Two species of Enaeta occur in the Recent fauna of the Tropical East Pacific: E. cumingii (Broderip, 1832), and E. barnesii (Gray, 1825). The fossil record from the Tropical East Pacific is represented by E. barnesii from the Pleistocene of Panama, and a new species, E. propecumingii from the Miocene Angostura Formation and the Pliocene Esmeraldas beds, Onzole Formation, of northwestern Ecuador. The occurrence of E. propecumingii in the Angostura Formation is the oldest known fossil record of the genus Enaeta in the Tropical East Pacific

Pitt, Lois J

Pitt, William D

English

Tulane University Journal Publishing

A NEW SPECIES OF ENAETA (GASTROPODA:VOLUTIDAE) FROM THE MIO-PLIOCENE OF NORTHWESTERN ECUADOR WILLIAM D. PITT 1 ·~ and LOIS J. PITT<! ABSTRACT Two species of Enaeta occur in the Re-cent fauna of the Tropical East Pacific: E. cumingii (Broderip, 1832) , and E. barnesii (Gray, 1825) . The fossil record from the Tropical East Pacific is represented by E. barnesii from the Pleistocene of Panama, and a new species, E. propecumingii from the Miocene Angostura Formation and the Pliocene Esmeraldas beds, Onzole Forma-tion, of northwestern Ecuador. The oc-currence of E. propecumingii in the Angos-tura Formation is the oldest known fossil record of the genus Enaeta in the Tropical East Pacific. INTRODUCTION The genus Enaeta Adams and Adams, 1853, which has sometimes been consi-dered a subgenus of Lyria (Keen, 1971, p. 619; Hoerle and Vokes, 1978, p. 106), is a New World genus (Woodring, 1964, p. 289; Abbott, 1974, p. 245 ; Skoglund, 1992, p. 94) represented by five species in the western Atlantic fossil record , with E. isabellae (Maury, 1910, p. 17) from the late Lower Miocene Chipola Formation of Florida the earliest recorded occurrence. Other spe-cies included are: E. trechmanni Jung (1971, p. 201), from the Middle Miocene Grand Bay Formation, Carriacou , West In-dies; E. perturbatrix (Maury, 1917, p. 76), from the Mio-Pliocene Gurabo Formation, Dominican Republic; and two species from the Pliocene Gatun Formation, Panama: E. economia (Woodring, 1964, p. 289) and E. olssoni Hoerle and Vokes (1978, p. 116). The eastern Pacific has two known fossil species: E. barnesii (Gray, 1825), a Recent species that also occurs in the Pleistocene beds of the Burica Peninsula , Panama, and E . propecumingii , n. sp. The genus Enaeta is represented in the Recent west-ern Atlantic by three species: E. cyllenifor-mis (Sowerby, 1844, p. 151), Florida to 1Field Associate , Dept. of Geology , California Academy of Sciences, San Francisco, Califor-nia, 94118 2Home address: 2444 38th Ave. , Sacramento, California, 95822 123 Brazil; E. guildingi (Sowerby, 1844, p. 151), Antilles to Brazil; and E. reevei (Dall , 1907, p. 353), Cuba to Honduras. There are two species in the Recent Tropical East Pacific: E. cumingii (Broderip, 1832, p. 33), and E. barnesii (Gray, 1825, p. 511); both occur from the Gulf of California to Peru. Enaeta propecumingii, n. sp., from the Late Miocene Angostura Formation of northwestern Ecuador, is the earliest known fossil record of the genus Enaeta in the Tropical East Pacific. The genus Lyria s.s. is known from older formations in the eastern Pacific, as far north as the state of Washington (Weaver, 1942) but not in the Tropical East Pacific. In the geological record there are more species of the genus Enaeta in the western Atlantic than in the Tropical East Pacific and it is probable that the genus originated in the western Atlantic. Abbreviations for Repository Institutions CAS - California Academy of Sciences, San Francisco, California. LACM - Los Angeles County Museum of Natural History, Los Angeles, Califor-ma. PRI - Paleontological Research Institu-tion, Ithaca, New York. TU - Tulane University, New Orleans, Louisiana. USNM - United States National Museum of Natural History, Washington, DC. ACKNOWLEDGMENTS We want to thank Dr. Emily Vokes of Tulane University for help with the manu-script and for making available specimens from Tulane collections, mcluding para-types, and Allan Me Makin, from Ham-mond, Oregon, for the photography. SYSTEMATIC PALEONTOLOGY Phylum MO~LUSCA Cuvier, 1797 Class GASTROPODA Cuvier , 1797 Subclass PROSOBRANCHIA Milne-Edwards, 1848 124 Tulane Studies in Geology and Paleontology Vol. 28 Superorder CAENOGASTROPODA Cox , 1959 Order NEOGASTROPODA Thiele, 1925 Superfamily MURICOIDEA Rafinesque, 1815 Family VOLUTIDAE Rafinesque , 1815 Subfamily LYRIINAE Pilsbry and Olsson, 1954 Genus ENAETA H. Adams and A. Adams, 1853 Enaeta H . Adams and A. Adams, 1853, The Gen e ra of Recent Mollusca, v. 1, p. 167. Type speci es: Voluta harpa Barnes, 1824, by subsequent designation, Cossmann, 1899; Re-cent, eastern Pacific. [Voluta harpa Barnes, 1824, non Mawe, 1823 = Voluta barnesii Gray, 1825 (as barnsii)]. E NAETA PROPECUMINGII, n. sp. Pitt and Pitt Plate 1, figure 1 Description: Shell elongate, of medium size, with seven whorls; protoconch of about three , smooth, rounded whorls with a blunt ending . Spire whorls (o rnamentation appearing im-mediately) evenly tapering, bearing two rows of nodes; one row of low nodes anterior to suture; a narrow smooth interspace; and one row of larger, e longated nodes just posterior to suture. Body whorl with a row of nodes anterior to the suture; narrow, smooth inte rspace, separating major axial sculpture , which consists of 11 to 13 smooth, rounded ribs, extending from in-terspace to base of shell. Aperture elliptical, more than one-half of shell height; outer lip thickened, with a small blunt tooth midway on inner side of outer lip . Columellar wall with three strong plications anteriorly , and three faint plications, evenly spaced posteriorly. Ante-rior canal recurved. Etymology: From the Latin, prope mea ning near and cumingii from the Recent E. cumingii (Broderip, 1832). Holotype: CASG 67695 .01 ; height 29 .6 mm, di-ameter 14.3 mm (Plate 1, fig. 1). Type locality: P-101, Esmeraldas beds , road cut (south side), immediately west of the village of Camarones, about 20 km (by road) east of the bridge over Rio Esmera ldas , Esmera ldas Prov., Ecuador ( = TU 1399). Paratype A: CASG 67695.02; height 31.4 mm, diameter 14.9 mm; locality TU 1397 , Esmeraldas beds , Ecuador. Paratype B: CASG 67695.03; height 24.2 mm, diameter 13.5 mm; locality P-103, Angostura Formation, Ecuador. Paratype C: USNM 484521; height 26.0 mm, diameter 13.7 mm; locality P-101 , Esmeraldas beds, Ecuador. Paratype D: USNM 484522; height 19.5 mm, diameter 8.8 mm; locality TU 1399, Esmeraldas beds, Ecuador. Paratype E: PRI 33194; height 17.9 mm, diam-eter 9.2mm; locality TU 1399, Esmeraldas beds, Ecuador. Paratype F: LACMIP 12298; height 20.9 mm, diameter 10.7 mm; locality TU 1399, Esmeraldas beds , Ecuador. Occurrence: Angostura Formation and E s-meraldas beds of the Onzole Formation , Ecuador. Discussion: Enaeta propecumingii, n. sp. , is represented by eight specimens, three from locality P-101 , three from locali-ty TU 1399, one from locality TU 1397 and one from locality P-103. The fossil speci-mens examined are most similar to the fos-sil E. trechmanni Jung, 1971, and theRe-cent E. cumingii (Broderip, 1832). Enaeta trechmanni differs in having a somewhat globose, but evenly tapering spire and 18 axial ribs rather than the slender, evenly tapering spire and approximately 12 axial ribs of E. propecnmingii. The body whorl of E. trechmanni does have a row of nodes anterior to the suture, a narrow smooth in-terspace, and axial ribs extending from the interspace to the base of the shell; thus, be-coming the closest species to E. prope-cumingii in the fossil record. Enaeta prope-cumingii is also similar to the Recent E. cumingii but the latter has only a single row of nodes about midway on the spire whorls , in contrast to two rows in E. prope-cumingii. Enaeta cumingii also differs in that the body whorl has a smooth in-terspace anterior to the suture, a row of nodes and nine axial ribs extending to the base of the shell with a secondary row of nodes at their mid-point. The Recent E. cumingii apparently arose in the Tropical East Pacific from E. propecumingii. LOCALITY DATA The following are Pitt localities: P-101. Esmeraldas beds, road-cut (south side) , immediately west of the village of Camaro-nes, about 20 km (by road) east of the bridge over Rio Esmeraldas, Esmeraldas Prov. , Ecuador. P-103. Angostura Fm., sea cliffs about 300 me-ters west of Punta Verde , about 2 114 km east of the mouth of Rio Verde and about 22 km east of the bridge over Rio Esmeraldas, Es-meraldas Prov ., Ecuador. No.4 New Enaeta From Ecuador 125 2 b PLATE1 Figures 1. Enaeta propecumingii Pitt and Pitt, n. sp. CASG 67695.01 (holotype); height 29:6 mm, diameter 14.3 mm (X 1.8). Locality: P-101, Esmeraldas beds, Ecuador. 2. Enaeta cumingii (Broderip, 1832) CASIZ 099363; height 33.2 mm, diameter 17.0 mm (X 1.4). Locality: PR-100, San Carlos Bay, Guaymas, Sonora, Mexico ; Recent. PR-100. Recent , San Carlos Bay, Guaymas, Sonora, Mexico. The following are Tulane University localities: 1397. Esmeraldas beds, Quebrada Camarones, cut-bank on east side of canyon, which is at east edge of village of Camarones, 20 km (by road) east of bridge over Rio Esmeraldas, or approximately 10 km east of mouth of Rio Es-meraldas , Esmeraldas Prov. , Ecuador. 1399. Esmeraldas beds, road-cut on west side of village of Camarones, which is 20 km (by road) east of bridge over Rio Esmeraldas, at Esmeraldas, Esmeraldas Prov., Ecuador. LITERATURE CITED ABBOTT, R. T. , 1974, American Seashells, Sec-ond Edition. Van Nostrand Reinhold Co. , New York, 663 p., 24 color plates, 6405 text-figs. ADAMS , H., and A. ADAMS 185:3 58 Tlw gen era of Recent Moll usca, arranged acc-ord ~ ~ to their organization. London, v. I. p. 'vt-xl, I 484; v. 2, p. 1-661; v. 3, pis. 1-1:>8 [da1ing o" parts, v. 2, p . 661]. BRODERIP, W.J ., 1832, CharaC''E'r" of new •me-cies of Mollusca and Conchif'era, collected by Mr. Hugh Cuming: Zoo!. Soc. Londor Proc. for 1832, pt. 2, p. 25-33. DALL, W.H., 1907 , A re\ 1ew of' the American Volutidae: Smithsoma n Misc. Col!.. v. 48, pt 3, no. 1663, p. 341-373 EMERSON, W.K., 1985, T wo new species of' Lyria from the western Atla n tic (Gastro-poda:Volutidae) : Nauttlus , v. 99, no. 1, p . 28-33, 15 text-figs. GRAY , J .E., 1825, Monograph on the Cy p-rae idae, a family of testaceous Mollusca: Zoo!. Journ., v. 1, p. 489-517, errata Sheet. pl. 12. . HOERLE, S.E., and E.H. VOKES, 1978, A r·e-view of th e volutid genera Lyria and Fal -126 Tulane Studies in Geology and Paleontology Vol. 28 silyria (Mollusca : Gastropoda) in the Tertiary of the western Atlantic: Tulane Stud . Geol. Paleont. , v. 14, no. 3, p. 105-130, 5 pis. JUNG, P. , 1971, Fossil mollusks from Carriacou , West Indies: Bulls. Amer. Paleontology , v. 61, no. 269, p . 14 7-262, 21 pis. , 2 text figs . KEEN, A.M. , 1971, Sea Shells of tropical west America, Marine mollusks from Baja Califor-nia to Peru , Second Edition. Stanford Uni-versity Press , Stanford, California , i-xiv + 1064 p ., 22 color plates , ca. 4,000 figs ., 6 maps. MAURY, C.J., 1910, New Oligocene shells from Fl orida: Bulls. Amer. Paleontology, v. 4, no. 1, p . 119-164, pis. 18-26. SKOGLUND, CAROL, 1992, Additions to the Panamic Province Gastropoda (Mollusca) lit-erature: The Festivus, v. 24, Supplement, 169 p. SOWERBY, G.B., Jr. , 1844, Descriptions of six new species of Voluta: Zoo!. Soc. London , Proc., pt. 12, p. 149-152. WEAVER, C.E. 1942, Paleontology of the ma-rine Tertiary formations of Oregon and Washington: Washington Univ. [Seattle] Pubis. Geology, v. 5, pts. 1-3, 789 p ., 104 pis. WOODRING, W.P., 1964, Geology and paleon-tology of Canal Zone and adjoining parts of Panama. Description of Tertiary mollusks. (Gastropods:Columbellidae to Volutidae): U .S. Geol. Survey, Prof. Paper 306-C, p. 241-297 , pis. 39-4 7. November 15, 1995 

A New Species of Enaeta (Gastropoda:Volutidae) From The Mio-Pliocene of Northwestern Ecuador

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A New Species of Enaeta (Gastropoda:Volutidae) From The Mio-Pliocene of Northwestern Ecuador

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