Nyssidium jiayinense sp. no v. (Cercidiphyllaceae) of the Early Tertiary from north-east China

Nyssidium jiayinense , a new species of the extinct genus JSyssidium , Cercidiphyllaceae, is described from the Palaeocene of north-east China. The infructescences of the fossil are paniculate with 14–22 follicles in individual racemose branches. The follicles occur in pairs with opposite ventral sutures. The follicle wall is three-layered, with a thin epidermis. Mesocarp fibres are longitudinal and endocarp fibres transverse. The distinct features of the infructescence structure differ from all other fossil Cercutiphyllum-like plants and living Cercidiphyllum . The fossil provides new morphological evidence supporting the hypothesis that the follicle clusters in extant Cercidiphyllum evolved by reduction from an elongated inflorescence.     

Betulaceous leaves and fruits from the British Upper Palaeocene

Fossil leaves and bracteate fruits are described from a new Upper Palaeocene locality in the Reading Beds near Newbury, southern England. The leaves are assigned to Craspedodromophyllum acutum Crane and correspond in many respects to those of living Betulaceae. The bracts and fruits are assigned to Palaeocarpinus laciniata Crane, which although referable to the Coryleae exhibits a novel combination of the characters of several living genera, particularly Corylus and Carpinus. An argument is presented for the association of these organs as a reconstructed fossil plant which is an extinct member of the Betulaceae. The evolution and fossil record of the Betulaceae are discussed, the late Upper Cretaceous and Palaeocene being regarded as the time at which the characters of modern genera were beginning to differentiate. Carpinus appears to have undergone a major Eurasian diversification during the late Palaeogene and early Neogene. Dispersal in Palaeocarpinus laciniata was probably less specialized than in most extant Coryleae.     

REPRODUCTIVE AND VEGETATIVE STRUCTURE OF NORDENSKIOLDIA (TROCHODENDRACEAE), A VESSELLESS DICOTYLEDON FROM THE EARLY TERTIARY OF THE NORTHERN HEMISPHERE

Nordenskioldia borealis Heer is described and its systematic position is reassessed based on examination of the type material and specimens recently collected from three Paleocene localities in North America (Almont, North Dakota; Melville, Montana; Monarch, Wyoming). The morphology of Nordenskioldia infructescences and fruits is clarified, and in particular, silicified specimens from Almont provide new details of fruit and seed anatomy. Fruits are schizocarpic, and individual fruitlets also dehisce to release flat reticulate seeds. These seeds occur in many Paleocene floras but have not been linked previously to Nordenskioldia. Anatomical details of infructescence axes are identical to those of distinctive long and short shoot systems that cooccur with Nordenskioldia, and neither the infructescence axes nor shoots have vessels in the secondary xylem. Comparison of the floras at Almont, Melville, and Monarch with those at other Paleogene localities in Asia, Europe, and North America provides association evidence supporting earlier conclusions that the Nordenskioldia plant bore simple, entire- to crenatemargined leaves with actinodromous venation. Such leaves have been previously assigned to extant genera such as Cercidiphyllum, Cocculus, and Populus but are treated here as Zizyphoides flabella (Newberry) comb. nov. Based on the combined morphological and anatomical details now available, the Nordenskioldia plant is assigned to the Trochodendrales as an extinct genus most closely related to extant Trochodendron.     

Betulaceous leaves and fruits from the British Upper Palaeocene

Fossil leaves and bracteate fruits are described from a new Upper Palaeocene locality in the Reading Beds near Newbury, southern England. The leaves are assigned to Craspedodromophyllum acutum Crane and correspond in many respects to those of living Betulaceae. The bracts and fruits are assigned to Palaeocarpinus laciniata Crane, which although referable to the Coryleae exhibits a novel combination of the characters of several living genera, particularly Corylus and Carpinus. An argument is presented for the association of these organs as a reconstructed fossil plant which is an extinct member of the Betulaceae. The evolution and fossil record of the Betulaceae are discussed, the late Upper Cretaceous and Palaeocene being regarded as the time at which the characters of modern genera were beginning to differentiate. Carpinus appears to have undergone a major Eurasian diversification during the late Palaeogene and early Neogene. Dispersal in Palaeocarpinus laciniata was probably less specialized than in most extant Coryleae.     

An extinct juglandaceous fruit from the Upper Palaeocene of southern England

A new genus of juglandaceous winged fruit, is described from the Reading Beds (Upper Palaeocene) of southern England. It comprises one of the earlier macrofossil records of the Juglandaceae, and is the earliest from the European Tertiary. The fruit represents an extinct genus related to the extant tribe Engelhardieae, but excluded from it by its simple unlobed bract. Cladistic analysis shows Casholdia to display generalized engelhardioid fruit morphology. It lacks the tri-lobed bract diagnostic of the Engelhardieae, and predates the first occurrence of such bracts in the fossil record. Casholdia adds to the mounting evidence indicating an early Palaeogene radiation of the Juglandaceae.     

Rhododendron seeds from the Palaeocene of southern England

Seeds closely resembling those of some species of the extant genus Rhododendron L. have been recovered from the Reading Beds near Newbury, Berkshire. The fossils are assigned to Rhododendron newburyanum sp. noV. on the basis of detailed comparisons with seeds of extant Rhododendron species, other Ericaceae, and taxa with seeds of similar morphology.     

IN SITU CERCIDIPHYLLUM-LIKE SEEDLINGS FROM THE PALEOCENE OF ALBERTA,CANADA

Fossil seedlings and seeds of an extinct Cercidiphyllum-like plant occur in the Paskapoo Formation (Late Paleocene) at Joffre Bridge near Red Deer, Alberta. Cotyledon and early seedling leaf stages are preserved in growth position. Morphological details of seedlings and seeds support a close relationship between the Paleocene fossils and extant Cercidiphyllum, and suggest that during the Upper Cretaceous and Tertiary (Paleogene) Cercidiphyllum-like plants were important early colonizers of open flood-plain environments.     

Flowers, fruits, seeds, and pollen of Landeenia gen. nov., an extinct sapindalean genus from the Eocene of Wyoming

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.     

Oldest known Eucalyptus macrofossils are from South America

The evolutionary history of Eucalyptus and the eucalypts, the larger clade of seven genera including Eucalyptus that today have a natural distribution almost exclusively in Australasia, is poorly documented from the fossil record. Little physical evidence exists bearing on the ancient geographical distributions or morphologies of plants within the clade. Herein, we introduce fossil material of Eucalyptus from the early Eocene (ca. 51.9 Ma) Laguna del Hunco paleoflora of Chubut Province, Argentina; specimens include multiple leaves, infructescences, and dispersed capsules, several flower buds, and a single flower. Morphological similarities that relate the fossils to extant eucalypts include leaf shape, venation, and epidermal oil glands; infructescence structure; valvate capsulate fruits; and operculate flower buds. The presence of a staminophore scar on the fruits links them to Eucalyptus, and the presence of a transverse scar on the flower buds indicates a relationship to Eucalyptus subgenus Symphyomyrtus. Phylogenetic analyses of morphological data alone and combined with aligned sequence data from a prior study including 16 extant eucalypts, one outgroup, and a terminal representing the fossils indicate that the fossils are nested within Eucalyptus. These are the only illustrated Eucalyptus fossils that are definitively Eocene in age, and the only conclusively identified extant or fossil eucalypts naturally occurring outside of Australasia and adjacent Mindanao. Thus, these fossils indicate that the evolution of the eucalypt group is not constrained to a single region. Moreover, they strengthen the taxonomic connections between the Laguna del Hunco paleoflora and extant subtropical and tropical Australasia, one of the three major ecologic-geographic elements of the Laguna del Hunco paleoflora. The age and affinities of the fossils also indicate that Eucalyptus subgenus Symphyomyrtus is older than previously supposed. Paleoecological data indicate that the Patagonian Eucalyptus dominated volcanically disturbed areas adjacent to standing rainforest surrounding an Eocene caldera lake.     

New genus <Emphasis Type="Italic">Sarbaicarpa</Emphasis> gen. nov. (Hamamelidales) from the Cenomanian-Turonian of Western Kazakhstan

Anatomically preserved infructescences of Sarbaicarpa shilinii gen. et sp. nov. are described from the Cenomanian-Turonian of Kazakhstan and assigned to the Hamamelidales on the basis of their microstructure. The infructescence consists of about 30 free broadly cuneate fruits. The fruits are monocarpellate, without stylode, and basally with hairs. The seed is solitary and anatropic. Two types of sterile elements are present: (1) semispherical structures that are comparable in size to the fruits and densely covered with rounded trichomes and (2) narrow linear structures reaching more than a half of the fruit length. The new genus is characterized by a mosaic of platanaceous and hamamelidaceous characters. The plant remains are found associating with fossil leaves of the typically Platanus aspect.     

FOSSIL CERATOPHYLLUM (CERATOPHYLLACEAE) FROM THE TERTIARY OF NORTH AMERICA

Fossil fruits and a vegetative axis assignable to the extant genus Ceratophyllum are described from four North American Tertiary localities. Fossil fruits assignable to the extant species C. muricatum and C. echinatum are reported from the Eocene Green River and Claiborne formations, and the Miocene Esmerelda Formation, respectively. An extinct species, C. furcatispinum, is described from the Paleocene Fort Union Formation and represents the oldest published report of Ceratophyllum in the fossil record. The existence of extant angiosperm species in the Eocene is very unusual and may be attributable in this case to slow evolutionary rates and unusual evolutionary properties associated with hydrophily in the genus Ceratophyllum.     

Anatomically preserved seeds of Nuphar (Nymphaeaceae) from the Early Eocene of Wutu, Shandong Province, China

Well-preserved seeds from the early Eocene of Wutu, Shandong, China are assigned to the genus Nuphar (Nymphaeaceae) based on morphology and anatomy. The seeds of Nuphar wutuensis sp. nov. are ellipsoidal to ovoid, 4-5 mm long with a clearly visible raphe ridge, and a truncate apex capped by a circular operculum ca. 1 mm in diameter bearing a central micropylar protrusion. These features, along with the testa composed of a uniseriate outer layer of equiaxial pentagonal to hexagonal surface cells and a middle layer 4-6 cells thick composed of thick-walled, periclinally elongate sclereids, correspond to the morphology and anatomy of extant Nuphar and distinguish this fossil species from all other extant and extinct genera of Nymphaeales. These seeds provide the oldest record for the genus in Asia and are supplemented by a similar well-preserved specimen from the Paleocene of North Dakota, USA. These data, together with the prior recognition of Brasenia (Cabombaceae) in the middle Eocene, indicate that the families Nymphaeaceae and Cabombaceae had differentiated by the early Tertiary.     

Cones, Seeds, and Foliage of Tetraclinis Salicornioides (Cupressaceae) from the Oligocene and Miocene of Western North America: A Geographic Extension of the European Tertiary Species

The cupressaceous genus Tetraclinis is recognized from the Oligocene and Miocene of western North America on the basis of co-occurring seed cones, seeds, and foliage branches. Morphological and anatomical comparisons with the two previously recognized European Tertiary species indicate that the North American specimens are morphologically inseparable from Tetraclinis salicornioides (Unger) Kvacek. The North American taxon is treated as a new variety, T. salicornioides (Unger) Kvacek var. praedecurrens (Knowlton) comb. et stat. nov., and is distinguished from the European representatives, T. salicornioides (Unger) Kvacek var. salicornioides, by slight anatomical differences in the leaf epidermis. Although cones and seeds of the fossil species are closely similar to those of extant Tetraclinis articulata, the foliage is more "spreading," composed of flattened segments with fused facial and lateral leaves that are apparently adaptive for a more mesic climate. The recognition of T. salicornioides in western North America along with the absence of Tetraclinis in the fossil and recent flora of eastern Asia provide evidence for communication of the species across the North Atlantic during the early or middle Tertiary.     

FRUITS AND SEEDS OF TRIBE GORDONIEAE (THEACEAE) FROM THE EOCENE OF NORTH AMERICA

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.     

The first Gondwanan Euphorbiaceae fossils reset the biogeographic history of the Macaranga-Mallotus clade

Premise

The spurge family Euphorbiaceae is prominent in tropical rainforests worldwide, particularly in Asia. There is little consensus on the biogeographic origins of the family or its principal lineages. No confirmed spurge macrofossils have come from Gondwana.

Methods

We describe the first Gondwanan macrofossils of Euphorbiaceae, represented by two infructescences and associated peltate leaves from the early Eocene (52 Myr ago [Ma]) Laguna del Hunco site in Chubut, Argentina.

Results

The infructescences are panicles bearing tiny, pedicellate, spineless capsular fruits with two locules, two axile lenticular seeds, and two unbranched, plumose stigmas. The fossils' character combination only occurs today in some species of the Macaranga-Mallotus clade (MMC; Euphorbiaceae), a widespread Old-World understory group often thought to have tropical Asian origins. The associated leaves are consistent with extant Macaranga.

Conclusions

The new fossils are the oldest known for the MMC, demonstrating its Gondwanan history and marking its divergence by at least 52 Ma. This discovery makes an Asian origin of the MMC unlikely because immense oceanic distances separated Asia and South America 52 Ma. The only other MMC reproductive fossils so far known are also from the southern hemisphere (early Miocene, southern New Zealand), far from the Asian tropics. The MMC, along with many other Gondwanan survivors, most likely entered Asia during the Neogene Sahul-Sunda collision. Our discovery adds to a substantial series of well-dated, well-preserved fossils from one undersampled region, Patagonia, that have changed our understanding of plant biogeographic history.     

Curtisia (Cornales) from the Eocene of Europe and its phytogeographical significance

Fossil remains of Curtisia Aiton (Cornales) are recognized for the first time from the Tertiary of Europe, based on early Eocene anatomically preserved fruits from the London Clay and Poole Formations of southern England. The modern distribution of this monotypic genus is limited to the cape of South Africa. Curtisia quadrilocularis (Reid & Chandler) comb. nov. fruits have globose tetralocular endocarps composed of isodiametric sclereids with a single seed per locule, a prominent axial vascular canal, apical placentation, and four germination valves. All of these characters, as well as size, correspond to extant Curtisia . Although many fossil taxa from the Eocene of Europe have been shown to have their closest extant relatives in Asia, this occurrence of Curtisia highlights Tertiary floristic exchange between Europe and Africa. The newly recognized fossil occurrences suggest a Laurasian origin for Curtisia , in conformity with the fossil record for several other genera of the Cornales. In addition, our rejection of the former assignment of this species to Leucopogon causes us to question whether Epacridaceae were present in the Tertiary of Europe.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 127–134.     

吉林延边早白垩世大拉子组植物化石新类型--星学异麻黄

报道产自吉林省延边早白垩世大拉子组植物化石新类型——星学异麻黄(Alloephedra xingxuei gen.et sp.nov.)。大拉子组的时代处于早白垩世的阿普特期-阿尔必期(Aptian-Albian)。化石标本保存了植物的茎枝、雌球花及种子;该种的茎枝分节,节间具细纵槽纹,叶退化,雌球花单个着生于小枝顶部,种子成对且种子顶部宿存珠孔管等特征与现存麻黄科植物最为相近,因此可能属于麻黄科。     

ATTACHED REPRODUCTIVE AND VEGETATIVE REMAINS OF THE EXTINCT AMERICAN-EUROPEAN GENUS CEDRELOSPERMUM (ULMACEAE) FROM THE EARLY TERTIARY OF UTAH AND COLORADO

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.     

Fungal spores of the genus Pesavis from the Lower Tertiary of Britain

Dispersed fungal spores from the Reading Beds (Palaeocene) near Newbury, Berkshire are referred to the genus Pesavis Elsik & Jansonius, and a possible affinity with aero-aquatic fungi is suggested. This highly distinctive Palaeogene sporomorph has not previously been described from the European Tertiary.     

First record of Cercidiphylloxylon(Cercidiphyllaceae)from the Palaeocene of Fushun,NE China

Cercidiphylloxylon spenceri(Brett)Pearson is described from the Lizigou Formation,Palaeocene in China.The growth rings are distinct; pores are diffuse,solitary,with somewhat angular outlines in cross section;vessel elements long with long scalariform perforation plates; intervessel pitting is opposite to scalariform; fibertracheids are present; axial parenchyma is scarce; rays are mostly biseriate and heterogeneous.All wood characters of the fossil specimen fall into the range of those of extant Cercidiphyllum(Cercidiphyllaceae).The finding is one of the earliest fossil wood records of Cercidiphyllaceae.