Conus juanensis (Wiedey, 1928)
Shell of small size; elongate
conical in outline, with a moderately elevated spire. Whorls, about six,
rounded, the succeeding increasing but slowly
in size. Apical angle slightly acute, being a little under ninety degrees.
Whorls nearly flat on their sides, each with a sharp shoulder at their angulation
above which the whorl tends to be slightly tabulate or concavely curved. Apex
sharp and approximately central. The suture is visibly depressed. The aperture
is moderate in width and nearly straight. Surface sculptured only by fine incremental
lines of growth.
Length, 26 mm.; breadth, maximum.
16 mm.; height of spire, about 10 mm.
Holotype: S.D.S.N.H.
type collection, type number 16, from S.D.S.N.H.
and L.S.J.U. locality 432. Collected from the east side of the first ridge west
of Syncline Hill, two miles west of Simmler, San Luis Obispo County,
California. L. Wm. Wiedey, collector; Temblor formation, middle Miocene.
This new species of Conus is
resembled most closely by a form from the Kern River Miocene, of Temblor age, C.
owenianus F. M. Anderson. It may be distinguished from the latter by
lacking the prominent spiral sculpture which characterizes it. This new form
also has a more sharply angulated spire of greater height than the Kern River
form. Upon examination of more extensive collections of both of these compared
species, sufficient variation of the Kern River form to embrace this group of
individuals might be shown. It is also resembled by C. interruptus Broderip
of the living cones uf the Gulf of California in having a similar spire,
but, for shells of corresponding stages of growth, the latter has a much higher
body whorl than the fossil species.
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Conus
juanensis
Plate 9 – fig. 3 Miocene California |
Bibliografia Consultata
·
(1) -
Anderson (1905) “A Stratigraphic study
in the Mount Diablo range of California”
·
(2)
- Wiedey (1928) “Transactions of the
San Diego Society of the Natural History, Vol.V n.0 – Notes on the Vaqueros and Temblor
formation of the California miocene…”
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