An aberrant sinistral Conus (Neogastropoda: Conidae) from the Miocene of Florida, USA

2009·1.3 MB·English

by  Jonathan R Hendricks

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THE NAUTILUS 123(4):317-318, 2009 Page 317
Research Note
All aberrant sinistral ConuH Hendricks (2()09b) noted that all sinistral individuals
(Neogastropoda: Conidae) from of othenvise dextral extant taxa wath knowm develop-
the Mioeene of Florida, USA mental modes belong to species with lecithotrophic lar-
\’al development. He also show^ed that this wars the case
for C. adversarins, andwas likely important to the initial
origin and establishment of that species. One of us
(|RH) obseiwed the protocouchs (Figure 3) ol five spec-
INTRODUCTION
imens of C. vegrandis using a FEI Quanta 200 scanning
Nearly all members oI the Inperdiverse genus Conus electron microscope at San Jose State University and,
from the resulting images, measured the diameter of
Rpically exhibit dextrah or right-1landed, shell coiling.
each protoconch, as w'ell as its numlier of w'hoiTs
Sinistral, or left-handed, shell coiling is a species-level
characteristic —of an extinct taxon Conns adversarUts a(ncodunLuttezd,u1s9i(n8g0,tahendmeTtnhrosdcohloagnidesGrdeeisfcerniedbeerd,in20J0a1b,lobnostkhi
Conrad, IS40 From the southeastern United States
ol wdiich gave similar results). On a\'erage, protocouchs ol
(see Hendricks 2009a, b), but sinistral coiling is other- mm
wise knowai Irom lewder than 30 indixidnals from seven C. vegrandis had diameters of about 0.76 (range
of about 0.73 to 0.(82 mm) and about 1.9 wdiorls (range
extant, tv'^rically dextral species (Ilemlricks, 2009b).
about 1.7to 2.1 whorls). These dataw^erethen considered
Civen tlie tremendous interest and energythat has been
in the conte.xt of Shutos (1974) model for predicting
put into the collection of cone shells overthe last several
developmental mode based on protoconch diameter and
centuries, as well as the remarkable diversit)' ol tlie
number of whorls, wdrich has been previously applied to
genus (over 1,500 fossil and extant species; Rockel
Conns by Kohn and Perron (1994) and Hendricks
et ak, 1995), these small numbers ot coufirmed reverse-
coiled Conns are remarkable. Here w'e present the first (2009b). All live specimens fall wdthin the lecithotrophic
portion of Shutos (1974) model (see Hendricks, 2009b,
record of an aberrant sinistral Conns fossil from an
extinct species and briefly discuss its significance. lig. 2), suggestingthat C. vegrandis had that developmen-
tal mode. Thus, the association between sinistral shell
coiling and lecithotrophic development also appears to
hold true forC. vegrandis.
MATERIALS, METHODS, RESULTS, AND Grande and Patel (2009) recently show^ed that the
DISCUSSION genes nodcd and P/Y.v, wRich relate to left-right mor-
— phological asymmetries in deuterostoines, are also
The sinistral Conus fossil (Eigure 1) UF 137S55, Flor- present in ga,stropods (lophotrochozoaus), and their po-
ida Museum—ofNatural Ili.stoiy, Division ofInvertebrate sition of expression in tlie developing embmi corre-
Paleontology was collected from the low'er Aliocene .sponds to shell coiling direction. Nevertheless, the
Chipola Formation (~18 Ala; Biyant et ah, 1992; Jones single maternal effects locus (see Uesliima and Asami,
et ak, 1993) at Tenmile Creek, Calhoun Countx', Florida, 2003; Schilthuizen and Davison, 2005; Davison et ak,
USA (UF locality CA020). Specimen UF 137(S55 is 2009) responsible for chiraliU in gastropods remains
broken and abraded, preventingus from making a defin- undiscovered. The discoveiy of specimen UF 137855
itive identification, but several features suggest that it is provides phenotvpic exidence for the first time that the
probably a specimen of the tx'i'iically dextral species sinistral allele w'as present in Co))ns by ~18 Ma, offer-
Cnmns vegrandis Hoerle, 1976 (see Hoerle, 1976,table 1, ing a small amount of insight into the genetic makeup
for a listing of characters that separate C. vegrandis of this extinct species.
Irom co-occurring Chipola species). These features in-
clude: spire and body w'horl outlines that are slightly
sigmoid in profile; the presence of raised spiral coixls
ACKNOWLEDGMENTS
(jn the anterior half of the body whorl; and the thin,
nriodtgeed-fboyrHmoinegrlcear(i1n9a76o)nitnhheesrhooruilgdienarlodfestchreipbtoidoyn owlTitohrel WethankS. Roberts (FloiidaMnseumol Natural Histon)
species (this feature is not present in C. advcrsaritis and forassistancewithdigitalphotography, J. Nimori (San Jose
negates the possibilitythat UF 137(855 is an individual of State UniversitX') for assistance with scanning electron
that younger Plio-Pleistocene species). The apex of UF microscopy, and A.J. Kohn and H.G. Lee for kielplnl
137855 is eroded, preventing ns from characterizing its commentsthatimprovedtlie manuscnpt. |RH's contribu-
protoconch and early postnnclear whorls. A paratxpe tions to this research w'ere supported by San Jose State
(UF 171658) of C. vcgnnidis from tlie same locality as University. This is University ol Florida Contribution to
UF 137855 is shown in Figure 2. Paleobiologx'625.
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Page 3IS THE NAUTILUS, Vol. 123, No. 4
Hendricks, J.R. 2009a (2008). The genus Conns (Mollnsca:
Neogastropoda) in the Plio-Pleistocene ofthe southeast-
ern United States. Bulletins of American Paleontology
375, 178 pp.
Hendricks, J.R. 2009b. Sinistral snail shells in the sea: devel-
opmental causes andconsecpiences. Lethaia42: 5.5-66.
Hoerie, S.E. 1976. The genus Conns (Alollusca; Castropoda)
from the Alum Bhdf Croup of northwestern Florida.
Tulane Studies in Ceologyand Paleontology 12: 1-31.
Jablonski, D. and R.A. Lutz. 1980. Molhiscan lan'al shell
moiphology: ecological and paleontological applications.
In: Rhoads, D.C. and R.A. Lutz (eds.^ Skeletal Crowth
of Aquatic Organisms. Plenum Press, New York, pp.
323-377.
Jones, D.S., P.A. Mueller, D.A. Hodell, and L.A. Stanley.
1993. ®'Sr/^'’Sr geochronology ofOligocene and Miocene
marine strata in Florida. In; Znllo, V.A., W.B. Harris, T.
M. Scott, and R.W. Portell (eds.) The Neogene ofFlorida
and adjacent regions. Proceedings of the third Bald
Head Island Conference on coastal plains
geology. Florida Ceological Society Special Publication
37, pp. 1.5-26,
Kohn, A. and F.E. Perron. 1994. Life Historyand Biogeogra-
J.
phy: Patterns in Conns. Clarendon Press, Oxford, 106 pp.
Rockel, D., W. Korn, and A.J. Kohn, 1995. Manual of the
Living Conidae, Volume L Indo-Pacific Region. Verlag
Christa Hemmen, Wiesbaden, .517pp.
Schilthnizen, M. and A. Davison. 2005. The convoluted evolu-
tion ofsnail chiralit)'. Naturwissenschaften 92: 504-515.
Shnto, T. 1974. Lanai ecology ofprosobranch gastropods and
its bearing on biogeography and paleontology. Lethaia 7:
239-256.
Figures 1-3. Specimens ol Conus vegrandis Hoerie, 1976. Tursch, B. and D. Creifeneder. 2001. Oliva Shells: The Cenus
1. UF 13785.5, sinistra! specimen ofConns cf. vegrandis- shell Oliva and the Species Problem. Linlormatore Piceno,
length = 12.6 mm. 2. UF 171658, paraU'pe, t\']3ical dextral Ancona, 570 pp.
specimen; shell length = 11.8 mm. Both specimens are Irom Ueshima, R, and T. Asami. 2003. Single-gene speciation by
the lower Miocene Chipola Formation of Tenmile Creek, Cal- left-right reversal. Nature425: 679-679.
houn Count)-, Florida, USA (UF locality CA020), Scale bar
(Figures 1, 2) = 1 cm. 3. UF 173382, scanning electron micro- Jonathan R. Hendricks
graph ot the protoconch and tnhercnlate early postnnclear Department ofCeology
whorls of a specimen from the lower Miocene Chipola Forma- San Jose State Universit)'
tion of Tenmile Creek, Calhoun Coimt\', Florida, USA (UF .307 Duncan Hall
localityCA017). Scale bar = 0.5 mm. One Washington Square
San Jose, CA 95192-0102 USA
LITERATURE CITED [email protected]
Bi-yant, J.D., B.J. MacFadden, and P.A. Mueller. 1992. Im- RogerW. Portell
proved chronologic resolution of the Hawthorn and Alum Division ol Invertebrate Paleontology
Bluff Croups in northern Floriila: Implications lor Mio- Florida Museum ofNatural Ilistoiy
cene chronostratigraphy. Ceological Society of America PO. Box 117800
Bulletin 104: 208-218. Universityof Florida
Conrad, T.A. 1840. New fossil shells from North Carolina. Caine,s\-ille,FL32611-7800 USA
American journal ofScience (Sei'ies 1) .39: 387-388. [email protected]
Davison, A., N.ll. Baiton, and B. Clarke. 2009. The effect of
coil plienoh'pes ami genot\q-)e.s on the fecundity and via- Greta L. Polites
bilityofFartnia sninmiis and Li/innacastagnalis: implica- School ol Management
tions tor the evohition ol sinistral snails. Journal of Bucknell University
Evoliilionai-y Biolog)'22: 1624—16.3.5. 319Taylor Hall
Cirande, C. ami N.II. Patel. 2009. Nodal signaling is involved Lewisburg, PA 17837 USA
in left-right asymmetiyin snails. Nature 4.57: 1007—1011. [email protected]