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1.
Fossils from the Oligocene of western Montana described in this treatment are the first structurally preserved ovulate cones of Pinus to be reported from the Tertiary of North America. They are about 5.5 cm long and have a maximum diam of 2.5 cm. Numerous scales are arranged spirally around the axis and each scale bears two winged seeds. The bract subtending the ovuli-ferous scale is 3-4 mm long and is free from the scale throughout its length. The pith and cortex of the axis are constructed of thick-walled parenchyma cells and 18-21 resin canals occur at the inner edge of the cortex. Resin canals entering the base of the ovuliferous scale are restricted to the abaxial side with vascular tissues occupying the adaxial side. Vascular strands near the tip of the scale are strongly rounded on the adaxial or phloem side. At the abaxial side of the tip of the ovuliferous scale is a broadly rhomboidal apophysis with a raised umbo that terminates in a short spine. The fossils differ from the several Recent cones examined in having fewer resin canals and biseriate rays in the secondary xylem of the cone axis. The shape of the cone, its anatomical features, and the morphology of the tip of the cone scale indicate affinity with the subgenus Diploxylon.  相似文献   

2.
Fossils described in this treatment are the first structurally-preserved ovulate cones of Picea to be reported from the Tertiary. They are 5.0-5.8 cm long and 1.6-1.8 cm at their widest diameter. Numerous ovuliferous scales are arranged spirally around the axis and each bore two winged seeds. The bract subtending the scale is 4.0-7.0 mm long and is fused to the scale for 1.0 mm. The base of the bract is inflated on the abaxial side extending for about 1.0 mm between the seeds of the adjacent scales. Both the scales and their subtending bracts are recurved at their point of divergence from the axis. The ovuliferous scales taper gradually to a point, and the thickness of the tissues at the scale apex indicates that they were woody. Anatomically, the silicified cones are very similar to those of the Recent species and indicate that all important features of the latter had evolved by Oligocene time.  相似文献   

3.
4.
Ovulate cones identified as Abietites ellipticus Fontaine, from the Early Cretaceous of northern California, have been reinvestigated. Rather than being preserved as imprints as originally described, the fossils are petrified. Two cones are attached to needle-bearing twigs. The organs are similar to those of the living Cunninghamia lanceolata. However, the scale portion of the bract-scale complex of the fossil cones is situated close to the bract apex, while that in modern Cunninghamia cones is midway between the bract base and apex. This plus other structural differences warrant treatment of the material as a new species of Cunninghamiostrobus Stopes and Fujii.  相似文献   

5.
A silicified cone from the Late Eocene of Washington is described as a new fossil species of Pinus. The cone was probably 9–10 cm long and 3–5 cm at its widest diam in the living condition and is peculiar in having abundant resin canals in the secondary xylem of the axis arranged in three concentric rings near the cone base. The bract of the fossil is also unusual in having resin canals of distinctly unequal sizes and a vascular strand that is adaxially concave. In the absence of external features of the scale tips, these anatomical conditions along with the construction of the outer cortex of the axis of thick-walled cells suggest closest affinity of the new species with the subsections Contortae, Oocarpae, and Sylvestres of the section Pinus, subgenus Pinus.  相似文献   

6.
This new species is based on a single semifusinized cone from the Late Cretaceous (Cenomanian) of New Jersey. The cone is flattened but essentially complete. It is 55 mm long and 8 by 13 mm in diam. Scale apices are thin, rounded, and entire, lacking evidence of an umbo or spine. The vascular cylinder of the cone axis is organized as a series of separate strands. The scale is made up of a basal portion that stands out nearly perpendicular to the cone axis and a sharply upturned distal portion. The bract base has a pronounced abaxial keel. Bract and scale traces diverge from the vascular cylinder of the cone axis separately from one another. A poorly developed interseminal ridge is present at the chalazal end of the seeds. An unusual feature of the cone is the presence of a trichome-bearing epidermis on the cone axis, bract-scale complex, and near the scale apex. Resin canals diverge into the bract-scale complex abaxial to the scale trace with branches becoming adaxial to the scale trace outward. A number of features of the new species occur in cones of Abies, Cedrus, Keteleeria, Larix, Picea, Pseudolarix, Pseudotsuga, and Tsuga as well as in the extinct genus Pseudoaraucaria. Features of Pinus are absent. This suggests that Pseudoaraucaria may have served as an ancestral source for modern genera other than Pinus with Pityostrobus pubescens representing an evolutionary intermediate.  相似文献   

7.
Nephrostrobus cliffwoodensis gen. et sp. nov., Nephrostrobus bifurcatus sp. nov., and Rhombostrobus cliffwoodensis gen. et sp. nov. are described based on anatomical studies of seed cone fragments from the Upper Cretaceous Magothy Formation of New Jersey. These species belong to the Taxodiaceae. As in Sequoia, Sequoiadendron. and Metasequoia, the vascular strands supplying the scale and bract in Nephrostrobus are about equal. These vascular strands are arranged in a reniform pattern resembling that found in Metasequoia, but the orientation differs by 180 degress. Nephrostrobus cliffwoodensis and Nephrostrobus bifurcatus differ from each other in the branching of the complex trace and associated resin canals. Rhombostrobus cliffwoodensis resembles Cunninghamia in the arrangement of vascular strands and associated resin canals in its bract-scale complexes. However, the relative amount of bract and ovuliferous scale making up the complex is more like that in Sequoia. This combination of cone features does not occur in any of the extant genera. Nephrostrobus and Rhombostrobus are not considered to be ancestral to any of the extant taxodiaceous genera, but are extinct members of an ancestral complex from which the extant genera were derived.  相似文献   

8.
The speciments described in the present paper were collected from Hezhou, Huanglong and Chuanshan Formations in Jiangsu and Anhui. They belong to 17 genera (including 1 new genus) and 24 new species or subspecies, together with a new species from the lowermost part of the Chihsia Formation in Jiangsu. Based on characteristics of tetracorals, the Huanglong Formation (Moscovian) and the Chuanshan Formation (Sphaeroschwagerina Zone) at Dushan of Guangde, Anhui may be divided into four assemblage zones as follows:  相似文献   

9.
A palaeocope ostracode with prominent cruminal dimorphism occurs in Lower Carboniferous strata of Nova Scotia and Ireland. It is believed to be the youngest representative of the Beyrichiidae Matthew 1886, a family hitherto only known from the Silurian and Devonian. Because of differences in lobation and adventral structures this ostracode is here assigned to the new genus Copelandelia. The occurrence of the type species Copelandelia novascotica in strata of comparable age (Viséan) in Nova Scotia and Ireland appears to add some support to the hypothesis that North America and Europe formed one supercontinent in the Paleozoic, since this species is assumed to have lived in a near-shore, or even a brackish or non-marine environment.  相似文献   

10.
Silicified rhizomes from Miocene strata near Yakima, Washington represent a new species of Osmunda. The stems are 8–13 mm in diameter and are surrounded by a thick sheath of adherent leaf bases, each of which shows stipular expansions typical of the Osmundaceae. The new species has an ectophloic siphonostele in which the xylem cylinder is dissected by leaf gaps with 12–14 strands being visible in a given stem cross section. Such sections also show 12–16 leaf traces in the cortex. The xylem of each leaf trace diverges from the xylem cylinder of the stem as an adaxially concave strand with its protoxylem organized into a single medial adaxial cluster. Initial bifurcation of the leaf-trace protexylem occurs as the leaf trace passes through the outer cortex of the stem. In the basal part of the stipular region of the petiole base, thick-walled fibers form an arch on the abaxial side of the sclerenchyma ring around the petiolar bundle. This arch persists throughout most of the length of the stipular region, with the thick-walled fibers becoming reorganized into two lateral masses in the distal part of the stipular region. Similar thick-walled fibers form an elongate strip of tissue in each wing of the stipule along with several small clusters scattered near the sclerenchyma ring. The new species belongs to the subgenus Osmunda and shows that during the Neogene, the latter existed as a group of closely related species much as it does today. Furthermore, Osmunda wehrii combines features of the modern O. regalis, O. japonica, and O. lancea with those of O. claytoniana and thus supports the inclusion of the latter species in the subgenus Osmunda.  相似文献   

11.
Daugherty , Lyman H. (San Jose State College, San Jose, Calif.) Itopsidema, a new genus of the Osmundaceae from the Triassic of Arizona. Amer. Jour. Bot 47(9): 771–777. Illus. 1960.—Itopsidema vancleavei, a new genus and species of the family Osmundaceae, is described. The specimen consists of several segments of an arborescent stem obtained from the Upper Triassic of the Petrified Forest National Monument near Holbrook, Arizona. The surfaces on 2 of the segments are covered by adventitious roots and the remaining segments are covered by leaf bases. The fronds are spirally arranged and have an 8/21 phyllotaxy. The cortex of the stem, which contains numerous leaf traces and adventitious roots, consists of parenchyma with cell walls of medium thickness. The leaf traces are oblong to crescent-shaped in the inner cortex and horseshoe-shaped in the outer cortex. The base of the petiole contains a single, large vascular bundle and is covered by multicelled, glandular spines. The adventitious roots originate on the abaxial side of the leaf traces in the region of the inner cortex. The center of the stem is occupied by an ectophloic, mesarch siphonostele without leaf gaps. The pith is composed of firm-walled parenchyma cells which have isolated tracheids with reticulate pitting scattered among them. These tracheids are so rare the pith cannot be considered a “mixed pith.” The relationship and morphological significance of Itopsidema with respect to other members of the Osmundaceae are briefly discussed.  相似文献   

12.
A silicified seed cone of Oligocene age from the Olympic Peninsula of Washington represents a new species of Pinus. The cone was about 8 cm long and 3 cm at its widest diameter in the living condition. Its scale apices are thickened and each has a dorsal umbo. Internal cone construction confirms the assignment of the new species to Pinus and suggests affinity with the subsections Australes and Ponderosae of the section Pinus, subgenus Pinus. The cone is peculiar in having a stout bract trace that is slightly concave on its adaxial side and in having resin canals that diverge from the axial secretory system toward the bract but constrict markedly and terminate before entering the bract.  相似文献   

13.
In addition to the complete lack of the usual spiral bands of thickenings in the elaters, the new genus Steereella is unique among the Hepaticae for the resemblance of its cellular organization in the thalloid gametophyte to that of some moss leaves. The taxon recognized is one genus, Steereella, gen. n., and one species S. linearis (Swartz) Kuwah. comb. nov., in which the variable nature of the gametophyte is particularly noted. The genus appears to be restricted to the West Indies.  相似文献   

14.
赵一之 《植物研究》2002,22(4):385-386
发表新疆婆婆纳属一新种  相似文献   

15.
中国水螅属一新种   总被引:4,自引:4,他引:4  
  相似文献   

16.
Mamay , Sergius H. (U. S. Geological Survey, Washington, D. C.) Litostroma, a new genus of problematical algae from the Pennsylvanian of Oklahoma. Amer. Jour. Bot. 46(4): 283–292. Illus. 1959.—Litostroma oklahomense, gen. et sp. nov. is described on the basis of fossil plant material found in a Pennsylvanian marine limestone from the vicinity of McAlester, Oklahoma. Litostroma is a simple plant consisting of a small, irregularly shaped thallus 1 cell thick. Some thalli have small perforations and filament-like marginal outgrowths. The reproductive organs are not known. A marine fauna is intimately associated with Litostroma, and includes epiphytic Foraminifera preserved in actual growth positions on surfaces of the plants. The evidence indicates a marine habitat for Litostroma and, accordingly, algal affinity. Without information bearing on its reproductive organs or pigmentation, however, Litostroma cannot with assurance be assigned to any known group of algae. It possibly represents a group of green, brown, or even red algae.  相似文献   

17.
菌落在PCA培养基上初分离时灰褐色,背面暗红褐色,产生赤褐色色素,气生菌丝絮状,不产生分生抱子,接种后再次分离时菌落赤褐色,气生菌丝致密,产生大量分生拖子。分生拖子梗单生,不分枝或偶有分枝.有分隔.壁光滑,榄褐色,直立或稍弯,一至多个曲膝状折点,32——105xsum。分生抱子单生,偶尔两个串生,倒棍棒形至圆柱形,金黄褐色,成熟时外壁具细瘤状突起,假隔膜4—11个,真隔膜0—6个,分隔处稍缢缩或不缢缩,纵隔膜极少见,在PCA上培养9天时抱身大小为50—120XIZ—20qm,嚎淡榄色,无分枝,有分隔,偶尔呈结节状,93—300X2—3…  相似文献   

18.
DuringthecourseofreviewofthephylogenyofthefossilNorthAmericantaxa.ofthecanidsubfamilyCaninae,TedfordandTaylor(MS)wereabletorecognizethatthetaxonCanisdavisiMerriam,1911,fromtheearlyHemphillianofOregon,anddefinedonamaxillaryfragmentbearingM1-2,couldbeassociatedwithabundantmaterialrepresentingallelementsoftheskeletonfromcorrelativeandlaterHemphillian(lateMiocene)depositsoftheUnitedStates.StudyofthesematerialsinthecourseofacladisticanalysisofphylogenyrevealedthatC.davisiassumedthepositionofa…  相似文献   

19.
描述了产自四川内江晚侏罗世的中国龟科(Sinemydidae)化石一新属新种──叶氏香港龟Hongkongochelys yehi。它以椎盾较横宽、第7、8椎板较退化、上臀板缺失、具腹甲后窗等特征区别于中国龟属(Sinemys)和满洲龟属(Manchurochelys)。这是中国龟科化石在四川的首次发现.  相似文献   

20.
滑刃属一新种记述(滑刃目,滑刃科)   总被引:1,自引:1,他引:1  
2002年从山东省乳山市牛筋草的根际土壤中发现滑刃属1新种,类刷尾滑刃线虫 Aphelenchoides parabrushmucronatus sp.nov,.该虫具有以下特征:雌虫虫体中等;唇区较高,缢缩明显;中食道球卵圆形;生殖系统发育良好,卵母细胞单列,受精囊和后阴子宫囊都含较大的圆形精子;雌虫尾圆柱形,尾端中间具有1试管刷状尾尖突.A.appendurus Singh,1967在形态上与新种相似,区别在于前者有两条侧线,虫体和口针更长,尾巴相对较短(L=720-880μm;stylet=16~17μm;tail=38.4μm).A.seiachicus Nesterov,1973在形态上也与新种相似,区别在于前者虫体更小,口针、尾巴更短(L=370-420μm;stylet=9.5μm;c'=3).  相似文献   

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