Metasequoia milleri n.sp., anatomically preserved pollen cones from the Middle Eocene (Allenby Formation) of British Columbia

1979 ◽  
Vol 57 (8) ◽  
pp. 958-970 ◽  
Author(s):  
Gar W. Rothwell ◽  
James F. Basinger
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Metasequoia Glyptostroboides ◽  
Plant Remains ◽  
Exine Ornamentation ◽  
Pollen Sacs ◽  
Pollen Cone ◽  
Fertile Region ◽  
A New Species ◽  
Subtending Leaves

The discovery of well preserved, permineralized plant remains in Eocene sediments near Princeton, British Columbia, provides an opportunity to describe Metasequoia milleri, a new species of taxodiaceous pollen cone. Individual specimens are up to 3.0 mm long and 2.9 mm in diameter and are subtended by a vegetative zone of scale-like leaves. Approximately 30 microsporophylls are attached to the axis, and each bears three ovoid pollen sacs. The distal-most subtending leaves imbricate and enclose the fertile region. Pollen is ovoid to subspheroidal with an erect, protruding leptoma. Grains measure 19–27 μn in diameter and have verrucate exine ornamentation with numerous orbicules. These fossils show that pollen cones anatomically similar to those of extant Metasequoia glyptostroboides were present as early as Middle Eocene time.

Fossil Mosses from the Bisaccate Zone of the Mid-Eocene Allenby Formation, British Columbia

1974 ◽  
Vol 11 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Marian Kuc
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Plant Tissues ◽  
Plant Remains ◽  
Lake Bottom ◽  
White Colour

New fossil taxa (Ditrichites fylesi, Muscites maycocki, M. ritchiei, Palaeohypnum jovet-asti and P. steerei); unnamed moss and moss-like fossils, detrital fragments of various plant tissues, and paleobotanical evidence of the bisaccate zone are described from the Middle Eocene Allenby Formation near Princeton, British Columbia. These remains occur in laminated, tuffaceous, silty and pyroclastic shale, deposited under lacustrine conditions.Detailed examination of the various laminae indicates that beds of white colour and composed of coarser silt grains are poor in fossils and could be related to periods of decreasing bioproduction; less silty and darker coloured beds are rich in macro- and microfossils and could be related to periods of extensive bioproduction. The rock features, lamination, and distribution of macrofossils indicate the slow and undisturbed accumulation of plant remains on a lake bottom.

Permineralized fruits and seeds from the Princeton chert (Middle Eocene) of British Columbia: Vitaceae

1990 ◽  
Vol 68 (2) ◽  
pp. 288-295 ◽  
Author(s):  
Sergio R. S. Cevallos-Ferriz ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Outer Zone ◽  
Structural Features ◽  
Anatomical Structure ◽  
Thin Walled ◽  
Polyhedral Cells ◽  
A New Species

Four permineralized vitaceous seeds are described from the Middle Eocene Princeton chert, Allenby Formation, British Columbia. Three distinct types of ruminate perchalazal seeds are recognized, one is described as a new species Ampelocissus similkameenensis Cevallos-Ferriz et Stockey sp.nov., while the remaining seeds are referred to as type 1 and type 2 seeds. Five integumentary zones are recognized in each seed: zone 1 is an outer zone of thin-walled rectangular to polyhedral cells; zone 2 is a zone of thick-walled sclereids; zone 3 is a zone of cells with spiral thickenings; zone 4 is a zone of rectangular thin-walled cells (when preserved); and zone 5 is a zone of tangentially elongated thin-walled cells with dark contents. The chalaza in seeds of A. similkameenensis and the type 1 seed has three distinct zones, while in the type 2 seed it contains cells similar to integumentary zone 2. These Princeton seeds illustrate that structural features of Eocene Vitaceae include characters unlike those of extant taxa. This information contributes to our knowledge of anatomical structure within the group as a whole and underscores the need for review of both fossil and extant Vitaceae. Paucity of vitaceous seeds in the Princeton chert compared to the large number of preserved aquatic and semiaquatic remains suggests that they represent plants that grew in a nearby environment. Abrasion of the integument suggests that like extant seeds, they may have been dropped after passing through the gut of a bird.

Seed cones of Metasequoia milleri from the Middle Eocene of southern British Columbia

1984 ◽  
Vol 62 (2) ◽  
pp. 281-289 ◽  
Author(s):  
James F. Basinger
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Close Association ◽  
Single Species ◽  
Metasequoia Glyptostroboides ◽  
Adaxial Surface ◽  
Close Resemblance ◽  
Cone Axis ◽  
Living Species ◽  
Cone Scale

Permineralized ovulate cones of Metasequoia milleri Rothwell and Basinger (Taxodiaceae) are preserved in silicified peats of the Middle Eocene Allenby Formation near Princeton, B.C., Canada. Cones are about 17 mm wide and 25 mm long and are borne terminally on sparsely leaved stalks or peduncles. Twenty to 30 cone scales are arranged decussately on the cone axis. Externally, cone scales are broadly hexagonal and labiate in appearance owing to a medial cleft. Several ovules, with micropyles directed toward the cone axis, are attached to the adaxial surface of the cone scale. Seeds are 3–4 mm wide and about 5 mm long, with two lateral wings each approximately equal in size to the central seed body. Anatomical similarity to and close association with pollen cones and vegetative remains of M. milleri indicate that all organs belong to a single species. The vegetative body and pollen cones of M. milleri differ in few respects from those of living Metasequoia glyptostroboides Hu and Cheng. The seed cones of M. milleri cannot be distinguished from those of the living species. The close resemblance of the two species indicates evolutionary near stasis, at least structurally, throughout the Tertiary.

Permineralized fruits and Seeds from the Princeton chert (Middle Eocene) of British Columbia: Lythraceae

1988 ◽  
Vol 66 (2) ◽  
pp. 303-312 ◽  
Author(s):  
Sergio R. S. Cevallos-Ferriz ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
New Species ◽  
Middle Eocene ◽  
A New Species

Two types of lythraceous fruit and seed remains are described from the Middle Eocene, Allenby Formation of Princeton, British Columbia. Small globose, pedicellate fruits with persistent sepals, four to six locules, septa complete to the fruit apex, axial placentation, a palisade-like endocarp, and pyramidal seeds are referable to the genus Decodon Gmel. Numerous dispersed anatropous seeds of the same morphology show rounded or angular comers, lack lateral wings, and have a raphe that begins near the micropyle, passing through the middle integumentary layer on the dorsal face to the seed chalaza. Integuments are three zoned and seeds bear a ventral germination valve composed of radially elongated rectangular cells similar to the outer integumentary layer. Seeds show a prominent hypostase and dicotyledonous embryos with remains of a suspensor. These fruits and seeds are described as a new species of Decodon, D. allenibyensis Cevallos-Ferriz et Stockey sp.nov., which represents the oldest known species of the genus described to date. One fruit with several large, pyramidal lythraceous seeds is described. Seeds have three integumentary zones, the outer of which appears to have been mucilaginous. These remains most closely resemble the genus Lawsonia L., but additional specimens are needed to confirm this comparison. These lythraceous remains add to our knowledge of the Princeton angiosperm flora and further support the idea that these plants lived along a lake or marsh.

Anatomically preserved plants from the Middle Eocene (Allenby Formation) of British Columbia

1977 ◽  
Vol 55 (14) ◽  
pp. 1984-1990 ◽  
Author(s):  
James F. Basinger ◽  
Gar W. Rothwell
Keyword(s):  
British Columbia ◽  
Plant Material ◽  
Developmental Stages ◽  
Middle Eocene ◽  
Vegetative Organs ◽  
Preliminary Examination ◽  
Early Tertiary ◽  
Plant Remains

Well preserved, permineralized plant material from the Middle Eocene, Allenby Formation of British Columbia provides the basis for this description of an extensive Tertiary flora. The flora comprises a diverse assemblage of abundant plant remains in a chert matrix which outcrops south of Princeton, B.C., Canada. Preliminary examination of this material reveals numerous fertile and vegetative organs of angiosperms, conifers, ferns, bryophytes, and fungi, most of which represent presently unknown taxa. Initial studies indicate that we are dealing with the most diverse Eocene permineralization flora ever discovered. Superb anatomical preservation, including developmental stages of various organs, characterize many of the taxa and promise to significantly increase our knowledge of early Tertiary plants.

Paleoecology of Eocene lacustrine varves at Horsefly, British Columbia

1977 ◽  
Vol 14 (5) ◽  
pp. 953-962 ◽  
Author(s):  
M. V. H. Wilson
Keyword(s):  
British Columbia ◽  
Depositional Environment ◽  
Middle Eocene ◽  
Lacustrine Sediments ◽  
Late Summer ◽  
Coarse Grained ◽  
Temperate Climate ◽  
Fish Scales ◽  
Plant Remains ◽  
Warm Temperate

Middle Eocene lacustrine sediments, cropping out in the valley of the Horsefly River, British Columbia, contain abundant fossils of fishes, fish scales, fish coprolites, insects, leaves, and diatoms. The fish scales, insects, and leaves are preserved in at least three sequences of alternating light tuff and dark sapropel laminae, separated stratigraphically by coarse-grained structureless sequences. The proportions of the main types of fossils occurring in the light laminae compared with the dark laminae are significantly different, and are consistent with the hypothesis that the laminations are varves, with dark organic winter laminae and light inorganic summer laminae. Occasional graded sandy layers contain carbonized allochthonous plant remains and represent turbidity deposits caused by storms in the drainage basin.It is proposed here that the varves were deposited in the deeper regions of a stratified, monomictic or meromictic lake in a warm temperate climate. The depositional environment was anaerobic, containing abundant hydrogen sulphide, and was free of turbulence and benthos. Fish were entombed mostly during the winter, insects during the spring and summer, coprolites during the summer, and deciduous leaves during the late summer and autumn. The fish died of starvation and (or) overturn-induced anoxia.

scholarly journals A new species of Amentotaxus (Taxaceae) from China, Vietnam, and Laos

PhytoKeys ◽  
2019 ◽  
Vol 130 ◽  
pp. 25-32
Author(s):  
Lian-Ming Gao ◽  
Shao-Lin Tan ◽  
Gui-Liang Zhang ◽  
Philip Thomas
Keyword(s):  
New Species ◽  
Population Size ◽  
Dna Barcoding ◽  
Leaf Size ◽  
Small Population ◽  
Habitat Destruction ◽  
Lao Cai ◽  
Pollen Sacs ◽  
Pollen Cone ◽  
A New Species

A new species Amentotaxus hekouensis L.M. Gao is described as new to science from Hekou, Yunnan of China, Lao Cai of Vietnam and Xiang Khouang of Laos. The new species is similar to A. argotaenia (Hance) Pilg. in linear or linear-lanceolate leaves, stomatal bands white and microsporophylls 6–8, each with 4–6 pollen sacs, but differs from the latter by its larger leaf size with 8–12.5 cm × 0.9–1.4 cm (vs. 2–11 cm × 0.5–1.1 cm in A. argotaenia), long acuminate leaf apex (vs. rounded to sharply triangular in A. argotaenia), stomatal bands with 25–30 rows (vs. 15–25 rows in A. argotaenia), stomatal bands equal to or slightly narrower than marginal bands (vs. narrower than marginal bands in A. argotaenia); pollen-cone racemes borne 1–2 (vs. 2–4 (10) in A. argotaenia), cones in 12–16 pairs (vs. ca. 12 pairs in A. argotaenia). Its distinctive nature has also been confirmed through DNA barcoding analysis of this genus. The new species is provisionally assessed as endangered (EN) due to its restricted distribution, small population size and the prevalence of habitat destruction within its range.

The vegetative body of Metasequoia milleri from the Middle Eocene of southern British Columbia

1981 ◽  
Vol 59 (12) ◽  
pp. 2379-2410 ◽  
Author(s):  
James F. Basinger
Keyword(s):  
British Columbia ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Middle Eocene ◽  
Secondary Phloem ◽  
Metasequoia Glyptostroboides ◽  
Stem Anatomy ◽  
Marsh Soil ◽  
Anatomical Features ◽  
Resin Ducts

Anatomically preserved vegetative remains of Metasequoia milleri Rothwell and Basinger are common in the Princeton chert of the Allenby Formation in southern British Columbia. Deposition of the Allenby Formation and associated volcanics occurred during Middle Eocene time. The Princeton chert locality is in the upper strata of the Allenby Formation and is of late Middle Eocene age. The Princeton chert was formed by siliceous permineralization of marsh soil. Dissolved silicates were probably introduced by periodic influx of water from mineral springs or geysers.Anatomical features of stems, wood, and leaves are well preserved. Mature wood of the fossil resembles that of Metasequoia glyptostroboides in having traumatic resin cysts; opposite pitting on radial walls of tracheids; taxodioid cross-field pitting; tall, uniseriate rays; smooth-walled ray parenchyma; and diffuse, resinous, smooth-walled wood parenchyma. Leaves are linear, hypostomatic, and borne decussately, and have one or three resin ducts and slightly undulate to smooth epidermal cell walls. Leaves of living M. glyptostroboides differ in consistently having three resin ducts and much more pronounced undulations of epidermal cell walls. Metasequoia milleri has leaves of a generalized structure from which leaf types of many taxodiaceous genera could be derived. Roots associated with M. milleri are dimorphic. Primary tissues and secondary phloem are exceedingly well preserved. Cortex of both long and short roots contains mycorrhizal fungi.Compression remains of M. occidentalis are not distinguishable from M. glyptostroboides. Anatomical features of M. milleri, however, do reveal differences between Eocene and living Metasequoia. Wood rays of M. milleri are much higher than those of M. glyptostroboides. Other features of stem anatomy are similar in both species. Pollen cones differ in developmental and minor anatomical features. The close similarity of most organs of M. milleri to M. glyptostroboides and the dissimilarity of leaf structure indicate mosaic evolution within the genus.

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