FLORI'IDA MUSEUM BULLETIN OF NATURAL HISTORY ® A MIDDLE EOCENE FOSSIL PLANT ASSEMBLAGE (POWERS CLAY PIT) FROM WESTERN TENNESSEE DavidL. Dilcher and Terry A. Lott Vol. 45, No. 1, pp. 1-43 2005 UNIVERSITY OF FLORIDA GAINESVILLE - The FLORIDA MUSEUM OF NATURAL HiSTORY is Florida«'s state museum of natural history, dedicated to understanding, preser¥ingrand interpreting].biologica[1 diversity and culturafheritage. The BULLETIN OF THE FLORIDA- MUSEUM OF NATURAL HISTORY is a peer-reviewed publication thatpziblishes.the result5 of origifial reseafchin zodlogy, botany, paleontology, and archaeology. Address all inquiries t6 the Managing Editor ofthe Bulletin. Numbers,ofthe Bulletin,afe,published,at itregular intervals. Specific volumes are not'necessarily completed in anyone year. The end of a volume willl·be noted at the foot of the first page ofthe last issue in that volume. Richard Franz, Managing Editor Erika H. Simons, Production BulletinCommittee Richard Franz,,Chairperson Ann Cordell Sarah Fazenbaker Richard Hulbert WilliamMarquardt Susan Milbrath Irvy R. Quitmyer - Scott Robinson, Ex 01#cio Afember ISSN: 0071-6154 Publication Date: October 31,2005 Send communications concerning purchase or exchange of the publication and manustfipt queries to: Managing Editor of the BULLETIN Florida MuseumofNatural-History University offlorida PO Box 117800 Gainesville, FL 32611 -7800 U.S.A. Phone: 352-392-1721 Fax: 352-846-0287 e-mail: [email protected] A MIDDLE EOCENE FOSSIL PLANT ASSEMBLAGE (POWERS CLAY PIT) FROM WESTERN TENNESSEE David L. Dilcher and Terry A. Lottl ABSTRACT Plant megafossils are described, illustrated and discussed from Powers Clay Pit, occurring in the middle Eocene, Claiborne Group of the Mississippi Embayment in western Tennessee. Twenty six species and eight types of plants, and two species of insect larval cases are represented in this study. They include Lauraceae, Annonaceae, Smilacaceae, Platanaceae, Altingiaceae, Myrtaceae, Fabaceae, Fagaceae, Salicaceae, Moraceae, Rhamnaceae, Sapindaceae, Nyssaceae, Theaceae, Apocynaceae, Rubiaceae, Araliaceae, Oleaceae, entire margin morphotype 1 -5 , tooth margin morphotype 1 , reproductive structure morphotype 1 , Folindusia, and Terrindusia. Specimens collected from Powers Pit are compared to those from previous studies from western Tennessee, the Claibome Group in general, and assessed in terms of extant relationships. The extant relationships of plant megafossils described in this study provide clues to the paleoenvironment of western Tennessee during the middle Eocene. The paleoenvironment may have been subtropical accommodating warm tropical to cool temperate plant species. Key words: Eocene, Claiborne Group, Powers Clay Pit, Tennessee, Angiosperms TABLE OF CONTENTS Dedication 2 Introduction 3 Materials and Methods X Systematic Paleontology 10 I mirnlpq 10 Magnoliales....................................„.,~,-,..,..........„,„~.....................,..~-............,10 Imdeq 11 Proteales 11 Saxifragales Myrtales 17 Fabales 1713 Fagalp.R Malpighiales 14 Rosales 1 5 Sapindales .......................................,.„„.,................„,~,...................„,.............,16 Cornales 1617 F.ricales Gentianales 17 Apiales 18 I Amialeq Incertae sedis 18 Insecta 19 Discussion 10 Acknowledgments 73 Literature Cited 73 'Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, email: <[email protected]>, <[email protected]>. Dilcher, D.L. & T.A. Lott. 2005. A middle Eocene fossil plant assemblage (Powers Clay Pit) from western Tennessee. Bull. Florida Museum Nat. Hist. 45(1):1-43. 2 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL„ 45( 1) IN DEDICATION TO: BRUCE ROGER MOORE 1r This paper is dedicated to Mr. Bruce Roger Moore, a student of Paleobotany whose interest in the fossil plants of western Tennessee and collections from the Powers Clay Pit helped contribute many fossils to the Paleobotany and Palynology Collection ofthe Florida Museum ofNatural History. His field-work, as part ofa team effort, resulted in collections ofseveral ofthe fossils presented in this paper. His intense passion for collecting and inquiries about the fossil plants and their depositional history encouraged continued study of fossil plants from the middle Eocene of western Tennessee. Roger Moore is a native of western Tennessee and completed a Masters of Science degree from the University of Tennessee in Agronomy. Subsequently, he went into business in western Tennessee. His interest in plants continued, and when Professor Michael Gibson introduced him to the fossils of western Tennessee and he saw how beautifully preserved the plants were, it was like striking a spark under dry kindling. The spark took and flamed into an intense interest in these fossil plants. We are happy to dedicate this paper to him in recognition of his significant contributions of collecting so many fossil plants and making them available for this study and future reports ofother fossil localities. DILCHER and LOTT: A fossil assemblage of Powers Clay Pit 3 INTRODUCTION are many localities in this region (Fig. 2) and each local- There are numerous clay deposits in western Tennes- ity yielded hundreds to thousands, even tens of thou- see, many which contain abundant plant fossils. These sands, of plant fossil remains. This report is the first clay deposits are of middle Eocene age and occur as publication in what we expect to become a series of isolated clay lenses of the Claiborne Group deposited papers detailing the floras o f each locality. Reasons for during the Mississippi Embayment of southeastern North breaking this very large flora of middle Eocene plant- America. These numerous clay lenses are distributed rich deposits into discreet units are elaborated upon in in the ancient coastal plains sediments o f the northeast- the discussion of this paper. ern part of the Mississippi Embayment (Fig. 1). There The fossil plants in the present report were col i ~ ILLINOIS-J KANSAS MISSOURI ' - ENTUCKY~ OKLAHOMA ARKANSAS K Twi ' E .SSEE Tpr TPT Twl 1 Tw. Ter 5 Tz Th T TC.. c Te ... r i..) MISSISSIPPI jALABAMA I Trm TEXAS l LOUISIANA '~ FLORIDA Ter Jackson group Claiborne group Wilcox group Tj Jackson Formation Tc Cockfield Formation Th Hatchetigbee Formation Eocene Ty Yazoo Clay ~ Tco Cook Mountain Formation Tw Wilcox Formation May include Paleocene locally Trn Moodys Branch Formation Ts Spana Sand Tpr Tz Zilpha Clay Tt Tallahatta Formation Paleocene Trm Reklaw Formation Kr F1 Cretaceous Figure 1. Geologic map of Mississippi Embayment. Stratigraphic units as recognized by U.S. Geological Survey. Modified from Tschudy (1973). 4 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 45(1) KENTUCKY 17··1 •2 GRA\'ES 9. '6-8 -13,1418 10• ·41.1 EY : - NRY TENNESSEE "962 I -15 16 IvUSS\%15\ ~ARSAL~ A Powers I Pit #14 N SR 54 Como A 190 M CR m Fr nc CR 140 -~ La e SR 2 US 79 -HEV-coMS_ B cKe e Carroll County Weakley (0199 Figure 2. A, Localities of clay pits in Kentucky, Tennessee, and Mississippi, Eastern United States. 1, Lamkin (UF15815). 2, South-40 (UF 15824). 3, Bell City (UF15803). 4, New Puryear (UF15819). 5, Puryear (UF 15820). 6, Martin (UF15809. 7, Foundry Hill(UF15810). 8, Buchanan (UF15806). 9, Warman (UF15826). 10, Gleason (UF15811). 11, Miller(UF15817). 12, Lawrence (UF15816). 13,Willbank 1&2(UF18884, UF18927). 14, Powers OF I 8810). 15, Bovay (UF 1 5737) 16, Bolden (UF15738). 17, Old Hickory (UF15742). 18, Richies Black (UF15828). 19, New Lawrence (UF15818). 20,New Haynes (Rancho, UF15921). B, Locality ofPowers Pit (#14), Weakley County, Tennessee. DILCHER and LOTT: A fossil assemblage of Powers Clay Pit 5 I. 1 t-.. -12 - 0 =hs:e - . t. 77 8 - - A - I . - 6 - , ''1 -I.~. , '. Figure 3. Powers Pit. A, Northeast comer. B, East side of pit. Photographed by Hongshan Wang. 6 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 45(1) S3IhIEIS WHITLATCH SCHNEIDER STEARNS HARDEMAN PARKS PARKS AND AND ETAL. AND BLANKENSHIP ARMSTRONG CARMICHAEL (surface) (subsurface) (subsurface) (surface) (surface) 1940 1950 1955 1966 1975 1990 JACKSON JACKSON JACKSON(?) JACKSON (?) FM. FORMATION FORMATION FORMATION o JACKSON COCKFIELC GRENADA AND FM. FM. 3N3003 CLAIBORNE ~ COOK CLAIBORNE GROUPS . .. ... D- ..18.. .1 ~ MOUNTAIN GROUP CLAIBORNE r HOLLY AND CLAIBORNE ~ FM. SPRINGS 0 GROUP FM. FM. WILCOX 5 0 FMS. WILCOX MEMPHIS WILCOX ACKERMAN WILCOX WILCOX SAND (?) FM. FM. GROUP GROUP PORTERS PORTERS PORTERS PORTERS PORTERS WILCOX 3N30031Vd CREEK CREEK CREEK CREEK CREEK CLAY 5 CLAY 0- CLAY 0- CLAY a. CLAY GROUP ODD 0 0 0 0 GROUP 1 0 0M r H ? 24 / > >s 07 ~ CLAYTON 5 CLAYTON ~ CLAYTON ~ CLAYTON MIDWAY o FM. 8 FM. a FM. g FM MIDWAY 5 E 5 GROUP 0 UPPER CRETACEOUS Figure 4. Stratigraphic chart ofwestern Tennessee. Modified from Parks (1975) and Parks and Carmichael (1990). lected at Powers Clay Pit in Weakley County, Tennes- site. The well preserved fossil leaves, flowers, fruits, see (Figs. 2,3). This clay pit was selected because we seeds, and insect larval cases occur as compressions/ have accumulated, during the past 5 years, a collection impressions, casts, and carbonized organic material. ofoyer400 specimens consisting mainly ofleaves, fruits, Many of the fossils collected in Powers Clay Pit can be and seeds through the efforts of B. Roger Moore, the related to the extant families Lauraceae, Fabaceae, authors, and numerous colleagues who have visited the Fagaceae, Theaceae, and Araliaceae, with less abun- DILCHER and LOTT: A fossil assemblage of Powers Clay Pit 7 GROUP FORMATION Jackson; upper Eocene Moodys Branch Cockfield Fm.