Conus heterospira (Harris, 1890)

Descrizione:

Shell acutely oval, biconic, with the anterior whorls of the spire gradated, the posterior ones more or less flatly depressed, rarely with a regular gradated spire throughout. The pullus arises abruptly from the spire as a small, smooth, shining papilla of one and a-half naticiform whorls. Spire-whorls five ; the penultimate one medially angulated, its anterior slope perpendicular, the posterior slope slightly inclined, but with a faint medial depression ; on the ante-penultimate, the keel is close to the anterior suture, thence to the pullus the whorls are flat with a slight backward inclination whilst the keel appears as a slight rim. The body-whorl is elongated and tapers to the front; the peripheral keel is sharp ; the posterior slope, as also that of the spire whorls, is ornamented with prominent, much-arched, growth-lines, crossed by a few, usually obscure, spiral threads ; the rest of the body-whorl is ornamented with close-set, equidistant, incised lines, punctatedly impressed by the faint growth-lines.

Aperture narrow ; outer lip ecurved medially and somewhat deeply arcuately sinuated at the posterior angle.

Dimensions. — Length, 34 ; greatest width, 16; length of aperture, 28 ; of body-whorl, 30.

Localities. — Blue clays at Schnapper Point, not uncommon ; calciferous sandstones, Bird Rock Bluff, near Spring Creek.

Affinities. — This species has much resemblance to C. ligatus, but it is more elongate and has not the rim-like keel of that species. A characteristic feature is the abrupt gradation of the anterior whorls in the adult ; in adolescent specimens the regular sloping low spire make it difficult at first sight to attach them to the adult ; at this stage it resembles C. complicatus, but differs by its ornamentation, and the young of C. cuspidatus, from which it differs by its obtuse pullus and by the strongly arched growth-lines on the slightly concave spire-whorls.

The elate variety closely resembles C. huttoni, mihi (C. trahillii, Hutton, non Adams), of the Pareora formation, New Zealand, which has a much narrower outline, more elongated spire, and a more inclined posterior slope of the whorls.

Questa specie è molto simile al C. ligatus, dalla quale differisce per essere più allungata e per le carene delle spire più basse. Inoltre, il rigonfiamento presente sulla spalla e su ciascuna spira è meno evidenziato, e le linee sulle rampe suturali della spira sono meno evidenti.

Distribuzione: Australia: Eocene – Oligocene – Miocene Medio

Conus heterospira ⁽¹⁾

mm. 34 x 16

Conus heterospira

Fossil Beach Victoria Australia - Middle Miocene

[Coll. Angus Hawke]

Conus heterospira

mm. 32,7 x 15,7 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-01]

Conus heterospira mm. 24,8 x 11,9 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-02]

Conus heterospira mm. 24,0 x 12,1 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-03]

Conus heterospira mm. 21,6 x 10,7 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-04]

Conus heterospira mm. 20,9 x 9,7 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-05]

Conus heterospira mm. 18,6 x 9,9 – Miocene – Muddy Creek, Victoria – Australia

[AZFC N. 487-06]

Conus heterospira

mm. 16,2 x 7,5 - mm. 13,4 x 6,9 - mm. 15,8 x 7,4 - mm. 15,9 x 7,4

[AZFC N. 487-07 - 10 ]

mm. 15,0 x 7,4 - mm. 11,9 x 5,8 - mm. 15,8 x 7,4 - mm. 15,6 x 7,2

[AZFC N. 487-11 - 14 ]

Miocene – Muddy Creek, Victoria – Australia

Conus Leptoconus diversiformis edwardsi

( Cossmann 1889 ) - [ 27,8 x 13,6 ] - Eocene, Luteziano

Shepherds Gutter Bed, Selsey Fm., Upper Bracklesham Beds – Brook, New Forest, Hampshire

[AZFC N. 219-01]


Conus heterospira mm. 32,7 x 15,7 Miocene - Australia [AZFC N. 487-01]	Conus heterospira mm. 24,8 x 11,9 Miocene – Australia [AZFC N. 487-02]	Conus heterospira mm. 24,0 x 12,1 Miocene – Australia [AZFC N. 487-03]	Conus heterospira mm. 21,6 x 10,7 Miocene – Australia [AZFC N. 487-04]	Conus heterospira mm. 20,9 x 9,7 Miocene – Australia [AZFC N. 487-05]	Conus heterospira mm. 18,6 x 9,9 Miocene – Australia [AZFC N. 487-06]

Conus heterospira mm. 16,2 x 7,5 Miocene – Australia [AZFC N. 487-07]	Conus heterospira mm. 15,9 x 7,4 Miocene – Australia [AZFC N. 487-10]	Conus heterospira mm. 15,8 x 7,4 Miocene – Australia [AZFC N. 487-09]	Conus heterospira mm. 15,6 x 7,2 Miocene – Australia [AZFC N. 487-14]	Conus heterospira mm. 15,0 x 7,4 Miocene – Australia [AZFC N. 487-11]	Conus heterospira mm. 13,4 x 6,9 Miocene – Australia [AZFC N. 487-08]

Conus heterospira mm. 11,9 x 5,8 Miocene – Australia [AZFC N. 487-12]	Conus heterospira mm. 11,8 x 6,0 Miocene – Australia [AZFC N. 487-13]

Bibliografia Consultata