Growth and reproductive biology of Joffrea speirsii gen. et sp. nov., a Cercidiphyllum-like plant from the Late Paleocene of Alberta, Canada

1985 ◽  
Vol 63 (2) ◽  
pp. 340-364 ◽  
Author(s):  
Peter R. Crane ◽  
Ruth A. Stockey
Keyword(s):  
Upper Cretaceous ◽  
Constant Field ◽  
Short Shoot ◽  
Early Tertiary ◽  
Late Paleocene ◽  
Large Numbers ◽  
Close Relationship ◽  
Field Association ◽  
Short Shoots ◽  
Floodplain Habitats

Six kinds of angiosperm compression fossils are described from the Paskapoo Formation (Late Paleocene) at Joffre Bridge near Red Deer, Alta. Pistillate inflorescences with attached carpels, folliculate infructescences, seeds, seedlings, leaves, and shoots arc all assigned to Joffrea speirsii gen. et sp. nov. Crane and Stockey. Evidence for treating the different organs under a single binomial includes attachment of inflorescences and leaf petioles to long and short shoot systems, morphological intermediates between carpels and follicles, follicles preserved expelling seeds, seeds preserved during germination, stages in seedling development, similarity between seedling and adult foliage, and constant field association. Joffrea is similar in many respects to the widespread Upper Cretaceous and early Tertiary fossil Nyssidium arcticum (Heer) Iljinskaja. Comparison of Joffrea to the extant genera Cercidiphyllum Siebold et Zuccarini, Trochodendron Siebold et Zuccarini, and Tetracentron Oliver indicates a close relationship to Cercidiphyllum; and Joffrea is interpreted as an extinct representative of the family Cercidiphyllaceae. The fossil material clarifies morphological interpretations of the pistillate reproductive structures in extant Cercidiphyllum. The probable staminate inflorescences of Joffrea, are also similar to extant Cercidiphyllum. They are budlike and composed of 10–20 bracts, some of which have stamens in their axils. Pollen has not been recovered from the anthers. Pistillate inflorescences developed from axillary buds on the short shoots and were probably wind-pollinated. The production of numerous small winged seeds, epigeal germination, and the preservation of large numbers of in situ seedlings suggest that Joffrea speirsii and similar extinct Upper Cretaceous and early Tertiary species may have been "weedy" plants capable of rapidly colonizing open floodplain habitats.

Unconformities on the Scotian Shelf

1974 ◽  
Vol 11 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Lewis H. King ◽  
Brian MacLean ◽  
Gordon B. Fader
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Upper Cretaceous ◽  
Scotian Shelf ◽  
Early Tertiary ◽  
Late Tertiary ◽  
Glacial Processes ◽  
Well Data ◽  
Seismic Reflection Profiles ◽  
Cut And Fill

Four erosional unconformities have been recognized within the Mesozoic-Cenozoic succession on the Scotian Shelf, on the basis of data from high resolution seismic reflection profiles. Older unconformities are known from well data and others may be revealed by detailed biostratigraphic studies.The oldest of the four unconformities discussed in this paper is of Early Cretaceous age and appears to mark, with discordance, the boundary between Jurassic and Cretaceous strata on the western part of the shelf. A second angular unconformity, of Late Cretaceous age, has been recognized on the central part of the shelf where the basal part of the Banquereau Formation (Tertiary and uppermost Cretaceous) oversteps the zero-edge of the Wyandot Formation (Upper Cretaceous) and lies upon truncated beds of the Dawson Canyon Formation (Upper Cretaceous). Cut-and-fill relationships characterize a third unconformity developed during Early Tertiary time. A fourth unconformity was developed in Late Tertiary – Pleistocene time by fluvial processes and later by glacial processes. Although in many areas the latest unconformity appears to be the most conspicuous one on the shelf, its configuration closely follows the geomorphic expression developed during the previous period of erosion. The regional extent of the Cretaceous unconformities is not known, and they might only occur near basin margins and on structural and basement highs.

Geochemistry and tectonic environment of the Şarkışla area volcanic rocks in central Anatolia, Turkey

1987 ◽  
Vol 51 (362) ◽  
pp. 553-559 ◽  
Author(s):  
E. Gökten ◽  
P. A. Floyd
Keyword(s):  
Upper Cretaceous ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Central Anatolia ◽  
Magmatic Arc ◽  
Early Tertiary ◽  
Tectonic Environment ◽  
Geochemical Study ◽  
Lithological Composition ◽  
Back Arc

AbstractThe volcanic rocks of the Şarkışla area in northeastern central Anatolia are associated with volcaniclastics, turbiditic limestones and pelagic-hemipelagic shales of Upper Cretaceous-Palaeocene age. A preliminary geochemical study was undertaken to constrain local tectonic models, and due to the variable altered nature of the volcanics, determine the lithological composition and magma type. Chemically the volcanics are an andesite-dominated suite of calc-alkali lavas, probably developed adjacent to an active continental margin in a local (ensialic back-arc?) basinal area. The volcanic activity was probably related to a postulated magmatic arc just south of the area during the early Tertiary.

Latest Cretaceous and early Tertiary Tudiclidae and Melongenidae (Gastropoda) from the Pacific Slope of North America

1988 ◽  
Vol 62 (6) ◽  
pp. 880-889 ◽  
Author(s):  
Louella R. Saul
Keyword(s):  
North America ◽  
New Genus ◽  
Eastern Pacific ◽  
Early Tertiary ◽  
Late Paleocene ◽  
The Pacific ◽  
Pacific Slope

Four species belonging in Tudiclidae and one in Melongenidae have been confused with perissityids. The new genus Rapopsis is proposed for a tudiclid species, R. joseana n. sp. of early Maastrichtian age. Three other tudiclid species may belong in the Tethyan genus Pyropsis, P. fantozzii n. sp. of early to middle Paleocene age, P. striata (Stanton, 1896) of later Paleocene age, and ?P. gabbi (Stanton, 1896) probably of early to middle Paleocene age. The melongenid genus Protobusycon, represented by P. judithae n. sp. of late Paleocene age, has not previously been recognized in eastern Pacific faunas.

Leaf area development on different shoot types in a young aspen stand and its effect upon production

1970 ◽  
Vol 48 (10) ◽  
pp. 1801-1804 ◽  
Author(s):  
D. F. W. Pollard
Keyword(s):  
Leaf Area ◽  
Total Production ◽  
Short Shoot ◽  
Area Index ◽  
Young Leaves ◽  
Long Shoots ◽  
Short Shoots ◽  
Area Development ◽  
Leaf Area Development ◽  
Photosynthetic Efficiencies

Different shoot types in aspen crowns carried leaves of different ages; leaders continued to produce leaves until early August and always carried some young leaves, whereas short shoots completed development by mid-June. Development of foliage on long shoots was intermediate between that on leaders and short shoots. Leaf area index of the 6-year-old stand reached a maximum of 2.4, of which 2.1 was contributed by short-shoot foliage. The rest was formed by leaders and long shoots. Young leaves on leaders and long shoots were not sufficient to influence total production in the stand appreciably, even though young aspen leaves may have high photosynthetic efficiencies. These young leaves could, however, influence height growth and lateral development of the canopy.

Shoot type demography and dry matter partitioning: a morphometric approach in apple (Malus ×domestica)

2001 ◽  
Vol 79 (11) ◽  
pp. 1270-1273 ◽  
Author(s):  
Pierre-Éric Lauri ◽  
Jean-Jacques Kelner
Keyword(s):  
Leaf Area ◽  
Malus Domestica ◽  
Detrimental Effect ◽  
Canopy Structure ◽  
Short Shoot ◽  
Dry Matter Partitioning ◽  
Fruiting Branch ◽  
Long Shoots ◽  
Short Shoots ◽  
Time Required

In a study of the apple (Malus ×domestica Borkh.) canopy structure, 5-year-old 'Fuji' and 'Braeburn' trees grafted on a low-vigour rootstock (M9) were compared at both fruiting branch and shoot levels. Percentages of short ([Formula: see text]5 cm) shoots and short shoot leaf area were significantly higher on 'Braeburn' than on 'Fuji', (76.8% vs. 72.6% and 46.9% vs. 42.9% for 'Braeburn' and 'Fuji', respectively). This high percentage of short shoots as compared with literature data was probably due to the training method, which reduced vigour. At shoot level, the ratio between dry masses of axis and leaf, called the axialization index, was determined to compare short and long shoots. Axialization values were higher for 'Braeburn' than for 'Fuji'. Although overall and individual leaf area was greater on long shoots, long shoot axialization (0.64 and 0.54 for 'Braeburn' and 'Fuji', respectively) was approximately twice that of short shoots (0.36 and 0.24, respectively). Therefore, for short shoots, the reduced carbon investment in supporting tissues may explain the significant role short shoots played in supporting early fruit development. For long shoots, the longer time required to reach the autotrophic and then exporting stage as well as the detrimental effect of early extension shoot development on fruit set might be explained by greater axialization.Key words: long shoot, short shoot, axialization index, apple, Malus ×domestica, biomass partitioning.

Palynological characteristic of the border cretaceous and paleogene deposits in the Sourth of Trans-Ural region (bh 9, Troizk)

2020 ◽  
Author(s):  
Olga B. Kuzmina ◽  
◽  
Natalia K. Lebedeva ◽  
Keyword(s):  
Upper Cretaceous ◽  
Western Siberia ◽  
Middle Eocene ◽  
Ural Region ◽  
The South ◽  
Spores And Pollen ◽  
Early Oligocene ◽  
Late Paleocene

The Upper Cretaceous and Paleogene sediments exposed in Borehole 9 (Troizk, Chelyabinsk Area) in the south of the Trans-Ural Region (Western Siberia) are studied by palynological methods. The BH9 has uncovered the Fadyushinskaya and Gan’kino formations of Upper Cretacious age and the Talitsa, Serov, Irbit, Chegan and Kurtamysh formations of Paleogene age. Nine dinocysts assemblages and nine spores and pollen assemblages were revealed. The Campanian, Maastrichtian, Late Paleocene, Low-Middle Eocene and Early Oligocene age of the sediments were substantiated.

Molecular phylogenetics of the Australian acacias of subg. Phyllodineae (Fabaceae: Mimosoideae) based on the trnK intron

2003 ◽  
Vol 51 (2) ◽  
pp. 167 ◽  
Author(s):  
Joseph T. Miller ◽  
Rose Andrew ◽  
Randall J. Bayer
Keyword(s):  
Dna Sequences ◽  
Molecular Phylogenetics ◽  
Sequence Divergence ◽  
Large Numbers ◽  
Close Relationship ◽  
Trnk Intron ◽  
Species Groups ◽  
Morphological Species ◽  
Sectional Classification ◽  
Relationship Of

With over 960 species, Acacia is the largest genus of plants in Australia with all but nine of these species classified as subgenus Phyllodineae. DNA sequences for the chloroplast trnK region were sequenced for over 100 species to test sectional classification and survey species relationships within this subgenus. Only one of the seven recognised sections was found to be monophyletic; however, the close relationship of sect. Botrycephalae to certain racemose, uninerved species of sect. Phyllodineae is confirmed. Support is found for an expanded version of Vassal's Pulchelloidea, with the addition of sect. Lycopodiifoliae and several members of sect. Phyllodineae. These species, while morphologically distinct in adult foliage, possess similar seedling characteristics. The multinerved species are unresolved, indicating a rapid morphological radiation with little chloroplast sequence divergence among these species. The low levels of sequence divergence, large numbers of morphological species groups and the adaptive radiation of the group are discussed.

Crown architecture of Larix laricina saplings: an analysis of higher order branching

1987 ◽  
Vol 65 (2) ◽  
pp. 268-279 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Simulation Modelling ◽  
Shoot Length ◽  
Larix Laricina ◽  
Structural Development ◽  
Short Shoot ◽  
Lateral Buds ◽  
Architectural Patterns ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Shoot

Quantitative analysis and simulation modelling of Larix laricina (Du Roi) K. Koch branches revealed a complex system of architectural patterns and correlations. Numbers of lateral buds and long shoots were positively correlated with parent-shoot length, but the relationships varied among shoot orders and for sylleptic shoots. For order 2 and sylleptic shoots, numbers of lateral long shoots were also correlated with associated terminal-shoot lengths. Sylleptic shoots produced more lateral long shoots than equivalent proleptic shoots. Lateral long-shoot lengths decreased basipetally and were correlated with terminal-shoot lengths. Lengths of order 2 lateral long shoots also varied independently with crown position. Generally, the degree of apical control decreased and the proportion of short shoots increased with positions of less vigour in the crown. Terminal long-shoot lengths varied with parent-shoot length, location, and to some extent parent-axis leader length. Terminal short-shoot production was associated with shorter parent shoots. Shorter order 2 shoots (<60 mm) and most order 3 shoots produced no lateral long shoots. The net result was that branch structural development ceased in less vigorous crown positions. The spatial disposition of shoots, as defined by elevation and divergence angles, varied with position of origin around and along parent shoots. Although variable, elevation angles decreased and divergence angles increased basipetally.

Monimiaceae sensu lato, an element of Gondwanan polar forests: Evidence from the late Cretaceous-early tertiary wood flora of Antarctica

2001 ◽  
Vol 14 (2) ◽  
pp. 207 ◽  
Author(s):  
Imogen Poole ◽  
Helmut Gottwald
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
First Record ◽  
Southern South America ◽  
Anatomical Features ◽  
Early Tertiary ◽  
Breadth Ratio ◽  
Ecological Dominance ◽  
Perforation Plates ◽  
The Antarctic

Palaeofloristic studies of the Antarctic Peninsula region are important in furthering our understanding of (i) the radiation and rise to ecological dominance of the angiosperms in the Southern Hemisphere during the Late Cretaceous and (ii) the present day disjunct austral vegetation. Investigations of Upper Cretaceous and Early Tertiary sediments of this region yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood which provides evidence for the existence, since the Late Cretaceous, of temperate forests similar in composition to those found in present-day southern South America, New Zealand and Australia. This paper describes two previously unrecognised morphotypes, which can be assigned to the Monimiaceae sensu lato, and represents the first record of this family in the wood flora of Antarctica. Specimens belonging to the first fossil morphotype have been assigned to Hedycaryoxylon SÜss (subfamily Monimioideae) because they exhibit anatomical features characteristic of Hedycaryoxylon and extant Hedycarya J.R.Forst. &amp; G.Forst. and Tambourissa Sonn. Characters include diffuse porosity, vessels which are mainly solitary with scalariform perforation plates, opposite to scalariform intervascular pitting, paratracheal parenchyma, septate fibres and tall (>3 mm), wide multiseriate rays with a length: breadth ratio of approximately 1: 4. Specimens belonging to the second morphotype have been assigned to Atherospermoxylon KrÄusel, erected for fossil woods of the Monimiaceae in the tribe Atherospermeae (now Atherospermataceae) in that they exhibit anatomical features similar to Atherospermoxylon and extant Daphnandra Benth., Doryphora Endl. and Laurelia novae-zelandiae A.Cunn. These characters include diffuse to semi-ring porosity, scalariform perforation plates with up to 25 bars, septate fibres, relatively short (<1 mm) rays with a length: breadth ratio of between 1: 4 and 1: 11.

The geology, crustal structure and evolution of the Rockall Trough and the Faeroe-Shetland Channel

1986 ◽  
Vol 88 ◽  
pp. 7-26 ◽  
Author(s):  
Roger A. Scrutton
Keyword(s):  
Oceanic Crust ◽  
Crustal Structure ◽  
Deep Water ◽  
Upper Cretaceous ◽  
Sedimentary Rocks ◽  
Acoustic Basement ◽  
The North ◽  
Early Tertiary ◽  
Late Palaeozoic ◽  
Rockall Trough

SynopsisFrom direct sampling, the deeper Rockall Trough and Faeroe-Shetland Channel are known to have a Tertiary-Quaternary sedimentary sequence up to 3000 m thick, which is in places, particularly in the north, underlain by early Tertiary basaltic volcanic rocks. The seamounts in the Rockall Trough are of basic volcanics of probable Upper Cretaceous age. The eastern shelf areas have a rifted basement of Precambrian-Devonian (-?Carboniferous) age, overlain by Permian + Mesozoic sedimentary rocks that reach 5000 m in thickness in rift basins. Tertiary sediments thicken rapidly from the shelf into deep water. The western shelf areas have extensive early Tertiary basalts from the Faeroe Islands to the southern part of Rockall Bank. A thin Tertiary—Quaternary cover exists and Precambrian basement lies beneath.The pre-Tertiary geology of the deep water areas and the overall crustal structure have been inferred from geophysical investigations. In the Rockall Trough the crust is of oceanic thickness, about 6 km, but it is probably slightly thicker beneath the Faeroe-Shetland Channel. This fact, coupled with the size of the channel compared with other small ocean basins and the knowledge that fully developed oceanic crust exists just outside the mouth of the Rockall Trough, strongly suggests that at least parts of the deep water areas are floored by oceanic crust. However, seismic reflection and magnetic anomaly profiles do not yield observations characteristic of normal oceanic crust.The age of any oceanic crust in the Rockall Trough and Faeroe-Shetland Channel is equivocal. Between 54° and 59° N a succession of largely sedimentary rocks up to 3000 m in thickness occurs between the Tertiary and the acoustic basement. To the north this succession is masked on seismic profiles by early Tertiary basalts but it is probably present; to the south it is interrupted by a series of acoustically opaque basement ridges. With slow sedimentation rates, this succession could extend back to the late Palaeozoic, but with rapid rates, only to the mid-Upper Cretaceous. An age of mid-Lower to mid-Upper Cretaceous for oceanic crust, equal to that of the ocean crust outside the mouth of the Rockall Trough, is accepted here. Although rapid subsidence and infill in Upper Cretaceous time is not characteristic of major shelf basins around Britain, it may be acceptable for the Rockall Trough and Faeroe-Shetland Channel if they are underlain by oceanic crust rather than continental crust.A likely model for the formation of the Rockall Trough and Faeroe-Shetland Channel is of continental rifting and subsidence from late Palaeozoic or earliest Mesozoic to mid-Cretaceous time, then sea-floor spreading in Albian (c.105My)–Santonian (c.85 My) time, accompanied and immediately followed by rapid subsidence and deposition. The Tertiary was heralded by widespread basaltic igneous activity which briefly arrested subsidence, but was largely a period of subsidence without sedimentation keeping pace.

Sign in / Sign up

Export Citation Format

Share Document