Interciencia ISSN: 0378-1844 [email protected] Asociación Interciencia Venezuela

Nieves-Rivera, Ángel M. Paleobotanical notes on mangrove-like plants of Interciencia, vol. 32, núm. 3, marzo, 2007, pp. 175-179 Asociación Interciencia Caracas, Venezuela

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How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative PALEOBOTANICAL NOTES ON MANGROVE-LIKE PLANTS OF PUERTO RICO

Ángel M. Nieves-Rivera

SUMMARY

Several new trace (ichnofossils) of mangrove-like plants herein described and illustrated, and a brief paleobotanical dis- are reported for Puerto Rico; all these fossils are new records cussion provided. To date, the data on ichnofossils of mangrove- for Puerto Rico. The earliest root casts in Puerto Rico were like plants are too poor to speculate on such subjects as disper- dated Late (probably Santonian, 85.8-83.5Ma). Ear- sal and island biogeography, especially in Puerto Rico. Most of lier paleobotanical studies in Tertiary-dated sites in Puerto the taxonomic information presented herein was collected from Rico are also discussed. Oligocene and Miocene lignitic rocks, fragmentary surveys. However, the data herein suggest that the traces of amber, and trace fossils (possibly mangrove rhizoliths) composition of fossilized mangrove-like plants is more complex also have been found in several geological formations of north- than previously suspected. Therefore, it would seem important to ern and southern Puerto Rico (e.g., Juana Díaz Formation and continue studying such paleoenvironments, in order to contribute Ponce ). Rhizoliths of Scaveola cf. plumieri (L.) Vahl to the conservation and knowledge of the paleoecology of man- has been collected from coastal Pleistocene eolianite terraces grove-like plants of Puerto Rico. that occur in northern Puerto Rico. The Puerto Rican material is

mangrove forest is 1974; Francis and Lowe, 2000; Little et new variety of the mangrove-associated considered a dynamic al., 2001), the most widely distributed plant, C. erectus var. sericeus Griseb. ecotone (or transition of which are the red mangrove (Rhi- (Combretaceae), unusual aerial roots zone) between terres- zophora mangle L.), black mangrove in A. germinans (Avicenniaceae) were trial and marine habitats. In its sim- (Avicennia germinans (L.) Stearns), reported for Puerto Rico (Nieves-Ri- plest sense “mangrove”, as used herein, white mangrove (Laguncularia rac- vera, 2005). The latter study produced encompasses a group of woody, halo- emosa (L.) Gaertn.), and buttonwood an actualized checklist of scientific phylic plants that occurs along shel- (Conocarpus erectus L.). Following and common botanical names (English/ tered tropical and subtropical coast- Tomlinson (1986), only three species Spanish), including 3 true mangroves lines. Mangroves are derived from a should be considered as “true man- (A. germinans, L. racemosa and R. variety of plant families and vary in groves” (A. germinans, R. mangle, and mangle), and 122 mangrove-associates their dependence upon littoral habi- L. racemosa) in Puerto Rico. Conocar- for Puerto Rico. tats. Mangrove forests are also referred pus erectus is frequently considered a The most common to as mangrove swamps, tidal forests, “true mangrove”, but Tomlinson (1986) trace fossils, also known as ichnofos- tidal swamp forests or mangals. Ca- suggested that it is better regarded as sils or “Lebensspuren” (‘living traces’ ribbean mangroves range from 30°N a mangrove associate because it lacks in German) left by plant activity are (northern Florida) to 8°N (northwest of the biological features (pneumato- root traces or casts (rhizoliths), which Colombia) and from 59°W (north of phores and vivipary) which character- show the branching and irregularities Guiana) to 89°W (eastern Guatemala) ize true mangroves; furthermore, it oc- of living root morphology. These casts (Tomlinson, 1986). Until recently, four curs in inland communities. A compi- also reveal plant behavior, by showing mangrove species were known to occur lation of 125 plants routinely found in growth. Their preservation taphonomy in Puerto Rico (Lugo and Snedaker, mangrove forests, the introduction of a was probably the result of early cemen-

KEYWORDS / Mangrove / Paleobotany / Puerto Rico / Received: 03/27/2006. Accepted : 02/01/2007.

Ángel M. Nieves-Rivera. B.S. in Biology, Inter American University of Puerto Rico, San Ger- mán, Puerto Rico. M.S. in Biology, University of Puerto Rico, Mayagüez (UPRM). Puerto Rico. Ph.D. in Marine Sciences, UPRM, Puerto Rico. Address: Agriculture Specialist, U.S. Customs and Border Protection, Office of Field Operations, John F. Kennedy In- ternational Airport, Terminal 4, Jamaica, NY 11430, NY, USA. e-mail: [email protected]

MAR 2007, VOL. 32 Nº 3 0378-1844/07/03/175-05 $ 3.00/0 175 tation around the original roots, fol- lowed by cementation of carbonate sand that filled the mold (Martin, 1996). The fossilized mangrove-like plants of Puerto Rico have been less studied. A total of 11 trace fossils (ichnofossils) of mangrove-associated plants are here- in reported for Puerto Rico (Table I). The earliest root casts in Puerto Rico were dated Late Cre- taceous (probably Santonian, 85.8- 83.5Ma; Santos, 1990, 1999). These plant ichnofossils (Figure 1a-e), along with scattered large, near-vertical trace fossils (Skolithos s. str.; Prothero and Schwab, 1996) are present on the top of bioturbated magnetite-rich units (magnetite lenses) of the oldest facies of the Cotuí Limestone, Cabo Rojo- San Germán, in southwestern Puerto Rico (Santos, 1990, 1999). The loca- tion of the Cotuí Limestone root casts is given on Table I and was at 25.3m elevation. Cretaceous root casts have been tentatively interpreted to have Figure 1. Santonian (Late Cretaceous) mangrove-like root casts reported by Santos (1990, 1999) from been caused by mangrove-like plants, the Cotuí Formation, Cabo Rojo-San Germán, southwestern Puerto Rico. a-b: Magnetite bioturbated e.g., Deltoidospora sp. (= Acrostichum) facies (lenses) where the roots are located, c-e: enlargement of the root casts.

Table I Location of mangroves and mangrove-associated plants palynomorphs (PL) or ichnofossils (IF) found in Puerto Rico, in order of geologic time Taxa Accession number1 Coordinates Geological Geologic References Formation2 time3 Mangrove-like root casts (IF) — 8°04.720’N, 67°05.312’W CM LC Santos (1990, 1999); Nieves-Rivera (2005)

Ilex sp. (PL) MO C-47, 15; ESF H-19 18°19.998’N, 66°56.918’W SC MO Graham and Jarzen (1969)

Myrica sp. (PL) MO C-42, 4; ESF N-43 18°19.998’N, 66°56.918’W SC MO Graham and Jarzen (1969)

Pelliciera sp. (PL) MO C-48, 1; ESF D-38,2 18°19.998’N, 66°56.918’W SC MO Graham and Jarzen (1969)

Rhizophora (sp.) doctrinalis Hollick (IF) 18°19.998’N, 66°56.918’W SC MO hollick (1928); YPM 27218 (type) Graham (1996) YPM 27196 (paratype) YPM 27199 (figure)

Rhizophora sp. (PL) MO C-47,1; ESF L-21,3 18°19.998’N, 66°56.918’W SC MO Graham and Jarzen (1969)

Tournefortia sp. (PL) MO A-12,10; ESF U-34,4 18°17.413’N, 66°53.411’W SL MO Graham and Jarzen (1969)

Mangrove-like root casts (IF)* — 17°58.412’N, 66°53.730’W BL MO Nieves-Rivera (2005)

Mangrove-like root casts (IF)* LACMIP 17772 17°58.947’N, 66°40.028’W PC LM Nieves-Rivera (2005)

Scaveola cf. plumieri rhizoliths (IF)* LACMIP 17768 18°30.873’N, 67°04.501’W ED PL Storrs L. Olson (pers. comm., 2005); Nieves-Rivera (2005)

Mangrove-like root casts (IF) -— 18°04.854’ N, 67°56.379’ W EF QT hernández-Ávila (1970); Nieves-Rivera (2005) * New record for Puerto Rico; ESF: England Slide Finder coordinates. 1 Museum abbreviations. LACMIP: Natural History Museum of Los Ángeles County, Department of Invertebrate Paleontology, Los Ángeles, California; MO: Herbarium, Missouri Botanical Garden, Saint Louis, Missouri; YPM: Yale Peabody Museum Herbarium, Yale University, Cincinnati. 2 Geological formations. BL: Barrio Luna, Juana Díaz Formation, Guánica; CM: Cotuí Mountains, Cotuí Formation, Cabo Rojo-San Germán; ED: Eolianite dunes, Punta Jacinto, Isabela; EF: Eolianite Formation, Carabinero, Mona Island; PC: Quarry, Ponce Limestone, Ponce; SC: Salto Collazo, San Sebastián Formation, San Sebastián; SL: Slope, junction of Roads PR-111 and PR-124, San Sebastián Formation, Lares. 3 Geologic Time. LC: Late Cretaceous (Santonian, 85.8-83.5Ma); LM: Late Miocene (11.2-5.3Ma); MO: Middle Oligocene (28.5Ma); PL: Pleistocene (1.8- 0.01Ma); QT: Quaternary (1.8Ma-10000 yr).

176 MAR 2007, VOL. 32 Nº 3 base of the first falls below the bridge) in the gray shales of the Collazo River, SSF, northwestern Puerto Rico. A type (YPM 27218), paratype (YPM 27196), and figure (YPM 27199) of R. (sp.) doctrinalis were deposited in the Yale Peabody Museum (Table I). Palynological studies in Puerto Rico were conducted by Graham and Jarzen (1969) and Graham (1996, 2003), collecting at many of Hollick’s original Tertiary surveyed sites, and adding new ones. Palynomorphs (pol- len) of these plant species were col- lected in the shales and organic-rich silty limestone layers of the San Sebas- tián and Lares Formations, northwest- ern Puerto Rico. In their study, Gra- ham and Jarzen (1969) obtained 165 palynomorphs; 44 were identified and 15 are unknown. Graham (1996, 2003) summarized Hollick’s works and dem- onstrated that there is further need for paleobotanical studies in the region on the diversity and importance of the fos- sil plant record of Puerto Rico. Graham (1995) carried out palynological studies in the Caribbean, with emphasis on the diversification of the Gulf/Caribbean mangrove communities, especially be- fore and after the appearance of the Isthmus of Panama in the Pliocene (5.3-1.8Ma; s. str. Graham, 1992). Although pol- len of Avicennia has not been col- lected in Puerto Rico, this mangrove was the first to be found in the Late Miocene (11.2-5.3Ma) of the Carib- bean (Graham, 1995), although Duke (1995) reported Avicennia in Early Figure 2. Pleistocene (Late Quaternary) plant ichnofossils pieces (LACMIP F.A.3912.2004-3), possibly Miocene (23.8-16.4Ma). Avicennia pol- mangrove-like root casts from the aeolian fossilized dunes of Punta Jacinto, Playa Jobos, Isabela, in len is also common in the Quaternary northern Puerto Rico. a-b: Aeolian dune views, c-e: root casts in situ, f: profile and sectioned views of (1.8-0.01Ma) of Costa Rica, Panama, weathered root casts. and in northern South America (Müller et al., 1987; Graham, 1995). Microfos- or the extinct Brevitricolpites sp., al- teristic of intertidal to shallow subtidal sils of Rhizophora first appeared in the though recent palynological studies marine environments with high energy Late Eocene (37.0-33.7Ma), Avicennia reported the origin of these two candi- (active waves and currents) (Santos, in Late Miocene, Laguncularia in the dates in the Eocene (Tomlinson, 1986; 1990, 1999). Pliocene (5.3-3.6Ma), and Conocarpus Rull, 1998). Another possible candidate In the 1920s, Hollick in the Quaternary (Graham, 1995). is the mangrove-associated palm Nypa, (1928) began a paleobotanical survey in More recent palyno- which nowadays is widely distributed Puerto Rico, which was summarized in logical surveys by Graham and Jarzen throughout southwestern Asia and dates his Paleobotany of Porto Rico, based (1969) and Graham (1995, 1996, 2003), back to Late Cretaceous (Tomlinson, on his field collections of seeds, leaves, reported Puerto Rican Tertiary (Middle 1986; Rull, 1998). These casts (2- and wood macrofossils of various spe- Oligocene) mangrove plant microfos- 20mm wide), which Santos suggested cies, including mangrove species such sils. Mangrove pollen included Rhi- that were derived from some mangrove- as Rhizophora, in the gray shale walls zophora sp. and Pelliciera sp. (Graham like plants, possess many anatomical of the Collazo and Guatemala Rivers of and Jarzen, 1969; Graham, 1995, 1996, traits also found in modern mangrove- the San Sebastián Formation (SSF), of 2003). Palynomorphs of both mangrove associated plants (e.g., Acrostichum Oligocene in age (33.7-23.8Ma). These species were collected in the light gray spp.). The original wood material was plant species were also collected in and gray shales of SSF. Both mangrove decomposed and no longer exists; how- other localities around the island (Hol- species are typical of coastal habitats ever, the spaces were filled with soft lick, 1928). This author reported leaves with brackish or marine waters; how- sediment, easily removed by physical of Rhizophora sp. (Rhizophora (sp.) ever, Pelliciera rhizophorae Triana & and biogeochemical mechanisms (Fig- doctrinalis Hollick; Figure 5b, plate 82 Planchon is now limited to the Pacific ure 1c-e). These features are charac- of Hollick, 1928) from station B (at the coasts of Costa Rica, Panama, and both

MAR 2007, VOL. 32 Nº 3 177 Pacific and Atlantic coasts of Colombia liths). The Isabela rhizoliths were de- Rico y las Indias Occidentales (Spanish (Tomlinson, 1986). posited in the Natural History Museum translation of “Silvics of native and exotic trees of Puerto Rico and the Caribbean Oligocene and Miocene of Los Ángeles County, Department of islands”). General Technical Report IITF- lignitic rocks, traces of amber, and Invertebrate Paleontology, Los Ángeles, 15. US Department of Agriculture, Inter- trace fossils (possibly mangrove rhizo- California (LACMIP). Pleistocene plant national Institute of Tropical Forestry, Río liths) also have been found in several rhizoliths (see LACMIP Isabela PR Piedras, Puerto Rico. 582 pp. geological formations of northern and 17768) are possibly from a mangrove- Frost SH, Harbour JL, Beach DK, Realini southern Puerto Rico (e.g., Juana Díaz like plant such as Scaveola cf. plumi- MJ, Harris PM (1983) Oligocene reef- Formation and Ponce Limestone s. str. eri (L.) Vahl (Storrs L. Olson, pers. tract development, southwestern Puerto Frost et al., 1983; MacPhee and Wyss, comm., 2005; Figure 2a-f; Table I). Rico (Sedimenta 9). Rosenstiel School of Marine & Atmospheric Science. Univer- 1990; MacPhee and Iturralde-Vinent, Similar rhizoliths have been found as sity of Miami. Miami, FL, USA. 144 pp. 1995; Iturralde-Vinent, 2001; Nieves- reefs at Key Biscayne Bay in Florida Rivera, unpubl. data, 2002; Table (USA; Hoffmeister and Multer, 1965), Graham A (1992) Utilization of the isthmian land bridge during the Cenozoic-paleobo- I). The biostratigraphy of the (Holi- in aeolian dunes of Hawaii (Olson and tanical evidence for timing, and the se- day Inn) outcrop, which is part of the James, 1982), and San Salvador Island lective influence of altitudes and climate. Ponce Limestone, is Late Miocene in in the Bahamas (Martin, 1996). Rev. Palaeobot. Palynol. 72: 119-128. age and is herein reported (María Ruiz- To date, the data on Graham A (1995) Diversification of Gulf/Ca- Yantín, pers. comm., 2004): “During ichnofossils of mangrove-like plants are ribbean mangrove communities through Late Miocene times, this area was ac- too poor to speculate on such subjects Cenozoic time. Biotropica 27: 20-27. tive tectonically, whereas the northern as dispersal and island biogeography, Graham A (1996) Paleobotany of Puerto part of Puerto Rico was passive. The especially in Puerto Rico. Most of the Rico: from Arthur Hollick’s (1928) sci- outcrop has four units. Unit 1 shows a taxonomic information presented herein entific paper to the present. In Figueroa lagoon environment and it is 1.2m in was collected from fragmentary surveys Colón JC (Ed.) The scientific survey of thickness. It is a wackestone composed from Puerto Rico. However, the data Puerto Rico and the Virgin Islands: an eighty-year reassessment of the island’s mainly of the foraminifer Miosorites herein suggest that the composition of natural history. Ann. N.Y. Acad. Sci. 776: cf. americanus Seiglie & Grove, soli- fossilized mangrove-like plants is more 103-114 tary corals, Pecten with original shells, complex than previously suspected. Graham A (2003) Historical phytogeography and internal gastropod molds. Unit 2 Therefore, it would seem important to of the Greater Antilles. Brittonia 55: represents a reef front environment continue studying such paleoenviron- 357-383. and is 4.5m thick; it is a massive unit ments, in order to contribute to the Graham A, Jarzen DM (1969) Studies in Neo- (packstone) containing solitary corals conservation and knowledge of the pa- tropical paleobotany. I. The Oligocene in growth position, colonial corals such leoecology of mangrove-like plants of communities of Puerto Rico. Ann. Mis- as Diploria and Porites, unidentified Puerto Rico. souri Bot. Garden 56: 308-357. burrows, Pecten, crabs remains, M. cf. Hernández-Ávila ML (1970) Beach studies at americanus foraminifers, rhizoliths of ACKNOWLEDGMENTS Isla Mona. Thesis. University of Puerto mangrove origin (LACMIP Ponce, PR Rico, Mayagüez. Puerto Rico. 171 pp. 17772), and internal gastropods molds; The author thanks Hoffmeister JE, Multer HG (1965) Fossil man- it shows a coral framework. Unit 3 rep- Hernán Santos, Jorge Vélez-Juarbe and grove reef of Key Biscayne, Florida. Geol. resents a reef crest environment and is María Ruiz-Yantín (Dept. of Geology, Soc. Am. Bull. 76: 845-852. 4.5m thick; The corals are out of place University of Puerto Rico at Mayagüez Hollick CA (1928) Paleobotany of Porto Rico. and are not as well as cemented in the –UPRM-) for their help in locating the Scientific Survey of Porto Rico and the underlying unit; there are solitary cor- trace fossils; “Storrs L. Olson (Smith- Virgin Islands. Vol. 7, part 2. New York als, Montastrea annularis (Ellis & So- Academy of Science. New York, USA. pp. sonian Institution, Washington, D.C.) 177-393. lander), Porites porites (Pallas), brain for his help on rhizoliths; Alan Graham corals that are probably Diploria; also, (Missouri Botanical Garden, St. Louis, Iturralde-Vinent MA (2001) Geology of the there are few gastropods, bivalves, and amber-bearing deposits of the Greater An- Missouri) for his aid on Table I; Juan tilles. Caribb. J. Sci. 37: 141-167. crabs remains; there is an erosion sur- A. Rivero (Dept. of Biology, UPRM) face between unit 3 and 4. Unit 4 is and Ariel E. Lugo (USDA, Institute of Little EL Jr, Wadsworth FH, Marrero J (2001) 8.05m thick and shows a lagoon envi- Árboles comunes de Puerto Rico y las Is- Tropical Forestry at Río Piedras) for las Vírgenes. 2ª ed. rev. Universidad de ronment similar to Unit 1”. corrections to the text; and Peter Roca- Pleistocene eolianite Puerto Rico. Río Piedras, Puerto Rico. fort (Dept. of Marine Sciences, UPRM) 764 pp. terraces (s.str. Taggart, 1992) that oc- for digitalization of figures. This proj- Lugo AE, Snedaker SC (1974) The ecology of cur in southwestern Mona Island and ect was supported by the University of northern Puerto Rico jut out from the mangroves. Annu. Rev. Ecol. Studies 5: Puerto Rico Alliance for the Graduate 39-64. coastline. The shoreline of Mona Is- Education and the Professorate fel- MacPhee RDE, Wyss AR (1990) Oligo-Mio- land terraces sometime shows “dead lowship (Grant Nº NSF/AGEP–HRD # mangrove roots” that protrude from cene vertebrates from Puerto Rico, with 0302696). a catalog of localities. Am. Mus. Novit. crannies and fissures, and coral fos- 2965: 1-45. sils (e.g., M. annularis, M. cavernosa L., Diploria sp., Acropora palmata La- REFERENCES MacPhee RDE, Iturralde-Vinent MA (1995) marck) are found everywhere (Hernán- Origin of the Greater Antillean land Duke NC (1995) Genetic diversity, distri- mammal fauna, 1: New Tertiary fossils dez-Ávila, 1970; Taggart, 1992). In butional barriers and rafting continents from Cuba and Puerto Rico. Am. Mus. Punta Jacinto, located at Playa Jobos in - more thoughts on the evolution of man- Novit. 3141: 1-31. Isabela, northern Puerto Rico, there is groves. Hydrobiologia 295: 167-181. Martin AJ (1996) Plant trace fossils. www.emory. a typical example of aeolian fossilized Francis JK, Lowe CA, eds (2000) Bioecología edu/COLLEGE/ENVS/research/ ichnology/ dunes having plant root casts (rhizo- de árboles nativos y exóticos de Puerto tf-plants.htm

178 MAR 2007, VOL. 32 Nº 3 Müller J, di Giacomo E, van Erve AW (1987) Prothero DR, Schwab F (1996) Sedimentary ge- southwestern Puerto Rico. Dissertation. Univer- A palynological zonation for the Creta- ology- an introduction to sedimentary rocks sity of Colorado. Boulder, CO, USA. 185 pp. ceous, Tertiary and Quaternary of north- and stratigraphy. Freeman. New York USA. Taggart BE (1992) Tectonic and eustatic cor- ern South America. Am. Assoc. Stratigr. 575 pp. relations of radiometrically dated Late Palynol. Contrib. Ser. 19: 7-76. Rull V (1998) Evolución de los manglares neo- Quaternary marine terraces on northwest- Nieves-Rivera AM (2005) Coastal mycology tropicales: la crisis del Eoceno. Interciencia ern Puerto Rico and Isla de Mona, Puer- of Puerto Rico: A survey and biological 23: 355-362. to Rico. Dissertation. University of Puerto aspects of marine, estuarine, and man- Rico. Mayagüez, Puerto Rico. 252 pp. grove fungi. Dissertation. University of Santos H (1990) The stratigraphy, paleoenviron- Tomlinson PB (1986) The botany of man- Puerto Rico, Mayagüez, Puerto Rico. 382 ments, and biofacies of the Cotuí Limestone: groves. Cambridge Tropical Biology Se- pp. http://grad.uprm.edu/tesis/nievesrivera. Cretaceous of southwestern Puerto Rico. ries. Cambridge University Press. New pdf Thesis. University of Colorado. Boulder, CO, York, USA. 413 pp. USA. 153 pp. Olson SL, James HF (1982) Prodromus of the USDA (2004) Plants database. National Re- fossil avifauna of the Hawaiian islands. Santos H (1999) Stratigraphy and depositional sources Conservation Service. US Depart- Smithsonian Contribution to Zoology 365: history of the Upper Cretaceous strata in the ment of Agriculture. http://plants.usda. 1-59. Cabo Rojo-San Germán structural block, gov/index.html

Notas paleobotánicas acerca de plantas PARECIDAS A MANGLES EN Puerto rico Ángel M. Nieves-Rivera

RESUMEN

Se informa para Puerto Rico varios nuevos fósiles traza puertorriqueño se describe y se ilustra y se proporcionó una (icnofósiles) de plantas parecidas a los mangles; todos es- breve discusión paleobotánica. Al presente, los datos sobre tos fósiles son nuevos registros para Puerto Rico. Los moldes icnofósiles de plantas parecidas a los mangles es muy escasa de raíces más antiguos en Puerto Rico fueron datados del como para especular sobre temas como la dispersión y bio- Cretácico Tardío (probablemente Santoniano, 85,8-83,5Ma). geografía de la isla, especialmente en Puerto Rico. La mayor También se discuten los estudios paleobotánicos previos en parte de la información taxonómica aquí presentada fue re- los yacimientos datados del Terciario en Puerto Rico. Las ro- unida de los reconocimientos fragmentados. Sin embargo, los cas ligníticas, trazas de ámbar y fósiles trazas (probablemen- datos sugieren que la composición fosilífera de las plantas te rizolitos de mangle) del Oligoceno y Mioceno también se parecidas a los mangles es más complejo que lo previamente han encontrado en varias formaciones geológicas del norte y sospechado. Por consiguiente, parece importante el continuar sur de Puerto Rico (e.g., la Formación Juana Díaz y la Ca- estudiando dichos paleoambientes para contribuir a la con- liza Ponce). Los rizolitos de Scaveola cf. plumieri (L.) Vahl servación y el conocimiento de la paleoecología de las plan- han sido colectados de las terrazas costeras de eolianita del tas parecidas a los mangles de Puerto Rico. Pleistoceno que ocurren al norte de Puerto Rico. El material

Notas paleobotÂnicas sobre plantas PARECIDAS A MANGUES EM Porto rico Ángel M. Nieves-Rivera

RESUMO

Informa-se para Porto Rico, vários novos fósseis traça (ic- de Porto Rico. O material porto-riquenho descrito e ilustrado nofósseis) de plantas parecidas aos mangues; todos estes fós- proporcionou uma breve discussão paleobotânica. Atualmente, seis são novos registros para Porto Rico. Os moldes de raízes os dados sobre icnofósseis de plantas parecidas aos mangues mais antigos em Porto Rico foram datados do Cretáceo Tardio são muito escassos como para especular sobre temas como (provavelmente Santoniano, 85,8-83,5Ma). Também se discu- a dispersão e biogeografia da ilha, especialmente em Porto tem os estudos paleobotânicos prévios nas jazidas datadas do Rico. A maior parte da informação taxonômica aqui apresen- Terciário em Porto Rico. As rochas ligníticas, traças de âm- tada foi reunida dos reconhecimentos fragmentados. No entan- bar e fósseis traças (provavelmente rizólitos de mangue) do to, os dados sugerem que a composição fossilífera das plantas Oligoceno e Mioceno também se têm encontrado em várias parecidas aos mangues é mais complexa que o previamente formações geológicas do norte e sul de Porto Rico (e.g., a suspeitado. Por conseguinte, parece importante continuar es- Formação Juana Díaz e a Caliza Ponce). Os rizólitos de Sca- tudando ditos paleoambientes para contribuir à conservação veola cf. plumieri (L.) Vahl têm sido recolhidos dos terraços e o conhecimento da paleoecologia das plantas parecidas aos costeiros de eolianitos do Pleistoceno que ocorrem ao norte mangues de Porto Rico.

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