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The lower part of the Shinarish Formation of Djebel Sinjar, northwest Iraq, yields an ammonite assemblage of Upper Campanian age dominated by heteromorph taxa: Nostoceras (Nostoceras) ellipticum new species, N. (N.)(?) budanyi Foldyna and Vasicek, 1977, N. (N.) cf. hyatti Stephenson, 1941, Exiteloceras(?) etequense Lewy, 1969, Didymoceras sp., unassigned nostoceratid fragments, Solenoceras reesidei Stephenson, 1941, and Lewyites oronensis (Lewy, 1969), together with the normally coiled Hauericeras (Gardeniceras) sp. Several of the species present also occur in the lower part of the Mishash Formation in Israel, in the Gulf Coast region of the United States, and as rarities in the U.S. Western Interior. All occurrences are compatible with an Upper Campanian attribution.

New collections from the Marshalltown Formation and basal Mount Laurel Sand along the Chesapeake and Delaware Canal in Delaware clarify the ammonite dating of the interval. The Marshalltown Formation yields Pachydiscus (Pachydiscus) sp., Menuites portlocki (Sharpe, 1855) complexus (Hall and Meek, 1856), a subspecies restricted to the Baculites gregoryensis and Baculites scotti zones in the Western Interior of the United States, and Didyrnoceras binodosurn (Kennedy and Cobban, 1993a) known only from the B. scotti zone of the Western Interior and correlatives in Arkansas and Texas. The basal part of the Mount Laurel Sand contains a complex assemblage preserved as phosphatic molds: Nostoceras (Nostoceras) rnonotuberculaturn Kennedy and Cobban, 1993a, Nostoceras (N.) sp., Didyrnoceras platycostaturn (Kennedy and Cobban, 1993b), D. stevensoni (Whitfield, 1877))previously thought to be from the Marshalltown) and Exiteloceras jenneyi (Whitfield, 1877). The last two are index species of their eponymous zones in the Western Interior. This sequence is compatible with ammonites from the Wenonah Formation, which lies between the Marshalltown and Mount Laurel to the north and contains ammonites indicative of the Baculites scotti zone, and the fauna from higher in the Mount Laurel Sand, which includes elements of the Didymoceras cheyenneme and Baculites compressus zones of the Western Interior sequence.

The Prairie Bluff Chalk of Alabama and Mississippi yields a diverse ammonite fauna of Maastrichtian age. Twenty-eight species, of which three are new, are recorded herein: Pseudophyllites indra (Forbes, 1846), Hauericeras rembda (Forbes, 1846), Pachydiscus (Pachydiscus) maconensis n. sp., P. (P.) cf. gollevillensis (d'Orbigny, 1850), P. (P.) jacquoti (Seunes, 1890), P. (P.) egertoni (Forbes, 1846), Sphenodiscus lobatus (Tuomey, 1854), S. pleurisepta (Conrad, 1857), Coahuilites sheltoni Bose, 1928, Nostoceras (Nostoceras) alternatum (Tuomey, 1854), N. (N.) mendryki Cobban, 1974a, N. (N.) magdadiae Lefeld and Uberna, 1991, N. (N.) irregulare n. sp., Glyptoxoceras torquatum (Morton, 1834), Glyptoxoceras sp. A, Glyptoxoceras? sp., Baculites lomaensis Anderson, 1958, Baculites spp. A-C, Eubaculites labyrinthicus (Morton, 1834), E. carinatus (Morton, 1834), Baculites? trabeatus (Morton, 1834), Trachybaculites columna (Morton, 1834), Discoscaphites conradi (Morton, 1834), D. gulosus (Morton, 1834), Jeletzkytes criptonodosus Riccardi, 1983, Trachyscaphites alabamensis n. sp., and T. yorkensis (Stephenson, 1941). One genus, Trachybaculites, is new. The bulk of the fauna can be referred to a Discoscaphites conradi assemblage zone, but some elements in the fauna are significantly older.

The Mount Laurel Sand at Biggs Farm, Delaware, yielded a diverse ammonite fauna comprising Pachydiscus (Pachydiscus) sp., Placenticeras cf. P. placenta (DeKay, 1828), Placenticeras n. sp., Eulophoceras sp., Nostoceras (Nostoceras) draconis Stephenson, 1941, Didymoceras cheyennense (Meek and Hayden, 1856a), Anaklinoceras reflexum Stephenson, 1941, Anaklinoceras tenuicostatum n. sp., Oxybeloceras meekanum (Whitfield, 1877), Solenoceras annulifer Morton, 1841, Baculites ovatus Say, 1820, B. undatus Stephenson, 1941, Hoploscaphites vistulensis Blaszkiewicz, 1980, and Jeletzkytes compressus (Roemer, 1841). The last named two species occur in Europe and indicate an upper but not uppermost upper Campanian horizon. Several species also occur in the Western Interior and suggest correlation with the Didymoceras cheyennense zone and part of the Baculites compressus zone of the upper Campanian in that region.

The condensed Upper Albian to Lower Cenomanian deposits of the Helvetic Shelf of France and Switzerland yield diverse ammonite faunas including representatives of the family Lyelliceratidae, subfamily Stoliczkaiinae that is the origin of the Upper Cretaceous Acanthoceratidae and its descendants, as well as representatives of the dwarf stoliczkaiine offshoot, the family Flickiidae, subfamily Salaziceratinae. The following are described and referred to the Upper Albian Mortoniceras inflatum Zone: Neophlycticeras (N.) brottianum (d'Orbigny, 1841), N. (N.) rhodanense Delamette, 1983, N. (Protissotia) itierianum (d'Orbigny, 1841), and Zuluscaphites helveticus n. sp. From the Upper Albian Stoliczkaia dispar Zone come Neophlycticeras (N.) blancheti (Pictet and Campiche, 1859), N. (Paradolphia) priscum Casey, 1965, Stoliczkaia (S.) notha (Seeley, 1865), S. (S.) tenuis Renz, 1968, S. (Lamnayella) tetragona Neumayr, 1875, Cenisella bonnetiana Pictet, 1847, Zuluscaphites orycteropusi Van Hoepen, 1955, Salaziceras (S.) salazacense (Hebert and Munier-Chalmas, 1875), and S. (S.) breistrofferi Scholz, 1979. The Lower Cenomanian Mantelliceras mantelli Zone, Neostlingoceras carcitanense Subzone yields Stoliczkaia (Stoliczkaia) villoutreysi Casey, 1965, S. (Lamnayella) tetragona Neumayr, 1875, and S. (Shumarinaia) hashimotoi Matsumoto and Inoma, 1975.

The Saratoga Chalk of Arkansas yields a rich ammonite fauna of 17 species, referred to the Nostoceras (N.) hyatti zone. Recognition that the northwest European N. (N.) pozaryskii Blaszkiewicz, 1980, is a synonym of N. (N.) hyatti Stephenson, 1941, and N. (N.) helicinum (Shumard, 1861) dates the zone as latest Campanian on the basis of co-occurrence with Belemnitella langei Jeletzky, 1948, in Poland. Most previous estimates of the Campanian-Maastrichtian boundary in the Gulf Coast have been drawn at too low a level, at least in terms of ammonite faunas. Elements of the N. (N.) hyatti zone fauna occur in the United States Western Interior, and show the base of the Maastrichtian there to lie above the Baculites jenseni zone.

Geological research in the Corsicana Formation in northeast Texas produced four previously undescribed collections of ammonites, bringing the number of these Maastrichtian ammonites found there to eleven. Similar fauna are found in northern Mexico, the Escondido Formation in Trans-Pecos Texas and the Prairie Bluff Chalk of Mississippi and Alabama. Maryland's Severn Formation and the Owl Creek Formation of Mississippi, Missouri and Tennessee have also produced elements of these fauna.

A detailed isotopic profile is presented for a stratigraphically expanded Cenomanian-Turonian boundary section in Chalk facies exposed at Eastbourne, Sussex and compared with data from Pueblo, Colorado. In both sections macro- and micropalaeontological markers (first appearances and disappearances) are well-constrained, and their relative positions and relationship to the structure of the carbon-isotope curve are identical. This consistent relationship between two independent phenomena, one geochemical, the other biostratigraphical, is taken as evidence for the likely synchroneity of both the biostratigraphical markers and the carbon-isotope excursion in these two areas. This interpretation contrasts with suggestions made recently by other authors whose data have been taken to imply a lack of correlation between the carbon-isotope excursion in Europe and North America.

The middle Campanian Wolfe City Sand in northeastern Texas yields a distinctive ammonite and inoceramid fauna with Patagiosites sp., Placenticeras sp., Hoplitoplacenticeras (Hoplitoplacenticeras) minor n. sp., Baculites mclearni Landes, 1940, Trachyscaphites spiniger (Schluter, 1872) porchi (Adkins, 1929), Inoceramus (Cordiceramus) azerbaidjanensis Aliev, 1939, and I. (Endocostea) balticus Boehm, 1907. The last-named four species allow a direct correlation with the Baculites mclearni zone of the Western Interior of the United States. The base of this zone has been dated at 79.9 plus or minus 3.2/79.2 plus or minus 1.6 Ma on the basis of K/Ar determinations on biotite from a bentonite. Inoceramus azerbaidjanensis is also known from the Campanian of the U.S.S.R. in Azerbaidjan (where the species was first described), western Turkemenia, Georgia, the northern Caucasus, the Crimea, and Donbass.

Ammonites are abundant in the phosphatic base of the Annona Chalk (Campanian) near Yancy in Hempstead County, Arkansas. The following are described: Pachydiscus (Pachydiscus) sp. (very rare), Placenticeras sp. (very rare), Nostoceras (Nostoceras) pulcher n. sp. (rare), N. (N.) monotuberculatum n. sp. (scarce), N. (N.) plerucostatum n. sp. (frequent), N. (N.) danei (frequent), Didymoceras sp. (rare), Didymoceratoides binodosum n. gen. and sp. (frequent), D. clardyi n. gen. and sp. (rare), Baculites taylorensis Adkins, 1929 (abundant), B. crickmayi Williams, 1930 (common), and Baculites sp. (abundant). The diverse Nostoceras association is typical of Gulf Coast upper Campanian rocks but Didymoceratoides is a Western Interior upper middle Campanian genus. Nostoceras (N.) monotuberculatum n. sp., however, is known from a single specimen from the basal upper Campanian Didymoceras stevensoni zone in Colorado.

The Roxton Limestone Member at the top of the Gober Chalk in northeast Texas yields a rich fauna, do Baculites haresi Reeside, 1927, and Inoceramus balticus Boehm, 1909, with sparse occurrences of Pach 1963), Anapachydiscus sp. juv., Placenticeras placenta (DeKay, 1828), Hoplitoplacenticeras aff. H. p (Delawarella) delawarensis (Morton, 1830), M. (D.) danei (Young, 1963), M. (D.) aff. M. (D.) vanuxem vandalinaense Young, 1963, Submortoniceras sp., Eubostrychoceras sp., and Scaphites hippocrepis (DeK The presence of S. hippocrepis III suggests a late early Campanian age assignment for the fauna. The known from the Western Interior, Gulf Coast, Atlantic seaboard, and western Europe., The Campanian ammonites from the Roxton Limestone member of the upper Cretaceous Gober Chalk in Lamar County, TX, are described. Baculites haresi and Inoceramus balticus dominated the formation, whereas Pachydiscus cf. P. paulsoni, Anapachydiscus sp., Hoplitoplacenticeras aff. H. plasticum, Placenticeras placenta, Menabites danei, M. delawarensis, M. vanuxemi, Submortoniceras vandalinaense Young, Submortoniceras sp., Eubostrychoceras and Scaphites hippocrepis III were sparsely distributed. Late early Campanian assignment for the assemblage is based on the occurrence of S. hippocrepis III.

Cretaceous/Tertiary boundary sections located in the Biscay region of southwestern France and northern Spain are among the most complete of all known land-based sequences across this boundary. New collections of ammonites and inoceramid bivalves from five localities show quite distinct extinction patterns for these two groups of characteristic Cretaceous molluscs: from eight to ten ammonite species extend into the latest Cretaceous, and possibly to the boundary. In contrast, inoceramid bivalve diversity gradually diminished from a minimum of six species in the early Maastrichtian to zero at the beginning of the late Maastrichtian, when they were replaced by the cryptic pteriomorph Tenuipteria. Extinction of typical inoceramids well before the end of the Maastrichtian is supported by data from other regions, indicating that it was a global rather than local phenomenon.

Two ammonite type specimens described in 1850 by Alcide D'Orbigny were given the names Ammonites silimani and Ammonites danae. The species names have been changed, but identification of these two types is valid for referring to either the old names or the new species names, Hoploscaphites nicoletti and Discoscaphites gulosus. The new descriptions are also based on the type specimens described by D'Orbigny.

Specimens collected from the Fox Hills Formation in west-central Dakota yielded three species of Baculites. Descriptions are given of the three species, including a new species and another endogastrically curved species whose nomenclature was left open to further study. The proposed name for the new species is Baculites larsoni. All the species are from the very high Cretaceous of the Western Interior of South Dakota.

Maastrichtian ammonites are described from two areas in Pakistan. The upper part of the lower unit of the Korara Shale in the southern Pab Range, Kirthar Province, southern Balochistan, is dated as Late Maastrichtian, based on the presence of Menuites fresvillensis (Seunes, 1890), which is accompanied by abundant Indoceras baluchistanense Noetling, 1897, common Baculites ambatryensis Collignon, 1971, and rarer Neophylloceras surya (Forbes, 1846), Gaudryceras kayei (Forbes, 1846), Anagaudryceras politissimum (Kossmat, 1895), Kitchinites spengleri n. sp., Pachydiscus (Pachydiscus) noetlingi n. sp., Libycoceras acutodorsatus (Noetling, 1897), and Diplomoceras cylindraceum (Defrance, 1816). A smaller assemblage from the Mughal Kot Formation near Kach, Suleman Province, northern Balochistan cannot be dated more precisely than Maastrichtian from the presence of Pachydiscus (Pachydiscus) neubergicus (Hauer, 1858), the first occurrence of which has been provisionally adopted by the Subcommission on Cretaceous Stratigraphy as marking the base of the Maastrichtian stage. It is associated with numerous Eubaculites binodosus (Noetling, 1897).