Geology and Paleontology of Canal Zone and Adjoining Parts of Panama Description of Tertiary Mollusks (Additions to gastropods, scaphopods, pelecypods: Nuculidae to Malleidae) GEOLOGICAL SURVEY PROFESSIONAL PAPER 306-E Geology and Paleontology of Canal Zone and Adjoining Parts of Panama Description of Tertiary Mollusks (Additions to gastropods, scaphopods, pelecypods: Nuculidae to Malleidae) By W. P. WOODRING GEOLOGICAL SURVEY PROFESSIONAL PAPER 306-E A contribution to the history of the Panama land bridge UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1973 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog card No. 72-600341 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, B.C. 20402 Price: Paper cover $1.75, domestic postpaid; $1.50, GPO Bookstore Stock No. 2401-00217 CONTENTS Page Descriptions of Tertiary mollusks Continued Abstract __ ____._____________._______-____----__-- 453 G astropods Continued Introduction. _.______________-_-_____---___-------- 453 Family Architectonicidae____________________ 473 Acknowledgments__ _ _______________---_--_-----_-_ 454 Family Calyptraeidae_______________________ 473 Change in age assignment_________________________ 454 Family Cypraeidae_______________________ 475 New generic and subgeneric names----___ ___-____-__ 454 Family Ovulidae____-____________-__________ 475 Faunal summaries-_________________________________ 454 Family Naticidae.__________________________ 475 Eocene series.._________________________________ 454 Family Cassididae._________________________ 476 Gatuncillo formation______________________ 454 Family Muricidae_________________________ 476 Marine member of Bohio(?) formation_______ 455 Family Buccinidae_______-__________________ 477 Oligocene series_________________________________ 455 Family Melongenidae_______________________ 478 Bohio formation.___________________________ 455 Family Xancidae_______-_________-_-------- 479 Caimito formation._________________________ 456 Family Cancellariidae.______________________ 481 Miocene series___--____---______________________ 456 Family Turridae.__________________ 481 Culebra formation._________________________ 456 Family Acteonidae._________________________ 481 Cucaracha formation._______________________ 457 Scaphopods__________________________________ 481 La Boca formation, including Emperador lime­ Family Dentaliidae_______________-------__- 481 stone member.___________________________ 457 Family Siphonodentaliidae.__________________ 486 Alhajuela formation_________________________ 460 Pelecypods________________________________ 488 Gatun formation___________________________ 461 Family Nuculidae________________________ 488 Chagres sandstone, including Toro limestone Family Nuculanidae________________________ 490 member-________________________________ 465 Family Arcidae____________________________- 495 Description of Tertiary mollusks continued from Family Noetiidae.__________________________ 517 chapter D_______________________________________ 465 Family Glycymerididae___________________ 519 Gastropods continued from chapter D___________ 465 Family Mytilidae___________________________ 522 Family Neritidae-__________________________ 465 Family Pinnidae________________________ 525 Family Vitrinellidae_-__-_-__________________ 467 Family Pteriidae_______________________ 526 Family Turritellidae-_____________________ 467 Family Isognomonidae______________________ 526 Family Pseudomelaniidae____________________ 468 Family Malleidae_________________________ 527 Family Thiaridae___________________________ 469 References cited.___________________________________ 528 Family Cerithiidae._____________________ 470 Index.____________________________________________ 533 ILLUSTRATIONS [Plates follow index] PLATES 67-69. Late Eocene mollusks from Gatuncillo formation. 70. Late Eocene mollusks from Gatuncillo formation and marine member of Bohio (?) formation, and late Oligocene mollusks from Bohio and Caimito formations. 71-72. Late Oligocene mollusks from Caimito formation, and early Miocene mollusks from Culebra and La Boca formations. 73. Early Miocene mollusks from Culebra, La Boca, and Alhajuela formations, and middle Miocene mollusks from Gatun formation. 74. Early Miocene mollusk from La Boca formation and middle Miocene mollusks from Gatun formation. 75. Middle Miocene mollusks from Gatun formation and late Miocene mollusks from Chagres sandstone. 76-79. Middle Miocene mollusks from Gatun formation. 80. Middle Miocene mollusks from Gatun formation and Costa Rica. 81. Middle Miocene mollusks from Gatun formation. 82. Middle Miocene mollusks from Gatun formation and late Miocene mollusks from Chagres sandstone. in GEOLOGY AND PALEONTOLOGY OF CANAL ZONE AND ADJOINING PARTS OF PANAMA DESCRIPTION OF TERTIARY MOLLUSKS (ADDITIONS TO GASTROPODS, SCAPHOPODS, PELECYPODS: NUCULIDAE TO MALLEIDAE) By W. P. WOODRING ABSTRACT of the 24 species of Anadara and half of the 12 species of the Chapter E adds 112 described species and subspecies (a few subgenus Rasia of that genus. In consideration of two battered briefly described) to the some 440 covered in preceding chapters: and worn specimens of a large form of the subgenus Grandi­ 27 additional gastropods, 18 scaphopods, and 67 pelecypods in arca, identified as Anadara grandis patricia?, the similar Ter­ 10 families. It is estimated that about 125 species are to be tiary forms in the Caribbean region are reviewed and divided added in chapter F, the final chapter. into a brackish-water group and a marine group. The Gatun The Arcidae is by far the largest family in the pelecypods so fauna now totals some 330 species. far studied: 30 species in six genera. The genus Anadara is the largest in that family: 25 species, representing the subgenera INTRODUCTION Hawaiarcaf, Rasia, Tosarca, Grandiaroa, Potiarca, and Cune- Chapter E covers 112 species and subspecies, dis­ arca. Potiarca, based on a living western Pacific species, is adopted for many American species heretofore assigned to tributed as follows: Cunearca. Eighteen of the 27 additional gastropods were found at a new Species and subspecies of mollusks described in chapter E locality in the late Eocene part of the Gatuncillo formation. Number of species and They are assigned to 16 genera, 14 of which are not represented Formation at other Gatuncillo localities. The genera include Faunus, Tym- Eocene series: panotonos, and Besanconia, which are rare in America, and the Gatuncillo 22 rare endemic American genus Harrisianella. Marine member of Bohio 1 (?) 8 The marine member of the Bohio(?) formation is now as­ Oligocene series: Bohio x _________ 5 signed to the late Eocene, instead of late Eocene or early Oligo- Caimito ______ 7 cene the only change in age assignment. Eocene affinities are Miocene series: especially strengthened by the presence of Samanoetia sama- Culebra ___ 7 nensis and Volvariellaf, if indeed the unnamed species represents La Boca proper__ 23 Alhajuela _ _ 5 that genus, as seems likely. Both the marine member of the Gatun 2 _______ 50 Bohio( ?) and the late Oligocene part of the Bohio contain early Chagres proper_ . 6 small species of Anadara, subgenus Rasia. 1 In Spanish orthography Bohio. The fossils from the moderately deep-water facies of the late 3 In Spanish orthography Gattin. Oligocene Caimito formation include the earliest hexagonal Den* talium of the subgenus Dentalium s.s., from the American main­ The original list of fossil localities was published on land, and a widespread and abundant species of the essentially pages 112-130 of chapter A, but others were added in deep-water subgenus Fissidentalium. succeeding chapters, except the present one. Anadara chiriquiensis chiriquiensis, a relatively small form In the distribution tables the designation "sp." in of the subgenus Grandiarca that is widely distributed in the locality columns indicates an incomplete or poorly pre­ Miocene Caribbean province, occurs in the Culebra formation. For the most part it indicates brackish water. served species that may or may not be the same as that Among the fossils from the La Boca formation proper, Cy- in the species column, and the designation " ?sp." indi­ phoma aff. C. intermedia is the earliest representative of an cates that the genus is questioned. Symbols for relative endemic American genus, and Isognomon mimeticus, a remark­ frequency are as follows: able, narrowly mytiliform species is the type of the new sub- genus Mimonion. Both the Culebra and La Boca, both of early Symbols used for relative frequency Miocene age, contain predecessors of Gatun species. Number As in other chapters, the largest number of species is from the of middle Miocene Gatun formation: 50 species. Bailya orossata Symbol specimens is the first Tertiary species of the genus from the Caribbean R, rare________ 1-2 F, few________ 3-5 region, and the earliest now known. A bizarre, incomplete gas­ C, common______ 6-20 tropod is described as xancid?, genus?. The Gatun contains 13 A, abundant ___ >20 453 454 GEOLOGY AND PALEONTOLOGY OF CANAL ZONE ACKNOWLEDGMENTS upper course of Rio Palenque, 3.4 km west of Nuevo San Juan. This locality was mentioned on pages 303 I am indebted to my colleague Druid Wilson for ad­ and 304 of chapter D, and was entered on page 301 as vice, especially concerning the family Arcidae and the report locality 23b. According to a communication from genus Exputens, and to members of the staff