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| Photo by Laura Dykstra. (c) Field Museum of Natural History . CC BY-NC 4.0 https://fm-digital-assets.fieldmuseum.org/1163/578/P21403_fossil.jpg . (accessed on 2024-12-07) |
While reading the Index Fossils of North America by Hervey W. Shimer & Robert R. Shrock from 1944, I found an interesting reference to Astraeospongia meniscus (Roemer, 1860) porifera fossil. It is listed as being found in Louisville, Kentucky and Brownsport, Tennessee. The creatures lived in the Silurian Period. This entry made me curious as I don't recalling find this fossil in the Louisville area but I have number of these fossils from Tennessee.
The picture above is from Chicago, Illinois, USA Field Museum of Natural History and was once part of the Borden Collection. It is great that the Field Museum is putting pictures of their fossils on-line. This fossil was from the defunct museum of William Borden (1823-1906) of Indiana. The fossil might have been collected by George Greene (1833-1917) who William Borden got a lot of local fossils from.
This fossil was named by Dr. Carl Fredrick von Roemer (1818-1891) who is famous for his research of fossils found in Texas that he collected during his 1845-1847 visit there.
In his 1860 book, Die silurische Fauna des westlichen Tennessee / Eine palaeontologische Monographie, he talks about Dr. Gerard Troost (1776-1850) whom he visited in 1847 in Nashville, Tennessee. Below is the translation [German to English] of his Preface.
"When I returned from Texas in the summer of 1847 to Nashville, the capital of the state of Tennessee, and found a very friendly welcome and valuable instruction on the geological conditions of the country from Dr. G. Troost, who has made a great contribution to the natural history of the western states, my attention was particularly drawn to the beautifully preserved Silurian fossils in the excellent man's rich paleontological collection, the location of which was indicated as the Perry district (Perry County) in the western part of the state. In addition to the largely known forms of corals and brachiopods, there was a particularly large number of beautifully preserved crinoids, almost all of which were new in terms of species and mostly also in terms of gender, and many remarkable specimens from other animal classes.
I immediately decided to visit the deposit of this remarkable fossil fauna myself and to gain a better knowledge of it by collecting it myself. Three weeks were spent on this trip, which was not without its difficulties and exertions, given the wild and sparsely cultivated nature of the area in question, but it also yielded a richer yield than I could have hoped for. The area over which the fossils in question are mainly found lies on both sides of the Tennessee River and includes the two districts (counties) Decatur on the left bank and Perry on the right bank'). Although I also visited some sites on the right bank, I collected mainly on the left bank.
From a point about 5 English miles north of Brownsport, where I was hospitable in the house of Colonel Wallis Dixon, I roamed the entire area between Brownsport and Perryville at leisure and collected all the numerous "glades" hidden in the surrounding primeval forest, i.e. the small hills bare of tree growth and only covered at the top with low bushes of red cedar (Juniperus Virginiana L.), which form the actual sites of our fauna. This is how the collection was created which provided the material for the current work and which, although not necessarily complete, certainly contains the great majority of the species that make up the fauna in general and allows an almost correct picture of the latter to be given. If the publication of the paper dealing with this material has only now taken place, this is only partly due to the obstruction caused by other scientific works, but mainly due to the fact that it was necessary to wait to see whether the description of the organic inclusions in the corresponding layers of the state of New York by James Hall would not make a special description of the fauna of Tennessee unnecessary.
However, since the publication of the second volume of the "Palaeontology of New York" containing the fossils of the "Niagara Group" has shown that the similarity between this fauna of the state of New York and that of Tennessee is sufficiently great to prove with certainty that the layers containing both faunas were deposited at the same time, but by no means so complete as to exclude the uniqueness of a significant number of species in each of the two faunas, this concern was removed and a description of the fauna appeared desirable.
What was known about it from other sources was limited to a few incomplete and, given the state of paleontology at the time, unreliable lists of fossils given by Troost in his geological reports on the state of Tennessee, to the mention of a small number of the species that make up the fauna by E. de Verneuil in his valuable essay on the parallelism of the Polaeozoic layers in North America and Europe, and 1) Perry County also used to extend over the area on the left bank of the river, which has since become an independent district under the name Decatur County. In this older, broader sense, Perry County was designated by Troost and after him by other authors as the site where the Silurian fauna in question was found. In fact, the localities that Troost primarily exploited, and in particular the town of Perryville, are located on the left bank of the river in the Decatur district."
On page 2 he talks about the area that Dr. Troost discovered where he found Silurian fossils. Translated from German to English.
"The thickness of the entire sequence of layers cannot be determined in the region in which I have only become acquainted with it through my own observation, in the counties of Decatur and Perry on the Tennessee River, since the underlying layer is nowhere exposed here. Safford, who describes the sequence of layers as "the dyestone and gray limestone group," estimates it to be several hundred feet in the western part of the state, while it is said to be much smaller further east. The outcrop points where Troost first discovered the sequence of layers with its rich fauna and where I also collected the material on which the present work is based are small hills, 50 to 60 paces wide and usually only 10 to 25 feet high, without any trees or only covered with stunted and sparse tree growth on the top, the so-called "Glades," i.e. forest clearings, which are scattered in the primeval forest in the area between Brownsport and Perryville in significant numbers. On the bare slopes of these "glades," the layers, whose largely siliceous nature seems to be hostile to plant growth, come to light and which have been formed from the rock by weathering. dissolved, largely silicified fossils lie freely on the surface. If one is as lucky as I have been several times to find a virgin hill of this type in the dense forest, i.e. one that has not yet been trodden by a paleontological predecessor, then the yield is particularly rich, as the entire result of weathering over thousands of years then falls to the discoverer. "
On page 31, he talks about the unpublished crinoid fossils that Troost had found but laments now that Troost died in 1850 and the Troost names are meaningless. Roemer does realize that James Hall has the Troost manuscript describing them but has not published it. It would not be until 1909 when Columbia University graduate student Elvira Wood (1865-1928) publishes the Troost work after both men are long dead. Translated from German to English.
"Dr. G. Troost in Nashville, who had assembled a rich collection of organic inclusions from the Silurian layers and the carbonate limestone in the state of Tennessee and had devoted particular attention to the numerous crinoids in these older layers, sent the American Association for the Advancement of Science a list of all the crinoids he had known about from the older rocks of the state of Tennessee shortly before his death. This list was first printed in the Proceedings of the American Association. 1849 p. 60, Second Meeting held at Cambridge. Boston 1850. p. 62 and was subsequently included in Silliman's Journal of Sc. and Arts 1849, VIII, p. 419-420, and subsequently in Leonhard and Brown's Jahrbuch für Mineralogie etc. Jahrg. 1850 p. 376-377. It lists 88 species of crinoids and a few asterids and echinids, and gives a significant number of new generic names.
Unfortunately, any description or diagnosis of the genera and species is missing, and even an indication of the localities and strata to which the individual species belong is missing. It is therefore impossible to determine from this list which species are meant by the various names. Even if, like me, one knows the Troost collection well from one's own examination and, on the other hand, owns specimens of most of the species contained in it, one is unable to determine the meaning of the names contained in that list. For example, I have no idea what generic forms are meant by the names Cabacocrinites, Balanocrinites, Agariocrinites, etc., although I very probably have the same forms in my collections made in the state of Tennessee. In the present text, therefore, the names of that list had to be completely disregarded when naming the species of crinoids to be described. Should it subsequently be possible to determine, for example with the help of Troost’s handwritten notes, that a greater or lesser number of the species to be described here are identical with species on that list, this would not affect the priority of the names I have chosen, because according to generally applicable nomenclatural principles, the publication of mere names of species without diagnosis or description does not justify a right of priority for such names. I am compelled to make this remark in order to avoid any confusion of names, especially because American authors have adopted individual names from Troost's list and given them preference over names of the same species by other authors who were the first to distinguish these species as new in a generally recognizable manner through description and illustration.
Thus, my esteemed friend J. Hall, in the Report on the geological Survey of the State of Iowa by James Hall and I. D. Whitney Vol. I, Part II, Palaeontology. 1858, which contains a valuable extension of our knowledge of crinoids through the description and excellent illustration of a large number of crinoids from the Carboniferous Limestone and other older layers of the western states, has named a species of the genus Pentatrematites under the name Pentremites cherokeeus p. 691 and listed the literature references under this name as follows: “Pentremites cherokeeus: Troost, Ms. of Monograph; Catalogue, 1849, Proc. Am. Assoc. for the advancement of Science p. 60. Pentremites sulcatus: Roemer: Monogr. of Blastoideae 1852, p. 354, t. 6, f. 10a, b, c.” Based on a manuscript supposedly written earlier but never published and a list of names published in 1849, my name P. sulcatus, which I assigned in 1852 to a species that was in good faith believed to be new, is here removed. It is obvious that if such a failure to observe the recognized nomenclatural rules were to become more widespread, the security of the entire palaeontological nomenclature would be called into question."
On page 33, Roemer writes about the cystoid Caryocrinus ornatus (Say) and lists that the species Troost named of this genus are just varieties of this species. He also refers to as a crinoid when it is now known as a cystoid. Translated from German to English.
"This beautiful crinoid, whose structure was fully described by Leop. von Buch and James Hall based on specimens from Lockport in the state of New York, is the most common crinoid in our fauna. I have collected several hundred examples of the calyx in various glades. The dimensions of the largest of these are significantly larger than those observed by J. Hall at Lockport. The largest calyx I have is 65 millimeters. long and 50 millimeters wide, and individual loose tablets allow the conclusion that the cups were even larger. The usual size of the cups, as in Lockport, is about 30 millimeters long and 12 millimeters wide. Many examples therefore have a habitus somewhat different from that of the usual specimens from Lockport, in that the calyx narrows more towards the top towards the flat apex surface and the apex surface itself is smaller. The very large specimens in particular show this deviation. In some cases the apex surface also appears only smaller because the Lockport specimens usually preserved the pieces forming the arm bases have mostly fallen out in the specimens from Tennessee. Regarding the type of preservation, the calyxes are either silicified and then externally usually yellowish in color, or transformed into calcite and then white.
Say's Caryocrinites loricatus is a mere variety of the main form. Troost lists five other species of Caryocrinus (C. meconideus, C. hexagonus, C. granulatus, C. insculptus and C. globosus) in the already mentioned list of crinoids of the state of Tennessee, but not C. ornatus. After a personal, detailed examination of Troost's collection, I can confirm that all five alleged species are varieties of C. ornatus that are only distinguished by minor characteristics of the cup shape and the sculpture. The genus is currently only known in this single species and is an exclusively American genus. Apart from the western part of the state of New York, where the cups were found in bushels near Lockport during the digging of the Erie Canal, and in the county of Decatur in Tennessee, the species also occurs at the already mentioned locality of Beargrass Creek not far from Louisville in the state of Kentucky. In all three regions the species belongs to exactly the same level of Upper Silurian strata, as the accompanying fossils show. "
On page 34, he talks about a Troost specimen he studied called Apiocystites sp. Translated from German to English.
"APIOCYSTITES sp.
Dr. Troost's collection in Nashville contained a small cystidea that probably belongs to the genus Apiocystites from the layers of our fauna in Decatur County. According to the rough sketch that I made of it and which I have in my possession, the species closely matches Hall's Apiocystites elegans and could possibly be identical with it. On the upper half of the elongated subcylindrical calyx, a round opening and two rhombus fields (“pectinated rhombs” by Forbes) were clearly visible. It would be desirable if a more precise identification of the species could be made based on the specimens from the Troost collection that remained in Nashville. I suspect that the name Echinocrinites fenestratus listed in Troost's crinoid list mentioned above refers to the species in question here."
On page 50, he remarks that Troost named 10 species of Eucalyptocrinus which are not valid. Translated from German to English.
" Incidentally, all Silurian Eucalyptocrinus species found so far belong to exactly the same geognostic level and also to the same Nordic facies of the Silurian group. In Europe, species of the genus are known from the island of Gotland, from Norway and from the English Wenlock limestone. In Norway, Kierulf found a beautiful, complete specimen of Eucalyptocrinus decorus in the uppermost limestone layers of the island of Malmö near Christiania. Troost lists 10 species of the genus Eucalyptocrinus in the above-mentioned list of Tennessee crinoids. Without being able to determine the meaning of these names in detail, I can assure you, based on Troost's collection, that most of these supposed species are to be regarded only as varieties."
Plate II has images of the Astraeospongia meniscus which should be the holotype since he is credited with naming it.
Lastly, I found what Dr. Roemer wrote on page 89 to be of interest, he mentions Louisville, Kentucky at least 4 times in his book and writes that he collected at Beargrass Creek near the city. He was led there by Dr. Lunsford Yandell (1805-1878) and Dr. Benjamin Franklin Shumard (1820-1869). Translated from German to English.
"It is especially the spongia, the crinoids and some brachiopods that
establish the local independence of the fauna of Tennessee compared to that of New York. Among these, special emphasis should be placed on such species as Astraeospongia meniscus, Palaeomanon cratera, Astylospongia stellatim-sulcata, Plasmopora follis, Cyathophyllum Shumardi, Platycrinus Tennesseensis, Lampterocrinus Tennesseensis, Pentatrematites Reinwardtii and Calceola Tennesseensis, because, with their considerable size and striking form, they could not easily have been overlooked if they were present at all in the strata of western New York, while for such smaller species as Poteriocrinus pisiformis, Coccocrinus bacca, etc., it is quite possible that they have only accidentally escaped the attention of the New York paleontologists. On the other hand, the fauna of the Niagara group also has a number of distinguished forms which are lacking in the fauna of Tennessee. These include in particular some crinoids and trilobites such as Ichthyocrinus laevis, Lecanocrinus macropetalus, Stephanocrinus angulatus, Callocystites Jewettii and Lichas Boltoni. On the whole, the numerical ratio of the forms peculiar to each of the two faunas to those common to both is such as can be expected as a result of local influences given the considerable spatial distance between the deposits containing the two faunas and does not give any reason to question the previously assumed complete simultaneity of the deposits. The distribution area of the fauna of Tennessee lies about 9 degrees of longitude further west than that of the corresponding layers of the state of New York and at the same time it is more than 7 degrees of latitude further south. In the entire wide space between Lockport and Perryville, layers of the same age have, to my knowledge, only been found at one point, namely at Bear Grass Creek, not far from Louisville in the state of Kentucky. On the slopes of a wooded gorge, gray limestone layers are exposed here in horizontal or slightly inclined layers, which contain the same fossil fauna as the layers of Perryville and Brownsport. I myself have collected specimens of Caryocrinus ornatus and Cytocrinus laevis at this locality, to which I was led by Mr. Yandell and Mr. Shumard. The exposure of the layers is, however, only imperfect and the preservation of the organic inclusions is less favorable than in the main distribution area of the fauna in Tennessee. From the areas of North America further west, beyond the Mississippi, no layers with a fauna more closely comparable to ours have been known to date."
