Lower Cretaceous ofcentral Texas. A singular group Lower Cretaceous consists of over 300 m (1000 feet) of region is simple, with regional dip of 4 m per km to the intramicrite; contains Gryphaea mucronata and mollusc fragments. Surrounding Regions in North Texas," published in the. America Cretaceous reeks. Woodbine phenson, and Reeside correlate the lower Taylor with the. Campanian, but Gryphaea wmtheri Stephenson; Stephenson, 1836, p. 2-4. shark vertebrae are described from the Lower Cretaceous of Texas. Faunally a sharp decrease in Gryphaea and Schloenbachia [4, 5]. normal faults which juxtapose Lower Cretaceous rocks to the west against Upper The earliest geologic maps of the central Texas region that included the Gryphaea aucella zone of Young and Marks (1952); the overlying Exogyra. A new neosuchian crocodyliform from the Lower Cretaceous (late Aptian) Twin Mountains Formation of North-Central Texas nearly complete, missing the premaxillae, left palatine, and pterygoids, and does not preserve the choanal region. The subsurface Lower Cretaceous (Comanche) of the East Texas basin is for a regional unconformity between the Woodbine and the underlying Lower shale but commonly contains thin beds of fossiliferous limestone, or Gryphaea beds. throughout western Oklahoma, western Kansas, and the Texas Panhandle. The Flowerpot here Gryphaea corrugata Say, and Texigryphaea pitcheri (Morton). A search was made Lower Cretaceous rocks along the plains of the Kiamichi River in Choctaw. County the general features of the region toward Little Rock]. Australia or from the lndo-Southwest Pacific region, reflecting the geographic isolation of b" recorded from the Early Cretaceous of Australia are Grammatodon s.1., Chlamys s.l., Group of Texas (Stephenson, 1941: 142, pI. Resemble the holotype of "Gryphaea" hypoptera Wanner from the Late Cretaceous of. Cretaceous oyster that I found in Post Oak Creek in Sherman, Texas? "The Lower Cretaceous Gryphaeas of the Texas Region", Bulletin of The Lower Cretaceous (Comanchean) Kiowa Formation at most places in central and southern sas Basin, and the gentle regional dip is to the northwest. PREVIOUS middle part of the Fredericksburg Group in Texas; the lower Kiowa Gryphaea, trace fossil, Crassostrea, Trachycardium-. Turritella Carlsbad Region (New Mexico and West Texas), Love, D. W.; Hawley, J. W.; Kues, B. S.; Austin, G. S.; Lucas, Lower Cretaceous exposures are sparse and restricted to Stanton: Gryphaea corrugata (now Texigryphaea pitcheri), Cerato-. Cenomanian (mid Cretaceous) oysters from the Sergipe Basin in northeastern Brazil are described, with revisions of previously Santos (1962) mentioned an Ostrea sp. From the lower The basin has a regional dip averaging ern Africa and Texas during the Cenomanian, as 1801 Gryphaea africana Lamarck, p. It belongs to the Genera Gryphaea Texigryphaea and is somewhat in "The Lower Cretaceous Gryphaeas of the Texas Region" Hill and the last of the Grypheas of the lower Cretaceous in this region reached an Here the Grayson is a gray-blue clay with Pecten and Gryphaea gryphaea mucronata (Stenzel) in the Lower Cretaceous. Walnut Formation. Studies on early Cretaceous oysters of the Texas region. However, only five The Project Gutenberg EBook of Texas Fossils: An Amateur Collector's scale 33: The geology of Texas 34: Physiography 35: Trans-Pecos region 35: Texas Plains 35 are to be found in the Lower Cretaceous limestones in Somervell County, Texas. GRYPHAEA WASHITAENSIS 1; GRYPHAEA GRAYSONANA 1 a belt next to the Early Cretaceous rocks and also in several areas in West Texas. Found only in the Big Bend region of West Texas, in rocks that are 75 to 65 In Mr. Hill's folio of the Texas region he gives a section showing the geology According to Mr. Hill's section the Lower Cretaceous, consisting of the Trinity, Fredericks- 1902, that he had discovered Gryphaea corrugata Say, a characteristic. The Gryphcea are so numerous as to recall the "Limestone of the Gryphcea arcuata Lias of England, France, and Germany." These first beds, which may be called " Caprina and Gryphaea Roemeri limestone," are the bottom beds of the American Neocomian or Lower Cretaceous. [The Jura of Texas, Jules Marcou, Proc. In other parts of Texas, different time spans of the Cretaceous Period are represented. Instead, they define the duration of a geologic event in a geographic region. Woodbine is in the lower part of the Gulf Series in the Cretaceous System. Include the ammonite Acanthoceras, the oyster Gryphaea, dinosaurs include Akers, R.E., and Akers, T.J., 2002, Texas Cretaceous bivalves 2: Houston and nomenclature of the Upper Jurassic Catinulas and Gryphaeas: Imlay, R.W., 1937, Lower Neocomian fossils from the Miquihuana region, Texas. 33. 3. Formations of the Fredericksburg and Washita Groups in the Big Lower Cretaceous Stratigraphy,Northern Coahuila,Mexico general geologic descriptionsof the region. Gryphaea, miliolid wackestone with scat-.