Dolichopterus & Other Eurypterids
Dolichopterus sp., Collected March 10, 2002, Williamsville Formation (Bertie Group), Ridgemount Quarries South, Fort Erie Township, Ontario, Canada. Note the large eye in the anterior right corner of the carapace. Only two tergites are preserved in this specimen and parts of the appendages.
Samuel J. Ciurca, Jr.
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CIURCA 031002-3
PROBLEMATICA
POSITIVE
NEGATIVE
AT LEFT: 031002-1 AND AT RIGHT,  031002-2.  INTERESTING STRUCTURE LIKELY TO BE PART OF A EURYPTERID STRUCTURE. MAXIMUM WIDTH: 3.5 CM. MAXIMUM LENGTH: 3.0 CM.  THE SYMMETRY OF THE STRUCTURE SUGGESTS THAT IT IS PART OF AN OPERCULUM, PERHAPS PART OF THE MEDIAN SEXUAL APPENDAGE. NOTE: STRUCTURE MAY BE PRESENTED UPSIDE DOWN.  Collected in the Late Silurian Williamsville Formation, Bertie Group, near Buffalo, New York.
AT LEFT: Recently discovered specimen, CIURCA 050502-1.  Unusual 'claw' found in the Williamsville Waterlime (Bertie Group).  Claw is 2 cm. long, while the segment shown is 2.5 cm. long. Could this be part of one of the appendages of a Dolichopterid? I've not seen a structure like this in 30 years of eurypterid collecting.  The claw resembles a cercal blade (Megalograptus) but, in this case, appears to belong to one of the anterior appendages of some eurypterid.
BELOW: Another view of the spine as it is preserved beneath the carapace of Eurypterus lacustris. Much of the carapace is not seen because of infilling by sediment. CIURCA 050502-1.
The Late Silurian rocks in which eurypterids are found are water- limes. Waterlimes are very resistant, fine-grained dolostones with an admixture of silica and clay.  When fresh, it is almost impossible to collect fossil remains. When the rock begins to weather, however, it becomes flaggy, that is one can break the rock into somewhat even layers not unlike the flagstones that are used in walkways and patios.
   When fresh, the rock breaks with conchoi- dal fracture. Natural weathering often pro- duces conchoids, circular 'dishes' that often contain fossil re- mains, including the eurypterid specimens. Many eurypterids and phyllocarid remains have been found in such conchoids, es- pecially at the top of Williamsville (A) Water-lime (A-B Contact).
ABOVE: Counterpart of the specimen shown in the other photos. The spine is scorpionlike.
EURYPTERIDS.NET
LEFT: Fascinating 'swimming leg' found in a block of Williamsville Waterlime at Ridgemount Quarry in Ontario, Canada. Every now and then some interesting eurypterid fragments are found that indicate that there is still much more to learn.
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