Portal de Periódicos da CAPES

Preliminary notice of a scorpion, a Eurypterus?, and other fossils from the Coal Measures of Illinois

1868; Yale University; Volume: s2-46; Issue: 136 Linguagem: Inglês

10.2475/ajs.s2-46.136.19

1945-452X

F. B. Meek, Amos Henry Worthen,

Marine and environmental studies

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 m Pterygotus.* These al.re in E. ,.em~e8, and other Silurian species, resemble body segments so closely that they were actually mistaken by Prof. Hall, for "anchylosed 1l.rst and second segments of the body" (palIllont.N. Y. vol.3, p. 398, fig.3, 1 and 2), and not suspected by him to be homologous with any part of the free operculum itself, of the genus Limulus.This error has been pointed out and correoted by Mr. Woodward, in his memoir on the genus Pterygotus, published by the Pe.-