NOTES ON THE FAUNA OF THE ClllPOLA FORMATION- XXV: ON THE OCCURRENCE OF THE ROTHPLETZIA SIMONELLI (: )

HAROLD E. VOKES TULANE UNIVERSITY

One of the unexpected discoveries in the Rothpletzia are associated with algal lime­ fauna of the Burdigalian (late lower Mio­ stones, mainly Lithothamnion. The excel­ cene) Chipola F ormation of Calhoun lent preservation of the initial coiled portion Cormty, Florida, is the occurrence of a of the basal plate of the Chipola specimens species of the hipponicid genus Rothpleztia as well as the ornamentation of its surface Simonelli, 1890, originally described as R. clearly indicates that it was not cemented to rudista on the basis of specimens collected a substratum but rather was apparently from Miocene (presumably Vindabonian) nestled in the algal mat; the upward growth deposits on Gran Canaria Island. Speci­ of the margins may well have been a func­ mens that seem certainly to be referrable to tion of the necessity of keeping the aperture the same genus, collected from the south­ above the level of the increasingly thick sur­ ern part of the island of Trinidad, were sub­ rounding algae. A cross section of the sequently described by Hodson and Harris "Stiitzklappe" of one of the specimens in 1931 as representing "an Oligocene figured by Simonelli (1890, pl. 36, fig. 6d) Rudistid" for which they proposed the shows transverse partitions, termed "sep­ name Neomonopleura weidenmayeri. ten" by the author, indicating that the ani­ Rutsch (1934) later synonymized Neamono­ mal found it necessary to move upward in pleura with Rothpletzia and reported the the shell as the algal growth forced increase presence of the Trinidad form in the An­ in height. The Chipola specimens are much tigua Limestone on the island of Antigua. less vertically extended than are those in The original specimens of "Neamono­ which these structures occur; apparently pleura" weidenmayeri were collected from the algal growth was not sufficient to re­ the Morne Diablo Quarry, No. 1, in the quire their development. southern part of Trinidad from strata re­ ported as of middle Oligocene age (Hodson Family Troschel, 1861 and Harris, 1931, p. 136). Kugler (1953, p. 42) Genus ROTHPLETZIA Simonelli, 1890 said that the Morne Diablo 'Marac,' in Rothpletzia SIMONELLI in ROTHPLETZ and which the quarry is located, consists of SIMONELLI, 1890, Zeitschr. Deutsch. Geol. upper Oligocene limestone, but subse­ Gesellsch., v. 42, p. 711. T ype species (by quently stated (p. 50) that these limestones monotypy); Rothpletzia rudista Simonelli are in the johsi and insueta planktonic fora­ (sup. cit. , p. 711, pl. 36, figs. 6, 6a-d): Miocene, miniferal zones. These zones are now con­ Gran Canaria Island. sidered as being uppermost lower Miocene Neomonopleura HODSON and HARRIS, 1931, and early middle Miocene (Blow, 1969). The Bulls. Amer. Paleontology, v. 16 , no. 61 , p. Chipola Formation is referred to the 135. Type species (original designation): Neomonopleura weidenmayeri Hodson and Globigerinatella insueta zone, N7 of Blow, Harris (sup. cit., p. 135, pl. I, figs. 1-3; pl. 2, although that deep-water species is not figs. 1, 2) "Oligocene" (? lower Miocene), actually present (Akers, 1972, p. 8). Trinidad. The similarity to the rudistid bivalves, ex­ pressed in the specific name given to the ROTHPLETZIA FLORIDANA H. E. Vokes, type species of Rothpletzia and in the tax­ n. sp. onomic assignment of the Trinidad form Text figures 1 - 3 appears to be the result of an unusual Description: The shell is relatively small and growth shape caused by the ecologic envi­ composed of two units. There is a "lower valve" ronment in which these forms developed. or "attachment plate" that is cup-shaped with a Many of the species of the hipponicid gen­ flattened basal disc and upwardly arched sides era Hipponix and Malluvium, as well as leading to a broadly ovate "aperture;" sides of the shell in this area are of unequal length, the Rothpletzia secrete a calcareous "Stiitz­ "posterior," which rises more or less directly klappe" or supporting plate that, as Keen above the apical end of the basal disc, is short and (1971, p. 451) states, is "in effect an attached straight to slightly concave in profile; that on the operculum ... on which the rests." opposite, or "anterior," side is broadly convex In all known occurrences the specimens of and in all specimens is at least twice the length of 51 52 Tulane Studies in Geology and Paleontology Vol.17

the other. The "upper valve" is of typically hip~ re produced by Wenz (1944, p. 887, fig. 2608) ponicid cup-shaped form. The apices of both the the dimensions were shown as "111 ." upper and lower units have a coiled protoconch Measurement of the original figures reveals of two smooth whorls succeeded by a teleoconch a total length of 36.2 mm for the largest ornamented with submicroscopically fine, specime n, a height of 24.2 and a width of rounded radial ribbing; the number of ribs is increased by intercalation until they number ap­ 20.2 mm for a smaller one with an attached proximately twenty-five to the millimeter on the "upper valve" that, separately figured, upper edge of the anterior side of the holotype shows a greatest length of 20.8 and a width specime n ; these ribs tend to be interrupted by of 17.1 mm. These dimensions indicate that irregularly spaced, moderately strong concentric species attained almost three times the size growth lamellae. Interior of the "valves" with of the present form. The figured types of typically hipponicid horseshoe-shaped muscle "Neomonopleura" weidenmayeri Hodson scars adjacent to the aperture, that in the "lower and Harris are somewhat larger than those valve" located around the shorter side, that on the upper one apparently above the apical end. of R. rudista, the holotype, an intemal cast that includes both "valves," is stated to Holotype: USNM 340288; greatest length 13.2 have a length " from beak to beak" of 34 mm; he ight of posterior side* 4.1 mm; height mm, and the paratypes to have "lengths" of of anterior side* 10.6 mm; aperture length 48 to 50 mm, and "greatest diameters" of 26 11.7 mm; aperture width 10.55 nun. Locality to30mm. TU 1048. One striking difference between the Paratype A: USNM 340289; greatest length 9.5 Chipola and the type species appears to lie mm; height of posterior side* 3.3 mm; height of anterior side* 5. 7 mm; aperture length 8. 2 in the position of the muscle scars. Simonelli mm; aperture width 7.1 mm. Locality TU states (freely translated, italics mine): 1196. "Near the aperture and always on the con­ Paratype B: USNM 340290; length, slightly in­ vex side of the shell curvature lies a large complete, 7.6 mm; width 7.9 mm; height 2.0 horseshoe-shaped muscle imprint;" in all of mm. Locality TU 1048. the specimens of R. florid.ana the scar is Type locality: TU 1048, Farley Creek, south situated adjacent to the shorter, straight to bank, about 0.8 mile east of bridge of Florida concave side with the broader convex side Highway 275 (NE 1(, Sec. 21, TIN, R9W), Cal­ apparently being the apertural one. The houn County, Florida. ornamentation on the Chipola specimens Remarks: None of the specimens from the appears to be very similar to that on the Chipola Formation attain the elongated "upper valve" of R. rudista, described as rudistid shape of the "lower valves" such as consisting of "weak, densely crowded, is present in both the type of the genus and erect radial ribs that are crossed near the lip the Trinidad species, and none show the by finer concentric striations." One of the transverse "septen" shown in the original paratypes of R. weidenmayeri (Hodson and illustrations of R. rudista (Rothpletz and Harris, 1931, pl. 2, fig. 2) has a portion of the Simonelli, 1890, pl. 36, fig. 6d); the writer is outer surface preserved on the "lower inclined to attribute this difference to a less valve," which is also very like that onflori­ rapidly growing algal mat in the, presum­ dana though ~omewhat coarser on the ably, slightly cooler waters present at the larger shell. Simonelli, however, described Chipola localities. The specimens of R. the exterior of the "lower valves" of R. florid.ana are also considerably smaller rudista as being formed of "superimposed than !.re those of the other two species. scaly lamellae," a feature that may reflect Simonelli did not cite the dimensions of his the erosion of the finer omament by the form, but it is to be noted that when illustra­ Lithothamnion algal masses, rather than tions of other species were enlarged they the original condition. were accompanied by an adjacent line indi­ Rothpletzia floridana is represented in cating their height or length; such indica­ the Tulane University collections from the tions are absent from those of Rothpletzia Chipola Formation by one "upper" and five rudista, and when they were subsequently "lower valves." All are from localities near the basal part of the formation on the upper *Assuming the basal disc as a flattene d basal reaches of Farley Creek, a tributary enter­ surface. ing the Chipola River from the east. The No.2 Fauna of the Chipola Formation - XXV 53 sediments here are primarily lime sands de­ these localities is exceedingly rich with rived in part from the erosion of the under­ many species of Mollusca, including abun­ lying Chattahootchee Limestone; there are dant shells of true Hipponix, plus solitary also occasional quartzite pebbles that appa­ and colonial corals, tube worms, and cal­ rently have been transported from much careous algae fragments. Similar conditions older sources to the north. The fauna at and faunas occur at many other Chipola

3a

1b

1d

Text figure 1, Rothpletziafloridana n. sp. 1-Holotype, USNM 340288, lower ."valve;" a) basal view, x 4; b) lateral view, x 4; c) dorsal vtew showmg muscle scars, x 4, d) VIew of flattened "attachment" area showing ornamentation and nuclear whorls, x 6. 2-Paratype, USNM 340289, lower "valve;" a) lateral view, x 4; b) dorsal view, x 4. 3-Paratype,USNM 340290, upper "valve;" a) lateral view, x 6; b) dorsal view showmg ornamentatiOn and nuclear whorls, X 6. 54 Tulane Studies in Geology and Paleontology Vol. 17

localities and it is difficult to determine those Plain: Tulane Stud. Geol. Paleont., v. 9, p. factors that seem to have resulted in the 1-139, pis. 1-60, 4 text figs., map. presence of Rothpletzia only at these sites. BLOW, W. H., Late middle Eocene to Recent Planktonic Foraminiferal B iostratigraphy: Proc. 1st. Int. Conference on Planktonic LOCALITY DATA Microfossils, v. I, p. 199-421,54 pis., 43 figs. HODSON, FLOYD, and G. D. HARRIS, 1931, The specimens of Rothpletzia were col­ An Oligocene rudistid from Trinidad: Bulls. lected from the following Tulane University Amer. Paleontology, v. 16, no. 61, p.l35-140, 2 localities in the Chipola Formation, as ex­ pis. posed in Calhoun County, Florida: KUGLER, H. G. , 1953, Jurassic to Recent Sedi­ mentary Environments in Trinidad: Bull. Ass. 823. Farley Creek, south bank about 2000 feet Suisse des Geol. et Ing. du Petrole, v. 20, no. east of bridge on Florida Highway 275 (SE y, 59, p. 27-60, 2 text figs. Sec. 21, TIN, R9W). ROTHPLETZ, A., and VITTORIO SIMONEL­ 1048. Farley Creek, south bank about 0.6 mile LI, 1890, Die marinen Ablagenmgen aug east of bridge on Florida Highway 275 (SW y, Gran Canaria: Zeitsch. Deutsch. Geol. NE y, Sec. 21, TIN, R9W). Gesellsch., v. 42, p. 677-736, pis. 35, 36. 1049. Farley Creek, south bank about 1.0 mile RUTSCH, R. F ., 1934, Beitrage zur Kenntnis east of bridge on Florida Highway 275 (NE % tropisch-amerikanischer Terticlrmoll usken; I. NE y, Sec. 21, TIN, R9W). Angebliche Rudisten aus dem Terticlr von 1196. Farley Creek, north bank about 0.65 mile Trinidad (Brit. Westindien): Eclogae Geol. east of bridge on Florida Highway 275 (SW y, Helvetiae, v. 27, no. 1, pl. 1-9, text figs. 1a, b. NEV.. Sec. 21 , TIN, R9W). SIMONELLI, VITTORIO, 1892, Sopra le affinita zoologiche della Rothpletzia rudista Sim.: BolL Societa Geol. Italiana, v. 11, p. 76-80, 2 text figs. LITERATURE CITED WENZ, WILHElM, 1938-1944, Handbuch der Pahlozoologie, Bd. 6, Gastropoda, Te il 1: AKERS, W. H., 1972, Planktonic Foraminifera Allgemeiner Teil und Prosobranchia: p. i-viii, and Biostratigraphy of some Neogene Forma­ 1-1639, 4211 text figs. [Lief. 4, p. 721-948, figs. tions, northern Florida and Atlantic Coastal 2084-2764 issued in 1940.]

October 28, 198 2 REVIEWS

THE GEOLOGICAL SCIENCES IN THE MARINE GEOLOGY, by James P. Ken­ ANTEBELLUM SOUTH, edited by nett. Published by Prentice-Hall, Inc., James X. Corgan. Published by The U ni­ Englewood Cliffs, New Jersey, 1982, xv + versity of Alabama Press, University, 813 pp., Illustrated, index, $35.00 Alabama, 1982, v + 195 pp., illustrated, This volume fulfills the need for a syn­ indexed, $17.50 thesis of marine geology, incorporating the This symposium contains nine papers by enormous advances in this field during the ten contributors offering insight into the last two decades. It is comprehensive and southern geological work (1796-1860) of thir­ should prove most useful as a beginning text teen scientists, all of which had significa nt in this subject as well as a reference hand­ impact on intellectual and scientific devel­ book for the working geologist and opment in the United States. Among these oceanographer. are Charles Lyell, already a celebrated Following the brief introduction a nd scientist when he first visited the South in history of marine geology, the book com­ 1841; Gerard Troost and W. B. Rogers from prises four sections: The Structural and early state-supporte d geological surveys; Oceanographic Setting, The Ocean Mar­ and Ebenezer Emmons, author of the ill­ gins, Oceanic Sediments and Microfossils, fated Taconic System. All did significant and Ocean History. Each section is we ll work in the southern states; this useful vol­ organized and clearly written; the book is ume illustrates their impact on American highly recommended. science. --H.CS.