Pliocene and Pleistocene Fissurella Bruguiere, 1789 (Gastropoda : Fissurellidae) from southern Peru

2008·12.6 MB·English

by  Thomas J Devries

THE VELIGER
© CMS, Inc., 2007
TheVeliger 50(2):129-148 (June 20, 2008)
Pliocene and Pleistocene Fissurella Bruguiere, 1789 (Gastropoda:
Fissurellidae) from Southern Peru
THOMAS DeVRIES
J. 1
Burke Museum ofNatural History and Culture, University ofWashington, Seattle, WA 98195, USA
Abstract. Twelve species offossil Pliocene and Pleistocene keyhole limpets, Fissurella (Fissurella)* from southern
Peru are reported, including fournew species: Fissurella aranea, sp. nov., F. geoglypha, sp. nov., F. mcleani, sp. nov.,
and F. persica, sp. nov. These species and others from Peru and Chile are assigned to several morphological species
DNA
groups that are nearly congruent with clades defined by sequences (Olivares, 2006). Fissurella (Fissurella)
probably appeared in western South America during the late Miocene or soon thereafter, possibly from the western
Pacific Ocean or South Africa, with major clades in existence in Peru by the late early Pliocene. A late Pliocene
extinction ofsome fissurellid species and the subsequent addition ofnew and often larger species in Peru, Chile, and
Argentina has produced the modern diverse Fissurella (Fissure/la) fauna.
INTRODUCTION GEOLOGY
In a systematic treatment of South American keyhole TheCenozoicstratigraphyofsouthernPeruvianforearc
limpets assigned to Fissurella (Fissurella) Bruguiere, basins (Figure 1) was reviewed by DeVries (1998).
1789, McLean (1984a) lamented their limited fossil Pliocenemarinedeposits ofthePiscoand LaPlanchada
record in western South America, a record comprised formations include bioclastic sandstones and balanid
only of Philippic (1887) description of one Pliocene coquinas (Beaudet et al., 1976; Muizon & DeVries,
species from Chile, F. concolor Philippi, 1887, Herm's 1985), theremnantsoflittoraldepositsthatlappedonto
(1969) list ofPleistocene species and passingmention of pre-Eocene crystalline platforms or accumulated at the
Pliocene Fissurella from Chile, and McLean's own foot ofsteep cliffs ofthe Andes Cordillera.
figures ofPliocene F. concolor and Fissurella sp., cf F. Two outcrops of Fissurella-bearing Pliocene strata
crassa Lamarck, 1822, both also from Chile. warrant mention. Bioclastic debris ofthe La Planchada
This article augments that sparse record with an Formation crops out along sweeping curves of the
account ofFissurella in Pliocene and Pleistocene strata Panamerican Highway southeast of Chala where the
from southern Peru, including the extant F. maxima road descends to the strandline at Playa Huacllaco
Sowerby, 1835, F. limbata Sowerby, 1835, F. crassa, F. (Figure 2). The sediments accumulated in high-energy
latimarginata Sowerby, 1835, and the extinct F. foreshore and rocky intertidal environments in front of
concolor, which were found in a Pliocene outcrop near a ruggedcoastline ofigneous rock (DeVries, 2003). The
the coastal town ofChala, as were two new species, F. age ofthe Huacllaco beds is constrained by basal beds
persica, sp. nov., and F. aranea, sp. nov. A specimen of containing specimens of the muricid gastropods Con-
F. pulchra Sowerby, 1835, was found in a nearby cholepas nodosa Moricke, 1896, Acanthina triangularis
Pliocene deposit and a worn specimen of F. cumingi DeVries, 2003, and Herminespina mirabilis (Moricke,
Reeve, 1849, was discovered on a nearby middle 1896), which collectively indicate a late early to early
Pleistocene marine terrace. A Pliocene exposure above late Pliocene age (DeVries & Frassinetti, 2003), and by
the Rio Acari has yielded specimens ofF. concolor, F. the uppermost and oldest marine terrace, whose
persica, and the extant F. peruviana Lamarck, 1822. elevation and largely extant taxa, including Acanthina
Pliocene sandstones near Yauca produced single unicornis (Bruguiere, 1789) and Concholepas conchole-
gsepoegcliympehnas, osfp.thneove.xtTihncetnFo.rtmhcelerannmio,stsp.rencoovr.d,faonrdanFy. p(aMsui(zBornug&uieDreeV,rie17s8,9)1,98s5u;gDgeesVtrieas,la1te9s9t5,P2l0i0o0c,en2e00a3g)e.
South American Fissurella (Fissurella) is formally Four lithologic units were designated in the Huacllaco
reported, a Pliocene specimen of F. peruviana from section: Unit I (crossbedded balanid coquina, late early
northern Peru. Pliocene), Unit II (bioclastic sandstone and polychaete
reefs, late early or early late Pliocene), Unit III
(ferruginous cobble-bearing bioclastic sandstone, early
late Pliocene), and Unit IV (conglomerates and massive
1Mailing address: Box 13061, Burton, WA 98013 USA coquina beds, late late Pliocene).
Page 130 The Veliger, Vol. 50, No. 2
became the principal means for diagnosing species,
with greatest emphasis placed on radial sculpture.
Comparative fissurellid material came from the
Natural History Museum of Los Angeles County
- JCA If /PERU u s 3 (LACM) and the author's personal collection. Selected
citations are given for known species, emphasizing
those that post-date McLean (1984a).
Pisco
Basin Locality and sample descriptions are listed in the
NAzpPj^p appendix. Lengths (L), widths (W) and heights (H) are
i&k&M- measured in millimeters. Dimensions of broken spec-
imens are enclosed by parentheses. Some figured
mBaacsaicno*7$S^"#^.'g.J*£J2- <;j§fpcj*jl asrpeecismheonwsnarewictohatetdrawnistmhitatemdmolnigihutmtcohlorreivdeea;l otchoelrosr
,. patterns. Types and other numbered specimens are
deposited at the University of Washington's Burke
Camana Museum of Natural History and Culture in Seattle.
Basin
, Washington (UWBM), the Departamento de Paleon-
Figure 1. Location of forearc basins (Pisco, Sacaco, Ca- tologia de Vertebrados, Museo de Historia Natural,
mana) along the coast ofsouthern Peru. Universidad Nacional Mayor de San Marcos, in Lima,
Peru (MUSM INV) and in the case ofone specimen of
Fissurella peruviana, the Orton Geological Museum,
Thesecondnotable outcroplieseast ofChauvifia, set The Ohio State University (OSU).
back from the southeastern rim ofthe Rio Acari, where
small knobs of bedded strata constitute a condensed SYSTEMATIC PALEONTOLOGY
section of lower Pliocene to uppermost Pliocene
bioclastic sandstone and coquina (Figure 3). The Acari Family Fissurellidae Fleming, 1822
section has a basal lag of igneous boulders with
mollusks (Herminespina saskiae DeVries & Vermeij, Subfamily Fissurellinae Fleming, 1822
1997, Trophon carlosmartini DeVries, 2005, and Genus Fissurella Bruguiere, 1789
Xanthochorus ochuroma DeVries, 2005) that indicate
an early Pliocene age (DeVries & Vermeij, 1997; Subgenus Fissurella Bruguiere, 1789
DeVries, 2005a, 2005b). Beds five and six meters above
Type species (by monotypy) Patella nimbosa Linnaeus,
the boulders contain Concholepas kieneri Hupe, 1854,
1758. Recent, Caribbean.
and Anadara aff. A. chilensis (Philippi, 1887), as well as
the aforementioned muricids, collectively indicating a
somewhat later early Pliocene age (Muizon & DeVries, Discussion: McLean (1984a) included within Fissurella
m
1985; DeVries, 1995, 2000). Beds nine and 1 1 above (Fissurella) all fissurellid gastropods with an aragonitic
the boulders with Concholepas camerata DeVries, 2000, inner shell layer and calcitic outer shell layer, i.e., 13
Stramonita chocolata (Duclos, 1832), Xanthochorus South American taxa and two species from the
xuster DeVries, 2005, and Xanthochorus cassidiformis northern hemisphere, F. (Fissurella) volcano Reeve,
(Blainville, 1832), indicate a late Pliocene age (DeVries, 1849 (California), and F. (Fissurella) nimbosa (Lin-
2000, 2005a, 2007). An overwhelming preponderance naeus, 1758) (Caribbean Sea, Brazil). Stuber (1991)
ofextant molluscan taxa (e.g., Concholepasconcholepas supported the monophyly of Fissurella (Fissurella)
and Xanthochorus cassidiformis) in the uppermost sensu McLean (1984a), but Olivares (2006) did not,
coquinas, coinciding with the most elevated and oldest concluding instead that molecular data showed F.
marine terrace, indicate a latest Pliocene age (Muizon nimbosa to be more closely related to the eastern
&
DeVries, 1985). Atlantic F. (Cremides) schrammi Fischer, 1857, than
South American species ofFissurella (Fissure/la). Until
MATERIALS AND METHODS molecular data become available for F. volcano,
McLean's (1984a) definition of Fissurella (Fissurella)
Specimens of fossil Fissurella described in this study will beutilized here, with thecaveat that removingboth
were found by the author. Most fossil examples had F. volcano and F. nimbosa from the subgenus would
lost their aragonitic inner layer, so features of the result in a South American subset of Fissurella
external calcitic layer (shape, radial and concentric equivalent to Perez-Farfante's (1943) imperfectly diag-
sculpture, ray patterns, margin width and coloration) nosed Fissure/la (Ba/boaina).
T. J. DeVries, 2007 Page 131
UNIT
IV — DV 1032-1 (F latimarginata, F maxima)
.. ...«. •.'.«;•
DV
60 1628-6 (F. maxima)
t=£^=Ws=g=7. •'fer•
^y**£?^"'=?r<
.
50-
DV
1254-Bal 10 (F maxima, limbata)
s?^.^^.^?'-^"^f
DV
1254-Bal 8, -5 (F maxima, limbata)
DV
40- 1254-6, 14 (F concolor, limbata)
-F. concolor, crassa
DV
{— 1254-2 (i? limbata, persica)
30
DV
1254-Bal 5 (F aranea, persica)
20-
O'W
H &::::;.:':.:.
1(M
«?;...•••.....
•'•:•..*."^s*..''"--'.;;;--.
'..•iiiv.V.'.V:.--'^.".•/••'
*.'..*»>••.'..•••••
SCALE
meters Contourintervalis100m.
Cobbles Massivesandstone Coquina
Pebbly sandstone Bioclastic rippled sandstone 4', 'I Igneous basement
B'ffl Polychaetecolony Bioclastic crossbeddedsandstone
Figure 2. The Huacllaco lithologic section southeast of Chala, type locality ofFissurella aranea, sp. nov. The location map is
shown in inset.
A
HH
Page 132 The Veliger, Vol. 50, No. 2
UPPERMOST SandycoquinaofGlycymerisovataandDiscinisca
MARINE (brachiopod) vnihXanthochorusxuster, Concholepas
TERRACE 16-i concholepas
14 Sandy coquinaofGlycymerisovataandDiscinisca
(brachiopod) withXanthochorusxuster, Concholepas
w
concholepas
u
o
H 12
Oh Bioclastic coarse-grained sandstone with Glycymeris
ovata,Discinisca, venerids, Choromytilus,
Xanthochorusxuster, Concholepascamerata
10-
DV923-1E
Balanid coquinawith Concholepascamerata,
DV
923-1 Xanthochorusxuster, Chlamys sp.; basewith
i?peruviana roundedandangularbasementboulders
F.persica
Balanid coquinawith Concholepaskieneri,
Xanthochorusochuroma,Anadaracf.A. chilensis
Balanid coquinawith Concholepaskieneri,
w Herminespinasaskiae,Anadaracf.A. chilensis
u
Balanidcoquinawith Concholepas kieneri,
o Herminespinasaskiae,Xanthochorusochuroma,
Anadaracf.A. chilensis, Chlamysvidali,Piscoacritia
I— collapsa
Shelly gravel andangularboulderswith
Oh
Herminespinasaskiae,Xanthochorusochuroma,
Trophoncarlosmartini, Concholepasnodosa
74,°38i'3.flh"W L 74°38'100"VY
< DV " k'dl 15°36'20"S-
923-1 Uppermost
F persica marineterrace
F concolor
COVERED Crbyasstaelmleinnte —
VdV923 rocks
W
Bouldersandcobbles /.', j1 Polychaetecolony /
~
Massivesandstone Coquina 400m /l5o36'40"S-
fti-'
Hi Ophiomorphaburrows StALE
1 1 1
Figure 3. Lithologic section attheAcari sitesoutheast oftheRioAcari, typelocality (DV923) forFissurellapersica, sp. nov. The
locationmapisshownininset. Associatedmolluskslisted insectionarediscussedinDeVries(2000, 2003,2005a,2005b), DeVries&
Hess (2004), and DeVries & Vermeij (1997).
T. J. DeVries, 2007 Page 133
Fissurella {Fissurella) maxima Sowerby, 1835 Fissurella {Fissurella) concolor Philippi, 1887
Figures 4-10, 17, 18 Figures 11-16, 19
Fissurella maxima Sowerby, 1835a, p. 123. Fissurella concolor Philippi, 1887, p. 98, pi. 58, fig. 8.
Fissurella maxima Sowerby, 1835b, p. 3, fig. 18. Fissurella concolor Philippi, 1887. McLean, 1984a,
Fissurella maxima Sowerby, 1835. McLean, 1984a, p. 15, fig. 17.
p. 25, figs. 51-63.
Fissurella maxima Sowerby, 1835. Oliva & Castilla,
Diagnosis: Shell medium-sized, elongate, tapered. Ribs
1992, p. 92, fig. 4.
Fissurellamaxima Sowerby. Alamo & Valdivieso, 1997, strong, well differentiated by size, weakly corrugate or
smooth. Margin moderately wide, coarsely crenulated.
P. 7, fig. 12.
Fissurella maxima Sowerby, 1835. Guzman et al., 1998, Description: Shell length up to 60 mm, elongate,
p. 29, with figure.
strongly tapered anteriorly. Height low. Sides of shell
Fissurella maxima Sowerby, 1834 [sic]. Forcelli, 2000, elevated. Ribs prominent, sharply rounded, smooth to
p. 48, fig. 23.
slightly imbricate, differentiated into primary ribs,
some bifurcated, usually with three intervening second-
Diagnosis: Shell large. Ribs strong, wide, well differen- ary ribs, the medial being stronger; smaller specimens
tiated by size, corrugated to imbricate. Purplish rays with one intervening secondary rib between primary
broad. Margin coarsely crenulated. Rays penetrate ribs. Margin moderately wide, crenulated by ribs. Rays
entire calcitic layer. narrow, purplish, generally coinciding with primary
ribs; anterior rays weak or absent. Aragonitic inner
Discussion: Small specimens with characters of Fissur- layer missing. Foramen anterior to center, shape
ella maxima, including coloration, were found in unknown.
bioclastic sandstones in theupperpart oftheHuacllaco
section (Figure 2) and assigned a late Pliocene age Discussion: Fissurella concolor was first described from
based on the presence of associated molluscan taxa Pliocene beds near Mejillones, Chile by Philippi (1887)
[Prisogaster valenciai DeVries, 2006, Acanthina unicor- and figured again by McLean (1984a). Peruvian
nis, Chorus transitional between C. giganteus (Lesson, specimens, like those from Chile, are elongate and
1830) and C. grandis (Philippi, 1887), Concholepas have ribs that are more sharply raised and less
camerata, Xanthochorus xuster (DeVries 1997, 2000, imbricate than those on specimens ofF. maxima. The
2003, 2005a, 2006)]. oldest example from Peru came from the lowest
Two Peruvian specimens of Fissurella maxima boulder bed ofthe Acari locality (DV 923-la) together
exhibit oval external scars from the epibiotic limpet, with F. persica, sp. nov., and mollusks indicating an
Scurria variabilis (Sowerby, 1839) [= Scurriaparasitica early Pliocene age [Acanthina triangularis DeVries,
(Orbigny, 1841); seeEspozet al., 2004] (Figure 8). Such 2003, Concholepas nodosa, C. kieneri, and Hermine-
scars are most often found on Recent specimens of F. spina saskiae (DeVries, 1995, 2000, 2003; DeVries &
crassa and F. limbata (Figures 22, 35). Vermeij, 1997)]. Other specimens were found in the
Material: MUSM INV 164, DV 401-1, Recent, lowest cobble-rich bioclastic sandstone in the Huacl-
L 44.4, W 30.9, H 10.1; MUSM INV 165, DV 1032- laco section (DV 1254-14); associated mollusks
91,843la7t,eLoPlmiaosc,enRe,eceLnt,37L.68,7.7W, W275.95.,4,HH 272..70;; UUWWBBMM u(nAiccaonrtnhisi;naCotrnacnhsoilteiopnaaslcbaemtewreaetan;A.Xatnrtihaoncguhloarruiss axunsdteAr.)
98438, Lomas, L 75.9, W 48.7, H 17.5; UWBM indicate an early late Pliocene age. Higher in the
98439, Lomas, L 55.3, W 36.9, H 13.2; UWBM Huacllaco section the only strongly ribbed Fissurella
98440, Lomas, L 51.6, W 31.7, H 10.6; UWBM specimens are referable to F. maxima.
9PU9U219l884.iWW4413o488,cBB1-3e1,,nMM,HeDD,lVa99V1tL880e44.14461P14;2336l1,,7.i832oU-,-cDD11eW,W,VVneBL,R11Me1(3L60c17.2e2428.n3,9--6t28)16.,.H4,,64,L4lL4,aW.t56e6;05D.2.P31UV7l,.,i5Wo,WWc1Be2Hn5Me344,525-...B9838La;,8,l4l4U8HHO32.,W,511,B34lD..aWM77tV;;e MPPH2MH8llauu.iiUtaa0ooecc,SccrlleeillWMnnaaaeelcc,,:ooI1,,6LNL.Me4Vla,U3ar(5tlH1S1.ey179.3M,1l3,P)a.l3,WtiD;eIoVcPWNUe2lVn2iWe.1o1,29cB,.51e174nM,L1-eH,1,49H4,L78D7.4.0Ve(962;a2,3.6r0,.lM;12Wy)0DU,3UlV2aSW-2tW29eM9,.B211P3.6lMe-I.ial9oNHr,aclV,e9Hyn8ee14a1,l056r7a..42lt98L,,y;e
Occurrence: Late Pliocene: southern Peru. Pleistocene: UWBM 98465, DV 1032-2, L 24.5, W 14.5, H 5.2
central Chile. Recent: north-central Peru to central UWBM 98466, DV 1032-2, L 19.6, W 16.9, H (5.1)
Chile. UWBM 98467, DV 1254-6, late Pliocene, L 19.3, W
Page 134 The Veliger, Vol. 50, No. 2
FFiigguurrees4.4-10U,WB17M, 1988.4F4i3s,suDreVlla16(2F8i-ss6u.reLlalta)emPlaixoicemnae.STorwaenrsbmyi,tt1e8d35.light showing rays. Length is 43.5 mm.
UWBM
FFFiiiggguuurrreee 567... UUWWBBMM 999888444444331.., DVDeoVnrtsra1al3l72vv-ii1ee.ww.,Reacreangto.niTtriacnisnmnietrteldayelrighmtissshinogw.ing rays. Length is 60.3 mm.
T. J. DeVries, 2007 Page 135
11.5, H 4.1; UWBM 98468, DV 1254-14, L 29.6, W Occurrence: Late early Pliocene to early late Pliocene:
18.4, H 3.9; UWBM 98469, DV 1254-14, L (37.9). southern Peru.
Occurrence: Early to early late Pliocene: southern Peru. Fissurella {Fissurella) limbata Sowerby, 1835
Pliocene: north-central Chile.
Figures 22-33
Fissurella {Fissurella) aranea, sp. nov.
Fissurella limbata Sowerby, 1835a, p. 123.
Figures 20, 21, 34 Fissurella limbata Sowerby, 1835b, p. 3, figs. 42, 66, 74.
Fissurella limbata Sowerby, 1835. McLean, 1984a,
p. 55, figs. 212-224.
Diagnosis: Shell small, elongate-quadrate. Height low. Fissurella limbata Sowerby, 1835. Oliva & Castilla,
Ribs sharply defined, alternating primary and second-
1992, p. 7, fig. 10.
ary. Margin wide. Fissurella limbata Sowerby. Alamo & Valdivieso, 1997,
mm p. 93, fig. 10.
Description: Shell small, less than 30 long, Fissurella limbata Sowerby, 1835. Guzman et al., 1998,
elongate-quadrate, slightly tapered anteriorly. Height
p. 28, with figure.
low. Ends slightly raised. Sculpture of well defined,
Fissurella limbata Sowerby, 1835. Forcelli, 2000, p. 49,
closely spaced, narrow ribs, alternatingly primary and
fig. 25.
secondary; moderately imbricate at intersections with
strong growth lines. No coloring preserved. Margin
wide, irregularly scalloped. Foramen probably slightly Diagnosis: Shell medium-sized. Ribs broad, subdued,
anterior to center. some with weak secondary ribs; ribs often obsolete
towards foramen. Margin wide. Calcitic outer layer
Discussion: Specimens of Fissurella aranea differ from with translucent veneer.
contemporaneous small specimens of F. persica, sp.
nov., by being more quadrate and having ribs that Discussion: Modern specimens of Fissurella limbata
alternate regularly in size, in contrast with fine equally have ribs that are less well defined than those of F.
sizedribs on specimensofF. persica. Ribs on specimens maxima. Such specimens wereencountered in bioclastic
ofF. concolor and F. maxima are coarser and alternate sandstones in the upper half of the Huacllaco section
near Chala (DV 1254-14), together with specimens of
less regularly.
F. concolor. One specimen (Figure 27) has a nearly full
Etymology: Latin noun 'aranea,' meaning 'spider net,' suite ofprimary, secondary, and tertiary ribs extending
referring to the intersecting ribs and concentric growth to the foramen, such as is seen on specimens of F.
lines on this species. maxima, although the ribs are subdued and lack the
imbricate texture ofthe latter species. Rays are seen to
Type Locality: DV 1254, section along Panamerican penetrate the entire calcitic outer layer, but perhaps
Highway above Playa Huacllaco, 27 m in measured only because the purple color ofthe flattened margin is
section (see Appendix). faded.
Associatedmollusks indicatea late Pliocene age. Not
UWBM DV
Material: 98479, 1254-Bal5, holotype, late one Pliocene specimen exhibited the external scarofthe
eDaVrly9P2l3i-olcee,nee;arLly27l.a4t,eWPli1o6c.e7n,eH, L(4.(9)1;7.U9),WBWM139.824,80H, espeiebniootnicmloimdpeert,n SscpuercriimaevnasriaobfilFi.s,lwihmibcathais(Fciogmurmeosn2l2y,
(2.7). 29).
FFiigguurree 98.. MMUUSSMM IINNVV 116655,, DveVntr1a0l32v-i1e.w.Late Pliocene. Dorsal view; arrow marks scar from Scurria limpet. Length is 37.6 mm.
Figure 10. UUWWBBMM 98440, Lomas. Recent. Dorsal view. Length is 51.6 mm.
Figure 17. 98443, lateral view, anterior to right.
UWBM
Figure 18. 98441. lateral view, anterior to right.
Figures 11-16, 19. Fissurella (Fissurella) concolor Philippi, 1887.
Figure 11. UWBM 98464, Huacllaco. Early late Pliocene. Dorsal view. Length is 47.9 mm.
Figure 12. MUSM INV 171, DV 1032-2. Late early Pliocene. Dorsal view. Length is 35.9 mm.
Figure 13. MUSM INV 171, transmitted light.
FFiigguurree 1154.. UMUUWWSBBMMMI98N4V65,173D,VDV103122-524.-1E4a.rlEyarllatyelPaltieocPelnieo.cenDeo.rsDaolrsvailewv.ieLwe.ngLtehngitsh24i.s528m.m0.mm.
Figure 16. 98464, ventral view.
UWBM
Figure 19. 98464, lateral view, anterior to right.
Pase 136 The Veliger, Vol. 50, No. 2
Figures20, 21, 34. Fissurella (Fissurella)aranea, sp. nov. UWBM 98479, DV 1254-Bal5. Holotype. LateearlyPliocene. Length is
27.4 mm.
Figure 20. Dorsal view.
Figure 21. Ventral view.
Figure 34. Lateral view, anterior to right.
Figures 22-33. Fissurella (Fissurella) iimbata Sowerby, 1835.
Figure 22. MUSM INV 167, DV 810-1. Holocene. Dorsal view. Length is 60.8 mm. Arrow marks scar from Scurria limpet.
Figure 23. MUSM INV 167, ventral view.
FFiigguurree 2245.. MMUUSSMM IINNVV 117700,, vHeunctarlallacvoi.ewE.arly late Pliocene. Dorsal view. Length is 37.6 mm.
T. J. DeVries, 2007 Page 137
Material: MUSM INV 163, DV 1372-1, Recent, L63.4, Discussion: Specimens of Fissurella crassa are more
W 43.7, H 15.3; MUSM INV 167, DV 810-1, elongate and less tapered than those ofF. limbata and
Holocene, L 60.8, W 43.6, H 18.7; MUSM INV 168, havenearlyobsoleteribs. A fragment ofFissurellafrom
DV 1254-5, late Pliocene, L 62.8, W 42.1, H 17.0; the lower halfofthe Huacllaco section (Figure 37) has
MUSM INV 169, DV 1254-14, early late Pliocene, L the same uniquely scalloped, fimbriate, upturned
(28.5); MUSM INV 170, lowest HuaWcllaco cobbles, margin as specimens of extant F. crassa and so is
PUU33UU370l7..iWWWW51om,,cBBBB,eHnMMMMHee,a(9r99198Ll858184y)44145;55.3523564l3,U;.a,,,t4LWe,DDoULBWmVPVoWalMmisBo2a18,c42s1M9.e50R,84n4-e,4e-1c,56,Le96H.n8,LLt4l4,86aD8.0t7.23LeV,2;87.,.5P26U0l1,,D.i2WW4oV5W,c4Be-Wn13Me44132,9.,234.653.89,.L4L9,87-,4,1H456H0H231H,..,96111,,821Dl6...a.WW899Vt5;;;;e RrMRL6621eaee..ftcc481eeee2,,rrnn.ritt6WeaW,,,dl:LLW3t9o3.65M6632t.2,..Uh3436i,.,H,sS1,WWsHM1pH5e.c334Ii151;e3.9N.s..91U6.3,V,;;WHHU1UB6116WW41M,..B7B3;;D9MM8UUV4WW591988BB,814045MMH-401u7,,a,99c88DlH44DloV44alV89co,,o8c1.LLe10noo3-3e7mm192,,aa-mss1LL,,,,
11111233327775522244-----11111,,,44,,LLLLL(33233862.64..6..99,66,),,,WWWWW222253131..6..99.99,,8,,,HHHHH98867.....09720;;;;; UUUUUWWWWWBBBBBMMMMM 9999988888444445565789278,,,,, DDDDDVVVVV PCeOhalciriclloueycr.erlneaetn:eceCP:hliilEoeca.ernlRey,eclLeantte(:19P.ln7io)or.ctehn-ec:entsroaulthPeerrnuPteoruC.hiLlaote.e
1254-2, early late Pliocene, L (27.7). Fissurella (Fissurella) peruviana Lamarck, 1822
Figures 38-42
Occurrence: Late Pliocene: southern Peru. Recent:
north-central Peru to Chiloe, Chile. Fissurellaperuviana Lamarck, 1822, p. 15.
Fissurella peruviana Lamarck, 1822. McLean, 1984a,
Fissurella (Fissure/la) crassa Lamarck, 1822 p. 21, figs. 31-50.
Fissurella peruviana Lamarck, 1822. Alamo & Valdi-
Figures 35-37
vieso, 1997, p. 7, fig. 13.
Fissurella crassa Lamarck, 1822, 6(2), p. 11. Fissurella peruviana Lamarck, 1822. Guzman et al.,
Fissurella crassa Lamarck, 1822. Sowerby, 1835b, p. 1, 1998, p. 29, with figure.
Fissurella peruviana Lamarck, 1822. Forcelli. 2000.
figs. 9, 11.
Fissurella crassa Lamarck, 1822. McLean, 1984a, p. 58, p. 48, fig. 22.
figs. 225-237.
Fissurella crassaLamarck, 1822. Oliva&Castilla, 1992, Diagnosis: Shell small, profile high. Fine primary and
p. 92, fig. 5. secondary ribs. Color usually charcoal gray; rays
Fissurella crassa Lamarck. Alamo & Valdivieso, 1997, obscured. Margin narrow. Foramen small, oval.
p. 6, fig. 11.
Fissurella crassa Lamarck, 1822. Guzman et al., 1998, Discussion: Specimenswith thehighconic shell and fine
ribs ofFissurellaperuvianawerefound in a coquinabed
p. 27, with figure.
nine meters above the valley floor ofthe Acari outcrop
Fissurella crassa Lamarck, 1822. Forcelli, 200, p. 46,
(Figure 3). Associatedmollusks(Concholepascamerata,
fig. 13.
Xanthochorus xuster, Stramonita chocolata) indicate a
late Pliocene age (DeVries, 2000, 2005a, 2007).
Diagnosis: Shell medium-sized to large, elongate, with A specimen (OSU 38157) assigned herein to Fissur-
upturned ends and margins; margin with fimbriate ella peruviana was found in the gravel-rich
edge. Ribs and rays poorly developed. Foramen cross-bedded sandstones ofthe basal Taime Formation
elongate. in northern Peru (DV 239-11; DeVries, 1986, 1988).
FFFFFiiiiiggggguuuuurrrrreeeee 2222378690 UUUUUUWWWWWWBBBBBBMMMMMM 9999988888444446566507126,,,,, DDDDDVVVVV 11111322227555524444-----11111.4440....ReLDDEcaaooertrrnlesstyaa.PllllaDivvtooiiecreeeswwPn..laeil.oLLceevDeinnoneggrewtt.s.hhaDlLoiiessrvnis33gea46tw..lh.66vLimmiseemmwn3...6g.tL9hemnismgt.3h6.Ai4rsmr4o2m.w.6mmamr.ks scar from Scurria limpet.
Figure 31 98460, transmitted light showing rays.
UWBM
Figure 32 98461, lateral view, anterior is to right.
UWBM
Figure 33 98462, lateral view, anterior is to left.
Page 138 The Veliger, Vol. 50, No. 2
Figures 35-37. Fissurella (Fissurella) crassa Lamarck, 1822.
Figure 35. MUSM INV 166, DV 810-1. Holocene. Dorsal view. Length is 61.1 mm. Arrow marks scar from Scwria limpet.
Figure 36. MUSM INV 166, ventral view.
Figure 37. UWBM 98451, Huacllaco. Early late Pliocene. Dorsal view offragment. Length is 19.7 mm.
Figures 38^-2. Fissurella (Fissurella)peruviana Lamarck, 1822.