This is Mazon Monday post #192. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Adult of Mischoptera nigra (a) and reconstructions of early (b) and late (c) larvae of Mischoptera douglassi
Mischoptera douglassi is a winged fossil insect from the Pennsylvanian Period. It belongs to Superorder Palaeodictyopteroidea and Order Megascoptera. The first specimen was found by Lincoln Douglass in Pit 6 of the Northern Illinois Coal Company. Lincoln, was the father of Dave Douglass. In September 1973, Dave founded the "Down to Earth Rock Shop" in Evanston, IL. The holotype specimen of M. douglassi is on display in the basement museum. Eugene Richardson called it "one of the most important fossil insects ever found" due to the insights it provides into the evolution of both insect metamorphosis and flight.
M. douglassi was described from a single specimen by Eugene Richardson Jr. and Frank Carpenter in December, 1968. The paper "Megasecopterous nymphs in Pennsylvania concretions from Illinois" was published in the journal Psyche. Psyche is a scientific journal of entomology established in 1974 by the Cambridge Entomological Club. The name of the journal is derived from the Ancient Greek word for butterfly.
This species is based on a single specimen of a nearly complete nymph with the following dimensions: length of body from head to the end of abdomen, 53 mm; width of abdomen at 6th segment, 5 mm ; length of antennae, 4 mm. as preserved ; length of fore wing, 13.5 mm; width, 3.5 mm. The specific characteristics of this insect are probably to be found in the nature and arrangement of spines on the thorax and on the abdominal terga and possibly in venational details.
Holotype: No. 39 (obverse and reverse) in the collection of Mr. David Douglass, Western Springs, Illinois; it was found by Mr. Lincoln Douglass in a spoil heap of the abandoned Pit 6 of the Northern Illinois Coal Company, about on the Grundy-Will County line, Illinois. The specimen consists of the two counterparts; the one shown in Plate 24 is herein designated the obverse; the reverse is nearly as complete, lacking only the distal portion of one of the hind wings. As is usually the case with fossil insects, the specimen is actually a composite of dorsal and ventral surfaces, each of which is included to some extent on each counterpart. The obverse half seems to have the normal dorsal structures more distinctly preserved
than the reverse; it probably represents a view of the inner surface of the dorsal wall, with some of the ventral structures more weakly imprinted.
The Field Museum appears to have a second specimen that was found by Jerry Herdina.
Insecta (Chapter 14A) in the "Richardson's Guide to the Fossil Fauna of Mazon Creek" has a short discussion of Megascoptera and Mischoptera on pages 187-189. The chapter was written by Frank Carpenter.
Order Megasecoptera
These palaeopterous insects were of small to large size. In many respects they were similar to the Palaeodictyoptera, but the wings were very slender basally and often subpetiolate. The two pairs of wings were much alike. Veins SC and R were very close together and very near the wing margin. Pronotal lobes like those of the Palaeodictyoptera were apparently absent, although in some families the pronotum was broad and spinose. The mouthparts and cerci were like those of the Palaeodictyoptera, but the legs were apparently relatively short. The nymphs had divergent wing pads like those of the Palaeodictyoptera. The order is known from the Upper Carboniferous and Permian, with its maximum development in the Permian.
Twenty-one families, with 32 genera, are known in this order, two of which are represented in the Mazon Creek fauna. Mischoptera douglassi Carpenter and Richardson (1968), of the family Mischopteridae, is based on a nymph with a striking resemblance to the adults of Mischoptera found in the Commentry Shale in France, including the spinose prothorax and the characteristic wing venation (Figure 14A.15). This was the first nymph to be found that could be definitely associated with Megasecoptera. The only other species of the order found at Mazon Creek is Eubrodia dabasinskasi Carpenter (1967) of the family Brodiidae, previously known only from the Upper Carboniferous of England (Figure 14A.16). The venation is typical of that of the Megasecoptera, but instead of a few cross veins the wing has a very fine network or archedictyon, which is unusual in this order.
Specimens
On display at "Dave's Down to Earth Rock Shop" in Evanston, IL.