Notes on the dentition and relationships of the Late Cretaceous insectivore Gypsonictops Simpson

1977 ◽  
Vol 14 (8) ◽  
pp. 1823-1831 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
Late Cretaceous ◽  
North American ◽  
The North

The most nearly complete maxilla known of the North American Late Cretaceous insectivore Gypsonictops hypoconus Simpson 1927 is described. The specimen exhibits P3–4M1 in place; alveoli present anterior to P3 indicate a total of four upper premolars of which the first was single-rooted. Relationships between Gypsonictops and its presumed ancestor Kennalestes gobiensis Kielan-Jaworowska 1969 are discussed.

LATE CRETACEOUS EXHUMATION OF UNDERPLATED METASEDIMENTARY ROCKS IN THE NORTH AMERICAN CORDILLERA

2019 ◽  
Author(s):  
William A. Matthews ◽  
◽  
Marie-Pier Boivin ◽  
Kirsten Sauer ◽  
Daniel S. Coutts
Keyword(s):  
Late Cretaceous ◽  
North American ◽  
North American Cordillera ◽  
Metasedimentary Rocks ◽  
The North

scholarly journals Late Turonian-early Coniacian belemnites from western and central Europe

1982 ◽  
Vol 31 ◽  
pp. 63-79
Author(s):  
Walter Kegel Christensen
Keyword(s):  
Central Europe ◽  
Late Cretaceous ◽  
North American ◽  
Evolutionary Trends ◽  
Taxonomic Character ◽  
Central European ◽  
The North ◽  
The Family ◽  
Early Late

A little known fauna of late Turonian--early Coniacian belemnites from the Central European palaeobiogeographic Subprovince is revised and the following species are recognised: Actinocamax strehlensis (Fritsch & Schlonbach), A. bohemicus Stolley, A. paderbornensis Schliiter, and A. esseniensis n. sp. The taxonomic value of various characters within Late Cretaceous belemnites belonging to the family Belemnitellidae Pavlov is discussed, and it is concluded that the shape of the guard is a more significant taxonomic character than the presence of granules. The species from the subprovince are compared to coeval species from the Central Russian Subprovince and the North American Province. The palaeobiogeography and evolutionary trends of early Late Cretaceous belemnites are discussed.

Early Campanian Multituberculates (Mammalia: Allotheria) from the Upper Milk River Formation, Alberta

1971 ◽  
Vol 8 (8) ◽  
pp. 916-938 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
Late Cretaceous ◽  
North American ◽  
Upper Cretaceous ◽  
Sampling Error ◽  
Taxonomic Diversity ◽  
New Genus And Species ◽  
The North ◽  
Evolutionary Radiation ◽  
Mammalian Teeth ◽  
Milk River Formation

Mammalian teeth collected from the early Campanian Upper Milk River Formation, southernmost Alberta, document a hitherto unknown evolutionary radiation of Late Cretaceous ptilodontoid and taeniolabidoid multituberculates. New species of the ectypodontids Mesodma and Cimexomys, the ptilodontid Cimolodon, and the cimolomyid Meniscoessus are defined, and teeth possibly pertaining to a second species of Mesodma and two species of Cimolomys are described. A new genus and species with uncertain relationships to known multituberculate families, is tentatively classified in the Taeniolabidoidea. Among North American Late Cretaceous multituberculates, at least Mesodma, Cimexomys, Cimolodon, Cimolomys, and Meniscoessus are seen to be evolutionarily conservative during early Campanian to late Maestrichtian times. The effects of sampling error on relative taxonomic diversity at horizons in the North American Upper Cretaceous are discussed.

scholarly journals The Late Cretaceous belemnite family Belemnitellidae: Taxonomy and evolutionary history

1997 ◽  
Vol 44 ◽  
pp. 59-88
Author(s):  
W. K. Christensen
Keyword(s):  
Northern Hemisphere ◽  
Late Cretaceous ◽  
North American ◽  
Evolutionary History ◽  
The North ◽  
Northern European ◽  
Nomen Dubium ◽  
The Family

The Late Cretaceous belemnite family Belemnitellidae Pavlow, 1914 occurs only in the Northern Hemisphere and includes nine genera and two subgenera: Praeactinocamax Naidin, 1964b, Actinocamax Miller, 1823, Belemnocamax Crick, 1910, GonioteuthisBayle, lS7S,BelemnellocamaxNaidin, 1964b,Goniocamax Naidin, 1964b, Belemnitella d'Orbigny, 1840, Belemnella (Belemnella) Nowak, 1913, Belemnella (Pachybelemnella) Schulz, 1979, Belemnella (Neobelemnella) Naidin, 1975 and Fusiteuthis Kongiel, 1962. The latter is most likely a nomen dubium. Diagnoses of the genera and subgenera are provided. The origin of the family is poorly known. The number of genera and subgenera, fluctuated during the Late Cretaceous. It was one to two in the Cenomanian, increased gradually to a maximum of six in the Early Santonian, decreased gradually to one during most of the Late Campanian and increased to two or possibly three in the Maastrichtian. The belemnitellids occur in the North European and North American palaeobiogeographical Provinces of the North Temperate Realm, in additon to the northern European margin of the Tethyan Realm. The centre of evolution lay in the North European Province and all known genera and subgenera occur there. Species of five genera and two subgenera occur on the northern European margin of the Tethyan Realm and the majority of these are conspecific with species from the North European Province. Species of essentially two genera occur in the North American Province and these are endemic, with a few exceptions.

Late Cretaceous gastropods from the Izumi Group of southwest Japan

1990 ◽  
Vol 64 (4) ◽  
pp. 563-578 ◽  
Author(s):  
Tomoki Kase
Keyword(s):  
Late Cretaceous ◽  
North American ◽  
Upper Cretaceous ◽  
Coastal Areas ◽  
Basal Part ◽  
Northwestern Pacific ◽  
New Genera ◽  
Southwest Japan ◽  
The North ◽  
The Family

The basal part of the Upper Cretaceous, mid-Campanian to Maastrichtian Izumi Group of the Izumi Mountains and Awaji Island, Southwest Japan, contains the most diverse gastropod fauna of this age in Japan. This paper discriminates 19 species and describes two new genera: Atira tricarinata n. sp., Ataphrus (s.s.) sp. A, Ataphrus (s.s.) sp. B, Globularia (s.s.) izumiensis n. sp., Lysis izumiensis n. sp., Trichotropis? sp., Deussenia takinoikensis n. sp., Volutilithes antiqua n. sp., Pseudoperissitys bicarinata Nagao and Otatume, Nekewis sp., Nipponitys inouei n. gen. and sp., Nipponitys acutangularis n. gen. and sp., Nipponitys sp. cf. N. magna (Kalishevitsch), Calorebama cretacea n. sp., Taniella japonica n. gen. and sp., Amuletum (s.s.) sp., Biplica osakensis n. sp., Biplica sphaerica n. sp., and Cylichna sp. The family Ampullospiridae is assigned to the suborder Architaenioglossa from the superfamily Naticacea. The enigmatic genus Lysis is tentatively assigned to the Calyptraeidae. Taniella japonica n. sp. is the oldest member of the family Olividae, and Calorebama cretacea n. sp. is the oldest member of the subfamily Pseudolivinae. Occurrence of Atira, Ataphrus, Biplica, and five perissityids further supports close communication of the northwestern Pacific Late Cretaceous gastropod faunas with those of the North American Pacific coastal areas.

Actinocamax cobbani n. sp. from the Coniacian of Montana and Wyoming and the occurrence of Late Cretaceous belemnites in North America and Greenland

1993 ◽  
Vol 67 (3) ◽  
pp. 434-446 ◽  
Author(s):  
Walter Kegel Christensen
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
North American ◽  
Ventral View ◽  
Morphological Characters ◽  
The North

Actinocamax cobbani, a new belemnitellid species from the middle Coniacian of Montana and Wyoming, is described, including univariate and bivariate biometric analyses. The species is stout and medium sized, lanceolate or strongly lanceolate in ventral view, and has adorally a low cone-shaped alveolar fracture. It may be granulated. It is compared to species of Actinocamax Miller and Gonioteuthis Bayle from the North American and North European paleobiogeographic provinces. The importance of various morphological characters, such as the shape of the guard and the structure of the adoral end, are discussed. The majority of the belemnitellids of the North American Province are endemic and the stratigraphic distribution is punctuated during the Late Cretaceous, suggesting short-lived migrations of populations from the North European Province.

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