wise not a probable candidate. Glyptosaurus sensustricto (Sullivan, 1.979)seems the most aptychifrom reasonabletaxonomic assignment based on Gephalopod tubercular arrangement and osteoderm size. LosMoyos Limestoro, Madera Group Biostratigraphic and biogeographic significance The discovery of cI. Glyptosaurusin the (MiddlePennsyluanian), BacaFormation of south-central New Mexico is significant in three ways: 1.)Glyptosaurus is a late Wasatchian-Uintan genus known from nearAlbuquerque, New Mexico Colorado, Utah, and Wyoming (Sullivan, 1979);its occurrence in the Baca Formation by Barry S. Kues,Department of Geology, University of New Mexico, Albuquerque, NM near Carthageis consistent with, though not conclusive proof of, the Bridgerian-age assignmentmade by Lucasand others (1982). Introduction sils, to discuss their relationships with the 2) Other glyptosaurs known from New Mex- cephalopod conchs in the fauna, and to pro- ico are from the San Basin and are of Aptychi are bivalved structures that prob- fuan vide a brief summary of the fauna itself, Paleoceneand early Eocene age (Sullivan, ably functioned asopercula on somecephalo- which includes some taxa not previously re- 1981);therefore, UNM BE-012 is the pods (see Yochelson,1983), although they ported from the Pennsylvanian of New Mex- youngest glyptosaur known from New Mex- have also been interpreted as cephalopod ico. Specimensmentioned and illustrated ico. 3) To our knowledge, UNM BE-012also lower jaws (Morton, 1981).Aptychi are here are in the University of New Mexico representsthe most southerly occurrenceof a known from many genera of Mesozoic Department of Geology paleontology collec- specimenthat apparently pertains to Glypto- ammonoids (Arkell, 1,957,p. L82) but are ex- tions and have been assigned UNM num- saurus. hemely rare in the Paleozoic.Only two finds bers. ACKNOWLEDGMENTS-Wethank Adrian of aptychi from the late Paleozoichave been Hunt and Donald Wolberg for field assist- reported. Closs and others (1964)noted Location and geologic setting ance in the BacaFormation, W. D. Turnbull aptychi in a unit containing the ammonoid (Field Museum of Natural History) for the Pseuilogastriocerasfrom the Permian of Utah, The assemblagereported herein was col- subloan of the Carnegie Museum Glypto- and Thompson and others (1980)described lected by the author, Kenneth Kietzke, and aptychi that, in life, were probably associated membersof a paleontology classfrom a road- saurusspecimen, and Richard Estes and firi Zidek for reading an earlier version of this with the nautiloid Lirocerasfrom the Bishop cuton theeast side of NM-I4,5.6mi (9.1km) Cap Member, Magdalena Formation (Des- south of the intersection of I-40 and NM-14 PaPer. moinesian), in Vinton Canyon, El Paso at Tijeras(Fig. 1). This Iocalityis just north of References County, Texas. The latter report is also im- the village of Cedro in the Manzano Moun- portant becauseit provides the first good cir- tains east of Albuquerque. The roadcut con- Gardner, J. H., 7910,The Carthage coal field, New Mex- ico: U.S. GeologicalSurvey, Bulletin 381,,pp. 452460 cumstantial evidence that some late sists primarily of light-brown to grayish- Lucas, S G , 1983,The BacaFormation and the Eocene- Paleozoicnautiloids may have possessed brown, sparsely fossiliferous, fissile mud- Oligocene boundary in New Mexico: New Mexico aptychi. Recently, well-preserved aptychi stones. Collections totalling approximately GeologicalSociety, Guidebook to the 34th field confer- have been discovered in the Middle Penn- 30 kg were made from severallevels within a pp ence, 787-192. sylvanian of central New Mexico, in an 2-m-thickinterval near the top of the roadcut, Lucas, S. G., Wolberg, D. L., Hunt, A , and Schoch, R M., 7982,A middle Eocenetitanothere from the Baca assemblagethat contains both ammonoid immediatelybelow a massivelimestone bed. Formation, south-central New Mexico: Journal of and nautiloid phragmocones. Theseunits are in the upper part of the Los Paleontology,v. 56, pp. 542-545 The purposeof this paper is to document Moyos Limestone (Madera Group) and are Sullivan,R. M,7979, Revisionof the Paleogenegenus in age, basedon fusulinid Glyptwaurus(Reptilia, Anguidae): American Museum a new occurrenceof these rare Paleozoicfos- IateDesmoinesian of NaturalHistory, Bulletin,v.763, pp.7-72- -, 1981,Fossil lizards from the San Juan Basin, New Mexico;ln Lucas,S. G., Rigby, J. K., Jr., and Kues, B. S. (eds.), Advances in San Juan Basin paleontology: Uni- versity of New Mexico Press,pp 7G88 ,,Fort -, 1982,Fossil lizards from swain quarry Un- ion formation," middle Paleocene(Tonejonian), Car- bon County, Wyoming: Journal of Paleontology, v. 56, pp.9G7,0r0. Wilpolt, R. H., and Wanek, A. A., 1951,Geology of the region from Socorroand SanAntonio eastto Chupadera Sedillol Mesa, Socono County, New Mexico: U.S. Geological Suruey, Oil and Gas Investigations Map OM-121. Wilpolt, R. H., MacAlpin, A. J., Bates,R. L., and Vorpes, G.,1946, Geologicmap and stratigraphicsections of the Paleozoicrocks of Joyita Hills, Los Pinos Mountains, and northern Chupadera Mesa, Valencia, Tonance, and Socono Counties, New Mexico: U.S. Geological Survey,Oil and GasInvestigations Preliminary Map 61.

BernolilloCounf y

FIGURE l-Map showing aptychi locality (x) in Cedro Canyon, south of Tijeras

November 1983 New Mexico Geology evidence at other localities (Myers and (1980), and the descriptive comments of ciesin the Los Moyos Limestone.Thompson McKay,1976). these authors, for the most part, are equally and others (1980)noted node fragments of Marine invertebratesare sparselybut rela- applicableto the Cedro specimens. The MetacocerasatVinton Canyon that indicated a tively evenly distributed through the aptychi smallestof the Vinton Canyon aptychi is 20 shell too large to be closed by an aptychus, horizon, and the invertebrate fossils within mm long, slightly larger than two of the three but no evidence exists for such large speci- the sampleswere examined and identified to measured Cedro specimens, but the largest mensof Metacocerasinthe Cedro assemblage. provide a general view of the fauna associ- Cedro specimen (Fig. 3) is slightly longer A full-sizedspecimen of M. cornutumhaving ated with the aptychi. than the largest Vinton Canyon specimen. a diameter of 70-90 mm would have had an Following the reasoning of Thompson and apertural diameter of approximately 30-40 Aptychi and cephalopods others (1980,pp.907-908), the Cedro aptychi mm, about the size that could have been Five aptychi and24 partial phragmocones are assignedto the form genus Cornaptychus coveredby a large aptychus. comprisethe remains of severaldifferent spe- sP. One other cephalopod in the Cedro ciesof cephalopodsin the assemblage.Com- A moderatenumber of cephalopod phrag- assemblagedeserves mention. It is the outer plete aptychi are paired structures consisting mocones were collected from the aptychi shell laver, without evidence of sutures or of right and left halves attachedat a symphy- horizon, but most were incomplete and ornamehtation, of one side of a moderately sis, but the specimensat hand are disarticu- many are poorly preserved.In all examples, large shell (UNM 5998)having a diameter of lated halves. One specimen (UNM 5991), the shells were flattened on bedding planes, 45 mm and an estimated apertural diameter however, does include both halves of an making it impossible to accuratelydetermine of about 25 mm (Fig. a). The umbilicus is aptychus still partially appressed (Fig. 2). cross-sectionalshape or apertural Propor- small and moderately deep, and the shell Eachhalf of an aptychus is roughly oval, very tions. Two ammonoid genera and at least appearsto be involute. On the basisof gener- thin shelled, has fine concentric growth lines three nautiloid genera are present in the al shell morphology, this specimen is very on the external surface, and has its apex dis- assemblage.Definite evidence of the associa- likely a nautiloid rather than an ammonoid, placedabout two-thirds of the distancealong tion, in life, of the aptychi with a particular and no observable features occur that pre- the symphysis. As noted by Thompson and cephalopod (for example, a shell preserved clude it from belonging to the Liroceratidae. others (1980),aptychi of this type superficial- with the aptychus covering its aperture) is Conceivably, the aptychi in the Cedro ly resemblebivalve mollusk shells. The three lacking; however, some speciesmay be dis- assemblagecould have come from specimens best preserved aptychi have the following missedas the possiblebearers of the aptychi of this cephalopod that were about the same dimensions:1) UNM 5991-length, t7 mm; on size considerationsalone. Both ammo- sizeor somewhat larger than the specimenat width, 9 mm; width/length, 0.53; 2) UNM noids are far too small to have borne the hand. 5996-length, 40 mm (est.); width, 19 mm aptychi. Most of the ammonoids are Anthra- (est.), width/length, 0.a8; 3) UNM 6005- coceras?,a small goniatitid having a maximum length, L8 mm; width, l.L mm; width/length, shell diameter in the Cedro assemblageof 0.61. approximately 18 mm. One fragmentary No significant differences are found be- ammonoid specimen is quite different from tween these specimensand those described Anthracoceras?in that it has fine. closelv and illustrated by Thompson and others spaced, transverse lirae covering the initiil half of the last whorl, fading to obscurity toward the aperture. Suture marks are not preserved in this specimen, but its external ornamentation resemblesthat of.Reticu- Ioceras.The shell diameter is approximately 13mm, much smaller than the aptychi speci- mens. Severalfragments of orthoconic nautiloids, probably representing both Pseudorthoceras and Mooreoceras,are present in the assem- FIGURE4-Largest nautiloid found in aptychi blage. The largest fragment possessessix horizon,a specimententatively assigned to the chambers,is approximately 28 mm long, and Liroceratidae(UNM 5998),x 1. hasa maximum diameterof 13mm. Estimat- ing the complete size of the phragmocone or of its aperture is difficult. as onlv a small In summary, several different types of portion-of the apical end of the shell is pre- cephalopods, including both ammonoids served.However, circular aptychi composed and nautiloids, are present in an assemblage of three, rather than two, elements are containing aptychi in the Los Moyos Lime- FIGURE2-Slightly disarticulated halves of a sin- stone. Only the nautiloids Metacocerascf. M. gle aptychus (UNM 5991),x 1.5. known from some European Silurian ortho- conic nautiloids (Thompson and others, cornutumandliroceratidae? are large enough 1980),and thus it is unlikely that the elliptical to be plausible as possible bearers of the Cedro aptychi belonged to the orthoconic aptychi. Becausethe aptychi reported by nautiloids in the assemblage. Thompson and others (1980)from Vinton Specimensof the nautiloid Metacocerascf . Canyon probably belonged lo Liroceras,a M.iornutum in the Cedro collectionsrange liroceratid, possibly the same associationex- up to approximately 30 mm in diameter-too isted in the contemporaneousLos Moyos small for the aptychi. However, shells of M. Limestone of central New Mexico. Definite cornutummore than twice this size have been identification of the nautiloid involved, reported from Desmoinesian and early Mis- however, must await the fortuitous discov- sourianunits in other areas(Girty, 1915,from eqr of a shell preserved with an aptychus at the Wewoka Shale; and Unklesbay, 1962, its aperture. from the Coffeyville Formation, both in Okla- homa), and it is certainly possible that the Associated fauna FIGURE 3-Fragment of a large aptychus (UNM few availableCedro specimensdo not repre- The shaleunit that yielded the aptychi and 5996),x 1.5. sent the maximum size attained by this spe- cephalopodconchs described above conta#

New Mexico Geology November 1983 TABLE 1-INvERTEBRATESFRoM THE AprycHr HoRrzoN, uppsn Los Moyos LrvrsroNn, Nren Cnono. Numbers oea21e1@a21@@1e1el are Percentage of entire assemblage represented by each taxon, based on approximately 500 specimens examined. Asterisks indicate taxa not previously reported from New Mexico. Geographicnames U,S.Board on Geographic Names *Modiolus ANNELIDA (?) (Modiolus)aff. M. (M.) radiata <1 Capitan Mountains-mountains, 34 km (21 mi) Claaulitessp. <1 Aaiculopectensp. <1 long, highest elevation 3,073 m (10,083 ft) at BRYOZOA Limipecten?sp. 1 Capitan Peak,northeast of the SierraBlanca and Fenestellasp. 3 Paleolimaretifera 3 35km (22mi) eastof Carrizozo; Lincoln County, BRACHIOPODA Str eblochondrin tenuilineata ) New Mexico;33'35' N., 105'12"W. (eastend), *Mesolobus *Sanguinolites? aff. M. lioderma 42 sp. 33"39'N., 105'33'W. (west end); 1907decision Chonetinellaaff. C. plebeia 1 *Solenomorpha?sp. (BGN *Eolissochonetes revised; not: Sacramento Mountains sp. 9 Edmondiaaff. E. ooata 1907). *E. Derbyiasp. <1 alf . E. meekiana Carrizo Mountain-mountain, highest elevation Cancrinellasp. 1 Astartellasp. 2,928 m (9,605 ft\ at Caritzo Peak in the Sac- rSchizodus Antiquatoniasp. <1 affinis ramento Mountains 14 km (9 mi) northeast of *New Phricodothyris?sp. <1 genus(?) Carizozo and 33 km (20 mi) north of Ruidoso; GASTROPODA unidentified bivalves 11 Lincoln County, New Mexico; T. 7 5., Rgs. 12 Glabrocingulumsp. 1 CEPHALOPODA (AMMONOTDEA) and 13E., NMPM;33'42' N., 105'46'20"W. (west Phymatopleurasp. <1 Anthracoceras?sp. 3 end),33"42'N., 105"41'W. (eastend); not: Cari- *afl. unidentified gastropods 1, Reticulocerus <1 zo Mountains, Carizozo Mountain. SCAPHOPODA (?) 1 CEPFIALOPODA (NAUTILOIDEA) Davenport Canyon-canyon/ 5.1 km (3.2mi) long, BIVALVIA Pseudorthocerasandl or Mooreoceras 1 heads in the Datil Mountains east of Davenpoit Phestiabellistriata 5 Metacocerascf. M. cornutum I Spring at 34"'16'43'N., 10f54'50' W., trends (l Solemya aneia)radiata Liroceratidae? <1 west 1..5km (0.9 mi) then south-southwest3.7 (1.) * S. att. S.(1.) radiata Cornaptychussp. (aptychi) 1 km (2.3rni) to White HouseCanvon 15.6 km (9.7 Parallelodonsp. ECHINODERMATA mi) northwest of Datil; Catron County, New Pteronites?sp. crinoid J *Leptodesma stem and cirri fragments Meico; sec.1, T. 1 S., R. 1l W., NMPM;34'15' (Leptodesma)aff. L. (L.) ohioense echinoid spines and plates 1 N., 10r56',25',W. *Monopteria?subalata ficarilla Mountains-mountains, 29 km (18 mi) long, north of Carrizoand PatosMountains 29 kn (18mi) northeast of Carnzozo; extend north from White Oaks Draw and Reventon Draw to a sparse,but moderately diverse, marine in- the midcontinent and eastern regions of the Ancho Valley and HasparosCanyon between vertebratefauna. Althdugh this fauna was United States.Eight of the bivalve taxa have the TularosaVa.lley on the west and the Pecos not studied in detail, each specimenencoun- not previously been reported from the Penn- River valley on the easf Lincoln County, New tered in the samples wai identified and sylvanian of New Mexico-a consequence Mexico;33d52'N.,105'40'w. (north endi 33%5' counted,and the relativeabundance of each more of the lack of study of this group in the N., 105'45'W., (south end); 1907decision re- vised; (BGN speciesdetermined. Several species not pre- state than not: SacramentoMountains 1907). of their rarity. Kid viously reported from the Pennsylvanian Spring-spring, in the Datil Mountains, be- of ACKNOWLEDGMENTS-IthanK Kenneth tween Blue Canyon and Main Canyon 13.4 New Mexico (Table km occur 1.). Kietzke for helping with the collectingand (8.3 mi) north-northeast of Datil and 5 km (3.1 The fauna is dominated by chonetid for originally bringing the specimens later mi) west-northwestof Madre Mountain; Catron brachiopods(Mesolobus, Chonetinella, and identified as aptychi to my attention. I also County, New Mexico; 34"16'37'N., 107"49'22' Eolissochonetes).Pelecypods are surprisingly thank the Spring 1983invertebrate paleontol- W.; not:Hidden Spring. diverse and collectivelyare aboul half"as ogy classat the University of New Mexico for Patos Mountain-mountain, elevation 2,588 m abundant as brachiopods. Non-chonetid their enthusiasticaid in sampling the fauna of (8,490tt),6.4km(4mi) across,northeast of Carri- brachiopods, as well as such typical Madera the aptychi locality. Ellis Yochelson, zo Mountain and south of the JicarillaMountains 23 km (14.3 mi) northeast of Carrizozo; invertebrates as bryozoans, crinoids, and SmithsonianInstitute, and RousseauFlower, Lincoln County, New Mexico; T. 6 and 7 5.,R. echinoids,are uncommon. The shellsof most New Mexico 12E., Bureau of Mines and Mineral NMPM; 33'44'77'N., 105'39'44"W.; not: Patos of the fossilswere originally unbroken, but Resources,reviewed the manuscript and Mountains. they are thin and to some extent decalcified offered helpful suggestionsfor its improve- RancheriaCanyon-canyon,72.9 km (8 mi) long, and tend to break off of bedding planes or ment. headsin the SacramentoMountains at Rancheria crumble when exposed, making retrieval of Springat 33"05'25'N.,105'53' W., trends west- complete specimensdifficult. Some taxa are References southwestto open out 3.2 km (2 mi) southeastof Tularosa; reportedly, groups of preserved primarily as molds. Large, Arkell, W. J., 7957, Introduction to Mesozoic Ammo- Indians once meandering grazing trails and undulating, noidea;in Moore, R. C. (ed.), Treatiseon Invertebrate lived here in brush camps, locally called "ran- elongate fecal casts are characteristic trace Paleontology,Part L, Mollusca 4: GeologicalSociety of cherias";Otero County, New Meiico; sec28, T. America 14 10 fossils that probably indicate and University of KansasPress, pp. L8l-L129. S.,R. E., NMPM; 33'03's5'N.,105'59'31' a significant Closs,D., Gordon, M., and Yochelson,E. L., 1964,Corn- W. density of soft-bodied organisms. The un- aptychi from the Permian of Utah: Journal of Paleontol- Rinconada Canyon-canyon, 16.9 km (10.5 mi) brokennature of most of the skeletons,along ogy,v.38, pp.899-903. long, in the SacramentoMountains, heads at Girty, G. H., 1915,Fauna with the preservationof delicate chonetid of the Wewoka Formation of 33'19'41'N., 105'51'35'W., trends southwest Oklahoma: U.S. Geological Suruey, Bulletin 5U, 353 spinesstill attached to the shells, Iong articu- pP' along the courseof RinconadaCreek to open out lated crinoid cirri, and complete fenestrate Morton, N., 1981,Aptychi-the myth of the ammonite 14.5km (9 mi) northwest of Mescalero;rincona- bryozoan zoaria, suggestsihat deposition operculum: Lethaia, v. 14, pp.57-47. da is a Spanish word meaning "little box occurred in a quiet environment. The low Myers,D. A., and McKay,E.J.,1976,Geologicmap of the canyon"; Otero County, New Mexico; sec.6, T. north end diversity of brachiopods,absence of corals of the Manzano Mountains, Tijetas and Sedi- 13S., R. 118., NMPM; 33'12'36'N., 105'54'24' Llo quadrang.les,Bernalillo County, New Mexico: U.S. w. and fusulinids, and paucity of crinoids and Geological Suruey,Miscellaneous Geological Investiga- RinconadaCreek-stream, 16.9km (10.5mi) long, bryozoansmay tions Mao I-968. indicate high sedimentation in the SacramentoMountains, Thompson,E. H., Yochelson,E. L., and Flower, R. H., headsat 33"19'41" rates or a slightly fluctuating salinity that N., 105'51'35'W.,flows southwestthrough Rin- made it difficult for large populations 1980,Aptychi from the Pennsylvanian of west Texas: of ste- Journalof Paleontology,v.54, pp.90T909. conada Canyon to join an unnamed creek to nohaline suspension feeders to colonize the Unklesbay, A. G.,1962, Pennsylvanian cephalopods of form Temporal Creek 14.5 km (9 mi) northwest seafloor for long periods of time. Oklahorna: Oklahoma Geological Suruey, Bulletin 96, of Mescalero;Otero Counfy, NewMexico; sec.6, Thechonetid brachiopods and many of the 150pp. T. 13 S., R. 11 E., NMPM; 33'12'36' N., bivalvesare similaror identicalto coniempo- Yochelson,E. L.,1,983,ADevonian aptychus (Cephalopo- 705'54',24',W. da) from Alabama:Journal of Paleontology, v.57, pp. raneousforms that havebeen reported from 124-727. - (continuedon page82)

November 1983 New Mexico Geology