Review of Palaeobotany and Palynology, 28(1979): 223--236 223 Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands

THE GENUS PLATYCHARA FROM THE WESTERN HEMISPHERE

RAYMOND E. PECK and RICHARD M. FORESTER Department of Geology, University of Missouri, Columbia, Mo. 65201 (U.S.A.) United States Geological Survey, Denver, Colo. 80225 (U.S.A.) (Received January 18, 1978)

ABSTRACT

Peck, R.E. and Forester, R.M., 1979. The genus Platychara from the Western Hemisphere. Rev. Palaeobot. Palynol., 28: 223--236.

The systematics of four species belonging to the genus Platychara (Charophyta) from the Western Hemisphere is discussed. Three of the species, as defined herein, occur in Cretaceous and Paleocene rocks from Mexico through South America. The type species, P. cornpressa (Peck and Reker) Grambast, also of Cretaceous and Paleocene age, is herein restricted to deposits north of Mexico. These latter restrictions geographically separate P. eompressa and P. perlata as presently defined but the relationship between these two species is still uncertain. A new species, P. grambastii, is proposed for specimens from Maestrichtian sediments in Jamaica.

INTRODUCTION

The genus Platychara incorporates highly distinctive gyrogonites that are f requent ly found in great abundance in some Upper Cretaceous and, to a lesser extent, Paleocene non-marine deposits in Europe and North and South America. Platychara presently includes eleven species of which four are known f rom the Western Hemisphere. Of these, the type species Platychara compressa (Peck and Reker) Grambast, and closely related species Platychara perlata (Peck and Reker 1947) are the pr imary components of the genus. The other two species, P. grambastii new species and Platychara aft. P. caudata (Grambast 1971) are known only f rom single localities.

The purpose of this paper is to update the systematics of those species of Platychara occurring in the Western Hemisphere. We have placed special emphasis upon Platychara compressa and P. perlata because of their abun- dance within the study interval.

MATERIALS AND METHODS

This study is based upon col lections that were obtained f rom various deposits occurring f rom Alberta, Canada, to Argentina. In addit ion to collec- t ions made by the authors, a large number of samples were obtained f rom the U.S. Geological Survey as well as f rom various universities, museums, and industry. Madame N. Grambast-Fessard furnished representatives of Platychara

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species from Europe for study and comparison. The collections have been assembled over the past thirty years by R.E. Peck. All illustrated specimens have been deposited in the USNM (United States National Museum). The remaining specimens are housed in the U.S. Geological Survey collection in Denver, Colorado.

Specimens of Platychara were extracted from the samples by various routine micropaleontologic techniques. A freeze-thaw technique using a supersaturated solution of glauber salt (Na2 SO4" 1OH2 O) (Surlyk, 1972) proved to be particularly useful for removing whole specimens from most lithified materials.

Several specimens were chosen from selected samples in order to deter- mine the largest equatorial diameter (LED), the longest polar axis (LPA), the isopolarity index (ISI) and the number of spirals visible in lateral view. The number of specimens measured from any one sample is, in general, small because many of the specimens have undergone post~depositional distortion that has rendered them unsuitable for biometrics. In other cases relatively few specimens were available for study. However, all of the specimens that were measured seem to be representative of the various populations sampled.

DISCUSSION

Table I summarizes the measurements made on most of the Platychara species in this study. The sample from Wales Canyon, Utah (Table I) is from the type area of Platychara compressa. The Price Canyon, Utah, sample is in close geographic proximity to the one from Wales Canyon, while the Willow Creek Formation, member A, sample is from Alberta, Canada. All three samples contain morphologically similar gyrogonites, have an average ISI ratio of 74 or 75 and are presumably conspecific. A fourth sample from a younger unit (Paleocene) of the Willow Creek Formation contains specimens of Platychara compressa? with an average ISI ratio of 81 and general mor- phology similar to P. perlata from Mexico and South America.

The majority of the specimens from Mexico and South America have an average ISI ratio of 81 or greater. Some of these specimens are morphologi- cally similar (i.e., number of spirals, spiral shape, size, etc.; see systematic section) to Platychara perlata, while others appear to be somewhat similar to P. compressa. Many of the latter specimens have been identified as P. cruciana (Horn af Rantzien, 1951) by various persons, which we place in questionable synonomy with P. perlata.

The relationship of Platychara compressa to P. perlata is unclear. The limited data available from North America suggests that the ISI ratio of populations of P. compressa increases with time. The stratigraphic informa- tion that is available for the samples from Mexico and South America does not allow a direct temporal comparison of these specimens to each other or to the North American specimens. Many possibilities could be invoked to explain the relationship between P. compressa and P. perlata. Some of these include: (1) two distinct species, with one possibly exhibiting greater

TABLE I

Numerical relationship of selected Platychara species from Cretaceous and Paleocene deposits in the Western Hemisphere (except for P. turbinata Grambast and Guti~rrez herein reported for comparison purposes)

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Sample description N R 1 Av. LED R 2 Av. LPA Av. ISI Av. no. (pm) (pm) (pm) (pm) spirals

Wales Canyon, Utah 16 950-1115 1023 700--830 765 75 6.63 P. compressa

Price Canyon, Utah 29 720--1000 881 550--750 656 74 5.93 P. compressa

Willow Creek Fm., member A, P. compressa

Willow Creek Fro., member E, P. compressa?

15 810-930 887 550--720 655 74 5.73

16 800-1030 929 600-870 749 81 6.44

Vi lquechicoFm., 9 750--860 809 600--760 672 83 7.11 P. perlata

Unnamed unit, Mexico, 23 700-840 770 590--700 639 83 6.96 P. perlata

YacoraiteFm., 5 910--1000 942 690--800 764 81 7.20 P. perlata?

Jamaica sample, 57 590--880 748 400-650 534 71 5.37 P. grambastii

P. turbinata from 8 520--620 576 400--500 448 78 6.33 Spain

Legend: N indicates the number of specimens measured, R~ is the total observed range of the Largest Equatorial Diameter (LED), Av. LED is the average LED value for the sample, R2 is the total observed range of the Longest Polar Axis (LPA), Av. LPA is the average LPA value for the sample, Av. ISI is the average Isopolarity Index for the sample, and Av. no. spirals corresponds to the average number of spirals observed in lateral view.

morpho log ic var ia t ion ; (2) geograph ic or eco log ic var iants or subspec ies ; (3) an ancestor - -descendent re la t ionsh ip ; and (4) morpho log ic convergence o f one spec ies w i th the o ther . However , none o f these or o ther poss ib i l i t ies can be eva luated unt i l we have a bet ter unders tand ing o f the tempora l - -geograph ic assoc ia t ions o f the var ious forms. G iven the l im i ted s t ra t ig raph ic in fo rmat ion avai lable, as wel l as the known geograph ic d i s t r ibut ion o f the two fo rms, we suggest that al l o f the Mex ican and South Amer ican fo rms be long to P. perlata and all o f the fo rms f rom areas nor th o f Mex ico be long to P. compressa. The spec imens f rom member E o f the Wi l low Creek Format ion may represent P. compressa that has converged towards the P. perlata morpho logy .

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This geographic subdivision of the two species is, in part, supported by the seeming absence of any major lacustrine systems within a region from north- ern Mexico to southern Colorado and Utah during the Late Cretaceous and Paleocene (Feth, 1964). The absence of a lacustrine system within this region might provide a sufficient geographic barrier to allow the formation of two species populations.

SYSTEMATICS

Family CHARACEAE L. C1. Richard 1815 Subfamily CHAROIDEAE Al. Braun ap. Migula

Genus Platychara Grambast 1962

Type species: Chara compressa Knowlton 1888 (non Chara compressa Kunth 1815), designated by Grambast, 1962. Characters of the genus: Large to very small oblate, suboblate, to oblate-- spheroidal gyrogonites with base and summit broadly rounded to flat, or the spirals turned sharply down at the base to produce a small column and give the gyrogonite a shape analogous to a top. Spirals flat to convex, on some species dominantly concave, generally wide, variably restricted in width and thickness as they turn onto the summit, smooth or ornamented by nodes or crenulate ridges. Peripheral furrow prominent to obscure, deep and well marked with terminal ends swollen to form rosette on most forms with convex spirals, but spirals invariably change in character as they pass from the sides onto the summit. Basal opening small, basal plate not well known. Remarks: As presently recognized, the genus Platychara incorporates gyro- gonites with a size of greater than one millimeter in width (P. compressa) to about one-third of a millimeter (P. stipitata Grambast and Guti~rrez 1977). Species may consist principally of gyrogonites that have spirals that are strongly convex, flat, or deeply concave, but in almost all species there is marked variation among individuals in the degree of calcification. The spirals may be smooth or possess a strong ornamentation of nodes or crenulate ridges.

Platychara species share the oblate to oblate--spheroidal shape, the small basal pore, and frequently the tapering basal extremity, as primary characters. These characters distinguish Platychara from all other genera of charophytes except for Gyrogona from the Eocene--Oligocene. Some species of Gyrogona are wider than high (LED > LPA), but the peripheral furrow is distinctly interrupted and consists of a series of unconnected or barely connected pits, the basal opening characteristically is funnel-shaped, and the basal plate is well developed.

Grambast (1962) stated that specimens of Platychara have short prismatic basal plates. We have sectioned or crushed about 100 specimens of P. com- pressa and have not found any evidence of a basal plate. The basal plate is not mentioned in the descriptions of other Platychara species. Distribution: Principally Upper Cretaceous of Europe and North and South

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America. The genus is recorded from the Montian of Mons (Grambast, 1971, p.20), the Montian of Argentina (E.A. Musacchio, written communication, 1973), and above the Cretaceous--Tertiary boundary in the Willow Creek Formation and equivalents in Alberta, Canada (Germundson, 1965).

Platychara compressa (Peck et Reker 1948) Grambast (Plate 1,1--6)

1888 Chara compressa Knowlton, pp.156--157, figs.l--2; Groves, 1933, p.14 (non Chara compressa Kunth 1815).

1948 Aclistochara compressa Peck and Reker, p.87, pl.21, figs.31--33 (non Lankford, 1953, p.109, pl.12, figs.3--7).

1954 Brachychara compressa (Peck and Reker) Grambast and Grambast, p.3. 1955 Tectochara compressa (Peck and Reker) M~dler, p.276; Peck, 1956, p.95, figs.3--4. 1956 Gyrogona compressa (Peck and Reker) Grambast, p.280. 1959 Nodosochara compressa (Peck and Reker) Horn af Rantzien, pp.81, 96. 1959 Peckichara compressa (Peck and Reker) Peck, p.118, fig.4. 1962 Platychara compressa (Peck and Reker) Grambast, p.76; Holifield, 1964, p.31,

pl.ll, figs.11--18; Germundson, 1965, p.98, pl.12, figs.l--12.

Diagnosis: Large-size gyrogonites, ranging from 500 to 800 pm in height and 720 to 1150 ~m in width, most with height two-thirds to three-fourths the width (ISI 60--75), a few specimens almost as high as wide (LED=LPA). Spirals wide, generally fiat to convex, a few concave, making almost two complete turns in the ascent from the basal pore to the center of the apical end with a total of 8 or 9 spirals from the basal pore to the apical center, while 5 to 7 spirals are readily visible in lateral view. Specimens with convex spirals have prominent peripheral furrows and well-developed rosettes; on specimens with fiat spirals peripheral furrow shallow and rosette not well developed; furrow and rosette indistinct on specimens with concave spirals. Base broadly rounded, almost flat, the basal opening small and inconspicuou.,, Spirals tend to expand slightly around the basal opening. Remarks: Platychara compressa is easily recognized by its oblate shape, generally large size, and wide spirals. It is the only known large gyrogonite occurring in North America and perhaps South America that is markedly wider than high (LED > LPA). P. perlata has greater ISI ratio and generally has more spirals visible in lateral view. P. grambastii is smaller and has a lower average ISI ratio, a more prominent peripheral furrow, and a pointed base.

As noted in the discussion, there are numerous occurrences of a Platychara species in South America that is similar in many respects to P. compressa and P. perlata. These specimens are all questionably assigned to P. perlata, thus restricting both the geographic and morphologic bounds of P. compressa. The Paleocene specimens from member E of the Willow Creek Formation are not included in this evaluation of P. compressa.

The specimens of P. compressa from the type area in Wales Canyon generally are much larger than those from other localities. There are at present no obvious explanations for these size differences.

The selection of the name Platychara compressa (Peck and Reker) Grambast

O0

~3

229

is based upon the Botanical Code Article 72. Note I. The latter ruling was kindly brought to our attention by Dr. W. Punt, University of Utrecht. Occurrence: P. compressa is widely distributed in the Upper Cretaceous non- marine deposits of North America (i.e., north of Mexico). It occurs in the Cretaceous portion of the North Horn Formation of Utah, the Lance Formation of southern Montana, and the Cretaceous portion of the Willow Creek Formation and equivalents in Alberta, Canada. Germundson (1965) recorded it f romthe Paleocene portion of the Willow Creek Formation near the Cretaceous--Tertiary boundary in Alberta, where sedimentation was continuous from the Cretaceous into the Paleocene (Carrigy, 1971).

Knowlton (1888) described Chara compressa from the "Wasatch Group of lower Tertiary age" near an old coal mine opening 2 miles west of Wales, Utah. These beds have since been assigned to the North Horn Formation (Spieker, 1946) and determined to be Cretaceous in age (E.M. Spieker, written communication) but have continued to be referred to as Tertiary (Peck and Reker, 1948; Grambast, 1971). Grambast (1974, p.75) recorded finding dinosaur egg fragments in sediments above the charophyte locality. Types: Lectotype, USNM 175788; paralectotype 175789, herein designated and selected from the type specimens of Chara compressa Knowlton. Figured specimens USNM 175788, 175789, 253230, 253231, 253232. Selection of types: The USNM material on which Knowlton based his description of Chara compressa consists of seven pieces of limestone with several genera of charophytes represented on the slabs. The drawing in Knowlton's paper {1888) must be a composite, because no individual speci- men is well enough exposed to serve for the drawing of an entire specimen. Knowlton's description states that about ten spirals are visible in a side view. This figure probably was obtained from viewing several specimens, some of which now probably would be referred to Retusochara. None of our topo- type specimens of P. compressa exhibits ten spirals in a side view, even if the specimen is tilted to count spirals on the rounded base and flattened summit.

We have selected as the lectotype a specimen that shows the summit extraordinarily well (Plate 1,2). Another specimen on the same slab is selected as a paralectotype (Plate II,1).

PLATE I

Platychara compressa (Peck and Reker) Grambast 1. Apical view of a gyrogonite from the Wales Canyon, Utah, locality of Knowlton.

Paralectotype, USNM 175789, 27. 2. Apical view of a gyrogonite from the Wales Canyon, Utah, locality of Knowlton.

Lectotype, USNM 175788, 33. 3,4. Apical and lateral view of a gyrogonite from the top of the exposed section at the

type locality in Wales Canyon, Utah. USNM 253230, 51. 5. Apical view of a gyrogonite from member E of the Willow Creek Formation in

Alberta, Canada. USNM 253231, 68. 6. Lateral view of a gyrogonite from member E of the Willow Creek Formation in

Alberta, Canada. USNM 253232, 68.

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The exposed portion of the lectotype measures approximately one milli- meter in diameter, the total would be somewhat more if the specimen were completely exposed; the height cannot be determined. The rosette is 600 pm in diameter. The spirals narrow and "thin as they turn onto the summit area, creating a conspicuous peripheral furrow. The furrow is interrupted by the apical terminus of the spirals (before thinning and narrowing) touching the sides of the swollen ends (rosette) of the next spiral on the right.

The rosette is persistent and is composed of the apical ends of the spirals widening and thickening in the central apical area. The spirals of the lecto- type are flattened to slightly convex; the number visible in a side view cannot be determined.

On the paralectotype the spirals are shallowly concave; therefore thinning on the apical periphery is slight. Narrowing also is much less prominent than on the lectotype, and the peripheral furrow is not so well marked. The apical ends of the spirals do widen and swell to create a rosette. The exposed portion of the paralectotype is approximately one millimeter in diameter; the total diameter is somewhat greater. The dimensions of both the lectotype and paralectotype represent the approximate known upper limit of the species (see remarks).

Platychara perlata (Peck et Reker) Grambast (Plate II,5,7,8)

1924 Chara elliptica Fritzsche, p.28, pl.2, fig.3 (non Chara elliptica Hislop, 1860, p.165). 1947 Chara perlata Peck and Reker, p.3, figs.19--21; Horn af Rantzien, 1951, p.661. 1951 ?Aclistochara cruciana new name, Horn af Rantzien, p.672. 1967 Platychara perlata (Peck and Reker) Grambast et al., p.2; Musacchio, 1972, p.231. 1972 ?Platychara cruciana (Horn af Rantzien) Musacchio, p.229, text figs.l--4, pl.1,

figs.l,4,7, pl.2, figs.15,17.

Diagnosis: Medium- to large-sized suboblate gyrogonites with flat to convex summit and gently rounded base, length ranging from 590 to 800 pm and width from 700 to 1000 ~m; ISI ratio ranging from 75 to 92, most about 82. Spirals medium to narrow in width, concave to strongly convex; 6 to 9 spirals, most with 7 or 8 in side view; may or may not form a rosette, gener- ally do not expand around the basal pore. Remarks: Specimens of P. perlata are smaller than representatives of P. com- pressa from Wales Canyon, Utah; they have a greater ISI ratio and narrower spirals, with more spirals visible in lateral view than is true of P. compressa. The spirals in P. perlata generally do not expand around the basal pore, whereas those in P. compressa do. Occurrence: Description of P. perlata was based on specimens from the Vilquechico Formation in Peru (Peck and Reker's 1947 topotype locality). All have concave spirals that thin on the summit and do not expand to form a rosette. Most, but not all, of the specimens from Mexico referred to this species have strongly convex spirals, well-developed peripheral furrows and prominent rosettes.

We also have questionably included in P. perlata all other specimens from

231

Mexico through South America that previously were referred to as P. cruciana or P. compressa (see Appendix on localities for a complete listing). Types: Primary types USNM 42254 (holotype); 42255, 42256 (paratypes); figured specimens USNM 253238, 253239, 253240.

Platychara grambastii nov. sp. (Plate II,3,4,6)

Diagnosis: Small to medium oblate gyrogonites with deep and continuous furrows separating the rosette from the convex portion of the spirals and, on most specimens, with the spirals turned downward around the basal pore to form a small cone. Gyrogonites ranging from 400 to 650/~m in height and 590 to 880 um in width, with an ISI ratio ranging from 58 to 82 and averag- ing 71. Spirals strongly convex to deeply concave; 4 to 7 spirals, although 5 to 6 spirals commonly visible in lateral view, 6 to 8 present if counting from the basal pore to the center of the summit. Basal pore small. Remarks: The deep and continuous furrow surrounding the rosette on the summit, combined with the small ISI ratio and the bluntly pointed base, serves to differentiate P. grambastii from all other described species of Platy- chara. Platychara turbinata Grambast and Guti6rrez (1977) is quite similar to P. grambastii (see Table I) but is smaller and has a larger ISI ratio. Occurrence: Maestrichtian, Jamaica. Types: USNM 253235 (holotype); USNM 253236, 253237 (paratypes). Etymology: The specific name is in honor of Professor Louis Grambast who made so many contributions to our knowledge of charophytes.

Platychara aff. P. caudata Grambast 1971 (Plate II,1,2)

1971 ?Platychara caudata Grambast, p.19, figs.7a--d, p1.14, figs.l--5, pl.15, figs.l--6. 1973 Platychara aft. P. caudata Grambast in Musacchio, p.3, pl.1, figs.l--4, 7.

Remarks: The material described by Musacchio from the Neuquen Group of Argentina is not well preserved, and most specimens have been distorted by compaction of the enclosing sediments. Although their condition makes specific identification difficult, the specimens appear to agree in most char- acters with those described by Grambast in Europe. Some of our specimens from Argentina do have convex spirals, which were not mentioned in Grambast's original description. Occurrence: Neuquen Group--Cretaceous. On the right bank of the Neuquen River approximately 2.5 km south of C. Cordero bridge, Province of Neuquen, Argentina (Musacchio, 1973, p.2). Types: Musacchio illustrated material no. 11892, Museo de La Plata, La Plata, Argentina; figured specimens, USNM 253233, 253234.

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PLATE II

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ACKNOWLEDGMENTS

We thank Jerome A. Eyer, Terra Resources, Inc., and J. Platt Bradbury, U.S. Geological Survey, for critically reading the manuscript and making valuable suggestions for its improvement. We especially thank Madame N. Grambast-Fessard for providing us with comparative material of the European Platychara species from the collections of Louis Grambast. Finally we would like to thank Elisabeth Brouwers Forester for providing assistance with the scanning electron microscope.

APPENDIX: LOCALITIES

United States

North Horn Formation: Upper Cretaceous (part). Near an old coal mine opening on both sides of a small valley in Wales Canyon, 2.6 km west of highway turnoff in Wales, Utah, in north center of section 26, T. 15 S., R. 2 E., Wales quadrangle. This is the type locality of Chara compressa Knowlton. Samples were taken throughout the exposed section and all yielded specimens of Platychara compressa and other species of charophytes.

Lance Formation: Cretaceous. Road cut on old highway No.10 at mouth of Unknown Creek, west of Hysham, Montana. Platychara compressa.

Canada

Willow Creek Formation member E: Paleocene. East bank of Willow Creek northwest of Granum, Alberta; lsd. 4, section 7, T. 11, R. 26, w. 4th meridian, Lethbridge GSC Map 20, 1967. Basal beds of Willow Creek and close to Cretaceous--Tertiary boundary (Germundson, 1965). Platychara compressa and two other species of charophytes common to the Hare- bell Formation of Wyoming.

PLATE II

Platychara aft. P. caudata Grambast, 1971 1. Oblique view of apical and lateral surface of a partly distorted gyrogonite from the

Neuquen Group, Argentina. USNM 253233, x 100. 2. Lateral view of a gyrogonite from the Neuquen Group, Argentina. USNM 253234,

121.

Platychara grambastii nov. sp. 3. Apical view of a gyrogonite from the Maestrichtian of Jamaica. Holotype, USNM

253235, 57. 4. Basal view of a gyrogonite from the Maestrichtian of Jamaica. Paratype, USNM 253236,

55. 6. Lateral view of a gyrogonite from the Maestrichtian of Jamaica. Paratype, USNM

253237, 63.

Platychara perlata (Peck and Reker, 1947) Grambast 5. Lateral view of a gyrogonite from an unnamed Upper Cretaceous unit in Coahuila,

Mexico. USNM 253238, 68. 7. Basal view of a gyrogonite from an unnamed Upper Cretaceous unit in Coahuila,

Mexico. USNM 253239, X 68. 8. Apical view of a gyrogonite from an unnamed Upper Cretaceous unit in Coahuila,

Mexico, USNM 253240, x 68.

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Willow Creek Formation member A: Cretaceous. Mudstones on bank of Rice Creek in lsd. 16, section II, T. 12, R. 2, W. 5th meridian, Lanford Creek GSC Map 981A, Alberta. Platychara compressa.

Mexico

Difunta Group: Cretaceous. About 96 km north of Saltillo, Coahuila, collected by Grover Murray, who stated (written communication, 1959) that Cretaceous fossils were collected above the occurrence of the charophytes. Murray further stated that charophytes are abundant in this area. Platychara perlata and Porochara sp.

Upper Cretaceous unit: Collected at 10131'W. long.; 2746'N. lat. on highway 75, from a section 171.5 km from Piedras, Corpus Christi Air Chart n-5, Sabino area, Coahuila, Mexico, below an ammonite locality. Sample RCR-S7-2, U.S.G.S. shipping no.F8-52-3 collected by R.C. Robeck. P. perlata and Porochara sp.

Jama~a

Maestrichtian. From shales in cuts of the Ducketts to Lamb River Road 1.84 km (air- line) south of Ducketts crossroad at 1816'32"W. long., 7754'42"N. lat., W. Marchmont Inlier U.S.G.S. no.30455. Collected by Norman Sohl. Platychara grambastii and Porochara n. sp.

Bolivia

Flora Formation: Cretaceous. East bank of Perolnigri--Eslabon anticline along the Rio Flora River, 14 km above Rio Flora--Madidi junction. This location is 315 km north- northwebt of La Paz in the province of Iturralde, Department of La Paz. Sample 20-2533 supplied by the Bolivian Gulf Oil Company. Platychara perlata and Porochara sp.

Argentina

Neuquen Group: Cretaceous. Sample taken on right bank of Rio Neuquen about 2.5 km south of C. Cordero bridge and in the valley which is on the west side of National Route 234, going away from the Colorados Mountains (see Musacchio, 1973, locality 3). Platychara aft. P. caudata.

Yacoraite Formation: Cretaceous. In the Tres Cruces and Yavi Chico provinces, Jujuy, Argentina (see Musacchio, 1972, for details). Type locality of Platychara cruciana (Horn af Rantzien)and Porochara ovalis (Fritzsche). Platychara perlata? and Porochara ovalis.

Paleocene-Montian: Above marine sediments of the Roca Formation in the province of Rio Negro. Platychara perlata ?.

Peru

Vilquechico Formation Bed D: Cretaceous. One kilometer southeast of Vilquechico and four kilometers southeast of Patina. Collected by N. Newell. Platychara perlata.

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