New species of Early Eocene small to minute mollusks from the Crescent Formation, Black Hills, southwestern Washington

14 Pages·1994·7.4 MB·

THE VELIGER
© CMS, Inc., 1994
The Veliger 37(3):253-266 (July 1, 1994)
New
Species of Early Eocene Small to Minute
Mollusks from the Crescent Formation,
Black Hills, Southwestern Washington
by
RICHARD SQUIRES
L.
Department of Geological Sciences, California State University,
Northridge, California 91330, USA
AND
JAMES GOEDERT
L.
15207 84th Ave. Ct. NW, Gig Harbor, Washington 98329, and
Museum Associate, Section of Vertebrate Paleontology,
Natural History Museum of Los Angeles County, 900 Exposition Boulevard,
Los Angeles, California 90007, USA
Abstract. Seven new species of small to minute gastropods and one new species of a minute bivalve
are reported from the early Eocene upper part of the Crescent Formation in the Black Hills west of
Olympia, Washington. These species lived in a rocky intertidal environment where accumulation of
basalt flows caused shoaling of marine waters. Their shells were deposited as the matrix of coquina
that infilled cracks between individual eroded boulders of basalt, but the small size of the new species
prevented them from being broken during transport. Associated macrofossils indicate a middle early
Eocene age ("Capay Stage").
Description of these new species extends the geographic and chronologic range of each of the su-
praspecific taxa to which the species are assigned. The fissurellid Emarginula washingtoniana is the
first reported Cenozoic species of this genus from the Pacific coast of North America. The trochid
CalliovaricapacificaisonlythesecondknownspeciesofthisearlyEocenegenusandextendsitsgeographic
range from California into Washington. The skeneid Haplocochlias tnontis is the first positively known
fossil species ofHaplocochlias and the earliest known representative offamily Skeneidae, whose previous
geologic range was early Miocene to Recent. The neritidNerita (Theliostyla) olympia isthe first "Capay
Stage" species of this subgenus from the Pacific coast of North America. The rissoid Lapsigyrus cres-
centensis is the earliest record of this genus, whose previous geologic range was Pleistocene to Recent.
ThecolumbellidMitrella (M.) blackhillsensisistheearliest recordofthisgenus,whose previousgeologic
range was early Miocene to Recent. The ellobiid Ovatella (Myosotella) coneyi is the first record of a
marine pulmonate in the lower Tertiary of the Pacific coast of North America. The tellinid bivalve
Linearia {Linearia) louellasaulae is the first confirmed species of this genus from the Pacific coast of
North America and the youngest record ofthis genus, whose previous geologic range was Early to Late
Cretaceous.
Page 254 The Veliger, Vol. 37, No. 3
INTRODUCTION
Molluscan assemblages from the Eocene Crescent For-
mation in Washington have received little study. Nearly
all ofthe previous reports deal with the Crescent Bay area
along the north shore of the Olympic Peninsula (Figure
1). One of these reports is by Weaver & Palmer (1922),
who described, named, and illustrated five species of gas-
tropods and two species of bivalves. Recently, Squires et
al. (1992) did a detailed study of the macrofossils of the
upper Crescent Formation at Pulali Point in the eastern
Olympic Peninsula just west of Seattle (Figure 1), and
thisstudy spawnedtwoadditional articles (Squires, 1992a,
1993) on certain bivalves from the Pulali Pointarea. More
recently, Squires & Goedert (in press) have done a de-
tailed study ofthe macrofossils ofthe upper Crescent For-
mation in the Little River area in the southern Olympic
Peninsula (Figure 1).
The present study, which is a continuation of our in-
vestigation of the macrofossil faunas of the Crescent For-
mation in western Washington, differs from our previous
studies in that many ofthe fossils are small to minute (i.e.,
mm
less than 5 in longest dimension). Eocene small to
minute gastropods and bivalves from the Pacific coast of
North America are not well known. They easily become
an integral part of the cement that holds a rock together
and, in nearly every case, cannot be extracted for study.
Previous investigations that included minutemoUuskscon- Figure 1
cern a part of the fauna found in the upper Eocene part
of the Lincoln Creek Formation in the "Cries Ranch Index map to CSUN collecting localities, Crescent Formation,
Black Hills area, west of Olympia, Washington.
beds" insouthwestern Washington (Eflinger, 1938),afau-
na from middle Eocene rocks in the Vacaville, northern
California area (Palmer, 1923), and a part of the fauna
sfoouutnhd-ciennttrhaelmCiadldilfeortnoiaup(pAenrdeEroscoenne&THeajnonnaF,or19m2a5t)i.oTnhien Ncaolritthyrindugmeb;erLsAaCrMe:,CSNaUtNu,ralCalHiifsotronriya MStuatseeuUnmiveorfsiLtoys,
present study area in the Black Hills of southwestern Angeles County, Malacology Section; LACMIP, Natural
Washington hasamore diversegastropodassemblage than History Museum of Los Angeles County, Invertebrate
these other locales because, as will be discussed below, the Paleontology Section; UCMP, University of California
bsteuednyparreesaercvoendtanienasrlayrinocpklyacien.teLritniddableragss&emSbqluaigreesth(a1t99h0a)s Museum of Paleontology (Berkeley).
noted that rocky intertidal organisms are poorly repre- GEOLOGIC AND DEPOSITIONAL
sented in the pre-Pleistocene fossil record because they are SETTING
usually swept away and broken up by wave action. The
Black Hills assemblages, therefore, containgenerathatare The basement rock in the Olympic Peninsula of south-
very rare in the fossil record due totwo factors: their small western Washington is the upper Paleocene to lower mid-
size and their preference for a rocky intertidal habitat. dle Eocene Crescent Formation, which consists predomi-
The molluscan stages used in this report stem from nantlyofoceanictholeiitebasaltflows. Severalmodelshave
Clark & Vokes (1936), who proposed five mollusk-based been proposed for the origin of these flows. Most of the
provincial Eocene stages, namely, "Meganos," "Capay," early models, which are reviewed by Snavely (1987), en-
"Domengine,""Transition,"and"Tejon."Thestagenames visage accretion of seamounts, but in recent years, the
are in quotes because they are informal terms. Givens modelsfavorarift-basinenvironment(Babcocketal., 1992).
(1974) modified the use ofthe "Capay Stage," and it is in The upper third of the formation ranges from a deep-to-
this modified sense that the "Capay Stage" is used herein. shallow marine environment to one that is locally terres-
The classification system used for taxonomic categories trial. Interbeddedmarinesedimentaryrockslocallycontain
higherthanthefamilylevelgenerally followsthatofHasz- fossils, especially at places like Pulali Point and the Little
prunar (1988). Abbreviations used for catalog and/or lo- River area where the extrusion of the basalt flows caused
&
R. L. Squires L. Goedert, 1994 Page 255
J.
shoalingofthemarinewaters (Squiresetal., 1992; Squires 1990). The presence of the marine pulmonate Ovatella
& Goedert, in press). further confirms an intertidal, or even a supratidal envi-
About 15 km west of Olympia (Figure 1), in the Black ronment. Modern species ofOvatella are air breathers that
Hillsarea in theWashington Coast Range, thereisa > 600 can tolerate short submersion at the highest spring tides
m-thick sequence of basalt flows and breccias, with minor and are never out of the reach of salt and spray in the
interbeds of basaltic sandstone and siltstone that are cor- following environments: high tidal or supratidal, upper
related with the Crescent Formation in the Olympic Pen- shore of estuaries, or salt marshes and the fringes of salt
insula (Globerman et al., 1982). The Black Hills is one marshes (Morton, 1955). Also at CSUN loc. 1563, there
ofseveral large basement uplifts in the Washington Coast is a diverse assemblage of other mollusks that elsewhere
Range and is heavily forested with rock exposures gen- on the Pacific coast of North America are indicative of
erally limited to roadcuts and quarries. Macrofossils were shelflike depths where silty deposits accumulated. These
found at only two localities in the Crescent Formation in mollusks include the gastropods Turritella, Bittium, Pa-
the Black Hills. One of these is near Larch Mountain at chycrommium, Colwellia, and Conus, and the bivalves Ve-
CSUN loc. 1563, which is the same site that Pease & nericardia, Glyptoactis, and Corbula.
Hoover (1957) first noted, but their coordinates differ The extrusion of the basalts in the vicinity of CSUN
slightly. Theotherlocality is about 3.5 km tothe northeast loc. 1563 caused shoaling and the establishment ofa rocky
and near Rock Candy Mountain at CSUN loc. 1564 (Fig- shoreline community whereNerita, Arene, Barbatia,Emar-
ure 1). ginula, Haplocochlias, and Mitrella lived alongside colonial
At the Larch Mountain locality, there is a roadcut ex- corals and coralline algae. The pounding surf broke and
posure oflight-colored sedimentary rock interbedded with pulverizedmostofthelargermacro-invertebrates, butmany
basalt. Theexposure is 1 m thick andconsists ofan eroded of the small to minute gastropods escaped destruction. All
vesicular basalt with the cracks between individual sub- the shell material, as well as the muddy debris and clasts
angularboulders filledwith fossiliferoussedimentary rock. ofbasalt, weretransported a short distance seaward where
The exposure is capped by pillow basalt. At and near the they were deposited in cracks between individual boulders
bottom of the cracks is a black silty mudstone containing ofbasalt. These boulders were adjacent to where mollusks
pulverized shell hash with many small to minute gastro- like Turritella and Venericardia lived, and some of their
pods that are complete and well preserved. The silty mud- shells also were washed into the cracks between the boul-
stone is poorly indurated, and shellscan be removed intact. ders. The minute-shelled Lapsigyruscrescentensis and Li-
The newspecies described in this paper were found in this nearia (L.) louellasaulae, a tellinid, may have also lived
silty mudstone, and the specimens, which could easily be among the Turritella and Venericardia because modern
m
missed by acursory examination oftheoutcrop, are fragile Lapsigyrus live in shallow water (approximately 20
and easily broken ifcare is not taken in their removal from depth) in warm-water bays (Shasky, 1970; Keen, 1971),
the rock. Also in the silty mudstone are some scattered, and modern tellinids are nearshore to offshore burrowers
large (up to 2.5 cm) fragments of colonial corals, gastro- (Abbott & Dance, 1982). Continued extrusion of basalt
pods, and bivalves. The abundance ofshell hash is usually covered this habitat before encrusting organisms could at-
sogreat that it forms coquinas. Nearthe tops ofthe cracks, tach to the cobbles and boulders, and further protected the
there are smaller, angular basalt clasts, up to 5 cm across, deposit from erosion.
supported by white-to-gray muddy siltstoneand sandstone The sedimentary rocks at CSUN loc. 1563 can be as-
with pulverized shell hash containing some scattered large signed to the "Capay Stage" (middle lower Eocene) on
(upto3cm) disarticulated bivalvesandcolonial-coral frag- the basis ofthe presence of Turritella andersoni Dickerson,
ments. Locally, there are also patches of well-indurated, which is restricted to this stage elsewhere on the Pacific
white-to-gray muddy siltstone with a great abundance of coast of North America (Squires & Demetrion, 1992).
fragments of coralline algae. At the Rock Candy Mountain locality, a thin exposure
The macrofauna at CSUN loc. 1563 is a mixture of of sedimentary rock is in a roadcut and in a small nearby
rocky intertidal and shallow-subtidal taxa. There are many quarry. The lithologies are the same as those at CSUN
shells of the gastropods Nerita and Arene and the bivalve loc. 1563, except that there is less mudstone matrix, less
Barbatia. These taxa, plus Emarginula, Haplocochlias, and coralline-algal remains, and more large bivalves. There
Mitrella, as well as the abundant fragments of colonial are also fewer small to minute gastropods, and the only
corals and coralline algae, indicate a warm-water, rocky new species ofgastropod present in the silty mudstones at
intertidal environment. Modern Nerita, Arene, Barbatia, CSUN loc. 1564 is Emarginula washingtoniana.
and Mitrella are indicative of rocky shores in tropical wa- The environment of deposition and age ofthe sedimen-
ters, and modern Emarginula live on rocky bottoms, in- tary rocks at CSUN loc. 1564 are the same as for CSUN
tertidally to several hundred meters deep, usually in trop- loc. 1563, on the basis of identical lithologies and similar
ical waters (Keen, 1971; Abbott & Dance, 1982). Modern fossil content. Globerman et al. (1982:1153) also reported
Haplocochlias live intertidally to 10 m on hard substrates a shallow-water depth (< 50 m) for the rocks at CSUN
in tropical waters (Keen, 1971; Hickman & McLean, loc. 1564, on the basis of benthic foraminifera, and they
Page 256 The Veliger, Vol. 37, No. 3
also reported an early Eocene age (K/Ar age of 53.1 ±2 also has an encrusting polychaete worm shell attached to
m.y.) for the associated basalts. it near the apex (Figures 2-4).
The new species is similar to Emarginula mariae Coss-
SYSTEMATIC PALEONTOLOGY mann (Cossmann & Pissarro, 1910-1913:pl. 2, fig. 9-4)
from the upper Paleocene (Thanetian Stage) of the Paris
Class Gastropoda Cuvier, 1797 Basin, France. Emarginula washingtoniana differs in the
following features: shell taller, apex notas strongly curved
Subclass Prosobranchia Milne-Edwards, 1848 posteriorly, and concentric ribbing not as well developed.
Order Vetigastropoda Salvini-Plawen, 1980 In the position of its apex, E. washingtoniana is more
similar to European Cretaceous species than to Caribbean
Family Fissurellidae Fleming, 1822 Cretaceous species. The European species usually have an
Genus Emarginula Lamarck, 1801 apex that is situated well forward ofthe posterior margin,
whereasthe Caribbean specieshavean apexthatdistinctly
Type species: Emarginula conica Lamarck, 1801, by orig- overhangs the posterior margin (Sohl, 1992).
inal designation, Miocene through Recent, living in Fin- Cox& Keen(1960)reportedthegeologicrangeoiEmar-
landand coastsofGreat Britain totheAdriaticSea (Palm- ginula to be Jurassic to Recent. Haber (1932) listed 41
er, 1937). species from Jurassic rocks, and all are restricted to Eu-
rope. The species occur mainly in shallow-water carbon-
Emarginula washingtoniana ate-bank,orreef-associatedassemblages (Sohl, 1992). Sohl
&
Squires Goedert, sp. nov. (1992) listed 80 species from Cretaceous rocks, most re-
strictedtoEurope.Theyaremostcommoninenvironments
(Figures 2-5)
similartotheirJurassicoccurrence. OnlythreeCretaceous
Diagnosis: Atall Emarginula with apexnot strongly curved species have been described from the Western Hemisphere
posteriorly, moderately deep slit, and 16 primary radial (Sohl, 1992). Two are from the Caribbean region, and the
ribs. third is E. gabbi Stewart (1926:313, pi. 23, fig. 10 [= a
Description: Shell small, high conical, up to 4 mm high, replacement name for E. radiata Gabb, 1864:140, pi. 21,
withheightabouttwo-thirdsoflength.Apexsituatedabout figs. 102, 102a]) from Cretaceous strata in northern Cal-
ifornia. The new species differs from E. gabbi Stewart in
one-third the distance from posterior end, curved poste-
the following features: aperture ovate-circular rather than
riorly, with beaklike appearance. Anterior slope convex
elongate, steeper sides, posterior slope more concave, and
and steep; posterior slope concave. Anal slit situated at
fewer ribs (16 rather than 20).
anterior margin, narrov/ and moderately deep, measuring
mm The number of known early Tertiary species of Emar-
0b.a5ndcoindceiedpent(=w1i1thprearicseendtaroefasehxeltlenldeinnggthn)e.arAlryetaoaopficslailt gmiannulna&is Pfairsslaersrsot(ha1n91t0h-a1t9k1n3)owinllufsotrrattheedMoensloyzotiwco.PCaolseso--
area. Sculptureofabout 16 primary radial ribsoriginating
cene species and seven Eocene species ofEmarginula from
near apex. Interspaces between primary radial ribs with
the Paris Basin, France. Similarly, Gilbert (1962) listed
a single, moderately strong, secondary radial rib; rarely a
two Paleocene, six Eocene, andoneOligocenespecies from
single tertiary radial rib in interspace between a primary
rocks of Europe.
and a secondary radial rib. Radial sculpture crossed by Palmer & Brann (1966) listed only one named species
intermittently prominent growth rugae, especially near
and two unnamed species (based on internal molds) of
margin ofaperture andon posterior slope. Apertureovate-
Emarginula from middle to upper Eocene rocks of the
circular.
southeastern United States. The new species differs from
Dimensions of holotype: Length 4.5 mm, width 3 mm, theseEmarginula by beingmuch smallerandwithahigher
height 3 mm. shell.
Holotype: LACMIP 12279. Since the Oligocene, Emarginula has been represented
by a relatively low number of species. Today, the geo-
Type locality: CSUN loc. 1563, Larch Mountain area, graphic range is mostly in warm waters in Europe, the
Black Hills, southwestern Washington, 47°59'03"N, Mediterranean, Georgia (U.S.A.) to Brazil, the Philip-
123°8'12"W. pines, New Zealand, Chile, Galapagos Islands, Colombia,
Paratype: LACMIP 12280. and the Gulf of California (McLean, 1970; Abbott &
Dance, 1982).
Discussion: Five specimensofthe new specieswerefound. Emarginulawashingtoniana isthefirstCenozoicspecies
Except for the holotype, they are fragments. Four of the ofthisgenus to be reported from the Pacificcoast ofNorth
specimens are from CSUN loc. 1563, and one specimen America. Otherthan theCretaceous speciesE.gabbi Stew-
is from CSUN loc. 1564. The holotype has been slightly art, the genus was unknown in this area until the descrip-
crushed, and this crushing may have affected the area of tion ofa Recent species from the GulfofCalifornia (Shas-
the slit band, causing it to appear raised. The holotype ky, 1961). Only three other species of Recent Emarginula
&
R. L. Squires L. Goedert, 1994 Page 257
J.
are known from the eastern Pacific: two from Chile and resented by C. eocensis Yokes (1939:183, pi. 22, figs. 20,
UCMP
one from the Galapagos Islands and Colombia (McLean, 23, 25, 28) known only from loc. 1817 in Urruttia
1970). Canyon, central California. Squires (1988) reported that
Etymology: The species is named for the state of Wash- othfisthleocaLloidtyoisFoinrmtahtei"oCn.apTahyeStnaegwe"sCpeecrireossdSihfafelresMfermobmeCr.
ington.
eocensis in the following features: shorter spire, presence
Occurrence: "Capay Stage" (middlelowerEocene). Cres- of teeth on inner lip and denticles on outer lip, and nar-
centFormation, Larch MountainandRock Candy Moun- rowly umbilicate. The new species extends the geographic
tain, Washington (CSUN Iocs. 1563, 1564). range of Calliovanca into Washington.
Hickman & McLean (1990) included Calliovanca with-
Family Trochidae Rafinesque, 1815 in the chilodontine trochids, whose shell morphology is
Genus Calliovanca Yokes, 1939 distinguished by apertural thickening and denticulation, a
circular aperture produced by this apertural thickening,
Type species: Calliovanca eocensis Yokes, 1939, by orig- and reticulate or cancellate shell sculpture.
inal designation, early Eocene, central California.
Etymology: The species is named for the Pacific Ocean.
&
Calliovanca pacifica Squires Goedert, sp. nov. Occurrence: "CapayStage" (middlelowerEocene). Cres-
cent Formation, Larch Mountain, Washington (CSUN
(Figures 6-8)
loc. 1563).
Diagnosis: Moderately low-spired Calliovanca having teeth
on inner lip, denticles on outer lip, and narrow umbilicus.
mm Family Skeneidae Clark, 1851
Description: Shell moderately small, up to 12.5 in
height, turbiniform, thick, with four to five convex whorls Genus Haplocochlias Carpenter, 1864
showing moderate rate of expansion. Spire moderately Typespecies:Haplocochliascyclophoreus Carpenter, 1864,
high, body whorl large, whorls subtabulate anterior to
by original designation. Recent, western Mexico.
moderately impressed suture. Basal edge of body whorl
angulate. Penultimate whorl with five to six prominent Haplocochlias montis Squires & Goedert, sp. nov.
spiral ribs. Body whorl with approximately 14 spiral ribs;
three to four at periphery strongest, eight ribs on base of (Figures 9-11)
bodywhorlapproximatelyequaltotworibsnearestsuture. Diagnosis: AHaplocochliaswith finespiral ribbing, nearly
All spiral ribs crossed by prosocline axial ornament pro-
closed umbilicus, and denticles on outer and inner lips.
ducing reticulate (beaded to scaly) pattern. Outer shell
mm
layergenerally missing; inner layer nacreous and showing Description: Shell minute, up to 2.5 in height, tur-
spiral ribs but lacking axial ornament. Aperture slightly biniform, with three to four convex whorls, increasing
oblique, circular, outerlipreflected and stronglythickened rapidly in size. Spire low, body whorl globose with medial
with multiple (about 10) irregular denticles. Inner lip angulation. Suture distinct and impressed. Whorls with
calloused with a prominent tooth and two smaller teeth many closely spaced, fine spiral ribs, coarsening toward
anteriorly. Heavy rim of parietal callus continuous with base of body whorl. Aperture ovate, nearly continuous,
inner and outer lips. Narrow umbilicus, nearly filled by oblique. Outerlipslightlyreflected,prosocline,manysmall
columellar callosity. denticles, especially on anterior end. Inner lip flattened
Dimensions of holotype: Height 13.5 mm, width 12.5 anteriorly, with a low ridge near inner margin and par-
mm. alleling it; ridge terminating posteriorly with a protuber-
ance. Umbilicus nearly closed, slitlike.
Holotype: LACMIP 12281.
Dimensions ofholotype: Height 2.5 mm, width 2.5 mm.
Typelocality: CSUN loc. 1563, Larch Mountain, Wash- Holotype: LACMIP 12283.
ington, 47°59'03"N, 123''8'12"W.
Paratype: LACMIP 12282, CSUN loc. 1563. Type locality: CSUN loc. 1563, Larch Mountain, Wash-
ington, 47°59'03"N, 123°8'12"W.
DCiSscUuNssiloonc.:E1l5e6v3e.nMsopsectimoefnsthweersehelflosunadr,eancdhaallklyardeuferotmo Paratype: LACMIP 12284.
weatheringand/ordiagensis,andfallapartwhencollected. Discussion: Six specimens were found, and all are from
The holotype ofthe new species is a resting-stage individ- CSUN loc. 1563. The holotype is the largest specimen.
ual on the basis of the well-developed apertural charac- Most of the others are fragments.
teristics and the presence ofthe thickened outer lip (J. H. The new species resembles H. cyclophoreus Carpenter
McLean, personal communication). (1864; Keen, 1971:fig. 119; Hickman & McLean, 1990:
Previously, the genus Callwvarica was monotypic, rep- fig. 95B), the type species of the genus, but diff'ers in the
The Veliger, Vol. 37, No. 3
Page 258
&
R. L. Squires J. L. Goedert, 1994 Page 259
following features: thinner shell, stronger spiral ribbing, Order Neritoida Golikov & Starobogatov, 1975
and an aperture with denticles.
Family Neritidae Rafinesque, 1815
Haplocochlias previously was known with certainty only
as a Recent genus in the eastern Pacific and western At- Genus Nerita Linne, 1758
lantic (Hickman & McLean, 1990). The fossil record of
the family Skeneidae had been reported as early Miocene Typespecies:Neritapeloronta Linne, 1758, bysubsequent
to Recent, with some of the Eocene species assigned to designation (Montfort, 1810), Recent, Caribbean Sea.
Colloma Gray, 1850 by Cossmann (1918:pl. 1, figs. 42-
Subgenus Theliostyla Morch, 1852
47; pi. 2, figs. 1-3) possibly included in the family (Hick-
man & McLean, 1990). The new species has a much Type species: Nerita albicilla Linne, 1758, by subsequent
higher spire and a much narrower umbilicus than these designation (Kobelt, 1879), Recent, Indo-Pacific.
Eocene species, which are from the Paris Basin, France.
Cossman & Pissarro (1910-1913:pl. 4, figs. 33-1 to 33- Nerita {Theliostyla) olympia
4, 33-7 to 33-13; pi. 5, figs. 33-14 to 33-28) illustrated Squires & Goedert, sp. nov.
additional Eocene species ofColloma from the Paris Basin,
France. Of these, the new species is most like Colloma (Figures 12-17)
2{C2i-r2so4ch[i=luTs)urgbnogngoringennosniesns(iDse];shCaoysess,ma1n8n64-&18P6i6s;saprlr.o,601,9f1i0gs-. Diagnosis: A Theliostyla with a body whorl having seven
to eight noded carinae separated by interspaces as wide as
1913:pl. 4, fig. 33-13) frommiddle Eocene (Lutetian Stage)
the carinae.
strata. The new species diff^ers in the following features:
mm
finer spiral ribbingon body whorl angulation, an aperture Description: Shell small, up to 7 in height, broader
with denticles, and no beaded umbilical cord. than high, with rapidly expanding body whorl. Spire flat-
The new species is the first positively known fossil spe- tened,apexbarelyelevatedabovenearlyflatdorsalsurface.
cies ofHaplocochlias and the earliest known representative Dorsal surface with three to four noded spiral ribs (ex-
of family Skeneidae. cluding carina on shoulder) that become coarser and more
Etymology: The species name is from the Latin montis, eelveevnaltyedsptaocweadrdanodutuesrulailpl.yBeoqduyalw-hsotrrlenwgitthhnsoedvoesnetcoaeriignhate,
mountain, and refers to the position of the type locality of
becoming, in some specimens, increasingly coarse toward
this species.
base of body whorl. Interspaces approximately as wide as
Occurrence: "CapayStage" (middlelowerEocene). Cres- carinae and with or without a single, beaded spiral rib.
cent Formation, Larch Mountain, Washington (CSUN Axial riblets fine, crossing spiral carinae and interspaces.
loc. 1563). Aperturelarge, quadrate. Outerlipflared,groovedatbody-
Explanation of Figures 2 to 29
All specimens coated with ammonium chloride. Pictures taken type LACMIP 12288, operculum, xll. 16. Exterior view. 17.
by the senior author. All from CSUN loc. 1563. Interior view. Figures 18-20. Lapsigyrus crescentensis Squires
Figures 2-5. Emarginula washingtoniana Squires & Goedert, & Goedert, sp. nov., holotype LACMIP 12289, x8. Figure 18.
sp.nov.,holotypeLACMIP 12279. Figure2. Dorsalview, x9.2. Apertural view. Figure 19. Lateral view showing outer lip. Fig-
Figure 3. Anterior view, xlO. Figure 4. Left-lateral view, x8.7. ure 20. Abapertural view. Figures 21-23. Mitrella (Mitrella)
Figure 5. Right-lateral view, x7.6. Figures 6-8. Callovaricapa- blackhillsensis Squires & Goedert, sp. nov., holotype LACMIP
cifica Squires & Goedert, sp. nov., holotype LACMIP 12281. 12291. Figure21. Aperturalview, x7.8. Figure22. Lateralview
Figure 6. Apertural view, x2.4. Figure7. Umbilical view, x2.5. showing outer lip, x7.5. Figure 23. Abapertural view, x7.5.
Figure 8. Abapertural view, x2.8. Figures 9-11. Haplocochlias Figures 24-26. Ovatella (Myosotella) coneyi Squires & Goedert,
montis Squires & Goedert, sp. nov., holotype LACMIP 12283. sp. nov., holotype LACMIP 12292, xl4. Figure 24, Apertural
Figure 9. Apertural view, xl4.4. Figure 10. Umbilical view, view. Figure 25. Apertural view, rotated so as to reveal parietal
xl3. Figure 11. Abapertural view, xl3. Figures 12-17. Nerita plica. Figure 26. Abapertural view. Figures 27-29. Lmearia (Li-
(Theliostyla) olympia Squires & Goedert, sp. nov. Figure 12. nearia) louellasaulae Squires & Goedert, sp. nov. Figure 27.
Holotype LACMIP 12285, apertural view, xl6. Figure 13. Holotype LACMIP 12294, right valve, x10.3. Figure28. Para-
ParatypeLACMIP 12286,deckarea, x9.5. Figure 14. Paratype typeLACMIP 12295,right-valvehinge, x14.6. Figure29. Para-
LACMIP 12287, abapertural view, x4.6. Figure 15. Holotype type LACMIP 12296, left valve, xl2.3.
LACMIP 12285, abapertural view, xH. Figures 16-17. Para-
Page 260 The Veliger, Vol. 37, No. 3
whorl carinae. Inner lip with seven teeth. Two posterior- third, N. cowlitzensis Dickerson (1915:58-59, pi. 5, fig. 7a,
most teeth stronger than rest, with tooth next to poster- b) from the Cowlitz Formation in southwest Washington
iormost tooth strongest. Five small, subequal teeth medi- alsodifferssignificantly from thenewspeciesbypossessing
ally. Deckwithnumeroussmalltubercles,roundtoelongate, a body whorl with only minute sculpture.
arranged loosely in rows. Operculum calcareous with peg- Theliostyla probably originated in the Old World Teth-
like projection anteriorly and two small protuberances on yan paleobiotic province and immigrated to the Pacific
inner lip side; exteriorly with numerous small tubercles coast of North America during the early Eocene (Squires,
medially and posteriorly arranged loosely in rows; inte- 1992b).
riorly smooth. Etymology: The species is named for thecity ofOlympia,
Dimensions of holotype: Height 2 mm, width 3 mm. Washington, which is near the type locality of the new
Holotype: LACMIP 12285. species.
Type locality: CSUN loc. 1563, Larch Mountain, Wash- OcecncturFroernmcaet:io"nC,apLaayrcShtaMgoeu"n(tmaiidnd,leWlaoswheirnEgotcoenne)(.CCSreUsN-
ington, 47°59'03"N, 123°8'12"W.
loc. 1563).
Paratypes: LACMIP 12286 to 12288, all from CSUN
loc. 1563. Order Caenogastropoda Cox, 1960
Discussion: Thirty specimens of Nenta olympia were Family Rissoidae Gray, 1847
found, and all are from CSUN loc. 1563. Most of the Genus Lapsigyrus Berry, 1958
shells are chalky due to weathering and/or diagensis and
fall apart when removed from the brittle, silty mudstone Type species: Alvania contrerasi Jordan, 1936 (= Alaba
that encloses them. Ten specimens ofthe operculum were mutans Carpenter, 1857), by original designation. Pleis-
found, and they are also all from CSUN loc. 1563. tocene to Recent, west Mexico.
The new species is similar to Nenta (T.) heberti Szots
(1953:30, 141-142, pi. 2, figs. 3-5) from the Eocene of Lapsigyrus crescentensis Squires & Goedert, sp. nov.
Hungary. The new speciesdiffers by having fewercarinae
(Figures 18-20)
on the dorsal surface and on the body whorl and stronger
carinae on the body whorl. Szots (1953) did not assign his Diagnosis: A Lapsigyrus having an elongate shell with 16
species to the subgenus Theliostyla, but A', heberti has a to 17 spiral threads on the body whorl.
dentate outer lip, a granulate deck area, and a finely den- mm
tate inner lip. These features are listed by Keen & Cox Description: Shell minute, up to 5.5 in height, elon-
(1960) as being diagnostic of Theliostyla, hence Szots' spe- gate,ovatelyconic,havingapproximately sixconvexwhorls;
spire high. Nucleus of IVi whorls, smooth and conical.
cies belongs in Theliostyla.
There are only two other known species ofNerita {The- Spiral sculpture ofthin ribs with 10 to 11 on penultimate
liostyla) from the Pacific coast of North America. One is whorl and 16 to 17 on body whorl; five terminal ribs on
N. (T.) tnangulata Gabb (1869:170, pi. 28, figs. 52, 52a) base are about twice as strong as preceding ribs; channels
from middle lower Eocene ("Capay Stage") to upper Eo- between spiral ribs filled with innumerable minute axial
threads producing finely netted appearance within chan-
cene ("Tejon Stage") deposits from southern Californiato
southwestern Oregon. Squires (1992b) reviewed the con- nels only. Suture indistinct. Body whorl strongly descend-
ing, exposing anteriormost part of preceding whorl. Ap-
siderable range of morphologic variation of this species.
The new species differs by having more carinae on the erture large, D-shaped. Outer lip slightly opisthocline,
body whorl, more widely spaced carinae, and fewer or no with narrow varix.
ribs in the interspaces. The other known species is A'. (7".) Dimensions ofholotype: Height 5.5 mm, width 2.3 mm.
n. sp. (?) Woods & Saul (1986:649, figs. 6.13, 6.16, 6.17) Holotype: LACMIP 12289.
from the upper Paleocene? or lower Eocene? ("Capay
Stage") Sepultura Formation, Baja California Sur, Mex- Type locality: CSUN loc. 1563, Larch Mountain, Wash-
ico. The new species differs by having many fewer carinae ington, 47°59'03"N, 123°8'12"W.
onTthheerbeoadryewthhroerelkannodwnmosrpeeciweisdeoilyNesnptaacesd.l.cfarrionmaeE.ocene Paratype: LACMIP 12290, CSUN loc. 1563.
rocks along the Pacific coast of North America. Two, N. Discussion: Three specimens were found, and they are all
vjashingtomana Weaver & Palmer (1922:28-29, pi. 11, fig. from CSUN loc. 1563. The holotype is the largest speci-
4) from the upper middle Eocene Cowlitz Formation, men. The new species is remarkably similar to the living
southwest Washington, and TV. vokesi Durham (1944:156, Lapsigyrus myrioshirissa Shasky (1970:189, fig. 3) from
pi. 17, figs. 11, 12) from the upper Eocene of northwest west Mexico. The new species differs by having a more
Washington (Squires, 1992b), are quite different fromthe elongate shell with thicker and more widely spaced spiral
new speciesbecause they possess smooth body whorls. The ribs.
M
&
R. L. Squires J. L. Goedert, 1994 Page 261
Previously, the geologic range of genus Lapsigyrus was does notbelongtoMitrella s.s. because it has spiral ribbing
Pleistocene to Recent, with asingle Pleistocene speciesand over the entire teleoconch.
a few living species (Shasky, 1970; Keen, 1971). The geo- The new species is the earliest record of Mitrella s.s.
graphicrangeofthegenuswasfrom Magdalena Bay, Baja
California Sur, Mexico, to Costa Rica (Keen, 1971; Pon- Etymology: The species is named for the Black Hills,
Washington.
der, 1985). The new species extends the geologic range to
theearly Eocene and thegeographic rangeto Washington. Occurrence: "CapayStage" (middlelowerEocene). Cres-
cent Formation, Larch Mountain, Washington (CSUN
Etymology: The species is named for the Crescent For-
loc. 1563).
mation.
Occurrence: "CapayStage" (middlelowerEocene). Cres-
Subclass Pulmonata Milne-Edwards, 1848
cent Formation, Larch Mountain, Washington (CSUN
loc. 1563). Order Basommataophora Schmidt, 1855
Family Ellobiidae H. & A. Adams, 1855
Family Columbellidae Swainson, 1840 Genus Ouatella Bivona, 1832
Genus Mitrella Risso, 1826 Type species: Ovatellapunctata Bivona, 1832 [= Auricula
Type species: Mitrella flaminea Risso, 1826, by subse- finninii (Payraudeau, 1826)], by original designation. Re-
quent designation (Cox, 1927), Recent, Mediterranean cent, Mediterranean Sea.
Sea.
Subgenus Myosotella Monterosato, 1906
Subgenus Mitrella s.s. Type species: Auricula myosotis Draparnaud, 1801, by
original designation. Recent, Europe and both east and
Mitrella {Mitrella) blackhillsensis
Squires & Goedert, sp. nov. west coasts of the United States.
(Figures 21-23) Ovatella (Myosotella) coneyi
&
Diagnosis: A small Mitrella having a broad body whorl Squires Goedert, sp. nov.
and no teeth on inner lip. (Figures 24-26)
Description: Shell small, up to 5.5 mm in height, oval- Diagnosis: A narrow shelled Ouatella having subtabulate
fusiform. Suture distinct and impressed. Spire high with whorls, inner lip with two plicae, and anterior end of
flat-sided, smooth whorls. Body whorl somewhat broad, aperture pointed.
smooth. Neck and siphonal fasciole areas with many fine mm
Description: Shell minute, up to about 3 in height,
spiral ribs. Aperture ovate. Outer lip varicose with 13
narrowly ovate-fusiform, with approximately five convex
denticles on interior. Inner lip smooth. Anterior notch
whorls; spire elevated (approximately 36 percent of shell
narrow.
height). Suturedistinctandimpressed. Whorls smoothand
mm
Dimensions of holotype: Height 5.5 (incomplete); subtabulate near suture; middle of body whorl with very
width 3 mm. faint shoulder. Aperture ovate, anterior end pointed and
Holotype: LAC IP 12291. flattened. Inner lip with two plicae continuing deep inside
of aperture, anteriormost plica formed by turning of lip
Type locality: CSUN loc. 1563, Larch Mountain, Wash- within the aperture and twice as strong as the posterior-
ington, 47°59'03"N, 123°8'12"W. most plica; posteriormost plica in parietal area. Outer lip
Discussion: Only two specimens were found. The new broken off.
species is most similar to Mitrella richthojeni (Gabb, 1869: Dimensionsofholotype: Height2.75 mm,width 1.5 mm.
(10K,eepin. 2&,fBige.nt1s6o)nf,ro19m4P4l)ioacnednetebnetdastiivnelnyorftrhoemrnloCwaelirfoMrinoi-a Holotype: LACMIP 12292.
cene beds in southern California (Loel & Corey, 1932). Type locality: CSUN loc. 1563, Larch Mountain, Wash-
The new species differs in the following features: smaller ington, 47°59'03"N, 123°8'12"W.
sizeW,ebnrzoa(d1e9r41b)odryepwohrotreld,thaendgeonloogtiecetrhanogneionineMirtrliepl.la s.s. Paratype: LACMIP 12293, CSUN loc. 1563.
to be Miocene to Recent. Several late Cenozoic species are Discussion: Only two specimens were found and both are
known from the Pacific coast of North America. Mitrella from CSUN loc. 1563. The new species resembles some
tenmlineata (Clark, 1918:173, pi. 22, figs. 2, 3) has been variants of the living species 0. (M.) myosotis (Drapar-
reported from Oligocene beds in northern California, but naud, 1801), aMediterranean andeastern Atlanticspecies
Page 262 The Veliger, Vol. 37, No. 3
dispersed by man to the east and west coasts of North (Figures 27-29)
ANmeewriZcae,altahnedW(eCsltimoIn,di1e9s8,2)S.ouOtvahteAlflraic(aM,.A)usmytorsaoltaissias,haonwds Diagnosis: A minute, circular-ovateLineana having beaks
located posteriorly, radial ribbingweakoncenterofvalves,
considerable variation in the number ofteeth on the inner
and posterior slope with different curvature than rest of
and outer lips. The inner lip can have two to four teeth,
valve.
andtheouterlipcanhaveonetoothornone (Climo, 1982).
mm
The new species resembles those specimens of 0. (M.) Description: Valves minute, up to 3 high, thin and
myosotis that have two teeth on the inner lip and are with- fragile,circular-ovateinplan: beakssmall,slightlyanterior
out teeth on the outer lip (e.g., Climo, 1982:fig. lA; and of center; anterior end rounded, posterior end truncate.
LACM
afew specimensin lot46780 from Purfieet, Essex, Sculpture ofclosely spaced, thin concentric ribs crossed by
England). When compared to these particular examples, numerous fineradial ribs, excepton umbonal area. Radial
the new species differs in the following features: smaller ribbingweakoncenterofvalves. Intersectionsofconcentric
size, spire whorls less convex, suture more impressed, sub- andradialribsbeaded,strongestanteriorlyandposteriorly.
tabulate rather than non-tabulate whorls, base of body Posterodorsal slope with different curvature than rest of
whorl more constricted, and aperture more elongate an- valve and with approximately seven serrated ribs; rib on
teriorly. umbonal ridge coarsest. Right-valve hinge with two car-
Climo (1982) discussed the nomenclatural history ofthe dinals separated from each other by deep and narrow
familynamethat Ovatella should be assigned to, and Paul- socket, anterior cardinal slender and obliquely directed
son (1957) reviewedthecomplexhistoryofthegenusname downward;posteriorcardinalshorter,thicker,anddirected
Ovatella. Zilch (1959-1960) discussed synonyms. nearly vertically downward. Dorsal margin of right valve
Zilch (1959-1960) reported the geologic range of Ova- beveledtoserveaslaterals. Left-valvehingenotobservable.
taerlelaftroobme tPhaelePoacreinse tBoasRienc,enFtr.anTchee,eaanrldytTheertniaerwy ssppeecciieess Dimensions ofholotype: Height 3 mm, length 4 mm.
somewhat resembles Ovatella {Myosotella) depressa (De- Holotype: LACMIP 12294.
ssahraryoe,s,1911806-41-911836:6p:lp.l.585,8,fifgi.gs.25169--82)1;frCoomsslmoawenrn E&ocPeinse- Type locality: CSUN loc. 1563, Larch Mountain, Wash-
(Cuisian Stage) strata ofthe Paris Basin. The new species ington, 47°59'03"N, 123°8'12"W.
differs in the following features: smaller size, body whorl Paratypes: LACMIP 12295, 12296, both from CSUN
much less inflated near the suture, no spiral band anterior loc. 1563.
to suture, anterior end of aperture more pointed, no pa-
rietal callus, and no tendency to have more than one pa- Discussion: Eight specimens were found. Four are right
valves, two are left valves, and two are fragments. The
rietal plica.
Ovatella {Myosotella) coneyi is the first record of a ma- very delicate left valves are embedded in well-indurated
matrix, and the hinges could not be exposed.
rine pulmonate in the lower Tertiary of the Pacific coast
of North America. The new species is remarkably similar to L. (L.) me-
tastnata Conrad (1860:279,pi. 46,fig. 7;Stephenson, 1923:
Etymology: The new species is named in memory of 329, pi. 84, figs. 1-5; Afshar, 1969:58, pi. 24, figs. 12-15;
Charles Clifton Coney, who made valuable contributions Keen, 1969, figs. E109-lla, lib) from Upper Cretaceous
to the study of Recent freshwater bivalves and terrestrial strata of New Jersey, Maryland, North Carolina, Ten-
pulmonates. nessee, and Mississippi. The new species differs in the
Occurrence: "CapayStage" (middlelowerEocene). Cres- following features: much smaller size, less elongate shell,
cent Formation, Larch Mountain, Washington (CSUN beaks posteriorly located, posterior slope with a difTerent
curvature than rest ofvalve, and right-valve posterior car-
loc. 1563).
dinal thicker and not oblique.
Class Bivalvia Linne, 1758 Keen (1969) reported that thegeologicrangeoiLineana
s.s. is Early through Late Cretaceous, with species in Eu-
Order Veneroida H. & A. Adams, 1856 rope, North America, and Africa, but Stoliczka (1871:pl.
Family Tellinidae de Blainville, 1814 5, figs. 6, 7) reported Lineana from the Cretaceous of
southern India. TheNorthAmerican speciesareprimarily
Genus Linearia Conrad, 1860 from the Upper Cretaceous ofthe east coast ofthe United
StatesfromNewJerseytoTexas (Stephenson, 1923, 1941;
Typespecies:LineanametastriataConrad, 1860,bymono- Wade, 1926).
typy, Late Cretaceous, Alabama. Only a few species of Lineana are known from the
Pacific coast of North America. Lineana suciensis Whi-
Subgenus Lineana s.s.
teaves (1879:146-147, pi. 17, fig. 12) has the external
Linearia {Lineana) louellasaulae featuresofLineana, but the hinge characters are unknown
Squires & Goedert, sp. nov. and the only known specimen has been lost. This species