Conus catus (Hwass in Bruguière, 1792)
Descrizione e
caratteristiche:
E’ una conchiglia di dimensioni da piccola a
medio-piccola, da moderatamente solida a solida; il peso relativo di esemplari
di dimensioni simili può variare del 40%. L’ultimo giro è generalmente da
ventricosamente conico a ventricosamente ampia e conica; il profilo è convesso
fino a circa metà e per lo più diritto sotto; il lato sinistro è
occasionalmente sinusoidale. La spalla è da angolata ad arrotondata. La spira è
bassa o di altezza moderata, con il profilo da leggermente concavo a
leggermente convesso. I primi 2-3 giri postnucleari sono tubercolati. Le rampe
sono piane o leggermente concave, con
scanalature spirali che da 1 aumentano fino a 4-8; le ultime rampe presentano
ulteriori strie spirale subsuturali. L’ultimo giro si presenta variabile per
quanto riguarda le sculture a spirale (1).
A single somewhat worn
shell from the Pleistocene beds at USGS locality 25715 on the Kere
River, Santo, New Hebrides, has the proportions and sculpture of C. catus,
and traces of original color on the spire are similar to patterns of C.
catus. On the body whorl, however, are spiral lines of reddishbrown dashes,
a pattern not found on any of the shells .in the large USNM
collections-collections that, however, do not include any shells from the New
Hebrides. Cernohorsky ( 1964, p. 70) reported such a pattern in his discussion
of this variable species. The figured fossil, USNM 214311, measures: length
25.6 mm, diameter 16.3 mm (2).
The first appearance of Conus
catus dates back to the Pliocene according to Harris: obtained from
a well-digging 10 feet in depth, Chatham Islands (New Zealand) G. 9502. Two
specimens. Transferred from the Museum of Practical Geology (5).
Lithoconus
holoformis (De Gregorio, 1880), whose height is 19 mm., is very
similar to the morphology of Conus
bitorosus. The latter could in turn be the ancient progenitor of the Conus
catus, present in the Red Sea as well as in the Indian and Pacific Ocean
areas. The presence of the Conus catus in the Miocene of Java, testifies
that already in the Oligocene, an ancestor of Conus
bitorosus could have also spread in the area currently inhabited by the
Conus catus.
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Conus catusmm. 32,2 Middle Miocene –
Indonesia [AZFC
562-01] Collected by local mining residents, from land lost
after rain in the highlands 1000 meters above sea level. Remnants of white color blocks in dorsal
view. "Jampang Regency". Southwest of Nyalindung. Edward J. Petuch definitely an ancestor of Pionoconus catus,
but not the same species as the living one. Being of Miocene age is far too
old to be the same species as catus---the average lifespan of a species is
roughly 1 million years; far less for cones, which have been shown to have
the ability to form a new species in only 7-10 thousand years (by changing
their biochemistry and venom) |
Conus catus rosamm. 31,8 x 16,6
Somalia
[AZRC N. 738-01]
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Conus catus (2)
mm. 25,6 x 16,3 USGS locality 25715 Kere River (Adsone River) Santo Island, Vanuatu, New Hebrides Pleistocene. USNM 214311 |
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Tabel 1. (3) Kesebandingan Stratigrafi Regional
Pegunungan Selatan Bagian Barat Jawa Barat |
Santo Island (2) |
Bibliografia