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

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.

Download Full-text

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

PeerJ ◽

10.7717/peerj.1509 ◽

2015 ◽

Vol 3 ◽

pp. e1509 ◽

Cited By ~ 2

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.

Download Full-text

Miocene rhinoceroses from the Texas Gulf Coastal Plain

Journal of Paleontology ◽

10.1017/s0022336000028559 ◽

1987 ◽

Vol 61 (2) ◽

pp. 388-423 ◽

Cited By ~ 11

Author(s):

Donald R. Prothero ◽

Earl M. Manning

Keyword(s):

New Species ◽

North America ◽

Coastal Plain ◽

Middle Miocene ◽

Early Miocene ◽

High Plains ◽

Gulf Coastal Plain ◽

Local Fauna ◽

Southeast Texas ◽

A New Species

Four species of rhinoceros occur together in the Barstovian (middle Miocene) faunas of southeast Texas, a unique situation in the Miocene of North America. Two are assigned to normal contemporary High Plains species of Aphelops and Teleoceras, and two to dwarf species of Peraceras and Teleoceras. The dwarf Peraceras is a new species, P. hessei. The dwarf Teleoceras is assigned to Leidy's (1865) species “Rhinoceros” meridianus, previously referred to Aphelops. “Aphelops” profectus is here reassigned to Peraceras.The late Arikareean (early Miocene) Derrick Farm rhino, erroneously referred to “Caenopus premitis” by Wood and Wood (1937), is here referred to Menoceras arikarense. Menoceras barbouri is reported from the early Hemingfordian (early Miocene) Garvin Gully local fauna of southeast Texas. The rhinos from the early Clarendonian Lapara Creek Fauna are tentatively referred to Teleoceras cf. major.The three common genera of middle late Miocene rhinoceroses of North America (Aphelops, Peraceras, Teleoceras) are rediagnosed. Aphelops and Peraceras are more closely related to the Eurasian Aceratherium and Chilotherium (all four together forming the Aceratheriinae) than they are to the American Teleoceras. Contrary to Heissig (1973), Teleoceras is more closely related to the living rhinoceroses and their kin (together forming the Rhinocerotini) than it is to the Aceratheriinae.

Download Full-text

First record of the Tethyan genus Volutilithes (Gastropoda: Volutidae) in the Paleogene of the Gulf Coastal Plain, with a discussion of Tethyan molluscan assemblages in the Gulf Coastal Plain and Florida

Journal of Paleontology ◽

10.1017/s0022336000036532 ◽

1989 ◽

Vol 63 (6) ◽

pp. 852-856 ◽

Cited By ~ 7

Author(s):

Charles R. Givens

Keyword(s):

North America ◽

Coastal Plain ◽

New World ◽

Carbonate Platform ◽

First Record ◽

Early Eocene ◽

Climatic Warming ◽

Gulf Coastal Plain ◽

The Third ◽

Northward Expansion

Lapparia sp. A of Toulmin (1977), from the early Eocene Hatchetigbee Formation of Alabama, is referable to the Tethyan genus Volutilithes and is conspecific with Voluta clarae Harris. This is the first certain record of Volutilithes in the Paleogene of the Gulf Coastal Plain and only the third record of the genus in North America. Trans-Atlantic migration of this tropical genus to the New World apparently occurred during the early Eocene. Its northward expansion into the higher latitudes of Alabama and southern California was probably in response to early Eocene climatic warming.In addition to Volutilithes, many other molluscs with Tethyan affinities are present in the Paloegene deposits of the Gulf Coastal Plain. These Tethyan elements, however, differ from those reported from the Eocene of peninsular Florida. The presence of a filter-bridge barrier, the Suwannee Channel, between the eastern Gulf shelf and the Floridian carbonate platform during the Paleogene may account for this difference.

Download Full-text

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

Journal of Micropalaeontology ◽

10.1144/jm.16.2.145 ◽

1997 ◽

Vol 16 (2) ◽

pp. 145-157 ◽

Cited By ~ 4

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.

Download Full-text

Late Neogene Neohipparion (Mammalia, Equidae) from the Gulf Coastal Plain of Florida and Texas

Journal of Paleontology ◽

10.1017/s0022336000029152 ◽

1987 ◽

Vol 61 (4) ◽

pp. 809-830 ◽

Cited By ~ 11

Author(s):

Richard C. Hulbert

Keyword(s):

North America ◽

Phylogenetic Relationship ◽

Late Miocene ◽

Coastal Plain ◽

Valid Species ◽

Intermediate Form ◽

Gulf Coastal Plain ◽

Alachua County ◽

Close Phylogenetic Relationship ◽

Late Neogene

Three successive species of Neohipparion are recognized from the Gulf Coastal Plain: N. affine from the early Clarendonian Lapara Creek Fauna of Texas; N. trampasense from the very late Clarendonian and early Hemphillian of Florida; and N. eurystyle from the late early and late Hemphillian of Florida. Numerous specimens from the Love Site, Alachua County, Florida, as well as from other faunas of similar age from Florida, Kansas, and Nebraska (e.g., the Xmas-Kat Quarries), are referred to N. trampasense. This species is ancestral to all later species of Neohipparion, as it shares with them many advanced dental characters, but often in a rudimentary or intermediate form. Five valid species constitute the monophyletic genus Neohipparion, which ranges from the late Barstovian to the latest Hemphillian (late Miocene through earliest Pliocene) in North America. A close phylogenetic relationship between Neohipparion and “Merychippus” republicanus and/or Pseudhipparion is proposed based on similarities of cranial and dental features.

Download Full-text