F. M. Carpenter, T. E. Snyder, C. P. Alexander, M. T. James, and F. M. Hull.
Fossil Insects from the Creede Formation, Colorado.
Psyche 45(2-3):105-119, 1938.

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Fossil Insects
FOSSIL INSECTS FROM THE CREEDE FORMATION, COLORADO
PART 1.
INTRODUCTION, NEUROPTERA, ISOPTERA AND
DIPTERA
BY F. M. CARPENTER, T. E. SNYDER, C. P. ALEXANDER, M. T. JAMES AND F. M. HULL
Harvard University
During the past twenty-five years, intensive geologic work in the Rocky Mountain region has revealed several Tertiary lake-bed deposits, the presence of which had not previously been suspected. One of these beds, termed the Creede for- mation by Emmons and Larson (1923), is extensively ex- posed on the slopes of Willow Creek, near the town of Creede, Colorado. The formation is highly fossiliferous with plants, and a preliminary account of its flora has been published by Knowlton (1923). In 1932, Mr. Allan Caplan, then a senior in the Creede High School, found that insects also were not uncommon in the formation, and an examination of some of his specimens convinced me that a collecting trip to this formation would be a practicable and profitable undertaking. With the aid of a grant from the Milton Fund of Harvard University, the collecting trip was made during the summer of 1934. In addition to the writer and his wife, the party consisted of Mr. C. T. Parsons, a student in Harvard College, and Mr. Caplan, who joined us at Creede. In the course of the summer about two thousand insects were secured ; most of these were actually found by Mr. Caplan, while the rest of the party collected in the Green River shales of Utah. The present series of papers is based mainly upon the spec- imens obtained on this trip, but it also covers a collection of



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106 Psyche [ June-Sept.
about two hundred other Creede insects, sent to me for deter- mination by Professor Case of the University of Michigan, who had previously secured them from Mr. Caplan. All of the fossils have been sorted into orders and most of them into families or superfamilies. As in the case of the insects of the Latah formation and of the Manitoban amber, I have referred these Creede fossils to specialists on various groups of living insects. Although this procedure tends to delay in large measure the publication of the results, it is the only way capable of yielding authentic determinations and con- clusions. Since several more years may elapse before all the specimens of the Creede collection have passed through the hands of specialists, it has seemed advisable to publish the results in several parts, all under the same general title, whenever a sufficient number of manuscripts have been completed. The descriptive part of the present paper deals with the fossils belonging to the following orders and families : Neuroptera (F. M. Carpenter), Isoptera (T. E. Snyder), Diptera, Tipulidae (C. P. Alexander), Bibionidae (M. J. James), and Syrphidae (F. M. Hull). To these spe- cialists and those who are working upon other families I am grateful for their indispensable cooperation. Since this is the first extensive account of the Creede insects, it is pertinent to include a brief discussion of their geologic occurrence and environment. The geology of Creede district has been thoroughly investigated by Emmons and Larsen (1923). According to them, the Creede forma- tion was deposited in a lake that occupied a valley carved out of the rocks of the Potosi volcanic series. The lower part of the formation consists chiefly of fine-textured, thin- bedded, rhyolite tuffs, usually light grey or light brown. Thicker beds of sandy material, lenses of conglomerate, and numerous bodies of travertine are also present. It is this lower part of the formation that contains the insects and the best plant material. The upper part is of coarser texture and consists of well bedded breccia and conglomerate, with some fine tuff. The origin of the formation seems to have been much like that of the Florissant shales, which lie more than a hundred miles to the north-east. Some of the ash thrown out by local volcanoes fell into the lake and together with sand and mud was deposited at the bottom. Insects



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19381 Fossil Insects 107
flying over the water were of course caught and entombed by the ash.
Knowlton's study of the Creede plants led him to conclude that the Creede formation was about the same age as the Florissant-deposit, i.e., upper Miocene. At the same time, however, he noticed an obvious difference in the composition of the two floras, the most abundant element in the Creede flora being Coniferae, which, although very rare at Floris- sant, comprised about a third of the species and nearly a half of the individual specimens. The general content of the Creede flora strongly indicates that the lake-bed was deposited at a considerable higher elevation than the Floris- sant shales2 As Cockerel1 has stated of the Creede flora, very few, if any, high altitude insect faunas have been pre- served. The chief importance of the Creede specimens, therefore, depends not so much on their geologic age as on the environment in which they existed.
It is of course far
too soon to say anything definite about the biotic indications of the Creede insects, but even a cursory survey of the col- lection at hand, made during the sorting of the specimens into families, indicates that the fauna is an exceedingly small one, there being an extraordinary duplication of a few species. This is of course typical of existing faunas at high altitudes.
ORDER NEUROPTERA
Eleven specimens of this family are contained in the col- lection from Creede. This is proportionally a much greater number than has been found in the Florissant shales, which have produced only about the same number in a total of approximately 40,000 specimens. Two species are repre- sented in the Creede series, one apparently being identical with a Florissant species, and the other, already described, being peculiar to the Creede formation. The phylogenetic significance of the Tertiary Chrysopidae has already been discussed in an earlier paper (1935).
lAt the present time, however, both lake deposits have an elevation of about 8200 ft.




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108 Psyche [ June-Sept.
Palaeochrysa creedei Carp.
Palseochrysa creedei Carpenter, 1935, Journ. Paleont., 9: 265, fig. 3.
This species, although similar to the following, is char- acterized by the extraordinary length of the basal Banksian cell of the fore and hind wings.2 The holotype is No. 4316 ab, Museum of Comparative Zoology.
Palaeochrysa stricta Scudd. (Fig. 1)
Palasochrysa stricta Scudder, 1850, U. S. Geol. Survey Terr. Kept., 13: 166; pi. 14, fig. 13, 14.
There are ten Chrysopids (4462-4471) in the Creede col- lection which seem to be identical in every way with this Fig. 1. Palasochrysa stricta Scudd. A. Fore wing (No. 4462, M. C. Z.), length, 12 mm.
B.
Hind wing (No. 4464, M. C. Z.), length,
9.8 mm.
Miocene of Creede, Colorado.
species, previously known solely from the Florissant shales. Since this is the only Creede species of those so far deter- mined which appears to be common to the two beds, I have included drawings of its venation.
It should, however, be
borne in mind that among the Recent Chrysopidae the vena- tion of closely related species usually shows no differences. 21n my account of the fossil Chrysopidae (Journ. Paleont., 9 : 259-271, 1935) the captions for figures 2 and 7 should be interchanged.



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Fossil Insects 109
Raphidia creedei Carp.
Raphidia creedei Carpenter, 1936, Proc. Amer. Acad. Arts Sci., 71: 150, fig. 12.
This species differs from those of Florissant by the more slender wings and narrower costal area. The holotype, No. 3639 ab in the Museum of Comparative Zoology, is the best preserved fossil snake-fly which has been found, apart from those in amber. The members of the Raphidiodea are ex- ceedingly rare in the Florissant shales, and the presence of even one in the relatively small Creede collection at hand is another indication of the biotic differences represented. Like the Florissant Raphidiodea, this Creede species belongs to a genus now restricted to the Old W~rld.~ Senior Entomologist, Division of Forest Insects, Bureau of Entomology and Plant Quarantine, United States Department of Agriculture The single fossil wing sent to me for identification proves to represent a species of Reticulitermes new to science. Five fossil species of this genus are already known-four from Baltic amber and one from the Miocene shale of Florissant, Colorado. Reticulitermes is confined to the temperate re- gions of the world. A living species (R. tibialis Banks) occurs in localities in Colorado, but nowhere in the state at an elevation of over 7,000 feet. The wing of tibialis is larger than in this fossil.
Reticulitermes creedei Snyder, n. sp. (Plate 13, fig. 3) Wing (hind wing (?) ) : Costal area indistinct. Median vein not free from stump or wing scale ; closer to subcosta than to cubitus ; branches to tip of wing. Cubitus running 3An account of the geographic distribution of the fossil and Recent Raphidiodea is contained in my revision of the Nearctic species (Proc. Amer. Acad. Arts Sci., 70: 89-157, 1936).



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110 Psyche [ June-Sept.
in about the middle of wing area, with numerous branches, to posterior margin of wing.
Length of wing-6.5 mm.
Width of wing -1.7 mm.
Wing smaller than in Reticulitermes fossarum Scudder from Florissant, Colorado, in Miocene shale. Holotype: Museum of Comparative Zoology, No. 4472 ab ; collected in the Miocene shales at Creede, Colorado. 6
BY CHARLES P. ALEXANDER
Massachusetts State College
I am greatly indebted to Dr. I?. M. Carpenter for the privilege of studying the series of Tipulidae collected by him at the fossil beds located near Creede, Colorado. As indi- cated elsewhere by Dr. Carpenter, the Creede formation is of approximately the same age as the Florissant shales (Miocene), about a hundred miles to the northeast, near Pikes Peak, Colorado.
All of the specimens pertain to the single genus Tipula Linnaeus and virtually all seem to belong to a single species that I am herewith describing as new under the name Tzpula carpenter!. In almost all of these individuals, the wings are the only parts that are well preserved. Throughout the vast complex of forms now included within the limits of the genus Tipula (approximately 1000 species, Recent and fossil), the wing venation is singularly uniform and offers but slight aid in the subdivision of the genus into smaller groups. In the recent fauna, the definition of species in this genus is based in great part upon the structure of the male hypogygium, characters that are quite unavailable in the present fossil series. A careful analysis of wing-pattern and venation has been made since any determination of the present series must depend chiefly or solely upon such characters.
More than a score of fossil Tipula and closely allied groups have been described from the early Tertiary of western



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19381 Fossil Insects Ill
North America by Scudder and Cockerell, the majority from the FIorissant shales. Scudder (1894) proposed four sup- posedly new generic groups centering about Tipah that must be analyzed and evaluated in relation to the great increase in our knowledge of the Tipulidae in the past thirty years.
Manapsis Seudder (LC., pp. 222,223) with cell Ml lacking or imperfectly developed. Affinities with other Tipulinae uncertain, due to the difference in venation in the two wings of the type. Several Recent Tipdine groups are now known in which cell MI is lacking (as Idiotipula Alexander, Xenotimt,la Alexander, and others).
Rhadinobrochus Scudder (I.c., pp. 223, 224) based on the character of an unusually narrow cell 1st MS,, which, in one wing of the unique type, shows an extra vein issuing there- from, lying between veins Ml+2 and MS of the normal Tipdine venation. The value of this character is question- able, especially in the present instance where the venation appears to be abnormal (see Alexander, 1919). Tipididea Scudder (I.c., pp. 238,239) was separated from Tipvla s.8. only on the basis of small physical size (wing, 9.5-13.6 mm.) and the relative shortness of Rs which is approximately equal to m-cw. Both of these characters are duplicated in the recent subgenus Schummeliu Edwards of the genus Tip&. The status of Tiputidea, must remain in question until more evidence becomes available but it seems possible that the group may be maintained as a valid sub- genus of Tipzda.
Micrapsis Seudder (I.c., pp. 242-243) is based on a single imperfect specimen. The characters upon which the group is founded are very weak, consisting of the shortness of Rs and of an unusually small 1st MS, with vein M^. forking at base of this cell, with m-cu placed some distance beyond the origin of M4. The latter combination of characters is much as in Nephrotoma and some Tipula and the status of the group is very much in question.
In my opinion, none of the four Tipdine groups discussed above is well founded and all should wait upon the discovery of further material to substantiate or disprove their claims. It appears to me that all except Tipulidea may well be found to be based on teratologieal specimens, while all are based



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112 Psyche [ June-Sept.
on uniques in an indifferent state of preservation. The
figures supplied by Blake do not always conform to the descriptions of Scudder (as in Manapsis, where in the left wing vein Rl+2 is shown as being distinctly preserved, whereas on the right wing it is not indicated and is either atrophied or poorly evident. In Rhadinobrochus, the vena- tion of the two wings of the unique type is so dissimilar that the veins of the two sides cannot be homologized). Tipula carpenter! Alexander, n. sp. (Plate 13, figs. 1, 2) Male.-Length about 16-17 mm. ; wing 17-18 mm. Female.-Length about 21-22 mm. ; wing 20-24 mm. General coloration dark. Praescutal pattern apparently consisting of three entire dark stripes on a somewhat paler ground. Abdomen dark, the tergites with a still darker median longitudinal stripe that is narrowly interrupted at posterior border of each segment; lateral tergal stripes narrower and less distinct; sternites with a similar but much narrower median vitta.
Antennae of male longer than in female, subequal to the combined head and thorax ; flagellar segments bicolorous, the basal enlargement darker than the apex; verticils short. In female, antennae about twice the length of head. In both sexes, flagellar segments with poorly developed basal enlargements to appear subcylindrical.
Wings subhyaline, with a conspicuous brown and white pattern; brown areas include a medium-sized marking at origin of Rs; stigma and a confluent seam on anterior cord ; m-cu and adjoining portions of vein Cu; a dark cloud in cells M and Cu at near midlength of vein Cu, with another similar dark area near outer end of Cu, chiefly in cell M, the two dark markings separated by a whitish or ground area at near two thirds the length of cell M; distal portions of cells R2 and R3 slightly darkened but outer half of cell R5 some- what paler; the white areas appear chiefly as a broad post- stigma1 fascia involving cell Sc2, basal third of cell R2, subbasal third of cell R3 and the subproximal end of cell R5; additional obliterative areas involving base of cell 1st M2 and the adjoining basal portions of cells M3 and M4. Wings relatively broad, the length about 3.6 times the



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19381 Fossil hects 113
greatest width. Venation: Rs relatively long, about one half longer than m-cu, or subewal to the width of cells R and M opposite its origin ; vein Rl+2 preserved ; petiole of cell MI variable in length, from one third as long to subequal to m; m-cu at fork of M3+4; cell 2nd A of moderate width. Hypopygium moderately enlarged, the outer end trun- cated. Ovipositor with relatively stout valves. Holotype: No. 4536, Museum of Comparative Zoology, collected by Allan Caplan ; thiss consists of a nearly complete insect.
Paratypes (both sexes) : twenty-three in the Museum of Comparative Zoology (Nos. 4473-4495), and one in the University of Michigan Museum
(No. 15383). The speci-
mens figured are the holotype and paratype no. 4489. I take unusual pleasure in naming this interesting Miocene Tipula in honor of Dr. F. M. Carpenter. As shown by the figures, there is a somewhat marked variation in the wing- pattern and venation in different individuals. The possi- bility exists that more than a single species is included in the present series but this does not seem to be the case. In some specimens the radial cells beyond the post-stigmatic white fascia are more uniformly darkened than in others, as shown by the figures, which represent extremes within the series. In No. 4489, figured, cell M.4 is more strongly narrowed at wing-margin than in the holotype, while vein R3 is slightly less extended. This individual, while repre- sented chiefly by the wings, is evidently a female and is the largest specimen whose measurements are given above. The species that is most similar to the present fly would appear to be Tipula Zimi Scudder, which is somewhat smaller, with narrower wings. Scudder describes the species as having a darkened cloud at origin of Rs but in neither of his figures (I.c., PI. 8, fig. 4, ; PI. 9, fig. 1, 8 ) is this distinctly shown. This Florissant species has distinct lateral stripes on the abdominal tergites in addition to the subequal median vitta.
The various allied Miocene species having patterned wings may be separated by the accompanying key: 1. Wings with vein Sc relatively short, Sc2 ending at near midlength of cell Rl and about opposite two thirds the length of Rs. 2




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114 Psyche [ June-Sept.
Wings with Sc longer, Sc2 ending beyond midlength of cell Rl and nearly opposite three fourths the length of Rs. carpenteri sp. n.
2. A conspicuous darkened cloud at origin of Rs. 3
No darkened cloud at origin of Rs.
4
3. Rs unusually long, approximately twice m-cu; wings broad, about 3.5 times as long as wide. tartari Scudder Rs of moderate length, approximately one and one half times as long as m-cu; wings narrower, approximately four times as long as wide.
limi Scudder
4. A conspicuous dark cloud at near midlength of vein Cu, extending caudad into cell Cu; abdominal pattern of individual tergites transverse ; size large (wing, female, 23 mm.) . maclurei Scudder
No dark cloud at midlength of vein Cu; abdominal pattern of the individual tergites longitudinal; size medium (wing, female, to 17.5 mm.).
carolmsQ Scudder
Tipula spp.
In addition to the material previously discussed, the Creede collections included seven specimens that appear to represent one or more additional species. These belong to the group with wings immaculate or virtually so and no attempt can be made to make a more detailed identification. The specimens included bear the numbers 4496. FAMILY BIBIONIDAE
BY MAURICE T. JAMES
Colorado State College
Plecia creedensis James, n. sp. (Fig. 2) This species differs from the Florissant species and from those described by Handlirsch from the Canadian Tertiary in that vein R2+3 arises from the radial sector a consider- able distance before the apex of Rl, is strongly and distinctly elbowed at its origin, and runs almost parallel to Rl for a considerable distance.




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19381 Fossil Insects 115
Q . A yellowish species, the thorax, head, palpi, and base of the proboscis brown; the abdomen is very light yellow along the narrow posterior margins and on the venter; the antennae are slightly darkened basally. Pile concolorous Fig. 2. Plecia creedensis James, n. sp., drawing of wing of holotype, No. 4523, M. C. Z.
with the background. Halteres evenly light yellow. Each tibia with a short, black preapical bristle. Wings slightly yellow-fumose, the veins yellow; those of the posterior part of the wing evident, though definitely lighter than the heavy anterior veins.
Length, 12 mm.; of abdoment, 8 mm.; of wing, 9 mm. The following measurements are in millimeters. Anterior femur, 2, tibia, 2.3, tarsus, 2.6 ; middle femur, 1.8, tibia, 1.8, tarsus, 1.9; posterior femur, 2.7, tibia, 2.8, tarsus, 2.4; length of head, .8, of antennae, .8, of thorax, 2.7; length of vein Rs to cross-vein r-m, 1.5, of Rs from r-rn to origin of R2+3, .7, of cmss-vein r-m, A, of M from r-m to the furca- tion, .4; distance of apex of Rl from base of wing, 6.4, of origin of R2+3 from base of wing, 5.1.
Holotype (female) : No. 4523, Museum of Comparative Zoology. This specimen is well preserved and is in lateral position, so that practically all characters of taxonomic importance are visible.
Paratypes : twelve females ; -eleven (Nos. 4524-4532) in the Museum of Comparative Zoology, and one in the Museum of the University of Colorado. Eight other specimens are present in the collection at the Museum of Comparative Zoology, but they are not designated as paratypes because of poor preservation.




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Psyche
[ June-Sept.
BY F. M. HULL
University of Mississippi
One species of Syrphidae is contained in the collection of fossil insects from Creede. This belongs to the Recent genus Platycheirus. The only other reference to fossil forms of this genus is that of Pongracz
(1928, p. 190), who places
here two species from Oeningen, originally included by Heer in Syrphus. I examined Pongracz's specimens in the British Museum and found them to be poorly preserved. Platycheirus persistens n. sp. (Fig. 3)
Male. Length 10.0 mm. ; of abdomen and scutellum 6.0 mm. ; of wing 7.2 mm. ; second specimen, length 10.0 mm. ; thorax and abdomen 6.2 mm.; of wing 8.8 mm. Head: hemispherical, obviously narrower than thorax. Eyes narrowly dichoptic. Face dark in color. No details of antennae visible. Thorax: dark, though very little pigment is preserved, and no details of pile can be seen. Scutellum semicircular, the margin evenly convex, the width about one and three fourths greater than the length. Abdomen: slender, the sides not quite parallel, but slightly convex, leaving the middle segments barely wider. The first segment juts beyond the rim of the scutellum by a fifth the latter's length. Second and third segments of nearly equal length, the former the longer. Fourth segment slightly shorter than third. Fifth segment two fifths as long as the preceding one. Hypopygium prominent and smoothly rounded. The segments are marked with brown. The pos- terior two-fifths of the second segment with a median wedge, pointing to and reaching the anterior border, and similar pattern on the two succeeding segments, the brown of the posterior border on the fourth segment occupying nearly the whole of the posterior half. The fifth segment is clear. Legs: slender. For the most part, they are not well pre- served, but one set of tarsi, apparently the left hind tarsi, is well preserved and shows decided expansion and thickening of the joints. Wings: poorly preserved.




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19381 Fossil Insects 117
Female.
Specimen Nos. 3950 and 3951 is without head, obverse and reverse. These wings are a little better pre- served and show the third longitudinal vein and costa ending quite beyond the tip of wing, though not nearly as much as in Rhingia.
The abdominal pattern is quite similar ; beyond the fact that the segments are slightly wider, I am unable to detect differences of importance. One whole hind leg Fig. 3.
Platycheirus persistens Hull, n. sp. A, abdomen; B, tibia and tarsus of holotype, No. 3949, M. C. Z. (right) is preserved. The femora were slightly thickened one and two-fifths the width of tibiae and the tarsi were not dilated. The obverse is fragmentary and poor. Perhaps a trace of antennae appears upon it. The opposite hind tarsus is shown, the maculation is deceptive and the abdomen also appears disproportionately short and wide. Holotype: 1 male, No. 3949; in the Museum of Com- parative Zoology.
Paratype: 1 female, No. 3950; in the Museum of Com- parative Zoology.




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Psyche
[ June-Sept.
REFERENCES
Alexander, C. P. 1919. The crane-flies of New York. Part 1. Cornell Univ. Agr. Exp. Sta. Memoir 25: 767-993. Carpenter, F. M. 1935. Tertiary Insects of the Family Chrysopidse. Journ. Paleon., 9 : 259-272.
Cockerell, T. D. A.
1933. A Fossil Sawfly from the Miocene Shales near Creede, Colorado. Bull. Brook. Ent. Soc., 28: 186-187. 1934. An Ancient Foxtail Pine. Nature, 133: 573. Emmons, W. H., and Larsen, E. S.
1923. Geology and the Deposits
of the Creede District, Colorado. Bull. U. S. Geol. Surv., 718. Knowlton, F. H. 1923. Fossil Plants from the Tertiary lake-beds of south-central Colorado. Prof. Paper U. S. Geol. Surv., 131G. Pongracz, A. 1928. Die Fossile Insekten von Ungarn. Annales Musei Nationalis Hungarici, 25 : 1-194.
Scudder, S. H. 1894. Tertiary Tipulidae, with Special Reference to those of Florissant, Colorado. Proc. Amer. Phil. Soc., 32 (143) : 1-83.
EXPLANATION OF PLATE 13
Fig. 1. Tipula carpenter! Alexander, n. sp. Photograph of holotype, No. 4536, Museum of Comparative Zoology. Length of wing, 18 mm.
Fig. 2. Tipula carpenteri Alexander, n. sp. Photograph of paratype, No. 4489, Museum of Comparative Zoology. Length of wing,
17 mm.
Fig. 3. Reticulitermes creedei Snyder, n. sp. Photograph of holotype, No. 4472, Museum of Comparative Zoology. Length of wing,
6.5 mm.




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19381 Fossil Insects 119
Psyche, 1988
VOL. 46, PLATE XIII.




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