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James Lamsdell's
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| Issue 1 (2001) EDITORIAL Welcome
to the first internet newsletter concerning those most spectacular
of fossils - the eurypterids. I would like to thank all of you
for providing information regarding your research interests. It
is good to see that research in these amazing arthropods is going
from strength-to-strength, and I look forward to reading about
the new taxa and data on eurypterid palaeoecology that is eluded
to in your contributions. I have deliberately kept the format
simple and excluded figures (to limit the size of the file). I
have also modified your contributions slightly (both to conform
to a standard format, make some of them a bit more concise, and
reduced relevant references to the 1990s). Many thanks Dr
Simon J. Braddy
CONTRIBUTORS
Dr
Radek Mikulás
Contact information: Institute of Geology, Academy of Sciences, Rozvojová 135, 165 00 Praha 6, Czech Republic. E.mail: <mikulas@gli.cas.cz> Current interests: Ichnofossils of the Paseky Shale (Lower Cambrian, Central Bohemia) yield the oldest known non-marine or brackish assemblage of macrofauna including eurypterids (Chlupác et al. 1995). The ichnoassemblage consists mostly of fodinichnia and repichnia of endemic arthropods Kodymirus vagans Chlupác & Havlicek, 1965 and Kockurus grandis Chlupác, 1995. These traces were attributed to ichnotaxa Monomorphichnus biserialis Mikulás, 1995, M. semilineatus Mikulás, 1995, M. multilineatus Alpert, 1976, M. lineatus Crimes et al., 1977, M. bilinearis Crimes, 1970, ?Rusophycus isp. A, ?R. isp. B, ?Dimorphichnus isp., and Diplichnites isp. Monomorphichnus biserialis is represented by two long series of four to six grooves parallel to each other. Roughly in a half of series, individual grooves intersect, so inner grooves turn into outer ones and vice versa. Length of grooves up to 60 mm, spacings between them 1-3 mm. Kodymirus, as reconstructed by Chlupác (1995), possibly produced these parallel striae on the bottom by spines of prosomal appendages during more or less active locomotion. Relevant references Mikulás, R. 1995. Trace fossils from the Paseky Shale (Early Cambrian, Czech Republic). Jour. Czech Geol. Soc., 40/4, 37-45.
Contact information: E.mail: <kinman@hotmail.com> Current interests: I am very interested in eurypterid systematics at order (and family) level. I had to make a decision (back in 1992-93) whether or not to classify scorpions and eurypterids together, as part of my general classification of organisms down to ordinal level (The Kinman System, 1994). It was not an easy decision, especially since the 1990 cladistic analysis of Shultz (Cladistics, 6:1-38) showed the scorpions embedded well within his arachnid "clade". However, I felt so strongly that scorpions are terrestrial descendants of eurypterids, that I proposed a new Class Scorpionea for scorpions and "sea-scorpions" (sensu lato). I divided Class Scorpionea into 5 orders: Scorpionida (mostly terrestrial), Cyrtoctenida, Pterygotida, Eurypterida, and Stylonurida. Today I might transfer Orders Chasmataspida and Diploaspida from Xiphosurea to Scorpionea, and perhaps make other changes. But the important thing was classifying scorpions and "sea-scorpions" together, making it clear that they are related and not just convergently similar. It also dramatically reduced any possibility of a polyphyletic Class Arachnidea. I was therefore quite happy when Braddy et al. 1999 (Lethaia, 32:72-74) presented strong synapomorphic evidence supporting an eurypterid-scorpion clade. It is clearly a very important step in showing that a Class Scorpionea (or whatever you wish to call it) should be recognized and placed between Class Xiphosurea and Class Arachnidea. Relevant references "The Kinman System" (1994) was published (but not in hardcover). In the UK there are not many public copies - University of Glasgow was the first, and I believe the copy that went through Blackwell's last year went to the British Library. Most public copies are in the US (Library of Congress, Harvard, Yale, Princeton, Cornell, and various other university libraries).
Contact
information: Institute of Geology and Palaeontology, Department
of Natural Sciences, Charles University, Albertov 6, 128 43 Praha
2, Czech Republic. Relevant references Chlupác,
I. 1994. Pterygotid eurypterids (Arthropoda, Chelicerata) in the
Silurian and Devonian of Bohemia. Jour. Czech Geol. Soc.,
39, 2-3, 147-162.
Contact information: Insitut für Systematische Zoologie, Museum für Naturkunde der Humboldt-Universität zu Berlin, Invalidenstraße 43, D-10115 Berlin, Germany. Email: <jason.dunlop@rz.hu-berlin.de> www: <http://members.tripod.com/~DrJasonDunlop/index.html> Current
interests: Currently working with Simon Braddy (Bristol) on whether
eurypterids form a monophyletic group and on their position within
the Chelicerata. Comparative morphological studies between eurypterids, especially those from Konservatt-Lagerstätte showing exceptional preservation, and the other chelicerates are yielding new characters which we are testing in cladistic analyses. Under some parameters eurypterids and scorpions emerge as sister taxa, mostly supported by gross morphological characters, but other data (see papers by Jeff Shultz, Maryland) places scorpions among the remaining arachnids with eurypterids holding a more basal position. Other interests: 1. History of eurypterid research. 2. Eurypterid functional morphology and systematics. 3. Relationships between eurypterids and the similar-looking fossil group Chasmataspida. Relevant references: Dunlop,
J. A. 1998. The origins of tetrapulmonate book lungs and their
significance for chelicerate phylogeny. Proceedings of the
17th European Colloquium of Arachnology, Edinburgh, 1997,
9-16.
Contact information: Department of Earth Science, University of Western Ontario, London, ON, Canada. E.mail < sdonato@julian.uwo.ca> Current research: A new eurypterid genus from the Upper Ordovician Georgian Bay Formation of Manitoulin Island. Excavations by University of Western Ontario graduate students in May of 2000, revealed a rich assemblage of well-preserved eurypterid remains immediately below an unconformity marking the Ordovician-Silurian boundary (uppermost Georgian Bay Formation) south-west of Little Current, Manitoulin Island. Hosting sediments grade from finely crystalline argillaceous dolostone to poorly lithified silty clay in a vertical sequence of approximately 30 cm. Preliminary investigations suggest that the eurypterid specimens represent a new genus, and is also the oldest known occurrence of eurypterids in Canada. The chitinous eurypterid remains are very well preserved, and almost all body parts appear to be present. The remains were restricted to a very small area and are disarticulated. Two nearly complete specimens were recovered. Tentative habitat reconstruction points to a poorly circulated tropical shallow marine shelf environment.
Contact information: Department of Earth and Environmental Sciences, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607, U.S.A. E.mail: <plotnick@uic.edu>. Web: <http//www.uic.edu/depts/geos/plotnick.htm> Current interests: I have a number of undescribed specimens that I will get to at some point in time (hopefully, soon). These include a Megalograptus from the Ordovician of Virginia and a Cyrtoctenus-like form from the Carboniferous of Virginia, as well as some Devonian pterygotid and stylonurid material from Michigan. I am also planning to carry out a cladistic analysis of the Late Paleozoic eurypterids. Relevant references: Plotnick,
R. 1990. Evolution of the arthropod cuticle. pp. 177-196 IN Mikulic,
D., ed., Arthropod Paleobiology. Short Courses in Paleontology,
number 3.
Contact information: 54 Appleton Street, Rochester, New York, USA. Email: <paleoresearch@yahoo.com> Current interests: Eurypterids, sedimentary structures and the paleoenvironment of the late Silurian Williamsville waterlime (Bertie Group) Ontario, Canada and western New York State. Current research includes the additional collection of hundreds of eurypterid specimens for a detailed analysis of the eurypterid and associated fauna and flora - including new eurypterids not reported previously from this well-known horizon. In addition, the first survey of the sedimentary structures is being completed. These have heretofore not been generally accessible in plane view. Notable is the occurrence of "boomerangs," large sedimentary structures interpreted as being generated by swift currents that scoured the surface of Williamsville (A). To date, over 100 of these structures have been mapped on a grid consisting of 25 square meter squares. A preliminary description of the discovery of these "boomerangs" and other observations was published previously (New York State Geological Association Guidebook, 1994). Also, a site has been discovered that yields abundant Late Silurian plants, including Cooksonia sp. and Medusaegraptus sp. The eurypterids, sedimentary structures, and the Late Silurian flora mentioned above, all occur within the Williamsville (A) Waterlime, about 20 inches thick, within a thick sequence of mostly dolomitic rocks termed the Bertie Group (Type section: Bertie Township, Ontario, Canada). Relevant references Accounts (abstracts) of two projects are being published in the near future by the Rochester Academy of Science.
Contact information: Paleontologisk Museum, Universitetet i Oslo, Oslo, Norway. E.mail: <o.e.tetlie@nhm.uio.no> Current interests: Early diversification and phylogeny of chelicerates, phylogeny and taxonomy of eurypterids. Material presently under investigation: A fourth specimen of Paleomerus hamiltoni from the Lower Cambrian of Sweden. The Silurian eurypterids and other chelicerates found at Rudstangen, Norway. Some arthropod trackways previously unknown from Rudstangen, Norway. Some early Devonian eurypterids and chasmataspids from Alken, Germany. PMO's scattered collection of eurypterids from Scotland, the USA and Gotland. Relevant references: Tetlie,
O.E. 2000: Eurypterids from the Silurian of Norway. Unpublished
MSc thesis. 152 pp. [the results from the thesis will be presented
in 2 or 3 papers in the near future]
Contact information: 23 Shepherd Place, Utica, New York 13502-5417. Email: <mtolrton@borg.com> Current research: My unpublished Master's thesis (from SUNY at Buffalo in 1992) dealt with the comparitive ontogeny of Eurypterus lacustris and Eurypterus remipes. I'm still obtaining data for eventual publication of my thesis. My current work inclcudes the description of a new species of Acutiramus from the Devonian? of New York State, and a new genus of eurypterid from the Silurian of New York State and Ontario, Canada. Two longer term projects include an annotated bibliography and index of the Eurypterida, and a paper intended to be a revision of the eurypterid parts of both the Treatise, and the Fossilium Catalogus. Unfortunately, both projects are going slow. I'm also doing some work on a cladistic analysis, and on the world-wide distribution of eurypterids on available paleogeographic maps. For some years now, I've been re-studying the Ordovician eurypterids of New York State, most of which were originally described by R. Ruedemann. In essence, my results are that with two exceptions (and one of those is a phyllocarid) all the specimens are inorganic sedimentary structures. I have also discovered a plausible and possible reason for Ruedemann's "error". I believe he had an eye condition known as strabismus, and as a consequence of this he was not able to see as well in three dimensions as individuals without this condition. My research on Ruedemann continues. I'd like to ask some questions of the readers of the newsletter. Has anyone beside myself and Rick Batt of Buffalo, New York, collected eurypterids in situ? If they have, have they noted the prevalence for the eurypterids to be situated so that they are on their backs? I've noted this condition at two eurypterid localities in New York State, and one in West Virginia (at Bass), while Rick has observed this condition at localities in Ontario, Canada. As a topic for discussion in the newsletter, I think this condition is in agreement with Simon's hypothesis of mass mate-moult occurrences. What would the readers of the newsletter think about establishing a specimen bank of eurypterid cuticles? I'll leave cladistics for the next newsletter. Relevant references: My bibliography includes a classification of the Order Eurypterida, published in 1989 in the Journal of Paleontology.
Contact information: Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ. UK. E.mail: <S.J.Braddy@bris.ac.uk> Current research: My research on the eurypterids is primarily concerned with their functional morphology and palaeobiology (reproduction, respiration and locomotion (particularly walking biomechanics, involving computer modelling and analysis of trackway data). I continue to work on exceptionally preserved Onychopterella material from the late Ordovician Soom Shale Lagerstätte of South Africa. I am investigating the palaeophysiology of eurypterid respiration and the functional morphology of pteygotid eurypterid chelicerae (with Stephen Rawlinson; ex-MSc Bristol). I am also interested in eurypterid palaeoecology (and have proposed a ‘Mass-Moult-Mate’ hypothesis; under revision for P3) and phylogeny, particularly of carcinsomatids (and the probable link with scorpions; with Jason Dunlop) and chasmataspids (which on recent evidence appear to be sister-group with Eurypterida). Relevant recent references: Braddy,
S. J., Aldridge, R. J. and Theron, J. N. 1995. A new eurypterid
from the Late Ordovician Table Mountain Group, South Africa, Palaeontology,
38, 563-581.
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