnosis. - A species of Bothriocidaris characteri zed by two velopment of interambulacra. widely spaced perforate tubercles, one on either side of the peripodium; The foss il record of the bothriocidarid echinoids is scant, and well ­ interambulacra that consist of numerous paired pl ates that tend to preserved specimens are rare. Two fairly well-preserved specimens alternate with a single plate near the ambitus; one to three perforate representing a new species, Bothriocidaris maquoketensis, have been tubercles on the interambulacral pl ates. fo und in the Cincinnati an (Upper Ordovician) Fort Atkinson Forma­ Material. - Two specimens, both free from the matrix, were avail a­ ti on, Maquoketa Group, of northeastern Iowa. The occurrence extends ble for study. The holotype (SUI 42700) is a nearl y complete specimen the geographic and strati graphic range of Bothriocidaris in North that for the most part has retained its ori gin al spherical shape . The test is Ameri ca. 9 mm in diameter and is composed of approx imately 135 plates . The On the basis of conodont faunas (Sweet et al. , 1959), the Fort paratype (SUI 4270 1) is a somewhat distorted specimen that was Atkinson Formation is considered to be late Edeni an in age. If so, it is probabl y about 16 mm in diameter. Some of the pl ates are disarticul ated likely th at 8 . maquoketensis n. sp. is approximately equivalent in age to and were pushed to the interi or or lost during preservation. Both specimens have been abraded and most of the surface detail has been B. parvus Manni! ( 1962) and B. globulus Eichwald ( J 860), both from the Upper Ordovician Yormsi F,b strata of Estoni a. destroyed . The pores and some sutures are fi ll ed with clear calcite cement. Both specimens are in the repository at th e Uni versity of Iowa, Io wa City , Iowa. SYSTEMATIC PALEONTOLOGY Description. - The plates of the api cal system in the holotype are Class ECHI NOIDEA Leske intact except forone radi al that is di splaced sli ghtly below the surface of Subclass PERI SCHOECHI NOID EA M' Coy the test and one or two disassociated plates at th e center. In thi s Order BOTHRIOCIDAROIDA Zittel specimen the apical system consists of fi ve relati vely large , th ick , Family BOTHRIOCIDARIDAE Kl em contiguous radial pl ates (text fi g . I B). The radi als are slightl y wider Genus BOTHRIOCIDARIS Eichwald than high. One radi al possesses a single , small , round pore situated half way between th e center of the plate and th e interradial suture. The four Type species. - Bothriocidaris globulus Eichwald, 1860, p. 654 . oth er radials do not appear to have pores or slits. Surface feat ures have Diagnosis.- Bothriocidaridae with ambulacra arranged in two col­ been abraded from all radials except one, whi ch possess two elevated umns that terminate adorally in a sin gle nonpori ferous plate and api ­ perforate tubercles. Eight or nine small er plates are located wi thin the cally in a single radi al (ocul ar), one of which is a madreporite; one pore circlet of radials; the fi ve largest plates are in th e interradi al position and pai r per ambulacral plate, pores diverging toward interi or; interam­ three or four small er plates are located at the center of the apical system. bulacra in a single column or with paired plates, interambulacra not reaching the peri stome; lantern and spines present. The apical system in th e parat ype is mostly disarti cul ated; onl y two Remarks. - Most species of Bothriocidaris are characteri zed by radials are intact. One of the radials clearl y possesses two widely sin gle-columned interambulacra and thus di ffe r fro m modern spaced pores. There are two closely spaced perforate tubercles on the echinoids, whi ch possess two columns of interambulacral plates , and other radial. In additio n, when viewed under xy lol there is an anas­ tomose network of dark cal cite, not seen on any other pl ate, near the base of the two tubercles, but it is not clear whether this structure passes ' Illinois State Geological Survey , Urbana, Illinois 6 1801 through the plate to the interi or as would be ex pected if it were the 2 Department of Geology, Uni versity of Iowa, Iowa City, Iowa 52242 madreporite (text fi g . IC). If thi s is the madreporite , it is possible that 3 Box 13, Ricevi lle, Iowa 50460 the two pores on th e remaining radial plate are genital pores.

Published by UNI ScholarWorks, 1977 1 Proceedings of the Iowa Academy of Science, Vol. 84 [1977], No. 4, Art. 7 A NEW SPECIES OF BOTHRIOCIDARIS 147

Figure I. Bothriocidaris maquoketensis n. sp., oral (A) and aboral (B) (C) aboral view ofp aratype SU14 2 70 I showing paired interambulacra views of holotype SUI 42700, approx. x 9. The interambulacra and plates. Position of anastomose network of dark calcite shown at arrow. obvious primary tubercles are stippled. See Plate I , figures 7 and 8. Th e interambulacra and the obvious primary tubercles are stippled, approx. x 5. See Plate I , figure 2.

The ambulacra consist of two columns of perforate pl ates with 12 to column the interambulacra terminate in a single pl ate at the interray 14 pl ates per column in the small er specimen (holotype SUI 42700) and suture outside of the circlet of oculars. The ambulacral columns con­ 13 to 14 in the larger specimen (paratype SUI 42701 ). The pl ates are verge adorall y and separate the interambulacra from the peri stome; the irregul arly hexagonal except for the last formed plates at the apical end, proximal interambulacral pl ate is situated between the second and third whi ch range from trigonal to pentagonal in outline. A pl ate at the plates of adjacent ambulacral columns. ambitus in the paratype is 3.2 mm wide, 1. 5 mm high, and 0 .9 mm The interambulacral plates are pentagonal to heptagonal in outline thick . The width-to-height ratio of ambulacral pl ates is greater in the and range from 11 to 16 per colu mn in the paratype and from 8 to 13 in larger specimen than in th e small er specimen. the holotype . At the ambitus in the holotype the pl ates are hi gher than The peripodi a are round, have a rim that is onl y slightl y raised above wide, but are approx imately equidimensional where a column is two the pl ate surface, and are generall y located at the center of the pl ate . plates wide . In the paratype the interambulacral pl ates are generall y The pore pairs are arranged obliquely, one above the other, at an angle wider th an high and they are larger than adjacent ambul acral pl ates . A of about 65° to the long ax is of the pl ate . The outer pore of a pore pair is pl ate at the ambitus in the paratype is 4 mm wide and 2 mm hi gh. One to more adapi cal than the inner pore. Small , irregul arly shaped calcareous three elevated , perforate tubercles occur on plates along the midzone in spic ul es of the tube feet, are still attached to some peripodia on the both the holotype and paratype . paratype. Most ambulacral pl ates have two elevated , perforate tuber­ In the holotype some of the basicoronal plates are disassociated , but cles , located on opposite sides of the peripodia. The peripodia and the it is clear that there were IO imperforate pl ates - 5 relati vely large tubercles generally lie on the long ax is of the plate. Tubercles at the radial plates alternating with 5 small er interradi al pl ates (text fi g. I A). ambitus of the paratype are commonl y 0.5 mm in diameter. Small These pl ates are surrounded by 10 contiguous primord ial ambulacral nodes and pustules also occur on the ambulacral pl ates. plates. The radial pl ates are essentiall y pentagonal and the adoral edge The interambulacra consist of numerous paired pl ates. The column is is broadl y roun ded. The height and width of the rad ials are approx i­ a sin gle pl ate wide adorall y, but consists of in creasingly more paired mately th e same. The interradials are slender and elongate and are pl ates api call y. The paired pl ates commonly altern ate with a single , approx imately half the size of the radials. The interradi als are parti ally large, wide pl ate along the length of the column. At the api cal end of the concealed by the stout radials . The basicoronal pl ates surround several

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(LL61) 178 "DS ·av:Jy VMOI ":)O~d 8171 Kolata et al.: A New Species of Bothriocidaris (Echinoidea) from the Cincinnatia the from (Echinoidea) Bothriocidaris of Species New A al.: et Kolata Proceedings of the Iowa Academy of Science, Vol. 84 [1977], No. 4, Art. 7 A NEW SPECIES OF BOTHRIOCIDARIS 149

undifferentiated peristomial plates. Occurence. - Both specimens were collected by Glenn Crossman of The basicoronal area is not well preserved in the paratype, but Riceville, Iowa, in road fill near exposures of the Fort Atkinson elements that are present appear to be very similar to those of the Formation. The associated fossils, including the brachiopods holotype. Lepidocyclus laddi Wang, Austine/la whitfle/di (Winchell) and Hypsip­ Several slender spines from 2 to 3 mm long are embedded in the tycha hybrida Wang, and the lithology (argillaceous, fine grained, buff matrix on the surface of the paratype. dolomite) strongly suggest that both echinoids came from the Cincinna­ Remarks. - Species concepts in Bothriocidaris are based largely on tian (Upper Ordovician) Fort Atkinson Formation (bed no. 8 of Parker the number and distribution of perforate spine tubercles, and on the et al. , 1959) of the Maquoketa Group. The holotype (SUI 42700) was shape and elevation of the peripodial rim. Seven species are presently found southeast of Fort Atkinson, Winneshiek Co., Iowa (NW NW NE known from the Middle and Upper Ordovician of Europe and North Sec. 17, T. 96N., R. 9W., Decorah Quad.). Theparatype (SUI 42701) America, including Bothriocidaris maquoketensis n. sp. and a species was found southwest of Eldorado, Fayette Co. , Iowa (SW SW Sec. 18 , to be described by Keir (in press) from the Bromide Formation of T. 95 N., R. 8 W. , Decorah Quad.). Oklahoma. Name. - The specific name refers to the Maquoketa Group, in which B. maquoketensis differs from B. parvus Manni) (1962) and B. the species occurs. globulus Eichwald ( 1860) both from the Upper Ordovician (Vormsi F,b) of Estonia and the Bromide species in having only two perforate ACKNOWLEDGMENTS primary tubercles on the peripodia rather than three or more. The new species is similar to B. pahleni Schmidt ( 1864) from the Middle We are grateful to Porter M. Kier, National Museum of Natural Ordovician (Joh vi , D,) andB. eichwaldi Manni I (1962) from the Upper History, Washington, D.C., and Daniel B. Blake, Department of Ordovician (Pirgu Stage, F ,c) of Estonia in having only two perforate Geology, University of Illinois, Urbana, for their many helpful sugges­ tubercles on the peripodia; however, in the latter two species the tions and comments. Terrence J. Frest, Department of Geology, The tubercles are much closer to each other, the peripodial rim is higher, University oflowa, Iowa City, reviewed the paper and assisted with the and the interambulacra lack perforate primary tubercles. B. final draft. We also thank the Illinois State Geological Survey and the maquoketensis is probably most closely related to B. solemi Kolata Department of Geology, University of Illinois, for the use of facilities (1975) from the Champlainian (Middle Ordovician) Grand Detour during the preparation of the manuscript. Formation, Platteville Group, near Dixon, Illinois. B. solemi also is characterized by two primary perforate tubercles on the peripodia and be primary tubercles on the interambulacra, but it differs from B. REFERENCES maquoketensis in having closer peripodial tubercles and numerous EICHW ALD, E. 1860. Lethaea Rossica ou Paleontologie de le Russie. 654 p. secondary perforate tubercles on the ambulacra and interambulacra. KIER, P. M. (in press). Echinoids from the Middle Ordovician Bromide None of the other species are known to have paired interambulacral Formation. plates as does the new species. KOLATA, D.R. 1975. Middle Ordovician echinoderms from northern Illinois Ontogenetic changes in morphology are evident in the two speci­ and southern Wisconsin. Paleont. Soc., Mem. 7, 74 p. mens of B. maquoketensis. One of the most noticeable changes is the MANNIL, R. M. 1962 . The taxonomy and morphology of Bothriocidaris increase in number of interambulacral plates per column, from 8 to 13 (Echinoidea). Trudy Inst. Geolog. Akad. Nauk. Eston. SSR. V. 9, P, in the smaller (diameter of test 9 mm) to 11 to 16 in the larger (diameter 143-190. of test 16 mm). The corresponding increase in the number of ambulac­ PARKER, M. C., F. H. DORHEIM , and R. B. CAMPBELL. 1959. Resolving ral plates, however, is only from 12 to 14 to 13 and 14. New interam­ discrepancies between surface and subsurface studies of the Maquoketa Formation of northeast Iowa. Proc. Iowa Acad. Sci. v. 66, p. 248-256. bulacral plates appear to have originated along the adradial suture SCHMIDT. F. 1864. "Uber einige neue und wenig bekannte Baltisch Siluris­ between the oculars and the fourth ambulacral plate. The number of chen Petrefacten. Mem. Acad. Sci. St. Petersburg, v. 21 , ser. 7. paired interambulacral plates increase apically, apparently as a result of SWEET, W. C., C. A. TURCO, E. WARNER, Jr., and L. C. WILKIE. 1959. the increasing size of the test and corresponding increase in width of the The American Upper Ordovician Standard; I: Eden conodonts from the interambulacra. Cincinnati region of Ohio and Kentucky. J. Paleont. v. 33, p. 1029-1968.

Plate I 1-8. Bothriocidaris maquoketensis n. sp.; Fort Atkinson Formation, Maquoketa Group, northeastern Iowa: specimens photographed under xylol. I, 2. Paratype SUI 4270 I, oral and aboral views, respectively, x 4. 3-8. Holotype SUI 42700, 3 and 5 are side views showing paired interambulacral plates, 4 and 6 are oral and aboral views, respectively, x 5. 7, 8, closeups of oral and aboral surfaces, x I I .

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