Stratigraphic Distribution of 

Species of the Megaspore Genus 

Minerisporites in North America 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E 
Stratigraphic Distribution of 

Species of the Megaspore Genus 

Minerisporites in North America 

By ROBERT H. TSCHUDY 

CONTRIBUTIONS TO PALEONTOLOGY 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E 

Taxonomy, stratigraphic ranges, and 

facies significance of Minerisporites 

megaspores 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1976 
UNITED STATES DEPARTMENT OF THE INTERIOR 

THOMAS S. KLEPPE, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

Tschudy, Robert H. 

Stratigraphic distribution of species of the megaspore genus Minerisporites in North America. 

(Contributions to Paleontology) (Geological Survey Professional Paper 743-E) 

Bibliography: p. 

Includes index. 

Supt. of Docs. no.: I 19.16:743-E 

1. Minerisporites. 2. Paleobotany-Cretaceous. 3. Paleobotany-Paleocene. 4. Paleobotany-North America. 

I. Title. II. Series. III. Series: United States Geological Survey Professional Paper 743-E. 

QE996.T7 560' .13 76-608080 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 

Stock Number 024-001-02892-1 
CONTENTS 

Page Page 

Abstract ............................................................................................... EI Systematics-Continued 

New species of Minerisporites............................................................ I Genus Minerisporites-Continued 

Stratigraphic distribution................................................................... I 

Significance of megaspores................................................................. 3 

Minerisporites succrassulus, n. sp ....................................... E7 

Minerisporites pseudorichardsonii..................................... 7 

Facies representation........................................................................... 4 

Systematics.......................................................................................... 5 

M inerisporites sp. A. . .. .. . . ... .. .. ....... .......... .. . . . . ... . . .. .. . . ... . . . . . .. .. 7 

Minerisporites sp. B............................................................. 8 

Genus Minerisporites .................................................................. 5 M inerisporites sp. C. . . ........ .. . ...... .. . . . . . . . . . . . . . . . ....... .. . . .. .. . . . ..... .. 8 

Minerisporite~ mirabilis ....................................................... 5 Methods............................................................................................... 8 

Minerisporites glossoferus, n. comb .................................... 6 Literature cited.................................................................................... 9 

Minerispoirtes dissimilis, n. sp ............................................ 6 Index .................................................................................................... II 

ILLUSTRATIONS 

[Plates follow index] 

PLATE I. Minerisporites mirabilis and Minerisporites glossojerus. 

2. Minerisporites dissimilis. 

3. Minerisporites succrassulus. 

4. Minerisporites pseudorichardsonii, M. sp. A, M. sp. B, and M. sp. C. 

Pa~e 

FIGURE I. Diagram showing stratigraphic distribution of species of Minerisporites reported 

from North America, including Greenland···················:························ .. ·············· E2 

TABLES 

TABLE 

Page 

1. Species of Minerisporites reported from localities outside of North America ........... E-3 

2. Important megaspore assemblages.............................................................................. 4 

3. Fossil megaspore localities.......................................................................................... 8 

III 

CONTRIBUTIONS TO PALEONTOLOGY 

STRATIGRAPHIC DISTRIBUTION OF SPECIES OF THE MEGASPORE 

GENUS MINERISPORITES IN NORTH AMERICA 

By RoBERT H. TscHUDY 

ABSTRACT 

Five species of megaspores assignable to the genus M inerisporites were 

found in samples from the Rocky Mountain region of the United States. 

One of these species had been reported previously from Alberta, Canada, 

and one from Montana. Of the three species previously unreported from 

North America, one is a new combination, and two are proposed as new 

species. These megaspores range in age from Albian to Paleocene. The 

stratigraphic ranges of all species of the genus reported from North 

America are also provided. A discussion of the significance of megaspores 

and their facies representation is presented. 

NEW SPECIES OF MINERISPORITES 

Two new megaspore species assignable. to the genus 

M inerisporites were found in Paleocene and Cretaceous 

rocks of the Rocky Mountain region of the United States. 

A third species, previously unreported from North 

America, was found in Paleocene rocks of Montana. This 

species, previously reported from the Paleocene of the 

Netherlands by Dijkstra ( 1961) as Triletes mirabilis forma 

glossoferus and later transferred to the genus 

M inerisporites by Potonie' ( 1966), is herein designated as a 

new combination-Minerisporites glossojerus. These 

three species are described and illustrated in the present 

report. 

A fourth species, which I consider to be conspecific with 

Minerisporites mirabilis (Miner) Pot. and which was 

previously reported by Miner (1935) from Montana, was 

also found, as were specimens of M inerisporites pseudorichardsonii1 Gunther and Hills and of three unnamed 

new species. 

The discovery of numerous specimens of three species 

new to North America of one megaspore genus was somewhat surprising in view of the apparent rarity of 

megaspores suggested by the scarce reports in the 

literature. Previous to the present work only 11 species of 

Minerisporites had been reported from North America. 

That this apparent rarity is probably more illusory than 

true will be discussed in the following section. 

•Original spelling pseudonchardsoni. See recommendation He, International code of 

botanical nomenclature, p. 61 (Lanjouw and others, 1966). 

STRATIGRAPHIC DISTRIBUTION 

The stratigraphic distribution of all species of 

Minerisporites reported from North America is shown in 

figure 1. 

M inerisporites mirabilis (al. Selaginellites mirabilis), 

the type of the genus, was reported by Miner (1935) from 

the Paleocene of Montana. I found specimens that I 

consider to be conspecific with M inerisporites mirabilis in 

the Paleocene of Wyoming. Hall (1963) reported the 

presence of M. mirabilis in the Dakota Formation 

(Cenomanian) of Iowa, Hall and Peake (1968) reportedM. 

mirabilis in the Windrow Formation of Minnesota 

(Cenomanian), and Agasie (1969) found specimens that he 

assigned to M. mirabilis in the Dakota Formation 

(Cenomanian) of Arizona. The specimen figured by 

Agasie is probably a specimen assignable toM. dissimilis, 

n. sp., as herein proposed. Hall's specimen may belong to 

the same species, but his figure, photographed by reflected 

light, does not show the detail necessary to allow one to be 

sure of such a designation. The specimen figured by Hall 

and Peake is not conspecific with M. mirabilis. 

Elsik (Stover and others, 1966) reported a form similar to 

Minerisporites mirabilis from the upper part of the 

Paleocene (or lower Eocene) of Texas. He named this fossil 

Minerisporites mirabiloides. Elsik proposed this species 

on the basis of five specimens, none of which appears to be 

complete (and unbroken). 

Miner (1932) described the species Minerisporites 

borealis under the genus Selaginellites borealis from the 

Upper Cretaceous rocks of Greenland. Singh (1964, 1971) 

found three species of Minerisporites from the Albian of 

Canada-M. macroreticulatus, M. marginatus, and M. 

venustus. The species M. macroreticulatus, and M. venustus were new;M.marginatus had previously been reported 

from Upper Jurassic and Lower Cretaceous localities in 

Europe and Australia. (See table I.) 

The work of Gunther and Hills (1972 is particularly 

significant because they found seven species of Minerisporites in the Brazeau Formation of Alberta, Canada. 

This formation ranges in age from middle Campanian 

through middle Maestrichtian. Two of the species, M. 

El 
E2 CONTRIBUTIONS TO PALEONTOLOGY 

(VVV'v 

Miner Hall and 

Miner 

·= (1932) Singh (1964, 1971) Gunther and Hills (1972) Peake Hall Agasie Elsik 2 

(1935) c.·- Green· Alberta Alberta (1968) (1963) (1969) (1966) This work 

o E Montana Minne- Iowa Arizona Texas 

·;:; ~ land sota 

~ > 

"0 

"QCI> 

:;,-0 e Q) c. Q) Fort c. Wilcox .... 0 <0·- Q) Union Group E:::: u 

0 't; E Q) Fm. Wyoming Montana 

w iii 

0.. @ @~ ~ 65 ~n~~~n;~~ ~~~~~r~~~ f-.-- l£!!!:..J 

Q; 

MAESTRICHTIAN a. 

a. 

:;) 

~ f- c. 

0 .. Q) 

·;:; 

70 ro "0 E 

~ e ~ e "0 ..... ·- 0 :::E u. 

~ ? 1-:;, ro 

Q) 

N 

~ ro 

a; 00 ~ 

75 ? 0 

...J 

CAMPANIAN 

CretaUpper 1-, ~ Cl) ceous :;, 

0 

Q) 

~ Q) Montana 

80 u 

a; - a. 

a. 

:::> Eagle Sandstone 

SANTONIAN Wyoming 

85 

- sp. A 

CONIACIAN Niobrara 

Formation 

TURONIAN 

90 

CENOMANIAN ~ @ @ Wmdrow Dakota 

(J) Formation For"lation 

I I 

~ sp.B 

95 ALBIAN sp. C 

Nebraska Fall A over 

a; Ss. eauivalent 

a. 

a. EXPLANATION :::> 

Cl) 

~ @ Minerisporites mirabilis -M. pseudorichardsonii -M. mirabiloides :;, 

0 1-

~ ~ Q) 

u M. borealis ~ M. delicatus @ M. dissimi/is ~ Q) 

u Q) 

-

=o w e '& M. macroreticulatus M. corrugatosus M. succrassulus 

a; "0 

~ ~ 0 e ~ M. marginatus ~ M. irregularis ~ M. g/ossoferus ...J 

f-

~ e M. venustus M. deltoides 

~ 1 From Obradovich and Cobban (1975). 0 

...J 1 In Stover, Elsik, and Fairchild (1966) . 

3 Not to scale below 95 m.y. 

FIGURE I.-Stratigraphic distribution of species of Minerisporites reported from North America, including Greenland. 

borealis and M. marginatus, had been reported previously. 

They considered the species M. pseudorichardsonii, M. 

delicatus, M. corrugatosus, M. irregularis, and M. 

del to ides to be new. 

In addition to the species Minerisporites mirabilis 

mentioned ea~lier, I have found specimens in the 

Paleocene of Montana which I consider to be conspecific 

with Dijkstra's (1961) forma glossoferus and have altered 
STRATIGRAPHIC DISTRIBUTION OF MINERISPORITES IN NORTH AMERICA E3 

TABLE I.-Species of Minerisporites reported from localities outside of North America 

Species Country Age Reported by 

Minerisporites mirabilis (al. Triietes 

mirabilis Dijkstra, 1961) Pot., 1966. The Netherlands ............. Paleocene ....................................................... Dijkstra (1961). 

M. mirabilis forma glossoferus (al. Triletes 

mirabilis forma glossoferus Dijkstra, 

1961) Pot., 1966. ... do ..................................... do................................................................ Do. 

M. mirabilissimus (al. Triletes 

mirabilissimus Dij kstra, 1961) 

Pot., 1966. Belgium ............................... do .............................................................. . Do. 

M. marginatus (Dijkstra, 1951) 

Pot., 1956. The Netherlands ............ . 

England ......................... .. 

Denmark ......................... . 

England .......................... . 

Australia ........................ .. 

Wealden (Early Cretaceous) ........................ .. 

... do ............................................................... . 

Late Jurassic. ................................................ . 

Late Jurassic, Early Cretaceous. 

Early Cretaceous (probably Albian). 

Dijkstra (1951). 

Batten (1969) . 

Gry (1969). 

Hughes (1958). 

Cookson and Dettmann 

(1958). 

Belgium........................... Wealden (Early Cretaceous) .......................... Delcourt and Sprumont 

(1955). 

M. richardsonii (Murray, 1939) Pot., 1956. England ........................... Middle Jurassic ............................................. Murray (1939). 

M. alius Batten, 1969 ......................................... do .................................. Wealden (Early Cretaceous) .......................... Batten (1969). 

M. volucris Marcinkiewicz, 1960 .......... .......... Poland............................. Jurassic.......................................................... Marcinkiewicz (1960). 

Denmark ............................. do ................................................................ Gry (1969). 

M. institus Marcinkiewicz, 1960 ..................... Poland ................................ do ................................................................ Marcinkiewicz (1960). 

M. gryensis (al. Triletes gryensis) 

Dijkstra, 1959 (not transferred).' The Netherlands ............. Wealden (Early Cretaceous) .......................... Dijkstra (1959). 

'Original description indicates that Trzletes gryens1s should be transferred to Minerispontes gryensis. However, the photograph of the type does not show enough detail to permit 

transfer without examination of the original specimens. 

the designation to Minerisporites glossoferus, n. comb. 

(See section entitled "Systematics.") In addition, I found 

specimens assignable to the proposed new species M. 

sucrassulus and M. dissimilis-the former from the 

Paleocene of Montana, and the latter from the Albian of 

Nebraska. I found specimens identical with the speciesM. 

pseudorichardsonii, named by Gunther and Hills (1972) 

from the Brazeau Formation of Canada, in the Eagle Sandstone (lower Campanian) of Montana and in the Niobrara 

Formation (Santonian-Coniacian) of Wyoming. Two new 

unnamed species were found in the Fall River Sandstone 

equivalent of Nebraska (upper Albian), and one new 

unnamed species was found in the Niobrara Formation of 

Wyoming (Santonian-Coniacian). 

A literature search of the 17 species of Minerisporites 

included in the genus prior to the present work revealed 

that II had been found in samples from North American 

rocks. Species reported from other regions of the world are 

listed in table I. 

Of the species listed in table I, only M inerisporites 

mirabilis and M. marginatus have heretofore been mentioned from North America. The present work adds the 

species M. glossoferus, n. comb., to that list. The 

remaining species are from European Jurassic or Lower 

Cretaceous rocks. Rocks (particularly those of Jurassic 

age) that are likely to yield magaspores because of their 

nonmarine nonoxidized carbonaceous· characteristics are 

uncommon in North America and, therefore, have not 

been examined for megaspores. Also, Lower Cretaceous 

rocks, and, to a lesser degree, Upper Cretaceous rocks form 

North America have not been routinely examined for the 

presence of megaspores. 

SIGNIFICANCE OF MEGASPORES 

I am convinced that once megaspores have been 

routinely searched for in continental Mesozoic rocks they, 

and the smaller palynomorphs accompanying them, will 

provide for the stratigraphic subdivision of nonmarine 

rocks as effectively as ammonites and baculites now serve 

to subdivide marine-rock sequences. The stratigraphic 

utility of megaspores is already well established for the 

Paleozoic (Zerndt, 1930, 1937, 1938; Dijkstra and Vierssen 

Trip, 1946; Dijkstra, 1952, 1955, 1957; Winslow, 1959; 

Chaloner, 1959; and many other authors). Present knowledge of megaspores from Mesozoic rocks suggests that 

these fossils will become as stratigraphically valuable as 

those from the Paleozoic. 

Representatives of the genus Minerisporites have been 

found sporadically throughout the Jurassic, Cretaceous, 

and Paleocene. Present knowledge of species belonging to 

this genus strongly suggests that most of the species have a 

comparatively short stratigraphic range. Admittedly, 

much more work is required to delineate the geographic 

and stratigraphic ranges of species of Minerisporites in 

particular and of megaspores in general. The facts that 
E4 CONTRIBUTIONS TO PALEONTOLOGY 

Gunther and Hills (1972) found seven species of Minerisporites in the Brazeau Formation of Canada, that Singh 

(1964, 1971) found three species in the Albian of Canada, 

and that I found five species (plus three unnamed species) 

during the present study suggest that the presence of 

megaspores in nonmarine Cretaceous and Paleocene 

deposits is much more common than published reports 

indicate. Also pertinent is the suggestion that more megaspores would be found if assiduously sought. 

The potential stratigraphic usefulness of megaspores in 

general is brought sharply into focus by the work of 

Gunther and Hills (1972). They found 15 genera and 33 

species of megaspores in a series of samples from a single 

formation-the Brazeau Formation of Alberta, Canada. A 

compilation of the more important reports dealing with 

megaspore assemblages is presented chronolbgically in 

table 2. The data presented indicate clearly that megaspores are significant fossils. 

In addition to the reports listed in table 2, there are 

several papers by various authors dealing with only one or 

two species rather than assemblages of megaspores. 

FACIES REPRESENTATION 

Megaspores of the genus M inerisporites are found in 

continental deposits often interpreted as deltaic. They 

probably grew within, or adjacent to, freshwater lakes or 

ponds, sometimes within a delta. This inference is derived 

from the fact that most reports dealing with the genus 

Minerisporites include mention of other taxa whose ecological tolerances are known. These associated fossil 

genera include Azolla, Molaspora, Ariadnaesporites, 

Balmeisporites, Salvinia, and Arcellites. These genera are 

all considered to be related to the water ferns, whose 

habitat is freshwater lakes or ponds. The fossil megaspore 

species of the modern water fern Azolla commonly 

accompany megaspores of M inerisporites, particularly in 

Campanian and younger rocks. Fossil Azolla is not known 

from pre-Campanian rocks (Hall, 1969). Modern Azolla 

grows in freshwater ponds or lakes. In the older part of the 

stratigraphic column, particularly in Cenomanian and 

Albian rocks, specimens of Minerisporites are commonly 

accompanied by specimens of Arcellites. A freshwater 

aquatic habitat has been suggested for Arcellites by 

Dijkstra (1951), Hughes (1955), Cookson and Dettmann 

(1958), and Ellis and Tschudy (1964). Arcellites is very 

probably closely related to the Hydropteridae, or water 

ferns, and very possibly to the family Marsiliaceae. 

In the present work Azolla specimens were found in all 

of the Minerisporites-bearing samples from the Paleocene 

and in the sample from the Eagle Sandstone (Campanian). 

TABLE 2.-Important megaspore assemblages. 

Author Number Number 

and year of 

genera 

Miner, 1932 .............................. 

Harris, 1935 .............................. 2 

Murray, 1939 ............................ 

Madler, 1955 ............................. 2 

Vangerow, 1954 ........................ 

Cookson and Dettmann, 1958 . 3 

Jung, 1960 ................................ 6 

Marcinkiewicz, 1960 ................. II 

Dettmann, 1961 ........................ 5 

Dijkstra, 1961 ........................... 2 

Marcinkiewicz, 1962................. 14 

Hall, 1963................................. 5 

Singh, 1964............................... 10 

Kondinskaya, 1966................... 2 

Binda and Srivastava, 1968 .. .... 5 

Hall and Peake, 1968............... 7 

Batten, 1969.............................. 3 

Gry, 1969.................................. 12 

Jain and Hall, 1969 ................. 3 

Snead, 1969... .... ............ .. ...... .... 2 

Jain, 1971 ................................. 3 

Kempf, 1971 ............................. 5 

Singh, 1971............................... 7 

Gunther and Hills, 1972.......... 15 

Bergad, 1973. .......... ...... .. ...... .... 2 

of 

species 

8 

22 

5 

8 

12 

6 

lO 

18 

7 

6 

25 

5 

19 

7 

Remarks 

All species have been 

transferred from the 

genus Selaginellites 

to other, more 

appropriate genera. 

All species but one were 

listed under the genus 

Triletes. Most have 

since been transferred 

to more appropriate, 

but less inclusive, 

genera. 

All included in the 

genus Triletes. (See 

above.) 

Included two species of 

Azolla and six species 

ot Thomsonia (now 

Paxillitriletes). 

All assigned to the genus 

Triletes. (See above.) 

Two species assigned to 

the genus Azolla, four 

to the genus Triletes. 

9 Silicified megaspores. 

6 

6 

16 

7 Five species of Azolla. 

10 Nine species of Azolla. 

4 Two species of Azolla. 

5 

10 

33 

7 Six species of 

Balmeisporites. 

The species Minerisporites dissimilis, from the upper 

part of the Lower Cretaceous, was accompanied by specimens of Arcellites disciformis. 

It is uncommon to find M inerisporites in rocks that 

yield dinoflagellates, hystrichospheres, or other fossils 

indicative of marine deposition (Wall and others, 1971 ). In 

general, when found, very few marine specimens are 
STRATIGRAPHIC DISTRIBUTION OF MINERISPORITES IN NORTH AMERICA E5 

present in the preparation, suggesting a very slight marine 

influence at the time of deposition. Such slight marine 

influence could have occurred in a deltaic depositional 

site. I have never found megaspores of Minerisporites, nor 

have I seen reports of Minerisporites known to have been 

in situ from rocks deposited in a strictly marine 

environment. 

The large size of the megaspores, always accompanied 

by abundant small spores or pollen grains, plus the fact 

that they are commonly found in coals or highly organic 

shales or siltstones, is further evidence for a low-energy 

depositional environment, such as might be found in 

freshwater lakes, swamps, or ponds. 

SYSTEMATICS 

Fossil megaspores of the type included in the genus 

Minerisporites were first reported by Miner (1932) under 

the appellation of Selaginellites borealis. Later, Miner 

(1935) described a new species and named it Selaginellites 

mirabilis. Potonie (1956) considered that it is inappropriate to include spores in the organ genus 

Selaginellites, previously erected to accommodate vegetative organs similar in structure to those of modern 

Selaginella. He strengthened his argument by pointing 

out that the spores discussed by Miner had not been found 

in organic union in fructifications of Selaginellites. He 

then proposed the genus Minerisporites to accommodate 

these distinctive dispersed megaspores. 

Genus MINERISPORITES Potonii, 1956 

1935 Selaginellites mirabilis Miner, Am. Midland Naturalist, v. 16, 

p. 618, pl. 23, figs. 1-6. 

1956 Minerisporites mirabilis (Miner) Potoni(, Beih. Geol. Jahrb., 

v. 23, p. 67, pl. 9, figs. 87, 88. 

Type species.-Minerisporites mirabilis (Miner) Pot., 

1956. 

Lectotype.-Plate 23, fig. 1 of Miner, 1935. Designated 

by Potonii, 1956. 

Diagnosis.-(translated from Potonie, 1956, p. 67). 

Holotype (including zona) 534 u.; trilete megaspores, the 

equatorial outline of the central body subtriangular to 

almost circular (not or only weakly inclined toward triangular); in the genotype the outline becomes more triangular through the elongation of the tecta into projecting points at the juncture of the zona, the remainder of 

the zona being narrower. Y mark extends about to the zona, 

tecta sometimes strongly erect and having flap, sheet, or 

board form; meridional outline of the spore body semicircular to circular, from which the erect high tecta 

towers above. The genotype shows a reticulum with vesicular lumina, and the muri are arched similar to those 

of the carboniferous species Triangulatisporites regalis 

that we have placed in the Selaginellales. 

Minerisporites (al. Selaginellites) mirabilis Miner, 1935 

Am. Midland Naturalist v. 16, p. 618, pl. 23, figs. 1-·6 

Diagnosis.-(from Miner, 1935) "Body of exine round, 

332-498 in diameter, the average being 395 P. ; exine 

covered with irregular reticulate ridges which extend up 

part way on the wings; triradiate markings extend beyond 

the periphery; diameter on the radii of the triradiate 

markings 430-630 p. ; triradiate markings winged, wings 

67-150 P. in width, the average being about 90 p. ; 

equatorial ring present. Bear Creek, Carbon County, 

Montana; Fort Union Formation." 

Discussion.-Dijkstra (1961) found megaspores conspecific with Miner's (1935) Selaginellites mirabilis in the 

Paleocene of the Netherlands. He said (1961, p. 6), "Both 

descriptions [Dijkstra's and Miner's] have so many points 

of similarity that it is clear that both spores are identical." 

Dijkstra included his spores under the name of Triletes 

mirabilis (Miner) S. W. and B. Dijkstra (1961) proposed 

the new species Triletes mirabilissimus for spores significantly larger (630-820 p. m) than, but otherwise identical 

to, his Triletes mirabilis. These species were transferred to 

Minerisporites by Potonie (1966). I do not consider this 

size distinction of species significant, as his size 

dimensions overlap. Dijkstra at the same time proposed 

the new subspecies Triletes mirabilis forma glossoferus, 

forma nov. I have found specimens conformable to the 

figures and descriptions of Minerisporites mirabilis 

. (Miner) Pot. from the PaleoceneofWyoming(pl.1, figs. 1, 

2). I have also found specimens apparently identical to the 

descriptions and figures of Dijkstra's Triletes mirabilis 

forma glossoferus. I consider these to constitute a distinct 

species, which will be discussed later. 

Three additional reports of the species Minerisporites 

mirabilis are those of Hall (1963) from the Dakota Formation of Iowa (Cenomanian), Hall and Peake (1968) from 

the Windrow Formation of Minnesota (Cenomanian), and 

Agasie (1969) from the Dakota Formation of Arizona 

(Cenomanian). 

The photograph presented by Agasie (1969) shows a 

specimen attributed to Minerisporites mirabilis whose 

acrolamellae appear to be more delicate than is characteristic of those of M. mirabilis and more closely 

approaching the appearance of the acrolamellae of M. 

dissimilis, n. sp., which is found in strata of a slightly 
E6 CONTRIBUTIONS TO PALEONTOLOGY 

older age. Hall (1963) presented a single photograph 

(reflected light) and no description of his Iowa specimen. 

The reflected light photograph does not show sufficient 

detail in the vicinity of the laesurae to permit this 

specimen to be clearly distinguished from Minerisporites 

dissimilis, n. sp., discussed later. One of the prominent 

characteristics of M. mirabilis is the presence of a 

singularly massive or robust acrolamella. This feature is 

clearly evident on Miner's (1935) specimens, on those 

figured by Dijkstra ( 1961 ), and on those here illustrated on 

plate 1, figures 1 and 2. It would be somewhat surprising to 

find the species M. mirabilis in Cenomanian rocks, then a 

great hiatus in the record throughout the remainder of the 

Cretaceous, followed by a reappearance in the Paleocene 

rocks of both Europe and North America. I think it 

probable that the specimens mentioned by both Agasie 

(1969) and Hall ( 1963) are specimens of Minerisporites dissimi lis. 

The specimen photographed by Hall and Peake ( 1968) 

from the Windrow Formation of Minnesota is problematical. It does not show the characteristics of Minerisporites mirabilis nor those of M. dissimilis. It may represent 

an abnormally smooth specimen of M. dissimilis. 

Minerisporites glossoferus (Dijkstra), n. comb. 

Plate 1, figures 3-9 

1961 Triletes mirabilis forma glossoferus Dijkstra. Mem. Geol. 

Foundation. The Netherlands, New Series No. 13, p. 6, pl. 

1, figs. 6:...8; holotype figs. 7a, 7b. 

1966 Minerisporites mirabilis forma glossoferus Potonie, Beih. Geol. 

Jahrb. v. 72, p. 95. 

Dijkstra (1961 p. 6) distinguished this form from M. 

mirabilis as follows: "From T. mirabilis can be distinguished the form glossoferus of which a few bars on the 

distal area have been merged into 100-120 long tongue 

shaped protuberances. Dimensions and other ornaments 

of forma glossoferus are similar to those ofT. mirabilis." 

Description.-Trilete megaspores; both equatorial and 

polar outline of central body circular, outline of entire 

spore triangular in polar view, owing to extensions of 

auriculae of zona opposite the laesurae; acrolamellae 

extending on to the zona, acrolamellae high, membranous 

at their outer margins, and shorter at the juncture of the 

laesurae, thereby developing a notch characteristic of 

other members of the genus. Exine granular, 6-12 p. m 

thick exclusive of sculpture; sculpture consisting of an 

irregular reticulum, the lumina elongated in the polar 

direction. Muri 4:....8 p. m wide, of irregular height; some 

parts of mur¥, particularly on the distal surface, extend 

into tongue-shaped proturberances as much as 120 p. m 

long. 

Size ranges based on the measurement of 20 

specimens. 

Measurements are minima and maxima,() indicates 

average. 

Total equatorial diameter including zona: 

Polar view 480(530)584 p.m. 

Equatorial view 496(522)592 p.m. 

Diameter of central body 376(396)448 p.m. 

Width of acrolamellae, polar view 40(62)80 J.4m. 

Height of acrolamellae, equatorial view 72(86)104 

p.m. 

Width of zona alternate to laesurae 20(33)40 p.m. 

Width of zona (auriculae) opposite laesurae 

100( 132)160 p.m. 

Dimensions of lumina 24(34)40x40(59)80 p.m. 

Protuberances 40(60)120 p.m long. 

Stratigraphic Distribution.-Paleocene of the Netherlands; Paleocene Tullock Member, Fort Union Formation of Montana, about 86 feet (26.2 m) above the base of 

the formation. 

Remarks.-Minerisporites glossoferus is easily distinguished from M. mirabilis by the type of surface 

ornamentation. M. mirabilis possesses low muri and more 

or less circular lumina of approximately uniform size in 

contrast to M. glossoferus which has high irregular muri 

with projections and irregular lumina elongated parallel 

to the polar axis. More than 200 specimens of this species 

were found. 

Minerisporites dissimilis, n. sp. 

Plate 2, figures 1-6 

Type specimens designated on plate explanations. 

Diagnosis.-Trilete megaspore, outline of central body 

circular; in polar view outline of spores rounded 

triangular to circular; acrolamellae prominent, but thin 

and membranous with faint striations or incipient reticulations at the bases; acrolamellae characteristically 

notched' at juncture of laesurae. and extend on to the 

narrow zona. Zona narrow~ but becomes wider opposite 

the laesurae by the development of slight auriculae. Exine 

thin, about 25 p.m including sculpture, two-layered, 

inner layer 2-4 p.m thick, outer about 20 p.m thick, with 

irregular reticulate sculpture. Individual reticulations 

compound-that is, a large lumina with prominent 

bounding muri surround several secondary smaller 

lumina with very low muri. 

Size range based on the measurement of 40 specimens. 

Diameter including zona 408(631)800 p.m. 

Width of acrolamellae, polar view 16(20)24 p.m. 

Width of zona alternate to laesurae 10(18)32 p.m. 

Width of zona (atJriculae) opposite laesurae40(73)104 

p.m. 

Major lumina up to 160 p.m, minor 48-56 p.m. 

Muri 2-8 p.m thick (wide). 

Remarks.-This species is distinguished from M. 

mirabilis principally by the possession of much narrower 
STRATIGRAPHIC DISTRIBUTION OF MINERISPORITES IN NORTH AMERICA E7 

acrolamellae. In M. mirabilis the acrolamella is heavy and 

forms a thick heavy boss on the proximal side as much as 

100 p. m wide. In M. dissimilis the width of the aerolamellae averages only 20 p.m. The surface ornamentation is also different, and M dissimilis has a significantly 

different stratigraphic occurrence. 

Stratigraphic distribution.-Lower Cretaceous Fall 

River Sandstone equivalent, Sioux County, Nebr., 10 feet 

(3.05 m) below top of the formation. Probably, the 

specimens reported by Agasie (1969) and Hall (1963) from 

the Upper Cretaceous Dakota Formation of Arizona and 

Iowa, respectively, should also be included here. 

Minerisporites succrassulus, n. sp. 

Plate 3, figures 1....:9 

Type specimens designated on plate explanations. 

Diagnosis.-Trilete megaspores; outline of central body 

circular in both equatorial and polar views; acrolamellae 

prominent, thick, unornamented; characteristically 

notched at juncture of the laesurae. Acrolamellae extend 

onto the zona forming prominent auriculae, thereby 

producing a triangular or rounded triangular spore 

outline in polar view; zona narrower in interlaesural areas. 

Exine about 20 p.m thick, in distal area provided with a 

few prominent blunt thickenings or protuberances that 

may attain a length of as much as 80 p.m. 

Size range based on measurement of 20 specimens. More 

than 150 specimens found. 

Diameter (not including auriculae), polar view 

304(339)360 p.m. 

Diameter (not including auriculae), equatorial view 

240(321 )400 p.m. 

Diameter including auriculae, polar view 376( 445 )4 72 

P.m. 

Width of acrolamellae 32(39)48 ftill. 

Height of acrolamellae 72(87)96 p.m. 

Width of zona (alternate to laesurae) 20(25 )32 p.m. 

Auriculae 72(107)130 p.m. 

Stratigraphic distribution.-Paleocene, lower part of 

Tullock· Member, Fort Union Formation in samples 

D4742-E and D4724-C. 

Remarks.-This species of Minerisporites is devoid of 

evidence of reticulation, such as is characteristic of the type 

species. In all other respects the species conforms to the 

genus. Singh (1964) proposed the new species Minerisporites venustus. This species possessed ( 1964, p. 159) 

"some indication of a small-meshed reticulation • • • no 

sign of reticulation on most specimens." Rather than 

propose a new genus to include nonreticulate forms, I 

have included the species succrassulus in the genus Minerisporites. I believe it to be closely related to other species of 

Minerisporites. The double-walled structure of the aerolamellae (one wall on either side of the proximal aperture) 

is shown clearly on plate 3, figure 4. 

Minerisporites pseudorichardsonii Gunther and Hills (1972) 

Plate 4, figures 1-6 

Description.-(From Gunther and Hills, 1972) "Trilete 

megaspore; equatorial outline of the spore triangular; 

zona (or cingulum) on the equator, widest at the apice; 

prominent triradiate lamellae on the trilete laesurae, 

extend to the outer margin of the zona; exine relatively 

thick and with a reticulate ornament on both proximal 

and distal surfaces, short spine-like projections often 

found at the junction of the muri; both triradiate lamellae 

and zona are striated in a direction perpendicular to the 

spore body. 

Dimensions.-Eq~atorial diameter 

of spore body 

Holotype 

Radial width of zona 

In terra dial width of zona 

Width of triradiate lamellae 

Height of triradiate lamellae 

Lumen diameter 

(10 specimens)." 

390( 448 )519 p. 

SlOp. 

30(60)105p. 

12 p. 

12(14)15p. 

90(1 02) 135P. 

12(18)2lp. 

Remarks.-The specimens found in our material 

conform to the description provided and to the photograph of the holotype. The equatorial view presented by 

some of our specimens clearly demonstrates the presence 

of a reticulum on the acrolamellae (pl. 4, figs. 1-3). The 

lumina are somewhat elongate in the polar direction, 

particularly as the outer extremities of the acrolamellae are 

approached. A polar view, such as that presented in the 

photograph of the holotype, shows these reticulations as 

striae. Shrunken specimens show the short projections at 

the junctures of the muri to good advantage. 

Stratigraphic distribution.-Lower part of the Belly 

River Formation equivalent in Alberta, middle Ca-mpanian. Eagle Sandstone of Montana, lower Campanian, 

and upper part of Niobrara Formation of Wyoming, 

San ton ian -Coniacian. 

Minerisporites sp. A 

Plate 4, figures 7-9 

Too few specimens (nine, only four of which showed 

characteristics to good advantage) were found adequately 

to circumscribe this species. A brief provisional description follows. 

Description.-Trilete m~gaspores; outline of central 

body circular in polar view, circular to oval in equatorial 

view; acrolamellae prominent, membranous and extend to 

the outer margin of the thin membranous zona; zona on 

the proximal hemisphere, auriculae developed on zona 

opposite the laesurae; exine thin, about 3 ,urn thick, 

commonly wrinkled; surface internally granulate with no 

evidence of surface reticulation. 

Diameter of central body 224(294)360 p. m 
£8 CONTRIBUTIONS TO PALEONTOLOGY 

TABLE 3.-Fossil megaspure localzties 

USGS 

p..tleobotany Local H) 

loc. Nos. 

D3159-A ............ NW'l.\NW'l.\ sec. 17, T. 19 N., R. 77 W. (Bengough 

Hill quadrangle), Carbon County, Wyo. 

D362:>-F ............. Road section SE. of Poplar, NE'l.\ sec. 4, T. 26 

N., R. 52 E., Richland County, Mont. 

D3718-F ............. Section measured in tilted fault block in the 

NW'l.\NW'l.\ sec. 13, T. 22 N., R. 17 E., Fergus 

County, Mont. 

D472-l-C ............ Sec. 33, T. I5 N., R. 56 E., from basal Tullock 

immediately abon· the Hell Creek Formation 

Dawson County, Mont. (Collected by D.A. 

Russell.) 

D4742-E ............ N\V'l.\ corner sec. I8, T. I5 N., R. 56 E., from 

immediately above the Hell Creek Formation 

in the basal Tullock, Dawson County, Mont. 

D4766 ................. I ,000 ft (305m) E. of W. line, 2,750 ft (840 m) 

T~chmly 

loc No. 

RT-19·1. 

S. of N. line of sec. 23, T. 45 N., R. II4 W., 

Teton County, Wyo. 

California Co. Mann I well, SE'l.\ NE'l.\NW'l.\ sec. 

27, T. 30 N., R. 56 \V., Sioux County, Nebr. 

Sample from 4,686 ft (I ,428 m) depth, Fall 

River Sandstone equi\·alenl, IO ft (3.05 m) 

below top of formation. 

Height of acrolamellae 74(90)109 ,urn 

Width of zona (auriculae) opposite laesurae 56(79)136 

/-till 

Width of zona alternate to laesurae 40(59)70 ,urn 

Formation and age 

Hanna Formation, Paleocene. 

Tullock Member of the Fort 

Union Formation, Paleocene. 

Eagle Sandstone, Campanian. 

Tullock Member of the Fort 

Union Formation, Paleocene. 

Tullock Member of the Fort 

Union Formation, Paleocene. 

Niobrara Formation equivalent, 

Santonian-Coniacian. 

Fall River Sandstone 

equivalent, Albian. 

Minerisporites sp. C 

Plate 4, figure 12 

Remarks.-These specimens bear some resemblance to 

specimens of M. venustus Singh. They differ in being 

slightly smaller, in possessing much larger, more 

prominent acrolamellae and zonal membranes, and 

possessing membranous auriculae in the zona opposite 

the laesurae. 

Only one specimen observed. 

Description.-(incomplete) Trilete megaspore; 

equatorial outline rounded triangular in polar view; 

central body also rounded triangular; arcuate lamallae 

widest in interlaesural areas (60 ,u. m); aero lamellae about 

30 ,u.m wide and 50 ,u. m high extending onto the arcuate 

lamellae. Wall thin, surface prominently and irregularly 

rugulate. Diameter of central body about 500 ,u. m; 

Stratigraphic Distribution.-Upper part of Niobrara diameter of spore about 600 ,u. m. 

Formation of Wyoming, Santonian-Coniacian. 

Minerisporites sp. B 

Plate 4, figures 10-11 

Too few specimens (five) were found to adequately circumscribe this species; hence, only a brief description is 

here presented. 

Description.-(incomplete) Trilete megaspores; 

equatoria~ outline of central body circular; outline of 

spore including prominettt auriculae triangular; aerolamellae thin, membranous, about 50 ,u. m high, 

extending onto the arcuate lamellae; arcuate lamallae 

narrow in interlaesural areas, as much as 100 ,u.m wide 

opposite laesurae. Wall thin, surface having delicate, low 

reticulum, muri narrow, lumina 10-20 ,u.m in diameter. 

Diameter of central body 200-300 ,u. m 

Diameter of spore including auricula 320-400 ,u. m 

Stratigraphic distribution.-Fall River Sandstone 

equivalent of Nebraska, upper Albian. 

Stratigraphic distribution.-Fall River Sandstone 

equivalent, upper Albian. 

METHODS 

The methods employed for processing samples and 

preparing slides are standard for this laboratory and have 

been reported previously (Tschudy, 1970). The fossil 

megaspore localities are listed in table 3. 

All specimens illustrated in this report are preserved on 

slides deposited in the paleobotanical collections of the 

U.S. Geological Survey, Denver, Colo. All illustrated 

specimens are within black inked circles marked directly 

on the slides; they may also be located on the slides by the 

mechanical-stage coordinates given in the plate captions. 

In order that other workers may convert their mechanicalstage readings to those recorded for specimens included in 

this report, the coordinates for the center point of a 1- by 3-

inch standard microscope slide are 108.0 and 12.3 mm 

(designated as 108.0xl2.3). The method of accurately 
STRATIGRAPHIC DISTRIBUTION OF MINERISPORITES IN NORTH AMERICA : E9 

locating the center of a standard microscope slide is 

described by Tschudy (1966, p. D78). If the slide label is 

placed to the left, the vertical coordinates decrease toward 

the near edge of the slide, and the horizontal coordinates 

decrease toward the right edge of the slide. 

In addition to slides of illustrated specimens, color 

photographs are available from the U.S. Geological 

Survey laboratory, Denver, Colo., on a limited-time loan 

basis. 

LITERATURE CITED 

Agasie, J. M., 1969, Late Cretaceous palynomorphs from northeastern 

Arizona: Micropaleontology, v. 15, no. 1, p. 13-30. 

Batten, J. D., 1969, Some British Wealden megaspores and their facies 

distribution: Palaeontology, v. 12, pt. 2, p. 333-350. 

Bergad, R. D., 1973, North American species of the Cretaceous megaspores Balmeisporites and Monophyllosporites: Micropaleontology, v. 19, no. 1, p. 53-67. 

Binda, P. L., and Srivastava, S. K., 1968, Silicified megaspores from 

Upper Cretaceous beds of southern Alberta, Canada: Micropaleontology, v. 14, no. 1, p. 105-113. 

Chaloner, W. G., 1959, Devonian megaspores from Arctic Canada 

[Northwest Territories]: Palaeontology, v. 1, pt. 4, p. 321-332. 

Cookson, I. C., and Dettmann. M. E., 1958, Cretaceous "megaspores" 

and a closely associated microspore from the Australian region: 

Micropaleontology, v. 4, no. 1, p. 39-49. 

Delcourt, A. F., and Sprumont, G., 1955, Les spores et grains de pollen 

du Wealdien du Hainaut: Soc. Beige Geologie, Paleontologic et 

Hydrologic Mem., new ser. 4, no. 5, p. 1-73. 

Dettmann, M. E., 1961, Lower Mesozoic megaspores from Tasmania 

and South Australia: Micropaleontology, v. 7, no. 1, p. 71-86. 

Dijkstra, S. J., 1951, Wealden megaspores and their stratigraphical 

value: Geol. Stichting Med., new ser. 5, p. 7-21. 

___ 1952, The stratigraphical value of megaspores: Avanc. Etudes 

Stratigraphie et Geologie Carbonifere Cong., 3d, Heerlen 1951, 

v. 1, p. 163-168. 

___ 1955, The megaspores of the Westphalian D and C: Geol. Stichting Med., new ser. 8, p. 5-11. 

___ 1957, Lower Carboniferous megaspores: Geol. Stichting Med., 

new ser. 10[1956), p. 5-18. 

___ 1959, On megaspores, charophyta fruits and some other small 

fossils from the Cretaceous: Palaeobotanist, v. 8, nos. 1, 2, p. 8-18. 

___ 1961, Some Paleocene megaspores and other small fossils: Geol. 

Stichting Med., new ser. 13, p. 5-11. 

Dijkstra, S. J., and Vierssen Trip, P. H. van, 1946, Eine monographische Bearbeitung der Karbonischen Megasporen, mit besonderer 

Beriicksichtigung von SUdlimburg (Niederlande): Geol. Stichting 

Med., ser. C-3-1, no. 1, 101 p. 

Ellis, C. H., and Tschudy, R. H., 1964, The Cretaceous megaspore 

genus Arcellites Miner: Micropaleontology, v. 10, no. 1, p. 73-78. 

Gry, Helge, 1969, Megaspores from the jurassic of the island of Bornholm, Denmark: Dansk Geol. Foren. Medd., v. 19, no. 1 p. 69-89. 

Gunther, P. R., and Hills, L. V., 1972, Megaspores and other palynomorphs of the Brazeau Formation (Upper Cretaceous), Nordegg 

area, Alberta, in Geoscience and Man, v. 4: Am. Assoc. Stratigraphic Palynologists Ann. Mtg., 3d, 1970, Proc., p. 29-48. 

Hall, J. W., 1963, Megaspores and other fossils in the Dakota Formation (Cenomanian) of Iowa (U.S.A.) [with French abs.]: Pollen 

et Spores, v. 5, no. 2, p. 425-443. 

___ 1969, Studies on fossil Azolla-Primitive types of megaspores 

and massulae from the Cretaceous: Am. jour. Botany, v. 56, no. 

10, p. 1173-1180. 

Hall, J. W., and Peake, N. M., 1968, Megaspore assemblages in the 

Cretaceous of Minnesota: Micropaleontology, v. 14, no. 4, p. 

4511-464. 

Harris, T. M., 1935, Ginkgoales, Coniferales, Lycopodiales and isolated fructifications, Pt. 4 of The fossil flora of Scoresby Sound, 

east Greenland: Medd. Gronland, v. 112, no. 1, 176 p. 

Hughes, N. F., 1955, Wealden plant microfossils: Geol. Mag., v. 92, 

no. 3, p. 201-217. 

___ 1958, Palaeontological evidence for the age of the English 

Wealden: Geol. Mag., v. 95, no. 1, p. 41-49. 

Jain, R. K., 1971, Pre-Tertiary records of Salviniaceae: Am. jour. 

Botany, v. 58, no. 6, p. 487-496. 

Jain, R. K., and Hall, J. W., 1969, A contribution to the early Tertiary 

fossil record of the Salviniaceae: Am. jour. Botany, v. 56, no. 

5, p. 527-539. 

jung, Walter, 1960, Die dispersen Megasporen der frankischen RhatLias-Grenzschichten: Palaeontographica, v. 107, ser. B, nos. 4-6, 

p. 127-170. ) 

Kempf, E. K., 1971, Electron microscop)( of Mesozoic megaspores from 

Denmark: Grana, v. 11, no. 3, p. 151-163. 

Kondinskaya, L. 1., 1966, Iskopaemye spory vodianykh paporotnikov 

v verkhnemelovykh i pal~ogenovykh otlozheniiakh ZapadnoSibirsko'i' Nizmennosti [Fossil spores of water ferns in Upper 

Cretaceous and Paleogene deposits of the West Siberian lowland] 

[in Russian] in A. F., Chlonova, ed., Palynology of Siberia: Moscow, Publishing Office "Nauka," p. 116-122. 

Lanjouw, joseph, chm., and others, 1966, International code of botanical nomenclature: Utrecht, Netherlands, Internal. Bur. Plant 

Taxonomy and Nomenclature, of the InternaL Assoc. Plant Taxonomy, 402 p. 

Madler, Karl, 1955, Azolla aus dem Quartar und Tertiar sowie ihre 

Bedeutung fUr die Taxionomie alterer Sporen: Geol. Jahrb., v. 

70, p. 143-158. 

Marcmkiewicz, Teres~, 1960, Analiza megasporowa osadow jurajskich 

okolic Gorzowa Slaskiego-Praszki [Megaspore analysis of Jurassic sediments near Garzow Slaski-Praszka (Ciacow-Wieh1n 

region)] [in Polish, with English summaryf Kwart. Geol., vo. 4, 

no. 3, p. 713-733. 

___ 1962, Rhaetian and Lias megaspores from bore-hole Mechowo 

near Kamien Pomorski and their stratigraphical value: Instytut 

Geologiczny, Prace, v. 30, p. 469-493. 

Miner, E. L., 1932, Megaspores ascribed to Selaginellites from the 

Upper Cretaceous coals of western Greenland: Washington Acad. 

Sci. jour., v. 22, nos. 18, 19, p. 497-506. 

___ 1935, Paleobotanical examinations of Cretaceous and Tertiary 

coals-1, Cretaceous coals from Greenland; 2, Cretaceous and 

Tertiary coals from Montana: Am. Midland Naturalist, v. 16, no. 

4, p. 585-625, 7 pis. 

Murray, Nesbitt, 1939, The microflora of the upper and lower Estuarine Series of the East Midlands: Geol. Mag., v. 76, p. 478-489. 

Obradovich, J. D., and Cobban, W. A., 1975, A time scale for the 

Late Cretaceous of the Western Interior of North America, in 

Caldwell, W. G. E., ed., The Cretaceous System in the Western 

Interior of North America: Geol. Assoc. Canada Spec. Paper 13, 

p. 31-54. 

Potonie, R., 1956, Sporites, Pt. 1 of Synopsis der Gattungen der Sporae 

dispersae: Geol. jahrb. Beihefte 23, 103 p. 

___ 1966, Nachtrage zu allen Gruppen (Turmae), Pt. 4 of Synopsis 

der Gattungen der Sporae dispersae: Geol. jahrb. Beihefte 72, 

244 p. 

Singh, Chaitanya, 1964, Microflora of the Lower Cretaceous Mannville 

Group, east-central Alberta: Research Council Alberta Bull. 15, 

238 p. 

___ 1971, Lower Cretaceous Microfloras of the Peace River area, 

northwestern Alberta: Research Council Alberta Bull. 28, v. I, 

299 p. 
ElO CONTRIBUTIONS TO PALEONTOLOGY 

Snead, R. G., 1969, Microfloral diagnosis of the Cretaceous-Tertiary 

boundary, central Alberta: Research Council Alberta Bull. 25, 

148 p. 

Stover, L. E., Elsik, W. C. and Fairchild, W. W., 1966, New genera 

and species of early Tertiary palynomorphs from Gulf Coast: 

Kansas Univ. Paleont. Contr., Paper 5, p. I-ll. 

Tschudy, R. H., 1966, Associated megaspores and microspores of the 

Creta.ceous genus Ariadnaesporites Potonie, 1956, emend., in 

Geological Survey research 1966: U.S. Geol. Survey Prof. Paper 

550-D, p. D76-D82. 

___ }970, Two new pollen genera (Late Cretaceous and Paleocene) 

with possible affinity to the Illiciaceae: U.S. Geol. Survey Prof. 

Paper 643-F, 13 p. 

Vangerow, E. F., 1954, Megasporen und andere pflanzliche Microfossilien aus der Aachener Kreide: Palaeontographica, sec. B, v. 

96, nos. l-2, p. 24-38. 

Wall, J. H., Sweet, A. R., and Hills, L. V., 1971, Paleoecology of 

the Bearpaw and contiguous Upper Cretaceous formations in the 

C.P.O.G. Strathmore well, southern Alberta: Canadian Petroleum 

Geology Bull., v. 19, no. 3, p. 691-702. 

Winslow, M. R., 1959, Upper Mississippian and Pennsylvanian megaspores and other plant microfossils from Illinois: Illinois Geol. 

Survey Bull. 86, 135 p. 

Zerndt, Jan, 1930, Megasporen aus einem FlOz in Libiaz (Stephanien): 

Acad. Polonaise Sci. Bull., Ser. Sci. Tech., p. 39-70. 

___ 1937, Les megaspores du bassin houiller polonais [two parts]: 

Acad. Polonaise Sci. Geol. 3, 78 p. 

___ 1938, Vertikale Reichweite von Megasporentypen im Karbon 

des Bassin du Nord-Pionowy zasiag megaspor w karbonie Bassin 

du Nord: Polskie Towarz. Geol. Rocznik, v. 13, p. 21-30. 
Page 

alius, Minerispontes .................................................... . 

Arcellites...................................................................... 4, 5 

disciformis...... ..... .... ......... ... ... ..... .... ........ .. ...... ....... 5 

Anadnaesporites ........................................................... . 

Arizona, occurrence of Minerisporites ......................... . 

Assemblages, megaspore .............................................. . 

Australia, occurrence of Minerisporites ...................... . 

Awlla ........................................................................... . 

Balmeisporites .............................................................. . 

Belgium, occurrence of Minerisporites ....................... . 

Belly River Formation equivalent, Minerisporites 

pseudorichardsoniz ................................. . 

borealis, Minerisporites .............................................. I, 2 

Selaginellites ....................................................... I, 5 

Brazeau formation, occurrence of 

Mmerisporztes........................................ I, 3 

significance of megaspores.................................... 4 

Canada, occurrence of M inerisporites ......................... . 

Continental deposits, facies representation ................. . 

corrugatosus, M inerisporites ....................................... . 

Dakota Formation, Mmerisporites mirabilzs .............. . 

Dakota Sandstone, Mmerisporites mirabilzs ............... . 

delicatus, MinerisponJes ...................................... .' ....... . 

deltoides, M inerisporites .................................................... 2 

Denmark, occurrence of Minerisporites ....................... 3 

disciformis, Arcellites ................................................... . 

dissimilis, Minerisporites ................................. I, 5, 6; pl. 2 

Distribution, stratigraphic............................................ I 

Eagle sandstone, Azolla ............................................... . 

fossil megaspore locality ...................................... . 

M inerisporites ....................................................... . 

pseudorichardsonii ........................................ . 

England, occurrence of Minerisporites ...................... .. 

Facies representation .................................................... . 

Fall River Sandstone equivalent, fossil 

. megaspore locality .................................. . 

Fort Union Formation, Minerisporites mirabilis ....... . 

Fossil megaspore localities........................................... 8 

glossoferus, Minensporites .................................. I, 6; pl. I 

Minerisporztes mirabilis ...................................... 3, 6 

Triletes mirabzlis ................................................ I, 5, 6 

gryensis, M inerisporites.. ........... .... ... ...................... ... ... 3 

Triletes ................................................................... 3 

Hanna Formation, fossil megaspore locality .............. . 

INDEX 

Page numbers in italic type indicate major references] 

Page 

ins titus, M inensporites ................................................ . 

Iowa, Mmerisporztes mirabilis ................................... I, 5 

zrregularis, Minerisporites ............................................ 2 

Localities outside North America................................ 3 

macroreticulatus, M ineri5pontes ................................. . 

marguinatus, Minerisporites ..................................... !, 2, 3 

Marsiliaceae................................................................... 5 

Megaspores, assemblages.............................................. 4 

fossil localities....................................................... 8 

significance............................................................ 3 

M inerisporites . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . ... . . .. .. .. . . . . . .. . . . . . . ... . . . . 5 

alius........................................................................ 3 

borealis................................................................. I , 2 

corrugatosus........................................................... 2 

delzcatus ..... ......... .... ............ ... ..... ... ......... ...... ......... 2 

deltoides ................................................................ . 

dissimzlis ............................................... I, 3, 5, 6; pl. 2 

glossoferus ............................................. I, 2, 3, 6; pl. I 

gryenszs .................. .................... .... .... ............. .... ... -3 

institus ................................................................... 3 

irregularis .............................................................. . 

macroreticulatus ................................................... . 

marguinatus ........................................................ l, 2, 3 

mirabzlis ............................................ I, 2, 3, 5, 6; pl. I 

glossoferus. ...................... ... ......... .............. .... 3, 6 

mirabilissimus ....................................................... 3 

mirabiloides .......................................................... . 

new species ............................................................ . 

pseudorzchardsonii ............................... I, 2, 3, 7; pl. 4 

rzchardsonzi............................................................ 3 

sp. A .................................................................. 7; pl. 4 

sp. B .................................................................. 8; pl. 4 

sp. c .................................................................. 8; pl. 4 

sucrassulus .................................................... 3, 7; pl. 3 

venus/us .............................................................. !, 7, 8 

volucris................................................................... 3 

Minnesota, occurrence of Minenspontes .................... . 

mirabilis glossoferus, Mmensporites ......................... 3, 6 

glossoferus, Trzletes ............................................ l, 5, 6 

Minerisporites ....................................... I, 3, 5, 6; pl. I 

Selaginellites. .. .... .... .... .... ....... ..... .... .......... ..... ....... I, 5 

Triletes .................................................................. 3, 5 

mirabilissimus, M inerisporites ..................................... 3 

Triletes .................................................................. 3, 5 

mirabilozdes, Minensporites......................................... I 

Mo/aspora .................................................................... . 

Montana, Minensporites ........................................... .. 

Minensporztes mzrabzlis ...................................... .. 

pseudorichardsonzi ........................................ . 

Page 

Nebraska, occurrence of Minerisporites ...................... . 

Netherlands, occurrence of Minerisporites ................. .. 

New species, Minerisporites ........................................ . 

Niobrara Formation, Minensporites 

pseudorichardsonii ................................. 3, 7 

equivalent, fossil megaspore locality.................... 8 

Paxillitnletes ................................................................ . 

Poland, occurrence of Minerisporites ....... : ................. .. 

pseudonchardsonii, Minerisporites ................. 2, 3, 7; pl. 4 

regalis, Triangulatisporites ......................................... . 

richardsonii, Minerisporites ....................................... I, 3 

Salvinia ........................................................................ . 

Sample processing, methods used................................ 8 

Selaginella .................................................................... . 

Selaginellales ................................................................ . 

Selaginellites ................................................................ . 

borealis................................................................. I, 5 

mirabilis............................................................... I, 5 

sp. A, Minensporites ................................................ 7; pl. 4 

sp. B, Mmerisporites ................................................ 8; pl. 4 

sp. C, Minensporites ................................................ 8; pl. 4 

Stratigraphic distribution............................................. 1 

sucrassulus, Minerisporites .................................. 3, 7; pl. 3 

Systematic description, Minerisporites......................... 5 

Minerisporites disszmilis ....................................... 6 

glossoferus. .... .. ................ ... .... ..................... ... 6 

mirabilzs.......................................................... 5 

pseudorichardsonii ......................................... 7 

sp. A ............................................................... . 

sp. B................................................................ 8 

sp. C ............................................................... . 

succrassulus ................................................... . 

Texas, occurrence of Minerisporites ............................ . 

Thomsonia ................................................................... . 

Triangulatisporites regalis .......................................... . 

Triletes ......................................................................... . 

gryenszs ................................................................. . 

mirabilis............................................................... 3, 5 

glossoferus ................................................... !, 5, 6 

mirabzlissimus. ... ........ ........... ..... ....... ........... ....... 3. 5 

Tullock Member, Fort Union Formation, 

fossil megaspore locality ........................ . 

venustus, Minerisporites ............................................ l, 7, 8 

volucris, Minerisporites ................................................ 3 

Windrow Formation, Minerisporites mirabilis .......... .. 

Wyoming, Minerisporztes mirabzlzs ........................... .. 

Minerisporites pseudorichardsonii ....................... . 

occurrence of Minerisporites ................................ . 

Ell 

~U.S. GOVERNMENT PRINTING OFFICE: 1976-677-340/108 

PLATES 1-4 

[Contact photographs of the plates in this report are available, at cost, from the U.S. Geological 

Survey Photographic Library, Federal Center, Denver, Colorado 80225) 
FIGURES 

PLATE 1 

[Magnification X 100) 

I-2. Minerisporites mirabilis (Miner) Pot., I956. 

I. USGS paleobotany loc. D3I59-A, slide Mega I, courdinates 101.2xi2.2. 

Equatorial view; note characteristic notch in acrolamella. 

2. USGS paleobotany loc. D3I59-A, slide Mega I, coordinates 101.0x22.3. 

Polar view; note robust, thick acrolamellae. 

3-9. Minerisporites glossoferus (Dijkstra), n. comb. 

3. USGS paleobotany loc. D3625-F, slide Mega 6, coordinates II3.5xi5.1. Note 

distal projections. 

4. USGS paleobotany loc. D3625-F, slide Mega I, coordinates I06.0x8.0. Note 

narrow zona. 

5. USGS paleobotany loc. D3625-F, slide Mega I, coordinates I07.4xi7.5. Note 

distal projections. 

6. USGS paleobotany loc. D3625-F, slide Mega 7, coordinates lll.8xl6.5. Note 

large muri on proximal surface. 

7. USGS paleobotany loc. D3625-F, slide Mega I, coordinates Il4.3x9.5. Note 

massive acrolamellae with Y mark at juncture. 

8. USGS paleobotany loc. D3625-F, slide Mega 2, coordinates 99.3xl2.8. Distal 

view; note granular structure of zona and auriculae. 

9. USGS paleobotany loc. D3625-F, slide Mega I, coordinates 100.7x I4.2. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E PLATE 1 

4 

MINERISPORITES MIRA BILlS AND MJNERISPORITES GLOSSOFER US 
FIGURES 

PLATE 2 

[Magnification X 100] 

1-6. Minensporites dissimilis, n. sp. 

I. Holotype. Sample RT 194, slide F, coordinates 110.7x8.3. Note narrow 

acrolamellae and aperture at their juncture. 

2. Paratype. Sample RT 194, slide F, coordinates l14.8x7 .I. Note notched 

acrolamellae and faint reticulations on their bases. 

3. Paratype. Sample RT 194, slide F, coordinates 10l.8x8.2. Note narrow 

acrolamellae and irregular compound reticulations. 

4. Paratype. Sample RT 194, slide D, coordinates 103.lx17.0. 

5. Paratype. Sample RT 194, slide F, coordinates 100.8x8.9. Zona shows at 

lower left. 

6. Paratype. Sample RT 194, slide A, coordinates 108.5x7.8. Reticulum appears 

heavier because focus is on raised acrolamellae. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E PLATE 2 

MINER!SPORITES DISSIMILIS 
PLATE 3 

(Magnification X 100] 

FIGURES l-9. Minerisporites succrassulus, n. sp. 

I. Holotype. Sample 04742-E, slide 3, coordinates ll0.5x23.1. Focus on distal 

projections. 

2. Holotype. Focus on massive notched acrolamellae. 

3. Paratype. Sample 04742-E, slide 24, coordinates 97.9x12.2 .. Note notched 

acrolamella, zona, distal projections, and lack of other ornamentation. 

4. Paratype. Sample 04742-E, slide 21, coordinates 99.lxl1.4. Note open laesurae bordered by acrolamellae. 

5. Paratype. Sample 04742-E, slide 21, coordinates 96.7xl5.2. 

6. Paratype. Sample 04742-E, slide 23, coordinates ll2.6·xl9.3. 

7. Paratype. Sample 04742-E, slide 23, coordinates 102.lx 14.9. Distal projection in the form of a ring. 

8. Sample 04742-E, slide 7, coordinates l05.3x7.4. Probably an immature 

spore. 

9. Paratype. Sample 04742-E, slide 21, coordinates 105.5x20.8. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E PLATE 3 

2 

4 

9 

MJNERISPORITES SUCCRASSULUS 
PLATE 4 

(Magnification X 100 unless otherwise mdicated) 

FIGURES 1-6. Minerisporites pseudorichardsonii Gunther and Hills (1972). 

I. Sample 04766, slide 5, coordinates 98.2x15.0. 

2. Same specimen as figure 1 except x 200. Magnified to show characteristics 

of reticulum and faint reticulation of the acro1amellae. 

3. Sample 04766, slide 4, coordinates 105.2x7.I. Note prominent reticulation 

of acrolamellae. 

4. Sample 04766, slide 5, coordinates 108.4x2.4. Central body appears 

shrunken. 

5. Sample 04766, slide 4, coordinates 104.9x12.8. 

6. Sample 03718-F, slide Mega 8, coordinates 112.3x14.8. 

7-9. Minerisporites sp. A. 

7. Sample 04766, slide 3, coordinates 107.3x13.2. 

8. Same specimen as figure 7. Taken with phase contrast. 

9. Sample 04766, slide 3, coordinates 112.8 x16.8. 

10-11. Minerisporites sp. B. 

10. Sample RT 194, slide C, coordinates 101.7x9.6. 

II. Same specimen as figure 10. Taken with phase contrast. Note delicate 

reticulum in figures 10 and 11. 

12. Minerisporites sp. C. Sample RT 194, slide K, coordinates 115.0xll.5. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 743-E PLATE 4 

MINERJSPORITES PSEUDORICHARDSONJJ, M . SP. A, M. SP. B, AND M. SP. C 

Tschudy-STRATIGRAPHIC DISTRIBUTION OF MINERISPORITES IN NORTH AMERICA-Geological Survey Professional Paper 743-E