This is Mazon Monday post #102. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Scorpions are very rare in the Mazon Creek fossil biota. Eoscorpius carbonarius was described by FB. Meek and A.H. Worthen in 1868. The paper was published in the America Journal of Sciences - "Meek, Fielding B. & A. H. Worthen. 1868. Preliminary notice on a scorpion, a Eurypterus? and other fossils from the Coal Measures of Illinois and Iowa. American Journal of Sciences and Arts 2(45): 22-25.", where they called it Eurypterus carbonarius.
ART. II.-Preliminary notice of a Scorpion, a Eurypterus? and other fossils, from the Coal-measures of Illinois; by F. B. MEEK and A. H. WORTHEN.
AMONGST some fossils discovered last summer by Mr. Joseph Even, in the iron nodules of the Coal-measures at Mazon creek, Grundy county, Illinois, and loaned by him for the use of the Illinois Geological Survey, there are a few types of such unusual interest, that we have thought it desirable to present a preliminary notice of them, in advance of more extended descriptions and illustrations, to appear in one of the reports of the Survey.
The first of these is a fine Eurypterus, or a species of a closely allied genus, between the size of E. remipes and E. robustus. The specimen consists of an impression in the matrix, of the under surface of all the thoracic, and a part of one or two of the abdominal segments, in a more or less nearly perfect condition; with the operculum or thoracic flap, the post-oral plate, and the maxillary or basal joints of the swimming feet, all in place. There are also prints of some of the succeeding joints of one of the latter organs, and its oar-like expansion, and obscure impressions of three of the smaller legs on one side, and some of the basal joints of the same on the other side. all converging to the position of the mouth immediately in front of the post-oral plate. As the carapace and the dorsal portions of the thorax are enveloped in the other half of the concretion, which was not found, and the posterior portions of the abdomen and the telson extended beyond the limits of the concretion, we know nothing of the nature of any of these parts.
*These legs are slender, apparently without lateral spines, and terminate in a single long, acutely pointed dactylus, as in Pterygotus.
Fielding Bradford Meek and Amos Henry Worthen were both prolific namers of taxa back in the middle 1880's. They collaborated on many papers through the years, including the description of Acanthotelson stimpsoni in 1865. Meek worked at the USGS. A.H Worthen was the second state geologist of Illinois and the first curator of the Illinois State Museum. He had an extensive fossil collection, which now resides at the Prairie Research Institute PRI at the University of Illinois.
F.B Meek
A.H. Worthen
There have been other species of Mazon Creek scorpions identified since E. carbonarius. Some of those species were described by Alexander Petrunkevitch in 1913. He was a Yale paleontologist during the early 20th century.
- Eoscorpius danielsi Petrunkevitch, 1913
- Eoscorpius granulosus Petrunkevitch, 1913
- Eoscorpius typicus Petrunkevitch, 1913
- Trigonoscorpio americanus Petrunkevitch, 1913
Alexander Ivanovitch Petrunkevitch (Russian: Александр Иванович Петрункевич, December 22, 1875 in Plysky near Kiev, now Ukraine – March 9, 1964 in New Haven) was an eminent Russian arachnologist of his time. From 1910 to 1939 he described over 130 spider species. One of his most famous essays was "The Spider and the Wasp." In it he uses effective word choices and some comic touch.
The holotype of E. carbonarius resides at the Field Museum, where the specimen and its labels were digitized and published online.
It's worth noting that this specimen came from the University of Chicago's famous Walker Museum and was part of the Gurley Collection. W.F.E. Gurley (1854 - 1943) was the Illinois State Geologist from 1893 to 1897. In 1900, he became associate curator at the Walker Museum, where he worked until his death in 1943. He exchanged fossils and opinions with many of the amateur and professional paleontologists of the day, including Edward Drinker Cope, Leo Lesquereux, Fielding Bradford Meek, Edward S. Morse, Charles Schuchert, Samuel H. Scudder, and L.E. Daniels. A memorial to him was published in the Proceedings Volume of the Geological Society of America Annual Report for 1943. His extensive letters and papers can be found at the University of Chicago Library.
The University of Chicago's Walker Museum in 1893.
In "The Mazon Creek Fossil Fauna", Eoscorpius sp. appears on Page 45.
Scorpions are the earliest known arachnids and are considered to be one of the first terrestrial animals. Examples are found from as long ago as the Middle Silurian. These animals likely possessed gills and were aquatic, living in marginal marine brackish water environments. The earliest scorpions had cover plates that probably only kept their gills moist enough for brief trips onto land. Mazon Creek scorpions are the first of their kind to show evidence of book lungs, and thus were completely adapted to terrestrial life.
Scorpions were alive during one of the most important times in the history of life: when animals began to move onto shore. However, they may not have been the first to do so; there were almost certainly invertebrates such as millipedes before them. In the scorpions' 400-million-year history, their lifestyle has evolved from living in shallow seas and hunting alongside eurypterids to the present day, where they are mostly terrestrial nocturnal predators living in hot and dry areas of the world. Another marked evolutionary change in this group is the transition from having compound eyes and excellent vision for hunting to having only simple eyes and poor vision, such that the animal has to rely on its sense of touch to find prey. This is a remarkable journey by one of the most adaptable animals in the history of life on Earth.
Holotype Specimen
Eoscorpius sp. specimen owned by ESCONI member Phil Anderson
