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Home , Anomotodon, Cretodus, Ischyrhiza, Ptychotrygon, Scapanorhynchus, Sclerorhynchidae

Selachiansfrom the Late Gretaceous ()Atarque Sandstone Member, TresHermanos Formation, Sevilleta Grant, SocorroGourty, New Mexico byDonald L. Wolberg,Paleontologist, New Mexico Bureau ol Minesand Mineral Resources, Socorro, NM 87801

Introduction found at the locality. On the Sevilleta Grant, 3.4m (11ft) to 13m (42ft) and canbe divided The Cretaceousfish faunasof NorthAmer- more than 396 m (1,300ft) of Upper Creta- into lower, middle, and upper parts. The basal ica are still poorly known (Applegate,1970). ceous rocks overlie shales of the Dockum Atarque consists of light-gray, fine-grained, Selachians,although not uncommon in Cre- Formation (Upper ).The Upper Cre- calcareoussandstones; the middle Atarque taceousrocks, are especiallypoorly under- taceoussequence consists largely of shales consistsof yellow-orange,fine-grained, thinly stood and in need of extensive study and sandstonesand includes units from the bedded, calcareoussandstone with shale (Cappetta,1973). Although Marcou de- Dakota Sandstoneto the CrevasseCanyon partings;the upper Atarque consistsof very scribed Ptychoduswhipplei from New Mexico Formation (Baker and Wolberg, 1981).The fine grained, gray-orangesandstones (Baker, as early as 1858, very little work on New overlies the Rio 1981). Mexico Cretaceousselachians has been pub- SaladoTongue of the Mancos Shale and un- Selachiansare very abundant in lenses lished. derlies the D-Cross Tongue of the Mancos within the middle part of the Atarque. In While conducting a geologic study of Up- Shale.The fossil-richlenses that yielded the addition to selachianfossils, turtle shell ma- per Cretaceousrocks exposedon the Sevil- selachiansdescribed below are found in the terial, crocodilianarmor and teeth, and two leta Grant near La foya, SocorroCounty, New middle part of the Atarque SandstoneMem- plesiosaurteeth have been recovered.Car- Mexico(Fig. 1), BruceBaker discovered a se- ber, the basalunit of the TresHermanos (Fig. bonate-cementedmollusk shell material oc- ries of fossil-richlenses in sandstonesof the 2). The stratigraphicnomenclature for the curs abundantly as well. The vertebrate lower part of the Tres Hermanos Formation region has been revisedby Hook and others material was recoveredby breaking down (Baker,1981). Baker and Wolberg(1981) pro- (1983).In the SevilletaGrant, the Atarque the rock matrix with dilute aceticand formic vided an interim report on the vertebrates SandstoneMember varies in thickness from acids followed by washing, screening, and drying the resultantconcentrate. Specimens then were picked with and without the use of a binocular microscope. rF Lodron

/Bernord\--.' Pinos-i -- Alsoin this issue .t\/-Mis.;/,.\s .{' ConchasLake State Park o. 8 l1l.^..Chupoderoj -: Enhancedoil recoverywith sMY veso--j- a. AKLA '.-_ CO2flooding p. 10 Magdoleno Z /"i?N llruy I ru = Gastropodsfrom the Solse lnitts . '1- MeteMember p. 11 Socorro Jornod o = Service/News p. 16 ^ dal--' 50nn Staffnotes p.20 tonio Muerto Z.S Gomingsoon Baritein north-centralNew Mexico Sedimentsorting in gravelly megaripplesfrom the RioGrande EspanolaSubsidence Project -u, ltl Abstractsfrom the 1984Mineral I 13 km Symposium

FIGURE l-Location map of the study area, Socorro County, New Mexico (after Baker, 1981). This paper is an abbreviated version of a The genus Hybodusis a common Mes- nus in north-central Texas. Leriche (1939) larger work to be published as part of a vol- ozoic form that is known from the Triassic- reported S, kaupifrom the ,San- ume on Late Cretaceouspaleontology Cretaceousin North America (Romer,1966). , and early of Africa. S. (NMBMMR, Circular195), and it attemptsto Hybodusistypical of hybodont ,a group falcatusis known from the Turonian of Texas acquaint the readerwith the diversity of New that had a Paleozoicorigin and were cos- (Bilelo, 1969)and South Dakota (Cappetta, Mexico's Cretaceousselachians; economies mopolitan in distribution. Hybodonts 1973).S. falcatus also is known from the Cen- have been made in taxonomic descriptions underwent their own adaptiveradiation and omanian,, and Campanianof Eu- and historic data for various taxa. The clas- were not at the origin of modern selachians. rope (Priem, 1.972). sification schemeused generally follows S. pristodontusranges from the late San- Romer (L966),Cappetta (1973),Cappetta and Family PrvcHoooNrrDAEWoodward, L9L2 tonian to the end of the Maestrichtian, al- Case(1975), and Cappetta(pers. comm. 1984). Genus PtychodusAgassiz, 1839 though a pre-Campanianage may be doubted Ptychoduszohipplei Marcou, 1858 on geologic grounds (Bilelo, 1969). S. pris- iTAGI ROCXUNITS ITHOLOGI Fig. 3-A todontushas a cosmopolitandistribution. De- spite a stratigraphic overlap, the S. kaupi-9. .9 P. whippleiis a very distinctive taxon, and pristodontussequence forms a suit- =t ;E exceptfor P. anonymus,not easily confused falcatus-9. U :1 with other of Ptychodus.P. whrpplei able evolutionary . The broad geo- H:-5 was first named for specimensfound in the graphic distribution of these taxa enhances Cretaceousof New Mexico. Marcou (1858) their utility for stratigraphic application. z J. F S. is not abundantly represented Sondstone reported P. whippleifrom "the gray sandy falcatus tr marls, three miles north of Galisteo,on the in the Joyita Hills fauna. No completespec- Sond ston€ imens have been recoveredvet. S. falcatus z f--t Srllslone road from Galisteoto Pecos,New Mexico." Distinguishedby their raisedcrown, teeth of was an active predator as evidencedby its e trenchant,serrated teeth. T -l Sho Ptychoduswere adaptedto crushing mollusk

I shells.Although the genus has a cosmopol- Order GalEronvns Colcorenile 9c E itan distribution, P. zohipplei,which occurs SuborderIsunorplI 3F commonly when it is found, seemsto be re- Family Isunroer Garman, 1913 t4l Con g omerote t'.l stricted to the Late Cretaceousof North Genus CretolamnaGlikman, 1958 America. Cretolamnaappendiculata Agassiz, 1835 tr I olurboied Ptychodusanonylrtus Williston, 1900 Fig. 3-R-T Eurrowed )t) Fig. 3-C, D .9 tr C. appendiculatahas cosmopolitan distri- o bution and occurs in rocks of E Concreiions P. anonymusis similar to P. uthipplei;both l e to late Paleoceneage. The family Isuridae td taxa display strongly raised apical crowns. z t-;l Fossi lized (Lamnidaein older literature) includes the g t__J However, the crown of P. anonymusis com- E mackerel sharks and consists of large, vo- U z Cross- parativelymore elongatedthin that of P o J> t I -tE strotificolion racious with lunate caudal The d. L,,I zohippleiand is less acutely conicai. Like P fins. l - F E whipplei,P. anonymusis restrictedto the Late E Coo L! E o_ Ss Cretaceousof North America and was orig- l E Unconforhrly inally describedby Williston (1900)from the t__l "Benton'"and "Niobrara" of Kansas.It seems New AAexnc@ 9 Foss L ocoiily likely that these two speciesare closely re- F lated,although the natureof the relationship is as yet unclear. GEOLOGY - I ::--51 Bardack(1968) figured a ptychodont from r Scionceand Service tt. ;T;. .9 lTi c to1.o the Boyne member of the Vermillion River Volume 7, No. 1, February 1985 Formationin Manitoba, Canada.I concurwith EdifolrDeborah A. ShaF Published quarterly by .9 I :1" Evetts (1979)that this specimencan be re- New Mexico Bureau of Mines and Mineral Resources P' ferred to P. anonymus. a division o(New MexicoInstitute ofMining & Technology z ;e BOARD OF REGENTS 3 Ptychoduspolygyrus Agassiz, 1839 z Ex Officio Fig. 3-B Toney Anaya, Goaernorof Nru Mexico zz Leonard Delayo, Superintend.entof Public lnstruction z P.polygyrusis a cosmopolitanspecies known ADDointed LtJ t ! from the Turonian through the Santonianof Donald W Monis, Pres.,1983-1989, Los Alqmos Robert Lee Sanchez,Sec.lTreas., 1983-1989, Albuquqque Dokolo the (Woodward, 1911), English Chalk the William G. Abbott, Hobbs Sondslone 1951 7985, "Niobrara" of Kansas(Williston, 1900),and Judy Floyd, Dn-1987, Ins Cruces E6 0ockum the Selma Group of Alabama (Applegate, Steve Torres, 1967-7985, SNorrc tg 1970). P. polygyrusalso is known from Bel- New Mexico lnstitute of Mining & Technology gium and the U.S.S.R.The abundanceand Pt$idilt.. .. LaurenceH.Lattman FIGURE2-Stratigraphy the New Mexico Bureau of Mines & Mineral Resources of SevilletaGrant, diversityof the ptychodontfauna in theAtar- D;reclor...... FrankE.Kottlowski SocorroCounty, New Mexico(after Baker and que Member clearly reflects the abundance DeputyDirector ...... Georges.Austin Wolberg,1981). of the mollusks that formed the food source Subwiptions:Issued quarterly, February, May, August, for theseselachians. November; subsaiption price 96.00/calendaryear. Ed.itorialruttq: Conhibutions of material for consideration Systematicpaleontology in future issuesof NMG arewelcome. Articles submitted Class Order LarnrNrFoRMES for publietion should be in the editor's hands a minimm Suborder LeuNoroEr of five (5) months before date of publication (February SubclassElasN,rosRAl'rcHr May, August, or November). Address inquiries to Order Strecnu Family Al.qconactpen Casier, 1947 Deborah A. Shaw, editor of Nru Mexico Geology,New MexicoBureau of Mines & Mineral Resources,Socono, Suborder Hynooorurorora Genus SqualicoraxWhitley, 1939 (Agassiz),1843 NM 87801. Family HysoooNnoer Owen, 1846 falutus Publishedas public domain, fhereforereproducible without Genus HybodusAgassiz, 1,837 Fig. 3-P permission.Source credit requested. 1,4N Hybodussp. The frenchant rec- Circulation: teeth of S. t'alcatusare Ptinter: Univqsily of New Mexico Printint Plant Fig. 3-E ognizedeasily. Bilelo (1969) discussed the ge-

2 February 1985 New MexicoGeology todusWIyWrus Agassiz (x4.2); C-D, 8-0130, Ptychodusanonymus Williston, . ( x 10); F-G, 8-0017, Cretodussemiplicatus (Agassiz) (x7.7); H, 8-0031, r'oodward)(x6.7); I, 8_01.62,Cretodus semiplicatus (Agassiz) (x4.2); K, V :hus raphiodon(Agassiz) (x 6.7); M, 8-0151, Odontaspisparoidens Cappetta norhynchusraphiodon(Aggasiz)(x6);P, 8-0015,Squnliconxt'alcatus(Aggasiz) tata(Aggasiz) (x 1.25);T, V0200, Cretolamnaappendiculata (Aggasiz) (x4.2).

Nsw Mexico Geology February 1985 FIGURE4-A modernrepresentative of the genus FIGURE 6-,{ modern catshark, Chiloscylliumgriseum. Lamna,the Porbeagle,Lamna nasus. The genera Cretolamnaand Cretodusorobablv resembled this form. mackerelsharks are aggressivepredators and include the modern GreatWhite, Carcharodon carcharias(Linnaeus), in addition to the mod- FIGURE 7-A modern goblin , Mitsukurina FIGURE8-A modern rePresentativeof the genus ern genusLamna (Fig.4). They generallyare owstoni. Odontasois,the , Odontaspistaurus. found near the surfaceand feed on fish, in- cluding other sharks, marine reptiles, and even . Cretodussemiplicatus (Agassiz, 1843) Fig. 3-F, G,l As noted by Cappetta (1973),C. semiplicatus is known from Europe where it is found in rocks of Cenomanian to Turonian age. It also is known from the late Turonian of Angola. Evetts (L979)and Cappetta (L973)reported the taxon from the Turonian of the Carlile Shaleof South Dakota. Cretodussemiplicatus and CretolamnaaVpendiculata are about equally FIGURE 9-A modern thresher shark, Alopinsaulpinus. represented in the Atarque fauna. Family Onpcroloarpee Gill, 1895 the extinct selachian family Scapanorhyn- The Odontaspidae (Carchariidae in older Genus ChiloscylliumOgllby, 1906 chidae and known only from fossils. Then, literature) today comprise the sand sharks Chiloscylliumgreeni (Cappetta, 1973) in 1898Mitsukurina ou)stoniwas taken from (Fig.8). Odontaspidsare primarily medium- Fig. 5-A, B great depths in the PacificOcean near japan sized sharks that inhabit shallow waters. They Firstdescribed by Cappetta(1973) from the (Fig. 7). Since1898, the modern specieshas are active swimmers and feed on fish, crus- (as Brachaelurusgreeni), C. greeni been recorded from Portugal, French Guy- taceans,and cephalopods. the of is distinguishedeasily by its smallsLe, smooth ana, South Africa, Australia, and Gulf Family CRsroxvRHrNpnr Glikman, 1958 (Cappetta, comm. unornamentedenamel, and lateraldenticles Gascogne, pers. Genus PlicatolamnaHerman, flanking a main cusp. This record oI C. greeni 1e84). in Cappetta and Case, 1975 is only the second record of the speciesand Plicatolamnaarcuata (Woodward, 1894) 1952 the first record from New Mexico. Cappetta Genus AnomotoilonArambourg, Fig. 3-H,I (1973)suggests that C. greenimay be ances- Anomotodonsp. tral Io Sauatirhina. Fig. 3-Q P. nrcuatawas recognized as a distinct spe- The fimity Orectolobidaeincludes the ciesby Herman (inCappetta and Case, 1975) This genus is present in the Cretaceousof nurse sharks, leopard sharks, and from the Campanian of England. It also is modem Morocco (Arambourg, 1952) and . catsharks.They are small- to medium-sized present in the Cenomanian of Lithuania, the Cappetta (1976) and Case (1980) note the that are benthonic, coastal dwelling Campanian of New and the Campan- sharks similarity of Anomotodonto fersey, in the warmer waters of ian and Maestrichtian of Belgium. forms, now found and include the genus within the Mitsuku- The genusChiloscyllium, the the Indo-Pacific. rinidae. In morphology, a strong resem- Family At opuoal BonaParte, 1838 is still extant and is characterized catshark, blance is seen to Scapanorhynchusrapax, but Genus ParanomotodonHerman, by strongly developed markings (Fig. 6). vertical striae are absent.The foyita Hills ma- in Cappetta and Case, 1975 Family MttsurunrNroan Jordan, 1898 terial may represent a new species of An- Fig. s-Q omotodon,but more material is need to make Genus ScapanorhynchasWoodward, 1889 Paranomotodonis known from the Ceno- (Agassiz, 1843) such a determination. Scapanorhynchusraphiodon manian-Santonian of Europe and the Late Fig. 3-K, L, O Cretaceousof Zaire and Japan.Cappetta and Family OpoNtespnan Muller and Henle, raphiodonhas cosmopolitan distribution. Case (1975)described Paranomotodoncf. an- S. t841. Some confusion exists in differentiating be- gustidensfrom the Late Carnpanian of New Genus OdontaspisAgassiz, L838 tween S. raphiodonand S. texanus(see Cap- Odontaspisparaidens Cappetta, 1973 Jersey. or rather in how some Paranomotodorzis included within the Al- petta and Case,1975), Fig.3-M, N paleontologistshave distinguished the taxa. opiidae, or thresher sharks. Modern thresher S. raphiodonis easily recognized by its long This species is distinguished from other sharks, distinguished by the extreme devel- and slender recurved blade, internally or- species of Odontaspisby its small size and opment of their caudal fin, are active pre- namented by fine vertical striae. root morphology. The |oyita Hills specimens dators, using their caudal fin to sfun prey Scapanorhynchzsis included with the gob- are only the second known occurrences of (Fig. 9). They are cosmopolitan in open ocean lin sharks and it was long thought that Sca- the taxon. O. parztidensis a common faunal waters, but also venture inshore (Castro, panorhynchuswas the sole representative of element. 1983).

February 1985 Nea Mexico Geology V S

FIGURE 5-A, 9-0019, Chiloscylliumgreeni (Cappetta), lateral view (x20); B, 8-0008, Chiloscylliumgreeni (Cappetta), lateral view (x20); C, 8-0100, Ptychotrygontrinngularis (Reuss), tangential view ( x 13.5);D, V0773, P. triangularis(Reuss), occlusal view ( x 13.5);E-F, 8-.0171.,P. tuiangularis(Reuss), occlusalandbasalviews(x10);G,8-0101,P.triangularis(Reuss),basalview(x13.5);H,B-0769,P.triangularis(Reuss),occlusalview(x13.5);I,B- 0025,lschyrhiza aaonicola Estes ( x 75);l, V0775, Ischyrhizamira Leidy ( x 2.5); K-M, 8-0012, "Batoid indet.," lateral, occlusal,and basal views ( x 13.5); N-O, 8-0159, "Batoid indet.," lateral and basalviews (x20); P, 8-0010, Rhinobatossp. (x13.5); Q,V0724, Paranomotodonsp., lateralview (x4.2); R-S, 8-0178, P. triangulnris(Reuss), basal and posterior views ( x 20); T-U, B-0767, P. triangularis(Reuss), occlusal and anterior views ( x 20); V, B- 0154,lschUrhiza cf. l. aaonimlaEstes, oblique view of oral tooth ( x 13.5).

New Mexico Geology February 1985 Order Relrronuns seas.However, they display a broad salinity tailed comparisons of larger samples may Suborder RHtNosetororr tolerance and commonly enter brackish or allow for finer stratigraphic differentiation of Family RHINosertpeEMuller and Henle, even fresh waters. the Turonian. Additionally, the Joyita Hills 1841 specimensvarv in color frorn almostblack to Genus RhinobatosLinck, 1790 Ischyrhizamira Leidy, 1,856 light yellow-brbwn. The significanceof these Rhinobatossp. Fig. 5-J color variations is unclear, but it may relate Fig. 5-P The rostral teeth of L mira are much larger to the thermal history of the area. Thesevery distinctive teeth are character- than those of I. aztonicola.This report of 1. "Batoidsindet." ized by a low, cap-like crown and massive, mira representsa modest range extension of Fig.5-K-O bulbous roots. Cappetta (7973)reported Rftl- the species.Cappetta and Case (1975)and are small teeth with dis- nobatosfrom the Turonian of South Dakota, Slaughterand Steiner(1968) report the range These specimens tinctive, flat, rhomboidal crowns that show and the genus is cosmopolitanin distribu- of L mira,in the broad sense,as Late Turon- a weak medial keel and sloping facets.The tion during the .In some re- ian to Late Maestrichtian (seeMcNultv and margin of the crown is thick and overhangs spects,the Hills specimensdiffer from Slaughter,1964). Slaughter and Steiner rec- Joyita a well-developedand divided root. In form, thosereported by Cappetta(7973), Cappetta ognized two subspecies: mira these specimensrecall Rhombodus,but it is and Case (1975),and Cappetta (1980).Re- schneideri(Late Turonian through Coniacian) impossibleto refer thesespecimens without ferralto a speciesof Rhinobatosis not possible and Ischyrhizamira mira (basal Campanian histological studies. For now, they at this time. through Late Maestrichtian).It seemslikely detailed will be included within the "batoids indet." Rhinobatosisa . These fish, which that the foyita Hills specimensof this report category. may enter estuaries(Smith, 1953),are mod- representl. mira schneideri. erate-sized,sluggish, bottom-living rays that Genus 1894 Conclusions are common on sandy bottoms. Guitarfish Jaekel, Ptychotrygon triangularis(Reuss, 1845) are poor swimmers and frequently conceal Selachians frequently compose a signifi- themselvesbeneath the sand (Fig. 10). Fig. 5-C-H, R-U cantportion of Cretaceousmarine, brackish, As figures indicate, and even freshwater faunas of the Western Suborder SclsnonuyNcHorDEr the of P. trinngularis the teeth appear to be quite distinctive. This Interior of North America. Only sporadic Family Sct-ERonsyNcHroanCappetta, 1974 speciesis representedabundantly in the studieshave been conducted on these faunas Genus IschyrhizaLeidy, 1856 |oy- ita Hills collections. for the Western Interior as a whole, and even lschyrhimaoonicola Estes, 1954 P. triangularis in distribu- lessis known of Cretaceousselachian faunas Fig. 5-I, V is cosmopolitan tion and is known from the Turonian of in the New Mexico record. The locality dis- I. aoonicolawas first described from the Czechoslovakiaand South Dakota (Cap- covered by Bruce Baker provides an oppor- Lance Formation (Maestrichtian) of Wyo- petta,1973;Evetts, 1979).Cappetta and Case tunity to study a relatively large and diverse ming (Estes,1964).lt also is known from ihe (1975)reported P. triangularisfrom the Cam- sample of the New Mexico fauna, and it is Early Senonian of Belgium and the Turonian panian of New jersey. However, Cappetta especially important because it is securely of South Dakota and Texas(Cappetta,1973). (1975)redescribed the New Jerseymaterial placed in a stratigraphic context by inverte- Cappetta noted that the Turonian specimens as a new species,Ptychotrygon oermiculata. brate data. In this report, 18 selachian taxa are significantly smaller than those from the Thus, it appears that P. triangularis has a are documented in the Atarque Sandstone Maestrichtian. stratigraphic range limited to the Turonian. Member of the Tres Hermanos Formation, The Sclerorhynchidaewere , The foyita Hills sample differs in some re- and most represent first documented occur- characterizedby a long, swordlike rostrum spectsfrom the South Dakota material. The rences in New Mexico (Table 1). This fauna studded with teeth and used for obtaining New Mexico specimensdisplay more arcuate compares well with that reported by Cap- food. Modern are found primarily crowns/ are not as triangular, and show mi- pena (1973)and Evetts (1979) tuom the Tu- in coastal waters of tropical and subtropical nor differences in ornamentation. More de- ronian portion of the Carlile Shale of South Dakota. This fauna also compares well with selachianfaunas of similar age from the up- per Midwest (Witzke, 1981).Figure 11 shows the distribution of comparable Turonian se- lachianfaunas. Given more complete samplesthrough the Cretaceous stratigraphic record, selachian

TABLE l-Faunal list Hybodussp. Ptychoduswhipplei Ptychodusanonymus Ptychoduspolygyrus Squalicoraxfalcatus Cret olamn"a' app en di cul at a Cretodussemiplicatus Chiloscylliumgreeni Supanorhy nchus r aphiodon Anomotodonsp. Odontaspisparcidens Plicatolamnaarcuata Paranomotodonsp. Rhinobatossp. Ischyrhizaaoonicola Ischyrhizamira Pty chotry gon tr iangularis FIGURE 10-A modern speciesof Rhinobatos,the guitarfish, Rhinobatosschlegeli. "Batoidsindet."

February 1985 Netrl Mexico Geology Sloan and Joseph Hartman, University of Minnesota, provided accessto comParative materialfrom Cretaceousdeposits in north- ern Minnesota.Michael Wooldridge, Teresa Mueller, and Linda Wells-McCowan Pro- vided drafting assistance.This manuscript was read critically by JiriZidek, New Mexico Bureauof Mines and Mineral Resources,and Henri Cappetta, Montpellier, France.Their suggestioniand commentsare appreciated. This researchwas suPPorted by the New Mexico Bureau of Mines and Mineral Re- sources.

References Applegate, 5., 1970,The vertebrate fauna of the Selma Formation of Alabama, part VIII, The : Fieldiana, GeologicalMemoirs, v 3, no 8, pp 385-433 Arambourg, C 1952, Les vert6br6s fossiles des gise- , of lands and seas during ments de phosphates(Maroc, Alg6rie, Tunisie):Service FIGURE l.2-Dstribution G6ologiqueMaroc, Notes et M6moires,no 92,372pp the Cretaceous (after Kennedy, 1978). Shaded areas Baker, B , 1981,Geology and depositional environments indicate land. of Upper Cretaceous rocks, Sevilleta Grant, Socorro FIGUREll-Late EarlyTuronian NorthAmerican County, New Mexico: Unpublished M S thesis, New Mexico Institute of Mining and Technology,159 pp paleogeography.Dots representcomparable se- sestenains secondaires (after Baker,B, and Wolberg,D, L , 1981,Upper Cretaceous Priem,F., 1912,Sur despoissons lachianfaunas Williamsand Stelck,1975) stratigraphy and paleontology, lower Tres Hermanos du sud de la France:Soci6t6 g6ologique de France,Bul- Shadedareas indicate water. Sandstone,Sevilleta Grant neN LaJoya,Socorro County, letin, v. 12, no 4, pp 250277. New Mexico: American Association of Petroleum Ge- Romer, A. S , 1966,Vertebrate paleontology: University ologists,Bulletin, v 65, p 554. of Chicago Press (3rd edition), 458 pp faunas, in particular the smaller faunal ele- Bardack,D , L968,Fossil vertebrates from the marine Cre- Slaughter,B. H., and Steiner,M., 1958,Notes on the ref- ments. mav offer the possibilitv of better taceousof Manitoba, Canada:Canadian Joumal of Earth rostral teeth of ganopristine sawfishes,with special Sciences,v. 5, pp 145-153 erenceto Texasmaterial: Journal of Paleontology,v 42, shatigraphit correlations.Selachian teeth and Bilelo,M A M ,1959,The fossilshark genus Squalicorax no.1, pp 233)39. dermal denticlescan occur abundantly and in north-central Texas:Texas Journal of Science,v 20, Smith, I L. 8., 1953,The sea fishes of southern Africa: over a wide geographicarea, can have lim- pt. 4, pp.339-348 Cenhal News Agency Ltd , South Africa ited stratigraphicrange, and areidentifiable. Cappetta,H ,1973,Selachians from the CarlileShale (Tu- Williams,G. D , and Stelck,C R ,1975,SPeculations on ronian) of South Dakota: Journal of Paleontology,v 47, the Cretaceouspaleogeography of North America; in Theseattributes lend themselveswell to bio- no 3, pp 504-514 Caldwell, W G E (ed ), The Cretaceoussystem in the stratigraphicapplications. Cappetta, H., 1975,Ptychotrygon oermiculata nov sp , s6- Western Interior of North America: Geological Asso- In general,the Cretaceouswas character- laciennouveau du Campaniendu New lersey: ComPtes ciation of Canada, SpecialPaper no 13, pp 1-20 ized by a distribution of land and sea that RendusSoci6t6 G6ologique de France:v 17,no 5, pp Williston, S. W , 1900,Cretaceous fishes-Selachians and 764-166 Ptychodonts: Geological Survey of Kansas, v VI, pt allowed mobile organismsrelatively easy ac- Cappetta,H , 1975,Sdlaciens nouveaux du London Clay rr, pp 237-255. cess to widely separatedgeographic areas de L'Essex(Ypresien) du bassinde Londres:Geobios, Witzke,B J , 1981,Cretaceous vertebrate fossils of Iowa (Fig. 12). It is this easy dispersion of orga- v 9, no 5, pp 557-574, and nearby areasof Nebraska, South Dakota and Min- nisms that highlights the potential for strati- Cappetta,H, 1980,Les s6laciensdu Cr6tac6sup6rieur nesota: Iowa Geological Suwey, Guidebook to Creta- du Liban, II: Batoides:Paleontographica (A), v. 168, ceousstratigraphy and sedimentationh northwest Iowa, graphic correlationsbased on selachians.It pp 1.-250 northeast Nebraska and southeast South Dakota, pp is also probable that selachianfaunas can Cappetta,H, and Case,G R,1975,Contributionil'€tude 105-r22 provide useful paleoenvironmental data. des s6laciensdu groupe Monmouth (Campanien- Woodward, A. S , 1,902-7972,The fishes of the English Modern analogsor actuallyrelated forms still Maestrichtien) du New Jersey: Paleontographica(A), chalk: PalaeontographicalSociety of London, pp.'- l- v 151,nos 7-3, pp 7-46 264. D existand provide an opportunity for relating Case,G R , 1980 A selachianfauna from the Trent For- fossil selachiantaxa to extant taxa. mation, Lower (Aquitanian) of eastemNorth Basedon availabledata, it seemslikely that Carolina:Paleontographica (A), v.171, pp 75-103. the Hills fauna occupiedu .teu.-ihot" Castro,J I , 1983,The sharksof North Americanwaters: foyita TexasA & M University Press, 180 pp environment.The presenceof relatively un- Estes,R , 1954,Fossil vertebrates from the abradedturtle, crocodile,and dinosaurbone LanceFormation, easternWyoming: University of Cal- fragmentsindicates a nearby shorelineand ifornia, Publications in the Geological Sciences,v 40, riverine or estuarinehabitats. The selachian pp 1-180 Evetts,M, I , 7979,Upper Cretaceoussharks from the fauna is relativelyunbiased in that both bot- Black Hills region, Wyoming and South Dakota: The tom-dwelling forms and active swimmers are Mountain Geologist,v 16, no. 2, pp 59-66. well represented. Hook,S. C , Molenaar,C M, and Cobban,W A, 1983, ACKNOWLEDGMENTS-BTuCeBaKeT discov- Stratigraphy and revision of nomenclature of upper Cenomanian to Turonian (Upper Cretaceous)rocks of ered the locality that yielded the specimens west-central New Mexico; in Hook, S C (compiler), describedin this paper when he did field Contributions to mid-Cretaceouspaleontology and studiesrelated to his graduateresearch at the shatigraphy of New Mexico-part II: New Mexico Bu- New Mexico Institute of Mining and Tech- reau of Mines and Mineral Resources,Circular 185,pp / -26 nology. With the assistanceof StephenHook, Kennedy,W J ,7978, Cretaceous;in McKenow, W S Getty Oil Company, Baker securelyplaced (ed ), The ecology of fossils:Massachusetts Institute of the locality within a stratigraphic context. TechnologyPress, pp 280-322 PeterRobinson, University of Colorado,gra- Leriche,M, 1939,Contribution e l'6tude des poissons fossiles des pavs riverains de la M6diterran6e ameri- ciouslyprovided accessto the MichaelEvetts caine (V6n6zuela,Trinit6, Antilles, Mexique): Soci6t6 collection of selachianteeth from the Turner Pal6ontologiqueSuisse, M6moires, v. 51,,pp 1-42 SandvMember (Turonian)of the Carli-leShale Marcou, J , 1858,Geology of North America: Zurich, pri- of South Dakota,as well as to other material vatelypublished, lM pp McNulty, C L., and Slaughter,B H ,1964, Rostralteeth repositedin the paleontologycollections of of Ischyrhizamira from northeast Texas:Texas Journal the University of Colorado, Boulder. R. E. of Science,v.76, pp 107-1.1.7 Microcline feldspar

Naa Merico Geology February 1985