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1.
Fossil twigs with attached foliage, fruits, and flowers from the middle Eocene of the Green River Formation in northeastern Utah and northwestern Colorado and from the early Oligocene Florissant beds of central Colorado provide a firm basis for reconstructing two species of an extinct ulmaceous genus that was widely distributed in the Tertiary of midlatitude western North America and Europe. The fruits are samaras of Cedrelospermum Saporta, a genus previously known only from isolated specimens. The distichously arranged, slender, pinnate-veined leaves vary from serrate with simple teeth to, less commonly, entire-margined. Corresponding isolated leaves in the Green River, Florissant, and other Eocene to Oligocene localities of western North America are now excluded from Zelkova and Myrica, to which they were previously misidentified. The anthers of the staminate flowers contain 3–5 porate pollen with rugulate sculpture. Based upon combined characters of phyllotaxy, and leaf, flower, fruit, and pollen morphology, Cedrelospermum can be referred to the extant subfamily Ulmoideae, and is similar to Phyllostylon, Zelkova, and Hemiptelea. The abundance of Cedrelospermum in lake sediments of volcanic areas, together with its production of numerous small winged fruits, suggest that it was an early successional colonizer of open habitats.  相似文献   

2.
The new genus Landeenia is recognized on the basis of flowers, pollen, infructescences, fruits, and seeds from the middle Eocene of southwestern and northwestern Wyoming. Landeenia aralioides (MacGinitie) comb.nov. has cymose inflorescences with actinomorphic, bisexual flowers, a pentamerous calyx, about ten stamens, and a superior gynoecium of ~18 carpels sharing a single style. The fruits are globose to oblate, loculicidally dehiscent capsules, with a persistent calyx, and contain flat, elliptical seeds that are surrounded by a small wing. Pollen removed from the anthers is tricolpate with finely striate sculpture. Although clearly dicotyledonous, the combination of characters found in Landeenia is not known in any modern genus. The familial affinities of the plant, though certainly not with the Araliaceae as previously thought, remain uncertain. However, the combination of characters is consistent with treatment as a member of the Sapindales. The fossil material is thus assigned to the rank of Sapindales-Incertae sedis.  相似文献   

3.
Stephania Loureiro is a large genus within Menispermaceae, with approximately 60 extant species naturally distributed in tropical to subtropical areas in Asia and Africa, and a few in Oceania. This genus possesses highly characteristic endocarps that facilitate identification of extant and fossil specimens. Here, we report some well-preserved fossil fruits of Stephania from North America and East Asia. The specimens indicate the endocarps were bony or woody with an obovate to obovate-rotund outline and a horseshoe-shaped locule. The endocarp length varies from 4.7 to 8.3 mm, and width from 3.7 to 7.0 mm. The endocarp has a clear foramen in the central area and is surrounded by a keel with ribs running along the dorsal surface. Only one lateral crest develops on each side of the endocarp. Two new species are recognized: Stephania wilfii Han & Manchester sp. nov. from the Paleocene to Eocene of Wyoming (USA), and Stephania jacquesii Han & Manchester sp. nov. disjunct between the late Eocene of Oregon (USA) and the late Oligocene of Guangxi Province (China). In addition, on the basis of more detailed morphological comparative analyses, we transfer the fossils formerly treated as Diploclisia auriformis (Hollick) Manchester from the early Eocene of London Clay, and the middle Eocene of Alaska and Oregon to Stephania auriformis (Hollick) Han & Manchester comb. nov. These fossil materials indicate a broader biogeographic distribution for the ancestors of extant Stephania lineages. This finding enhances our knowledge of the taxonomic and morphological diversity of Stephania and provides new evidence concerning its phytogeographic history.  相似文献   

4.
The enlarged inflorescence bract diagnostic of extant Tilia has an extensive Tertiary fossil record in the Northern Hemisphere. Diversity of bract morphology, and the extent of adnation between peduncle and bract, is reviewed for fossil and extant species of Tilia. An extinct type of bract with an orbicular outline and palmate venation is documented by the fossil species Tilia circularis (Chaney) comb. nov. from the early Oligocene of Oregon and is designated Type A. Living species of the genus have elongate bracts with predominately pinnate venation that are borne in two basic configurations: Type B, with the peduncle fused only to the extreme base of the bract lamina, as in extant Tilia endochrysea Hand.-Mzt. of southern China; and Type C with the peduncle fused medially along the basal one-third of the bract lamina, as in most extant species. Bracts of Type B were widely distributed in the Tertiary of western North America (late Eocene to Miocene) and Europe (early Miocene to Pliocene), while those of Type C are known in the fossil condition only from the middle and late Tertiary of Asia and Pliocene of Europe. The bracts of T. circularis, like those of type B, are borne on relatively long stalks and have the peduncle fused only at the extreme base. The fossil record supports recognition of the following characters as apomorphic in Tilia bract evolution: bracts sessile, peduncle adnate to the upper surface of the bract, and pinnate bract venation.  相似文献   

5.
Deviacer guangxiensis Chen & Manchester sp. nov. is described based on asymmetric samaras from the Oligocene Ningming Formation in Guangxi, South China, representing the first documentation of Deviacer fossils in Asia. The Oligocene species, with relatively large fruits, represents the youngest record of the genus so far known; all other records are from the Paleocene and Eocene, or late Eocene—early Oligocene in western North America and Europe. It indicates that the extinct genus, Deviacer, was widely distributed in the northern hemisphere during the Paleogene.  相似文献   

6.
A new genus is recognized on the basis of wind-dispersed fruits from the Eocene of western North America and Miocene of eastern Asia. The fruits consist of an accrescent hypogynous calyx of five obovate sepals and one or more globose fruit bodies. Although the fossils were formerly placed in the extant genera Porana (Convolvulaceae) and Astronium (Anacardiaceae), our investigation of numerous specimens from several floras in the western United States (e.g., Florissant, Green River, Clarno) and Canada (Whipsaw Creek, British Columbia) and the Yilan and Shanwang floras of China reveals unique characters that indicate that the fossils are a distinct genus, which we name Chaneya. Unlike Porana and Astronium, the fossil calyces have stomata that are longitudinally aligned, and early stages of fruit development show a gynoecium of five apocarpous carpels, of which only one or two usually enlarge at maturity. Precise systematic placement of the fossil genus is uncertain, but similarities to the extant Picrasma of the Simaroubaceae are suggestive of possible affinities. Two species are recognized: Chaneya tenuis (Lesq.) comb. nov., from the Eocene of western North America and northeastern China, and Chaneya kokangensis (Endo) comb. nov., from the Miocene of eastern Asia.  相似文献   

7.
《Comptes Rendus Palevol》2008,7(4):211-216
A new leaf-mimicking katydid (Orthoptera: Tettigoniidae: Pseudophyllinae), Archepseudophylla fossilis gen. et sp. nov. is described based on tegmina from the Early Oligocene of France. Lithymnetes laurenti Théobald, 1937 from the Late Eocene of France is transferred to Archepseudophylla comb. nov. The enigmatic ‘Poekillopteramelanospila Cockerell, 1921 from the Early Oligocene of the Isle of Wight (UK) is transferred to Archepseudophylla comb. nov. The present discoveries in the Palaeogene of the Isle of Wight, Céreste, and Marseilles Basins represent the first fossil records of Pseudophyllinae. In addition, these records support warm and humid forest conditions near the palaeolakes of the Isle of Wight, Camoins-les-Bains, and Céreste.  相似文献   

8.
A new genus of fossil angiosperms (Spanomera gen. nov.) is established for flowers from two localities in the mid-Cretaceous Potomac Group of Maryland, eastern North America. The type species, Spanomera mauldinensis sp. nov., from the early Cenomanian Elk Neck beds, has inflorescence units with terminal pistillate, and lateral staminate flowers. The organization of inflorescences and flowers is opposite and decussate. Staminate flowers typically have five tepals: two lateral, one posterior, and two in the anterior position. Each tepal is opposed to a stamen with a short filament, dorsifixed anther, and two pairs of pollen sacs. Stamens contain pollen comparable to the dispersed pollen species Striatopollis paraneus (Norris) Singh. Pistillate flowers have two lateral tepals and two anterior-posterior tepals that are opposed to two carpels. Carpels are slightly fused basally along their ventral margins and are semicircular in outline with a long, decurrent, papillate ventral stigma. Frequently this stigmatic surface has abundant attached pollen of the Striatopollis paraneus type. Spanomera marylandensis sp. nov., from the late Albian Patapsco Formation, is similar to S. mauldinensis but is known only from isolated flowers and floral parts. Staminate flowers have four stamens with dorsifixed anthers and each is opposed to a tepal. Stamens contain pollen comparable to the dispersed pollen species Striatopollis vermimurus (Brenner) Srivastava. Carpels have pollen of S. vermimurus on the stigma. Spanomera provides further evidence of unisexual but probably insect-pollinated flowers among mid-Cretaceous, early nonmagnoliid (“higher”) dicotyledons, and is interpreted as closely related to extant Buxaceae. Characters that Spanomera shares with other taxa suggest that the Buxaceae themselves may be closely related to Myrothamnaceae and other “lower” Hamamelididae.  相似文献   

9.
A new sterculiaceous wood, Chattawaya paliformis gen. et sp. n., was collected from a Middle Eocene locality in the type area of the Clamo Formation of north central Oregon. The wood differs from all known extant woods in having very large and irregularly shaped tile cells. However, other features of the xylem indicate a close natural relationship between Chattawaya and the extant paleotropical genus, Pterospermum. It is suggested that the xylem organization of the Eocene fossil represents a more primitive condition than that observed in Pterospermum. Comparative xylotomy indicates three evolutionary trends within the complex to which Chattawaya and Pterospermum belong: development of storied structure, increased uniformity in shape and size of tile cells and loss of multiseriate rays. Chattawaya is part of a growing body of paleobotanical evidence indicating that the Sterculiaceae was well differentiated by the early Tertiary, but that the lineages leading to extant genera have undergone an appreciable amount of evolutionary change since the Eocene.  相似文献   

10.
Reproductive and vegetative remains of Eucommia from 25 localities in the United States, Canada, and Mexico document the wide distribution of this genus in North America during the Cenozoic. Autofluorescent elastic latex filaments bearing capitate termini are preserved in nearly all of the remains and provide conclusive evidence of their affinity to Eucommia. Four species of Eucommia are recognized on the basis of the characteristic samaras: E. eocenica from middle Eocene strata of the Mississippi Embayment in Missouri, Tennessee and Mississippi; E. montana from early Eocene to early Oligocene localities in British Columbia, Washington, Oregon, Utah, Colorado, and Montana; E. constans from Neogene rocks in central Mexico; and E. jeffersonensis n. sp. from the latest Eocene or earliest Oligocene John Day Formation of Oregon. Atypical specimens of E. montana and E. eocenica are the first records of two-seeded fruits for the genus. Eucommia leaves from Eocene localities in British Columbia and Mississippi are the first records of Eucommia foliage in North America whose identifications are confirmed by the presence of capitate latex strands. These leaves and a specimen from Oregon are referred to E. rolandii n. sp. Fruit evolution in Eucommia may have involved increases in samara size and symmetry, and reduction in seed number from two to one, perhaps as adaptations for wind dispersal. All fossil Eucommia samaras from North America are smaller and less symmetrical than those of the living species, E. ulmoides. Preliminary flight tests of E. ulmoides samaras and of models of the fossils suggest that E. ulmoides fruits are aerodynamically better suited for wind dispersal than the fossils.  相似文献   

11.
Rubovietnamia coronula Alejandro and Meve, a new coastal Rubiaceae species from Davao del Sur, Philippines is here described and compared with Rubovietnamia nonggangensis and R. sericantha. This third species of Rubovietnamia is distinct from the two known species by its long leaf petioles, prominently keeled stipules, reduced calyx and corolla, outward curling of corolla lobes in anthesal flowers, included anthers and stigma, glabrous fruits with nectariferous disk, and numerous seeds.  相似文献   

12.
斋桑盆地自晚白垩世以来即为淡水湖泊环境,其始新世至中新世湖相及湖边缘相沉积物产有丰富的轮藻化石。文中建立三个轮藻化石组合:(1)Harrisichara mitella—Peckisphaera zajsanica组合(中始新世早期);(2)Lychnothamnus formosus—Peckichara组合(中始新世晚期--渐新世早期);(3)Gyrogona aralica—sphaerochara clearus组合(中--晚渐新世)。斋桑盆地轮藻化石出现的最高层位为下中新统且化石稀少,推测系盆地环境日益干旱所致。  相似文献   

13.
<正> 南宁盆地脊椎动物化石地点目前所知不下七处。本文着重记述了1974和1979年笔者采自邕宁县五塘公社莲塘村的石炭兽化石,并对盆地东部下第三系作一初步划分。本文首次报道南宁盆地发现脊椎动物化石,对研究石炭兽的演化、发展和分布,对盆地第三系地层的划分和对比,提供了新的依据。一、化石地点及地层概况莲塘村位于南宁市东北约32公里、五塘圩东5公里、邕宾(南宁—宾阳)公路南侧。石炭兽化石产于莲塘村东约300米远的小煤窑、距地表8.3米深的褐煤层顶板(灰色泥质粉砂岩)中。  相似文献   

14.
Numerous megafossils of Lauraceae have been reported from the early Tertiary of North America, but the subfamilial affinities are usually not well understood due to the great morphological variability found in extant taxa. The flowers of Androglandula tennessensis gen. et sp. nov. Taylor, from the Middle Eocene Claiborne Formation, are six-parted, pedicellate, bracteate, and have stamens with paired basal staminal glands. The flowers have ethereal oil cells and paracytic stomates throughout. The fossil species has affinities with the subtribe Cinnamomineae, and this supports suggestions that the Middle Eocene climate of the southeastern U.S. was subtropical. The existence of this fossil, and reports of the subtribe from the Eocene of Europe, indicate a South American-North American-European-southeast Asian paleodistribution suggesting that extinction in North America and Europe was the cause of the tribe's current disjunct distribution.  相似文献   

15.
Silicified wood collected from the Lower Miocene Nawamata Formation at two localities, Nakaya and Nigoriike, Monzen-machi, Noto Peninsula, central Japan, were identified. Among the 58 specimens there are two species of conifers and eleven species of dicotyledons:Taxodioxylon cunninghamioides (Watari) Watari andT. sequoianum (Merckl.) Gothan (both Taxodiaceae),Carya protojaponica Watari (Juglandaceae),Pterocarya rhoifolia Siebold et Zucc. (Juglandaceae),Ostrya monzenensis sp. nov. (Betulaceae),Quercus anataiensis (Watari) Watari (Fagaceae),Liquidambar hisauchii comb. nov. (Hamamelidaceae),Prunus iwatense (Watari) Takahashi et Suzuki (Rosaceae),Gleditsia paleojaponica comb. nov. (Leguminosae),Acer watarianum Takahashi et Suzuki (Aceraceae),Meliosma mio-oldhami sp. nov. (Sabiaceae),Reevesia miocenica Watari (Sterculiaceae), andFraxinus notoensis sp. nov. (Oleaceae). The fossil wood floras at the two localities are compared to the Daijima Flora, and warm-and/or cool-temperate mesic forests are suggested to occur in the Early Miocene of Monzen.  相似文献   

16.
We studied planktic and small benthic foraminifera from the Fuente Caldera section, southern Spain, across the Eocene–Oligocene transition. Benthic foraminifera indicate lower bathyal depths for the late Eocene and earliest Oligocene. Detailed high-resolution sampling and biostratigraphical data allowed us to date precisely layers with evidence for meteorite impact (Ni-rich spinel), which occur in the lower part of the planktic foraminiferal Globigerapsis index Biozone and in the middle part of the small benthic foraminiferal Cibicidoides truncanus (BB4) Biozone (middle Priabonian, late Eocene). Major turnovers of foraminifera occur at the Eocene/Oligocene boundary, only. The impact did not occur at a time of planktic or benthic foraminiferal extinction events, and the late Eocene meteorite impacts did thus not cause extinction of foraminifera. The most plausible cause of the Eocene/Oligocene boundary extinctions is the significant cooling, which generated glaciation in Antarctica and eliminated most of the warm and surface-dwelling foraminifera.  相似文献   

17.
We examined the molecular phylogeny and ultrastructure of Chlorogonium and related species to establish the natural taxonomy at the generic level. Phylogenetic analyses of 18S rRNA and RUBISCO LSU (rbcL) gene sequences revealed two separate clades of Chlorogonium from which Chlorogonium (Cg.) fusiforme Matv. was robustly separated. One clade comprised Cg. neglectum Pascher and Cg. kasakii Nozaki, whereas the other clade included the type species Cg. euchlorum (Ehrenb.) Ehrenb., Cg. elongatum (P. A. Dang.) Francé, and Cg. capillatum Nozaki, M. Watanabe et Aizawa. On the basis of unique ultrastructural characteristics, we described Gungnir Nakada gen. nov. comprising three species: G. neglectum (Pascher) Nakada comb. nov., G. mantoniae (H. Ettl) Nakada comb. nov., and G. kasakii (Nozaki) Nakada comb. nov. We also emended Chlorogonium as a monophyletic genus composed of Cg. euchlorum, Cg. elongatum, and Cg. capillatum. Because Cg. fusiforme was distinguished from the redefined Chlorogonium and Gungnir by the structure of its starch plate, which is associated with pyrenoids, we reclassified this species as Rusalka fusiformis (Matv.) Nakada gen. et comb. nov.  相似文献   

18.
Caviomorphs (South American hystricognaths) are recorded in the continent since the middle Eocene. The middle Eocene–early Oligocene is considered a key moment for their evolutionary history because by the early Oligocene they were differentiated into four superfamilies: Octodontoidea, Cavioidea, Chinchilloidea and Erethizontoidea. Due to their generalized dental patterns and abundance in the fossil record, Octodontoidea are interesting for analysing the origin and early history of caviomorphs. The phylogenetic relationships of the earliest octodontoids are studied herein. Results confirmed a basal caviomorph diversification in the middle Eocene (c. 45 Mya), with one lineage leading to Pan‐Octodontoidea, and another leading to Erethizontoidea, Cavioidea and Chinchilloidea, which is not in accordance with analyses based on molecular data. Three major radiations were identified: the first one (late Eocene?/early Oligocene?) occurred in low latitudes with the differentiation of Pan‐Octodontoidea and the earliest crown‐Octodontoidea. The second radiation (late Oligocene) was a large‐scale South American event; in the southernmost part of the continent it is recognized as the first Patagonian octodontoid radiation, which provided the characteristic high morphological disparity of the superfamily. The third radiation (late Miocene) is characterized by the replacement of ‘old’ by ‘modern’ octodontoids; the nature of this third event needs to be study in a broader taxonomic context. © 2015 The Linnean Society of London  相似文献   

19.
A new genus and species Gordoniopsis polysperma and two new species of Gordonia (Gordonieae, Camellioideae, Theaceae) are described based on fossil fruit and seed remains. These specimens are part of a large flora consisting of various plant organs from the middle Eocene Claiborne Formation in western Kentucky and Tennessee. Gordoniopsis is a five-valved loculicidally dehiscent capsule similar to capsules of Gordonia but differing in having unwinged seeds and a greater number of seeds per locule. The two Gordonia species are among the earliest unequivocal records of the genus and two of only four fossil Gordonia species known with in situ seeds. Two extinct genera, Gordoniopsis and Andrewsiocarpon, and the extant genus Gordonia in the tribe Gordonieae are known from the middle Eocene Claiborne flora, suggesting an early radiation within the tribe. Based on a survey of Recent fruits and seeds we concur with Keng's proposal to merge Laplacea with Gordonia.  相似文献   

20.
Two new fossil members of the subfamily Myrmeciinae are described: Archimyrmex wedmannae, sp. nov (Grube Messel, Germany, Middle Eocene) and Prionomyrmex wappleri, sp. nov. (Rott, Germany, Late Oligocene). Members of the genus Archimyrmex were known earlier from Eocene deposits of the United States and Argentina, and members of the genus Prionomyrmex were known from Late Eocene Baltic amber.  相似文献   

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