The lower Eocene floras of southeastern North America

Berry, Edward W.

doi:10.3133/pp91

Cited by 100 publications

(122 citation statements)

References 0 publications

Supporting

Mentioning

117

Contrasting

Unclassified

Order By: Relevance

“…Perhaps the main argument against such a hypothesis is the lack of an ancient fossil record. The earliest pollen dates to the Eocene and Miocene from Louisiana (Berry, 1916) and West Africa (van Steenis, 1969). Pollen deposits of Avicennia are generally light, as this is an insectpollinated genus, which may partly account for the absence of earlier pollen records.…”

Section: mentioning

confidence: 99%

Evolutionary divergence in the pan‐Atlantic mangrove Avicennia germinans

Dodd¹,

Rafii²,

Bousquet-Mélou³

2000

New Phytologist

View full text Add to dashboard Cite

Cuticular hydrocarbon composition was determined for 18 populations of Avicennia germinans (Avicenniaceae) collected from West Africa, Florida, the Pacific coast of Mexico and French Guyana. Variation in covariance structure among the hydrocarbons was evaluated from correlations among the traits for each of the populations and from a hierarchical common principal components analysis. Principal components ordinations of populations based on the 171 z* transformed correlation coefficients, onto which a minimal spanning tree was superimposed, suggested a network in which French Guyanan populations formed a nexus from which African populations differentiated biochemically from Floridan and Mexican groups. Common principal components analysis provided further support for the differentiation in covariance structure among these biochemical traits of African populations. Pacific coast Mexican populations appeared to have diverged less in covariation among traits from Atlantic American sources than did the northern (Floridan) and southern (French Guyanan) Atlantic American populations from one another. The complete isolation of Pacific coast sources after emergence of the Central American isthmus during the Pliocene provides a reference for comparison of levels of differentiation among regions that suggests an underlying pattern of divergence in this species. Partial Mantel matrix tests revealed significant geographic effects, with no significant climatic effects. Our results provide support for recognition of a major differentiation between Old and New World sources within the taxon and indicate the need for a full revision of this species.

show abstract

Section: mentioning

confidence: 99%

Evolutionary divergence in the pan‐Atlantic mangrove Avicennia germinans

Dodd¹,

Rafii²,

Bousquet-Mélou³

2000

New Phytologist

View full text Add to dashboard Cite

show abstract

“…Conditions on the Gulf Coast during the Miocene were probably ideal for direct precipitation on the shallow nearshore shelf and in basins and lagoons of elevated salinity. Faunal and floral studies (see Dorf, 1960;Berry, 1916aBerry, , 1937 indicate that tropical and sub-tropical climates existed throughout eastern and southeastern United States during this time. The accompanying lateritic weathering would have made the nearshore waters rich in colloidal and dissolved silica.…”

Section: Georgia-florida Depositsmentioning

confidence: 99%

Discussion of the Occurrence and Origin of Sedimentary Palygorskite-Sepiolite Deposits

Isphording

1973

Clays and clay miner.

View full text Add to dashboard Cite

Abstract--Marine and non-marine palygorskite-sepiolite deposits are found throughout the world and occur interbedded with chert, dolomite, limestone, phosphates and other non-detrital sedimentary rocks. The origin of these high-magnesium clays has long been attributed to either alteration of volcanic ash or the structural transformation of smectite clays. More recently, others have argued origin by direct crystallization (neo-formation). Recent laboratory studies support this latter concept, particularly in environments where the concentration of alumina is low, the silica concentration high, and the pH alkaline. Such an origin is proposed for the Georgia-Florida deposits in southeastern United States, since major obstacles exist against formation by alteration of volcanic ash or by transformarion of smectites. Lateritic weathering during the Miocene would have favored direct precipitation of these clays in the shallow, marginal seas. The basinward increase in the MgO: AI~O3 ratio is further support.Deep weathering of crystalline rocks in northern British Honduras and Guatemala would have produced similar high silica, low alumina conditions on the adjacent submerged Yucatan Platform during the late Tertiary. The seaward increase in the MgO:Al203 ratio, the lack of associated detrital constituents, and the absence of associated smectites strongly indicate a similar origin by direct crystallization of these Yucatan palygorsldte-sepiolite clays.Some occurrences of palygorskite and sepiolite may well be related to the alteration of smectite clays or volcanic ash. However, many of the large sedimentary deposits are more probably the result of direct crystallization adjacent to areas undergoing tropical or subtropical weathering.

show abstract

“…39, 40), display a vascular pattern very similar to that of Oreomunnea: the central portion of the bract is supplied by three major strands that pass almost directly to the apex of the lobe, and the lateral lobes are each independently supplied from the base of the bract by three veins. Comparative morphology (Manning, 1940) and the fossil record (Berry, 1916;Dilcher, Potter and Crepet, 1976;Crane and Manchester, 1982) Fig. 3-14. then Platycarya has subsequently reverted to an unlobed bract, though it has retained the basic venation.…”

Section: )mentioning

confidence: 99%

The Platycarya Perplex and the Evolution of the Juglandaceae

Wing

Hickey

1984

American J of Botany

View full text Add to dashboard Cite

We report on the leaves, fruits, inflorescences, and pollen of two fossil species in the genus Platycarya. The association of these dispersed organs has been established by their repeated co‐occurrence at a large number of localities, and for two of the organs (fruit and pistillate inflorescence, and pollen and staminate inflorescence) by apparent organic attachment of compression fossils. Each of the two species can be distinguished by characteristics of all the known megafossil organs. We also review the fossil record of dispersed platycaryoid fruits and inflorescences, recognizing three additional species of Platycarya and two of Hooleya. Two of the fossil Platycarya species are morphologically very different from the living Platycarya strobilacea Sieb. et Zucc., but they show the diagnostic features of the genus. Hooleya is a generalized member of the Platycaryeae that is probably close to the ancestry of Platycarya. The two Platycarya species known from multiple organs provide a remarkable example of mosaic evolution in which fertile and foliar structures have attained different levels of morphological specialization. The leaves, often considered the most plastic of plant organs, retain several features that are otherwise seen only in the Engelhardieae. These similarities in leaf architecture between the fossil Platycarya species and Engelhardieae are advanced features for the Juglandaceae, and thus indicate a sister‐group relationship between the two lines. In contrast to the leaves, the fruits, inflorescences, and pollen of the fossil Platycarya species are almost as specialized as those of the extant P. strobilacea and bear little resemblance to the same structures in other genera of the family. The morphology, taphonomy, sedimentary setting, and geographic and stratigraphic distribution of three of the fossil platycaryoid species suggest that they were wind‐dispersed, early successional plants that grew in thickets. This habit is retained by Platycarya strobilacea and is typical of many of the amentiferae (e.g. Myricaceae, Betulaceae). The r‐selected life‐history pattern of the Platycarya line may well have contributed to its low diversity through geologic time.

show abstract

The lower Eocene floras of southeastern North America

Cited by 100 publications

References 0 publications

Evolutionary divergence in the pan‐Atlantic mangrove Avicennia germinans

Evolutionary divergence in the pan‐Atlantic mangrove Avicennia germinans

Discussion of the Occurrence and Origin of Sedimentary Palygorskite-Sepiolite Deposits

The Platycarya Perplex and the Evolution of the Juglandaceae

Contact Info

Product

Resources

About