scholarly journals The genus <i>Krithe</i> (Ostracoda) from the Campanian and Maastrichtian (Upper Cretaceous) of the northern US Gulf Coastal Plain

1997 ◽  
Vol 16 (2) ◽  
pp. 145-157 ◽  
Author(s):  
T. Markham Puckett
Keyword(s):  
North America ◽  
Dissolved Oxygen ◽  
Causal Relationship ◽  
Coastal Plain ◽  
Upper Cretaceous ◽  
Single Species ◽  
Dissolved Oxygen Concentration ◽  
Gulf Coastal Plain ◽  
Wide Range ◽  
The Relationship

Abstract. The ostracode genus Krithe is one of the most common genera in the Upper Cretaceous (late Santonian to Maastrichtian) deposits of the northern Gulf Coastal Plain of North America. Although it is never abundant, the genus occurs in sediments that were deposited under a wide range of palaeoenvironments, including nearshore sandy marls to offshore, nearly pure, chalk. The taxonomy of this taxon has been problematical, and what is herein considered to be a single species, K. cushmani, has been referred to in the literature under five different names. Two morphotypes were observed: relatively large individuals with ‘mushroom’-shaped vestibules collected from chalk, and smaller individuals with pocket-shaped vestibules collected from nearshore deposits. Species of Krithe have been hypothesized to be useful in estimating dissolved oxygen concentration in ancient ocean floors, based on details of their morphology. Whereas the relationship between size and environment corroborates with previous predictions (larger individuals live in deeper water), the morphology of the vestibules contradicts predictions (the larger vestibules occur in the nearshore deposits and the smaller, more constricted vestibules occur in the chalk). A causal relationship between environment and morphology is discussed.

Exogyra in Upper Cretaceous chalky strata of western Kansas, U.S.A.: a biogeographic enigma

1995 ◽  
Vol 69 (1) ◽  
pp. 187-191 ◽  
Author(s):  
Donald E. Hattin
Keyword(s):  
Coastal Plain ◽  
Upper Cretaceous ◽  
The Other ◽  
Gulf Coastal Plain ◽  
Wide Range ◽  
Siliciclastic Rocks

Upper cretaceous strata of the U. S. Gulf Coastal Plain are rich in species and numbers of Exogyra, which occurs in a wide range of facies including siliciclastics, marls, and chalks. Specimens of Exogyra belonging to numerous well-defined species are also common to abundant locally in Upper Cretaceous siliciclastic rocks at many localities within the U. S. Western Interior, but the genus is exceedingly sparse in marly and chalky rocks of the same region. Intensive collecting in the chalky outcrops of western Kansas has yielded only two specimens of Exogyra, which are notable not only for good shell preservation but also for uniqueness of their respective occurrence. One of these specimens was collected from the Smoky Hill Chalk Member, Niobrara Chalk (Figure 1), and the other was collected from the Fairport Member, Carlile Shale (Figure 1). Principal paleontological works that treat the Niobrara fauna, especially including those of Meek (1876), Stanton (1893), Logan (1898), Scott and Cobban (1964), Miller (1968), and Hattin (1982), make no mention of the genus in that formation. Hattin (1962) documented a lone occurrence of Exogyra in the Fairport Member of Kansas, and sparse occurrence of E. cf. E. suborbiculata Lamarck in the Fairport was recorded by Kauffman (1961), whose material was collected in Huerfano Park, Colorado, where the member is calcareous or marly shale. Stratigraphic occurrence of the two Kansas specimens is presented in Figure 1, which also depicts ranges of other Exogyra species that have been recorded in the Upper Cretaceous of western Kansas.

scholarly journals Description of an extant salamander from the Gulf Coastal Plain of North America: The Reticulated Siren, Siren reticulata

PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0207460
Author(s):  
Sean P. Graham ◽  
Richard Kline ◽  
David A. Steen ◽  
Crystal Kelehear
Keyword(s):  
North America ◽  
Coastal Plain ◽  
Gulf Coastal Plain

Ostracodes and chronostratigraphic position of the Upper Cretaceous Arkadelphia Formation of Arkansas

1994 ◽  
Vol 68 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Kasana Pitakpaivan ◽  
Joseph E. Hazel
Keyword(s):  
Coastal Plain ◽  
Upper Cretaceous ◽  
Gulf Coastal Plain ◽  
Number Of Species ◽  
Sublittoral Zone ◽  
Upper Maastrichtian

The ostracode assemblage of the Arkadelphia Formation, upper Maastrichtian, of southwestern Arkansas is characterized by a well-preserved, relatively diverse, and abundant fauna representing 36 podocopid species and an undetermined number of species of the platycopid genus Cytherella. Thirteen of these account for 85 percent of the fauna. The dominant forms are Cytherella spp., Brachycythere rhomboidalis (Berry, 1925), Haplocytheridea renfroensis Crane, 1965, Haplocytheridea bruceclarki (Israelsky, 1929), and Brachycythere ovata (Berry, 1925), which account for about 57 percent of the specimens found. Other species that are less common, but are characteristic of the Arkadelphia, are Antibythocypris macropora (Alexander, 1929), Ascetoleberis hazardi (Israelsky, 1929), Aversovalva fossata (Skinner, 1956), Brachycythere ledaforma (Israelsky, 1929), Curfsina communis (Israelsky, 1929), Cytheromorpha arbenzi (Skinner, 1956), Escharacytheridea micropunctata (Alexander, 1929), and Veenia arachoides (Berry, 1925). The ostracode assemblage indicates that the Arkadelphia was deposited in the inner sublittoral zone.The species Veenia parallelopora (Alexander, 1929) and Brachycythere foraminosa Alexander, 1934, are restricted to the Arkadelphia Formation and allow correlation with other Gulf Coastal Plain Upper Cretaceous units. A new ostracode interval zone, the Veenia parallelopora Zone, is proposed. This zone divides the Platycosta lixula Zone.Calcareous planktic microfossils reported from the Arkadelphia and its correlatives in the Veenia parallelopora Zone indicate that these deposits are late Maastrichtian in age, not middle Maastrichtian as some authors have thought.

Late Santonian megaspore floras from the Gulf Coastal Plain (Georgia, USA)

2011 ◽  
Vol 85 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Richard Lupia
Keyword(s):  
New Species ◽  
North America ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Eastern North America ◽  
Gulf Coastal Plain ◽  
Two New Species ◽  
Western Interior Basin ◽  
Heterosporous Ferns

Fossil megaspore floras from the Late Cretaceous of North America have been studied extensively, but primarily from the Western Interior Basin. Two new megaspore floras are described from eastern North America along the Gulf Coastal Plain. Cumulatively, 10 genera and 16 species of megaspores are recognized from Allon, Georgia and along Upatoi Creek, Georgia (both late Santonian in age, ~84 Ma). Megaspores identified have affinities to both heterosporous lycopsids, e.g., Erlansonisporites, Minerisporites, and Paxillitriletes, and to heterosporous ferns, e.g., Ariadnaesporites, and Molaspora. Lycopsid megaspores are more diverse than fern megaspores in the Allon and the Upatoi Creek floras. Two new species—Erlansonisporites confundus n. sp. and Erlansonisporites potens n. sp.—are proposed.

scholarly journals A late-surviving apatemyid (Mammalia: Apatotheria) from the latest Oligocene of Florida, USA

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1509 ◽  
Author(s):  
Nicholas J. Czaplewski ◽  
Gary S. Morgan
Keyword(s):  
New Species ◽  
North America ◽  
Coastal Plain ◽  
Eastern North America ◽  
Gulf Coastal Plain ◽  
Early Oligocene ◽  
Alachua County ◽  
The Family ◽  
Distal Edge ◽  
A New Species

A new species of Apatemyidae,Sinclairella simplicidens, is based on four isolated teeth that were screenwashed from fissure fillings at the late Oligocene Buda locality, Alachua County, Florida. Compared to its only congenerSinclairella dakotensis, the new species is characterized by upper molars with more simplified crowns, with the near absence of labial shelves and stylar cusps except for a strong parastyle on M1, loss of paracrista and paraconule on M2 (paraconule retained but weak on M1), lack of anterior cingulum on M1–M3, straighter centrocristae, smaller hypocone on M1 and M2, larger hypocone on M3, distal edge of M2 continuous from hypocone to postmetacrista supporting a large posterior basin, and with different tooth proportions in which M2 is the smallest rather than the largest molar in the toothrow. The relatively rare and poorly-known family Apatemyidae has a long temporal range in North America from the late Paleocene (early Tiffanian) to early Oligocene (early Arikareean). The new species from Florida significantly extends this temporal range by roughly 5 Ma to the end of the Paleogene near the Oligocene-Miocene boundary (from early Arikareean, Ar1, to late Arikareean, Ar3), and greatly extends the geographic range of the family into eastern North America some 10° of latitude farther south and 20° of longitude farther east (about 2,200 km farther southeast) than previously known. This late occurrence probably represents a retreat of this subtropically adapted family into the Gulf Coastal Plain subtropical province at the end of the Paleogene and perhaps the end of the apatemyid lineage in North America.

TAXONOMY AND PALEOECOLOGY OF RUDIST BIVALVES FROM UPPER CRETACEOUS STRATA, GULF COASTAL PLAIN, USA

2020 ◽  
Author(s):  
Alex Zimmerman ◽  
◽  
Claudia Johnson ◽  
George E. Phillips ◽  
Dana J. Ehret
Keyword(s):  
Coastal Plain ◽  
Upper Cretaceous ◽  
Gulf Coastal Plain ◽  
Rudist Bivalves
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