Coleoptera fossils: their potential value for dating and correlation of late Cenozoic sediments

1977 ◽  
Vol 14 (10) ◽  
pp. 2339-2347 ◽  
Author(s):  
John V. Matthews Jr.
Keyword(s):  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Fossil Plants ◽  
Late Cenozoic ◽  
Extinct Species ◽  
Extant Species ◽  
Late Tertiary ◽  
Climatic History ◽  
Cenozoic Sediments ◽  
Insect Fossils

Coleoptera (beetle) fossils play an important role in paleoecological research, but as yet have contributed little information bearing on dating and correlation. The reason for this is that most Quaternary fossils represent extant species, precluding the evolutionary approach to dating, while the rarity and poor preservation of Tertiary beetle fossils, many of which are from extinct species, seriously limit their application to stratigraphic studies.Tertiary beetle fossils recently discovered in Arctic Canada and Alaska are both well preserved and abundant. Most of them represent extinct species that are closely related to living forms, hence they have potential stratigraphic value. In one case treated herein comparison of fossils of an Alaskan Tertiary species with those of a related species from the Beaufort Formation on Meighen Island (Canadian Arctic Archipelago) implies that the latter sediments were deposited less than 5.7 Ma ago. However, this conclusion requires testing because it is at odds with the date on Meighen Island exposures reached by study of fossil plants. I submit that further study of the insect fossils from the Beaufort Formation and other late Tertiary sites will help resolve such problems of dating and correlation.Quaternary beetle fossils have stratigraphic value even though fragments of that age represent for the most part only existing species. For example, it has been shown that late Pleistocene fossils of stenothermal Coleoptera species can provide a sensitive record of climatic change, and thus such fossils may be used for site to site correlation in areas where climatic history is well documented. In exceptional cases beetle fossils appear to provide a more accurate basis for correlation than even fossil pollen.

Late Cenozoic paleomagnetic record of Duck Hawk Bluffs, Banks Island, Canadian Arctic Archipelago

1990 ◽  
Vol 27 (1) ◽  
pp. 124-130 ◽  
Author(s):  
R. W. Barendregt ◽  
Jean-Serge Vincent
Keyword(s):  
Canadian Arctic ◽  
Unconsolidated Sediments ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Gradual Change ◽  
Canadian Arctic Archipelago ◽  
Late Cenozoic ◽  
Precise Position ◽  
Banks Island ◽  
Late Tertiary

Detailed paleomagnetic investigations have been completed on unconsolidated sediments from Duck Hawk Bluffs on Banks Island, in the Canadian Arctic Archipelago, that record some of the oldest late Cenozoic glacial and nonglacial events in Canada. The preglacial Worth Point Formation, the overlying Duck Hawk Bluffs Formation, including marine and glacial deposits laid down during the Banks Glaciation, and the lower part of the interglacial Morgan Bluffs Formation have magnetically reversed directions and therefore are of Matuyama age (>790 ka). Upper Morgan Bluffs Formation organic beds and deposits of the younger Thomsen Glaciation, Cape Collinson Interglaciation, and Amundsen Glaciation are normally magnetized and therefore of Brunhes age (<790 ka). The Brunhes–Matuyama boundary is recorded in the upper portion of the Morgan Bluffs Formation. Its precise position within the interglacial sequence can be identified, since the sediments document the gradual change from reversely inclined directions to normally inclined ones. These results confirm that the preglacial Worth Point Formation is at least Early Pleistocene in age and that the Banks Glaciation (the oldest and strongest continental glaciation recorded in the western Arctic) and a good part of the Morgan Bluffs Formation are of Early Pleistocene age. The study also documents a rare site in Canada where terrestrial sediments record the Brunhes–Matuyama transition and in doing so permits a precise correlation of part of the Banks Island stratigraphy with other key late Tertiary and Early to Middle Pleistocene arctic terrestrial and marine sequences.

Evolution of the subgenus Cyphelophorus (Genus Helophorus, Hydrophilidae, Coleoptera): description of two new fossil species and discussion of Helophorus tuberculatus Gyll.

1976 ◽  
Vol 54 (5) ◽  
pp. 652-673 ◽  
Author(s):  
John V. Matthews Jr.
Keyword(s):  
Intraspecific Variation ◽  
Canadian Arctic ◽  
Morphological Features ◽  
Canadian Arctic Archipelago ◽  
Evolutionary Trends ◽  
Fossil Species ◽  
The North ◽  
Extant Species ◽  
Late Tertiary ◽  
North American Arctic

Exposures of late Tertiary sediments in the North American Arctic contain well-preserved fossils of Coleoptera (beetles). Two sites, Lava Camp in western Alaska and locality 2-73 on Meighen Island (Canadian Arctic Archipelago), have yielded fragments referable to two fossil species of the helophoran subgenus Cyphelophorus (Hydrophilidae). The only extant species in the subgenus, Helophorus tuberculatus Gyll., is characterized by a distinctive array of elytral tubercles, the intraspecific variation of which is documented here as an aid for distinguishing H. tuberculatus from the two fossil species.The two fossil species are obviously related to H. tuberculatus and probably represent sequential species in the lineage leading to H. tuberculatus. If so, they provide information on evolutionary trends within the Cyphelophorus lineage, and when examined in the light of the morphological features of species in other Helophorus subgenera, show that the tuberculate elytron seen in H. tuberculatus is probably a derived character that developed by modification of an elytron initially having raised alternate interstices.

Magnetostratigraphy of Quaternary and late Tertiary sediments on Banks Island, Canadian Arctic Archipelago

1998 ◽  
Vol 35 (2) ◽  
pp. 147-161 ◽  
Author(s):  
R W Barendregt ◽  
J -S Vincent ◽  
E Irving ◽  
J Baker
Keyword(s):  
Climate Changes ◽  
Direct Evidence ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Banks Island ◽  
Pleistocene Climate ◽  
Late Tertiary ◽  
Normal Polarity ◽  
Continental Glaciation ◽  
Geocentric Axial Dipole

Sediments approximately 50 m thick from Banks Island (Canadian Arctic Archipelago) contain one of the longest terrestrial records of Pleistocene climate changes in North America. Samples have been obtained from 126 horizons distributed among four localitites, of which 116 horizons yielded acceptable paleomagnetic data. In sediments of the Matuyama Reversed Zone, there are recorded at least two and possibly as many as five full continental glaciations, two interglacial intervals, and a nonglacial interval at the beginning which is considered preglacial. Subzones attributable to the Olduvai and Jaramillo are present within the Matuyama Reversed Zone. The Brunhes Normal Zone records three full continental glaciations and three interglaciations. The Brunhes-Matuyama boundary occurs within interglacial deposits. The preglacial Worth Point Formation records a climate milder than today, and cooler than that of the late Tertiary. Based on floral, faunal, stratigraphic, and paleomagnetic constraints, a normal polarity sequence in the Worth Point Formation is assigned to the Olduvai normal polarity subzone (1.95-1.77 Ma). The earliest direct evidence of glaciation on Banks Island occurs in sediments that postdate the Worth Point Formation ( <<1.77 Ma). Consequently, in the western Canadian Arctic, the first continental glaciation postdated the first glaciation in the Canadian Cordillera (2.6 Ma) by at least a million years. The overall mean direction of the Quaternary geomagnetic field in Banks Island does not differ significantly from the geocentric axial dipole field, and these sediments contain no inclination error.

The late Tertiary – Quaternary stratigraphic record of the Duck Hawk Bluffs, Banks Island, Canadian Arctic Archipelago

1983 ◽  
Vol 20 (11) ◽  
pp. 1694-1712 ◽  
Author(s):  
J.-S. Vincent ◽  
S. Occhietti ◽  
N. Rutter ◽  
G. Lortie ◽  
J.-P. Guilbault ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Glacial Deposits ◽  
Amundsen Sea ◽  
Glacial Sediments ◽  
Marine Deposits ◽  
Banks Island ◽  
Late Tertiary ◽  
Composite Section ◽  
Glaciomarine Sediments

The Duck Hawk Bluffs, of southwestern Banks Island in the Canadian Arctic Archipelago, record a succession of late Tertiary – Quaternary events. Organic-bearing sediments of eolian, fluvial, and lacustrine origin that overlie the Late Cretaceous Kanguk Formation and the Miocene Beaufort Formation record preglacial events of Pliocene and (or) early Quaternary age and are assigned to the Worth Point Formation. These are covered by glacial sediments of the Duck Hawk Bluffs Formation associated with the Banks Glaciation, the oldest of the three recognized glaciations to reach the island. Associated with the glacial deposits are marine or glaciomarine sediments deposited in the glacio-isostatically depressed area as the ice both advanced and retreated. These sediments are in turn covered by interglacial sediments (Morgan Bluffs Formation), by marine deposits (Big Sea sediments associated with the Thomsen Glaciation), and by younger interglacial sediments (Cape Collinson Formation). Events associated with the early Wisconsinan M'Clure Stade of the last or Amundsen Glaciation are recorded in a coastal section east of the Duck Hawk Bluffs. There, marine deposits (pre-Amundsen Sea sediments) are covered by glacial deposits (Sachs Till) of the M'Clure Stade, D/L ratios of aspartic acid in fossil wood from the Morgan Bluffs and Cape Collinson interglacial sites, respectively, vary between 0.22 and 0.31 and 0.12 and 0.13, while Holocene wood is 0.08. A composite section is proposed for these bluffs that record some of the oldest events in the Canadian Quaternary and the various units are correlated with the previously published Quaternary framework for Banks Island.

Clay mineralogy of late Cenozoic sediments in the CESAR cores, Alpha Ridge, central Arctic Ocean

1987 ◽  
Vol 24 (8) ◽  
pp. 1562-1569 ◽  
Author(s):  
Robert W. Dalrymple ◽  
Oliver C. Maass
Keyword(s):  
Arctic Ocean ◽  
Canadian Arctic ◽  
Clay Mineralogy ◽  
Potassium Feldspar ◽  
The Arctic ◽  
Late Cenozoic ◽  
Central Arctic Ocean ◽  
Glacial Ice ◽  
Western Arctic ◽  
Cenozoic Sediments

The clay-sized (< 2 μm) fraction of the silty and arenaceous lutites constituting CESAR cores 14 and 103 (Alpha Ridge, central Arctic Ocean) is composed predominantly of mica (40–60%), with subequal percentages (10–20%) of kaolinite and chlorite and lesser amounts (< 5%) of smectite, quartz, plagioclase, and potassium feldspar. Calcite and dolomite also occur, but only intermittently in the upper 1.2 m; dissolution is probably responsible for their absence in other units. The silty lutites have a constant mineralogy throughout the 4.5 m long (~ 4.25 Ma) section, whereas some of the arenaceous intervals in the upper 2.1 m have markedly higher amounts of kaolinite, calcite, dolomite, and, to a lesser extent, smectite. The silty lutites were most likely derived from the Beaufort Sea shelf during nonglacial periods, whereas the distinctive components in the sandy layers suggest that they were transported from the Canadian Arctic Islands and Greenland by glacial ice. The absence of kaolinite peaks in the lower half of the core implies that the western Arctic Islands were not glaciated prior to 2.1 Ma, a conclusion supporting previous findings that the climate of the Arctic was warmer in the Pliocene.

West Palearctic cobras of the genus Naja (Serpentes: Elapidae): interrelationships among extinct and extant species

1990 ◽  
Vol 11 (4) ◽  
pp. 385-400 ◽  
Author(s):  
Jean-Claude Rage ◽  
Zbigniew Szyndlar
Keyword(s):  
Monophyletic Group ◽  
Close Relative ◽  
African Species ◽  
Naja Naja ◽  
Extinct Species ◽  
Extant Species ◽  
Asiatic Species ◽  
Extinct Genus

AbstractSome basic osteological cranial features of living and fossil members of the genus Naja are described. The extinct genus Palaeonaja Hoffstetter, 1939, is synonymized with the modern Naja Laurenti, 1768, and the extinct species Palaeonaja crassa Hoffstetter, 1939, is synonymized with Naja romani (Hoffstetter, 1939). Anatomically, the genus Naja can be divided into two main complexes, composed of: (1) living African species, N. antiqua from the Moroccan Miocene, and N. iberica from the Spanish Miocene; (2) living Asiatic species and N. romani from the Miocene of France, Austria, and Ukraine. Living members of the Asiatic complex make up a monophyletic group; they belong to at least three distinct lineages: N. oxiana, N. naja s.s. ( = N. naja naja), and the remaining taxa named here informally the 'East Asiatic Naja'. The African complex is thought to be most primitive and perhaps paraphyletic; Africa is presumed to be the centre of earliest radiation of the genus. The precise relationships of Walterinnesia, a close relative of Naja occupying the area between Asiatic and African ranges of Naja, remain unclear.

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