Jedria meeki (Knight, 1933)

Jedria meeki (Knight, 1933) Jedria meeki (Knight, 1933)
Jedria meeki (Knight, 1933)

General abundance:  Common
This specimen is from the Clayey Shell Hash Limestone section

Special thanks to Dr. Tom Yancey for the identification and

This is Jedria meeki (Knight, 1933). This species is illustrated in
Knight (1933) (as Naticopsis) and in Hoare (1961) and is listed in
Yochelson (1967). It has a distinctive rounded shell with regular
short ribbing extending down at an angle from the suture at the
top of the whorl. The ribbing is like that of Jedria ventrica
("ventricosa" of Hoare and of Knight), but the rounded outline
instead of stepped profile makes species separation easy.
This species (meeki) is of special interest because it is the type
species for the genus Jedria, named by Yochelson in 1953.
Yochelson proposed the name Jedria for a group of species
with shells having a prominant shoulder on the whorl, but
surprisingly chose this species (meeki) as the type species.
This is a surprising choice for type species because meeki
does not have the notable shoulder that is so typical of most
species assigned to Jedria. It is atypical in that character. At
the time of Yochelson's proposal of the genus, J. meeki had
been reported only from strata in Missouri.

Dr. Tom Yancey


Hoare, 1961, Desmoinesian Brachiopoda and Mollusca from
Southwest Missouri; University of Missouri Press, 263 p.
Knight, 1933, The gastropods of the St. Louis, Missouri,
Pennsylvanian outlier: 6, The Neritidae; Journal of Paleontology,
v. 7, p. 359-392

Yochelson, 1953, Jedria, a new subgenus of Naticopsis; Washington
Academy of Sciences Journal, v. 43, p.65.
Yochelson, 1967, A bibliographic index of North American late
Paleozoic Hyolitha, Amphineura, Scaphopoda and Gastropoda;
U. S. Geological Survey Bulletin 1210, 271 pages.

Phylum Mollusca
chitons cephalopods clams gastropods rostroconchs

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