Conus (Lautoconus) sp. (Psarras, Merle & Koskeridou, 2022)
Conus (Lautoconus) sp. 1 (Psarras, Merle
& Koskeridou, 2022)
Shell
description
Medium-sized shell (SL: 35 mm, base broken) with low conical
spire. Spire whorl outline conical. Early spire whorls conical, worn out. Later
spire whorls conical, straight, slightly convex. Shoulder smooth, with maximum
diameter below shoulder. Suture channeled. Subsutural flexure very shallow,
very weakly curved, nearly symmetrical (Fig. 40C).
Description
of colour pattern
The colour pattern consists of closely related,
delicate, elongated, wavy spiral rows of dashes. On the spires, the pattern
consists of very thin axial flammulae, closely related to each other. The
flammulae are vaguely connected with a spiral band, at the center of the
sutural ramp.
Remarks
This species is very similar in morphology (Table 3)
to Conus (Lautoconus) ictini sp. nov. It differs in the
wider shoulder and the relatively lower conical spire outline. It can also be
distinguished by its relatively shallower subsutural flexure relative depth
(SSFd = 4.88 in Conus (Lautoconus) ictini sp. nov.).
Moreover, it displays a very different colour pattern from the brick-like
pattern of Conus (Lautoconus) ictini sp. nov. (Fig. 6).
Another species with a similar colour pattern on the last whorl is Conus (Leporiconus)
suessi Hoernes & Auinger, 1879 (see Harzhauser & Landau 2016),
but Conus (Lautoconus) sp. 1 does not possess striate
spire whorls. Therefore, it does not match the description of Conus (Leporiconus)
suessi.
Stratigraphic range
Upper Tortonian Crete,
Greece.
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Fig. 6. Conus (Lautoconus) sp. 1 specimen MNHN.F.A82982 from the Tortonian of Crete (Greece), in
abapertural and apical views under natural (A2) and UV light. Scale bar = 1 cm. |
Conus ponderoglans (Sacco, 1893) Holotype - mm. 52,8 Tortoniano – Stazzano Museo Regionale di Scienze Naturali di Torino |
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Conus ponderoglans (Sacco, 1893) Holotype - mm. 52,8 Tortoniano – Stazzano |
Fig. 6. Conus (Lautoconus) sp. 1 specimen MNHN.F.A82982 mm. 29,5 |
Conus (Lautoconus) sp. 2 (Psarras, Merle
& Koskeridou, 2022)
Shell description
Medium-sized shells (51.92 mm), with
medium to low conical, straight to slightly coeloconoid spire. Early spire
whorls faintly striate, highly pointed. Later spire whorls smooth, straight to
slightly coeloconoid. Faint spiral grooves on spire whorls, diminishing on late
spire whorls. Suture channelled. Subsutural flexure shallow, moderately curved,
moderately asymmetrical (Fig. 40D). Shoulder rounded, with an angulation at
suture height. Maximum diameter right below shoulder. Last whorl conical, with
variable elongation of the last whorl, not constricted. Spiral grooves present
on anterior third of last whorl. Aperture moderate, widening anteriorly.
Fasciole indistinct, slightly twisted.
Description of colour pattern
The colour pattern consists of two levels of
colouration. The first consists of yellow axial stripes on a non-fluorescent
base. Those stripes are either continuous from the shoulder, where a
non-fluorescent disruption exists (Fig. 8), until the anterior of the shell, or
are not continuous, showing patterns of axial disruptions, convergences with
other stripes, and divisions of individual stripes into more (Fig. 8A). The
second level consists of two axial bands; the first one is placed just above
the middle of the shell and the second one is placed on the anterior part of
the shell, along with the last spiral groove. The bands are not always
continuous or visible (Fig. 8B). In some shells, they resemble closely
arranged, thin spiral dashes (Fig. 8E, G–H), some of them axially arranged
(Fig. 8H).
Remarks
This species is the most common Conus (Lautoconus)
in the Tortonian of Crete. The study of more than 100 specimens (Table 4) consistently shows the
recurrence of the morphology and colour pattern of this species (Fig. 8).
From the Serravallian of Turkey,
Erünal-Erentöz (1958: 121, pl. 20 figs 4–5) described Conus (Chelyconus)
pyrula var. mucronata, but the binome Conus mucronatus is
occupied by a recent species, described by Reeve (1843). The Turkish material
displays a morphology similar to the Cretan specimens, with pointed early spire
whorls, low conical late whorls and an angulated shoulder. As no colour pattern
has been studied for that material, we cannot consider with certainty that the
Cretan and the Turkish specimens belong to same species.
The type specimen of the Pliocene Conus
bitorosus var. elatoastensis Sacco, 1893 (Sacco 1893b),
illustrated by Hall (1966: pl. 23 fig. 24), is very similar to Conus (Lautoconus)
sp. 2, but we have not observed its colour pattern.
The shell morphology of the Pliocene Conus
(Lautoconus) ponderosus Brocchi, 1814 resembles
that of Conus (Lautoconus) sp. 2, but differs by lacking the
early, pointed spire whorls, by the occurrence of spiral grooves on last whorl
and by the frequent angulation on shoulder. Its colour pattern seems not
preserved (Harzhauser & Landau 2016; Annalaura Pistarino pers. comm.). One
syntype of Conus (Lautoconus) conoponderosus Sacco, 1893b
(MRSN BS.038.05.082, Tortonian of Colli Tortonesi) was figured in Davoli (1972:
pl. 4 fig. 19). It bears a similar morphology, but displays a lower spire and a
stout last whorl differing from most of the specimens studied here. Its colour
pattern was not observed. Despite the discussed differences in shell
morphology, Conus ponderosus and Conus conoponderosus might be
different morphotypes of a same species. Since we observed similar morphotypes
from Crete, we cannot disregard the possibility of them being conspecific.
Thus, we refrain from attributing the Cretan material to Conus (Lautoconus)
ponderosus, Conus (Lautoconus) conoponderosus or Conus
elatoastensis. Further examination needs to be done on the Italian
types by using UV light in order to clarify whether the colour pattern allows
distinguishing these species.
Conus (Lautoconus) pyrula Brocchi, 1814 differs from Conus (Lautoconus)
sp. 2 by a more robust morphology and a weaker angulation on shoulder (Fig. 7).
The colour pattern of Conus (Lautoconus) sp. 2 bears additional
spiral bands (Figs 8–9), whereas that of Conus (Lautoconus) pyrula
bears irregular, ochre-coloured longitudinal lines (see the description by
Sacco 1893b). We examined Italian Pliocene specimens stored at the MNHN Paris
(Vegga coll., MNHN.F.B32569), that are identified as Conus pyrula Brocchi,
1814 and we confirm that they display the colour pattern described by Sacco
(1893b).
Conus (Lautoconus) steinabrunnensis Sacco, 1893 (Sacco 1893b) from the
Langhian of Austria bears large irregular blotches and flammulae on spire
whorls (Harzhauser & Landau 2016), differing from the colour pattern of Conus
(Lautoconus) sp. 2.
Conus (Lautoconus) steindachneri Hoernes, 1879 from the Langhian of Austria
has a colour pattern of numerous thin spirals (Harzhauser & Landau 2016),
also differing from that of Conus (Lautoconus) sp. 2.
Stratigraphic range
Tortonian of Greece (Achladhia, Sitia Basin and Messara Basin, Crete)
(this work).
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Fig. 7. Shell morphotypes of Conus (Lautoconus)
sp. 2 from the Tortonian of Filippi, Crete
(Greece) in apertural view under natural (A1,
A3–A4, B1, C1, D1, E1) and UV light.
B. Specimen MNHN.F.A83004, Crete: a small
specimen showing vivid colour pattern under UV light. C. Specimen AMPG(IV) 3786, Filippi: a
specimen with unusual pattern of spiral dashes instead of bands. D. Specimen MNHN.F.A82996, Crete: a
specimen with relatively low LW. E. Specimen AMPG(IV) 2768, Crete: Symeonidis & Kostantinidis’s specimen with unclear colour pattern. Scale bar = 1 cm. |
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Conus (Lautoconus) sp. 2 mm. 28 x 16 [AZFC 448-01] N. 2556019 |
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Conus bitorosus var. elatoastensis
(Sacco, 1893) |
Conus (Lautoconus) sp. 2 mm. 32,3 x 18,3 [AZFC 448-02] |
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Conus (Lautoconus sp.2) mm. 42,0 x
23,5 Miocene – Rethymno a 800 m. s.l.m. – Creta [AZFC 448-03] |
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Conus (Lautoconus sp.2) mm. 42,0 x 23,5 Miocene Rethymno a 800 m. s.l.m. – Creta [AZFC 448-03] |
Conus (Lautoconus) sp. 2 mm. 32,3 x 18,3 Rethymno a 800 m. s.l.m. –
Creta [AZFC 448-02] |
Conus (Lautoconus) sp. 2 mm. 28 x 16 Rethymno a 800 m. s.l.m. – Creta [AZFC 448-01] N. 2556019 |
Conus (Lautoconus) sp. 3 (Psarras, Merle & Koskeridou, 2022)
Shell
description
Large (estimated SL: 172.7 mm), elongate, sturdy
shell. Spire whorl outline conical. Early spire whorls conical, later spire
whorls conical, with slightly convex outline. Shoulder rounded, with maximum
diameter just below shoulder. Suture slightly impressed. Subsutural flexure
very shallow, very weakly curved, nearly symmetrical (Fig. 40E). Last whorl
elongated, straight. Aperture straight. Apertural canal short, wide, fasciole
twisted.
Colour
pattern variation
Three levels of colouration are present in this
species. The first one consists of two fluorescent bands, which are on the
middle and anterior parts of the shell. The second one is a pattern of spirally
arranged alterations of non-fluorescent and fluorescent dots. The third level
is displayed between the spiral alterations of dots. It consists of a series of
fluorescent, arrow-like blotches-tents, pointing in the opposite direction of
the shell growth, alternated by non-fluorescent areas. The non-fluorescent
areas might have one or two dots between the fluorescent arrows. Along with the
second level of fluorescent dots, irregular fluorescent flammulae appear on the
spire whorls.
Remarks
The colour pattern of the species is unique in the
studied material. The relatively rounded spire whorls and the lack of tubercles
on early spire whorls allow us to categorize it as an elongated Conus (Lautoconus).
Caze (2010) identified this specimen (MNHN.F.A30844) (Fig. 10) as Conus (Chelyconus)
clavatulus d’Orbigny, 1852, originally described from the
early Miocene of Saubrigues (France). Hall (1966: pl. 23 figs 23–24)
illustrated the type material (a syntype from the early Miocene of
“Dax-Saubrigues”, Aquitaine) of Conus clavatulus from the collection of
Grateloup. The shell of this specimen resembles Conus (Lautoconus)
sp. 3.
Conus subclavatus d’Orbigny,
1852, another species of the early Miocene of the Aquitaine Basin, is known
from a syntype (MNHN.F.A13055) of the d’Orbigny’s collection and is rather
similar to Conus clavatulus. Since the patterns of both species remain
unknown, we refrain from attributing the Cretan specimens to one of these
species. Additionally, C. (Lautoconus) sp. 3 differs from the
figured specimens of Kovács & Vicián (2013) from the Langhian of Hungary,
named Varioconus clavatulus (d’Orbigny, 1852), in the higher spire and
the more angulated shoulder. Finally, this species is not Conus (Lautoconus)
ponderosus Brocchi, 1814 as it has a slightly higher spire and more
elongate last whorl.
Stratigraphic
range
Tortonian
of Greece (Voleones, Apostoli Basin, Crete).
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Fig. 10. Conus (Lautoconus) sp. 3 from the Tortonian of Crete, (Greece) on apertural, abapertural and apical
views, under natural (A1, A3, A5, A6) and UV light.
Scale bars: A1–A4, B1–B2 = 1 cm;
A5 = 500 μm; A6 = 1 mm. |
Conus (Lautoconus) sp. 4 (Psarras, Merle & Koskeridou, 2022)
Shell
description
Medium-sized shell (SL max.: 29.43 mm). Early spire
whorls conical to convex, of low to medium height. Later spire whorls conical
in outline, with convex, smooth sutural ramp. Subsutural flexure moderately
deep, strongly curved, moderately asymmetrical (Fig. 40I). Shoulder smooth at
early spire whorls, slightly angulated at later spire whorls. Maximum diameter
below shoulder. Last whorl conical, slightly widened. Aperture narrow,
straight, widening towards slightly twisted fasciole. Shell smooth, except for
two faded spiral cords near fasciole.
Colour
pattern variation
The colour pattern on the spire whorls consists of
irregular blotches. The colour pattern on the last whorl consists of two levels
of colouration. The first one consists of fluorescent blotches. The second
level consists of spirally arranged irregular rows of fluorescent dashes,
interrupted by non-fluorescent tents. The tents can be either as small as dots,
or small non-fluorescent dashes, or can be axially wide enough to unite with
other tents and create an axial non-fluorescent area. The resulting pattern is
variable and depends on the number of tents, as well as on the size of those
tents. The Cretan specimen shows an axial unification of the tents, while the
Turkish specimen displays a spiral unification of the tents, in the middle part
of the last whorl.
We noticed that the specimen from Apomarma
(MNHN.F.A83015) had different grades of erosion, with non-fluorescent areas
being more resistant to erosion, than those being previously with colour
patterns (see Fig. 17A4 in comparison to the right side of Fig. 17A3, where the
shell is not so eroded). This might indicate that the substance enclosed in the
shell structure, which is responsible for the pigments, is more prone to
erosion than the non-pigmented areas.
Remarks
This species is placed in Lautoconus, as it has
smooth early spire whorls and a convex sutural ramp. The Pliocene Turkish
specimen identified by Caze (2010) as Conus (Chelyconus) ?pyrula
Brocchi, 1814 and the Cretan specimen of Conus (Lautoconus)
sp. 4 share smooth and convex spire whorls with a slightly angulated shoulder
(Fig. 17) and have a similar colour pattern. Thus, they very likely belong to
the same species. The typical Pliocene Conus pyrula bears
a colour pattern of axially arranged stripes. Conus (Lautoconus)
sp. 4 differs from the Paratethyan species of Conus (Lautoconus)
(Harzhauser & Landau 2016) in the presence of tents in its colour pattern. Conus
(Lautoconus) sp. 5 (see below) has a similar colour pattern of
tents, but it differs morphologically from this species in the smooth outline
of the spire whorls and the olive-like morphological outline. As such, we
consider these specimens as two separate species. Unfortunately, in lacking
more specimens with similar morphological characteristics and colour pattern,
we do not name this species. Conus (Lautoconus) sp. 4 has a very
common shell outline and is not easily distinguishable from other species
without the help of UV light. The colour pattern is also reminiscent of extant
species of Conus (Lautoconus), such as the West African species Conus
(Lautoconus) saragasae Rolán, 1986 (Tenorio et al.
2020). The morphological outline of Conus (Lautoconus) sp. 4 can
be compared with several Conus (Stephanoconus) species discussed
in this work (e.g., Conus (Stephanoconus) cf. taurinensis Bellardi
& Michelotti, 1841 and Conus Conus (Stephanoconus) moissettei
sp. nov.). Both species, however, possess the tuberculate early spire
whorls, lacking in Conus (Lautoconus) sp. 4. Furthermore, their
colour pattern is not comprised of tents.
Stratigraphic
range
Tortonian of Greece (Messara
Basin, Crete) (this work) and Piacenzian (Pliocene) of Turkey (Antakya Basin,
Samandag Fm.) (see Tarı et al. 2013 for the age).
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Fig. 17. Conus (Lautoconus) sp. 4 from the Tortonian of Crete (Greece) and
the Piacenzian of Antakya (Turkey) (figure altered after Caze 2010),
displayed under natural (A3–A5) and UV light.
Scale bars: A1–A3, A5–B3 = 1 cm; A4 = 500 μm. |
Conus (Lautoconus) sp. 5 (Psarras, Merle & Koskeridou, 2022)
Shell
description
Moderately small (SL max.: 26.93 mm), biconical shell.
Spire conical, straight. Early spire whorls straight to concave. Later spire
whorls straight to convex, smooth. Suture moderately incised, undulated.
Subsutural flexure very shallow, weakly curved, moderately asymmetrical (Fig.
40J). Last spire whorl with broad, straight to convex sutural ramp, continuing
into smooth to subangulated shoulder and down to squished, rather sigmoidal
last whorl. Maximum diameter right below shoulder. Aperture narrow, widening
abapically. Siphonal canal long, straight. Fasciole indistinct. Faint spiral
cords on quarter anterior part of last whorl.
Description
of colour pattern
The colour pattern on the spire whorls consists of
fluorescent irregular blotches and, inside those, randomly positioned,
non-fluorescent tents. The tents continue until shoulder height. The colour
pattern on the last whorl consists of two levels of pigmentation. The first
pattern consists of amorphous, fluorescent blotches, disrupted by
non-fluorescent tents. The second pattern consists of discontinuous, evenly
distanced, spiral lines. The spiral lines are a series of alterations of
fluorescent dots-dashes and non-fluorescent dashes. The second pattern, when
overlapping the non-fluorescent tent level, displays only the fluorescent
dots-dashes of the continuous spiral lines (Fig. 19).
Remarks
This species comprises only one specimen, partly
broken (Table 10). Its biconical morphology is unique in the Greek collection. It
could be compared with those studied by Davoli (1972) and named as ?Conus
clavatulus d’Orbigny, 1852 (MOD n°5569 bis and MOD n°5610).
These specimens have not been studied under UV light; therefore, we place them
within Conus (Lautoconus) sp. 5. The specimen (AMPG(IV) 3861) is
similar to several species of Conus described from the Paratethys,
discussed in Harzhauser & Landau (2016) as Leporiconus Iredale,
1930. This species differs from the Conus (Leporiconus) in
lacking tubercles on the early spire whorls. Also, the shell is smooth, except
for the faint spiral cords near the anterior part of the shell. For this
reason, we prefer placing it into Conus (Lautoconus).
The specimen has a morphology similar to Conus
mucronatolaevis var. permamillata Sacco, 1893 (Sacco
1893b: pl. 6 fig. 33). Harzhauser & Landau (2016: fig. 35j) noticed that
its colour pattern consists of a series of closely positioned lines of dots, a
pattern very different from the Cretan material.
Chelyconus spongiopictus Sacco,
1893 (Sacco 1893b: pl. 10 fig. 16) has a morphology of similar outline, but
lacks the subangulated shoulder of the studied species. The colour pattern of
irregular blotches and spiral lines of dots is similar to that of Conus (Stephanoconus)
cf. taurinensis Bellardi & Michelotti, 1841. They are easily
differentiated by the pyriform morphology of this specimen, with no tubercles
and a not so inflated shoulder.
Stratigraphic
range
?Tortonian
of Italy from Montegibbio (Davoli 1972) and Greece (Messara Basin, Crete).
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Fig. 18. Conus (Lautoconus) sp. 5 from the Tortonian of Filippi, Crete
(Greece) shown under natural (A1, A4, A7–A8) and
UV light. A. Specimen AMPG(IV) 3861, Filippi: notice the shallow subsutural flexure in
A8. Scale bars = 1 cm. |
Conus
dertogibbus (Sacco, 1893) mm. 23,6 x
11,9 Rethymno a
800 m. s.l.m. – Creta [AZFC N. 330-02] |
Bibliografia Consultata