Slimonia acuminata
Eurypterids
Specimen of the Month
Samuel J. Ciurca, Jr., Rochester, New York          by Eurypterids.net
OCTOBER 2009
Slimonia acuminata
A Unique Eurypterid from Lesmahagow
ADDITION TO THE CIURCA EURYPTERID COLLECTIONS AUGUST 7, 2009
I purchased the specimen shown on this page in August 2009. It is from
an old collection and is labeled Logan Water, Lesmahagow, Scotland.
Sites in this region of Scotland have yielded fine specimens of Silurian
eurypterids and fossil fish for over 100 years. Clarke & Ruedemann, in
their monumental monograph, THE EURYPTERIDA OF NEW YORK
(1912, p. 131) figured a complete specimen (shown near the bottom of
this page).
Below are photographs of the anterior portion of the carapace. I wanted to
capture the interesting ornamentation occurring along the margin and
note the fine pustular ornamentation covering the carapace. The eyes
have fine facets preserved.
MORE EURYPTERID OF THE MONTH PAGES  
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18   19   20   21   22   23   24   25   26   27   28   29   30
An illustrated guide to some of the
eurypterids I have collected over the
years is forthcoming:
EURYPTERIDS ILLUSTRATED    
Chasing Sea Scorpions
BELOW:
A swimming leg is nicely preserved,
note the various joints. Forward, one
of the legs preserves a large spine. It
is directed forward and provides an in-
dication that this was likely a predator.
Many eurypterids have spinose legs
wherein the spines are fine and were
directed downward and used in loco-
motion and probably filter feeding.
BELOW:
Drawings from page 131 of
Clarke & Ruedemann (1912)
THE EURYPTERIDA OF NEW
YORK.

LOWER RIGHT:
A wonderful specimen
showing the characteristic
telson of
Slimonia acuminata.
Size of telson: 6+ inches. A
median keel, as in pterygotids,
is prominent.
telson
telson
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