A new species of the extinct genus Austrohamia (Cupressaceae s.l.) in the Daohugou Jurassic flora of China and its phytogeographical implications

Abstract A new conifer, Austrohamia acanthobractea, sp. nov., is described from the Jurassic Daohugou flora, Inner Mongolia Autonomous Region, China. The material consists of impressions represented by well‐preserved leafy twigs and branches as well as ovulate cones. Leafy shoots with at least two orders of branching; ultimate branchlets alternate or sub‐opposite with helically arranged leaves, decurrent at base with distal rounded tip; dorsiventrally flattened and univeined. Ovuliferous cones elliptical, less than 1 cm long, terminally borne on ultimate and penultimate branches, composed of helically arranged bracts with ovules disposed on their adaxial surfaces. The presence of similar, if not identical taxa, on both sides of the Pacific indicates the cosmopolitan distribution of primitive Cupressaceae between East Asia (Eurasia) and South America in the Pangaea.     

FERTILE CONIFEROPHYTE REMAINS FROM THE LATE TRIASSIC DEEP RIVER BASIN,NORTH CAROLINA

Seed cones (Compsostrobus neotericus gen. et sp. nov.), pollen cones, and vegetative remains of coniferophytes occur in Upper Triassic rocks of the Deep River Basin (Pekin Formation) of Central North Carolina. Seed cones have spatulate ovuliferous scales, each with two ovules and subtended by an elongated bract with an attenuate tip. Cuticle of seed cones resembles that of leaves on vegetative axes. Slender leaves are borne along two sides of the axis. Pollen cones have helically arranged microsporophylls, each with two abaxial sporangia bearing pollen grains of the Alisporites type. Seed cones, pollen cones, and vegetative remains suggest a coniferophyte very modern in aspect.     

Elatides sandaolingensis n. sp. (Cupressaceae sensu lato) — A new fossil conifer with cones from the Middle Jurassic of Xinjiang,northwestern China

Here we describe a new conifer fossil, Elatides sandaolingensis Z.X. Wang and B.N. Sun n. sp., from the Middle Jurassic Xishanyao Formation in the Turpan-Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China. The materials consist of compressions represented by well-preserved leafy shoots, pollen cones, and seed cone. Leaves are characterized by long triangular shapes, with straight apex and entire margins, and two stomatal bands on the abaxial surface. Pollen cones are terminally disposed on the ultimate leafy shoots, borne singly or in clusters. Pollen sacs are long-oval shaped, with three pollen sacs fused together. Pollen grains are spherical and have small germinal papilla and few wrinkles. The seed cone is oblong, with more than 35 helically arranged bract-scale complexes, which are characterized by long-oval shape and triangular apex. Compared with the extant nine genera of Taxodiaceous Cupressaceae in the morphology of seed cone and pollen cones, the present fossil consistently shares many characteristics with the extant genus Cunninghamia, but differs in other aspects. After being compared with the reported fossil records of the fossil plants, the current species is found to be different from any known species; thus, the present fossil is referred to as a new species of Elatides. From the similarity between the present fossil and Cunninghamia, it can be inferred that there may be a genetic relationship between these two genera. Additionally, the new species has thin cuticles and slightly sunken stomata, which can provide evidence indicating that the climate of the Turpan-Hami Basin in Middle Jurassic might have been warm and humid. By studying the geological history and geographical distribution of Elatides, it can be inferred that this genus may have originated in Switzerland, and it was migrated from Xinjiang to North and South China through the Ural Mountains.     

Reconstruction of the Jurassic conifer Sewardiodendron laxum (Taxodiaceae)

Compressed seed cones and pollen cones of Sewardiodendron laxum are described from the Middle Jurassic of Yima, Henan, central China. They are either organically attached to or associated with leafy shoots. Seed cones are terminally borne. Each cone is ovate to elongated, up to 6.5 cm long and 3.5 cm wide, and consists of a stout axis and numerous helically arranged bract-scale complexes. The bract protrudes beyond and is partially fused with the reduced ovuliferous scale. The ovuliferous scale bears approximately six inverted, small, and flattened seeds. Pollen cones are borne in terminal clusters. Microsporophylls are helically arranged, each bearing three abaxial, basally fused pollen sacs. Pollen is assaccate, rounded, and with an inconspicuous pore. Morphological, structural, and cuticular features of seed cones, pollen cones, and leafy shoots of S. laxum are compared with those of fossil and extant conifers. S. laxum is included in Taxodiaceae and believed to have its closest affinities with a Mesozoic conifer Elatides and a group of Cunninghamia-like conifers. It is reconstructed as a half-evergreen tree that lived in a humid, warm-temperate climate.     

100-million-year-old ant–conifer associates inside French amber: a fortuitous or ecological association?

Ants exhibit a plethora of ecological interactions with terrestrial plants. These interactions are broadly surveyed in modern ecosystems, but are much more difficult to unveil in the fossil record. Here, we report a unique ant–conifer association preserved in an opaque piece of 100-million-year-old amber from Charentes in Western France, revealed by propagation phase-contrast X-ray synchrotron microtomography (PPC-SRμCT). Most legs of the ant encircle the conifer twig, and the arthropod harbours a hooked position onto the leafy axis. The conifer is assigned to Glenrosa carentonensis Moreau, Néraudeau, Tafforeau and Dépré, whereas the ant is ascribed to Gerontoformica occidentalis Perrichot, Nel, Néraudeau, Lacau and Guyot. The purpose of this study was to discuss diverse hypotheses that could explain the natural association of these fossils (including random and ecological associations) and its palaeoecological implications. While a mutualistic interaction between Gerontoformica and Glenrosa cannot be unambiguously demonstrated here, these associates raise questions on the ant–conifer interactions during the early ant evolution.     

Upatoia barnardii gen. et sp. nov., an araucarian pollen cone with in situ pollen from the Late Cretaceous (Santonian) of Georgia,USA

Upatoia barnardii gen. et sp. nov., a conifer pollen cone from the Late Cretaceous (Santonian) Eutaw Formation of Upatoi Creek, Georgia, USA, is known from lignified and fusainised mesofossils that preserve its three-dimensional structure. The cone consists of numerous helically arranged microsporophylls, each composed of a thin stalk and distal lamina. Three elongate pollen sacs are attached to the base of the lamina. Pollen grains isolated from the pollen sacs are relatively large (52 – 75 μm), spheroidal to ellipsoidal in outline, lack sacci, and have a thickened equatorial exine that is often strongly folded. Pollen of Upatoia barnardii indicates a close relationship to extant Araucariaceae. Microsporophylls of U. barnardii confirm suggestions from previous studies of fossil material that some Mesozoic Araucariaceae had only three pollen sacs per microsporophyll, in contrast to extant species that often have more than ten pollen sacs per microsporophyll.     

MORE EVIDENCE FOR CONIFER DIVERSITY IN THE UPPER TRIASSIC OF NORTH CAROLINA

An ovulate strobilus from the Upper Triassic Deep River Basin, North Carolina, has helically arranged, loosely aggregated, elongated, spatulate bracts with axillary ovule-bearing appendages with about 8–10 ovules attached in two lateral rows, with outwardly directed micropyles. The axillary ovuliferous appendage is homologous with the voltzialean fertile dwarf shoot, but probably not directly evolved from it. More credible is a suggested origin from a completely fertile axillary appendage such as that of the Lower Permian Trichopitys. The occurrence of this cone, Metridiostrobus palissyaeoides, gen. and sp. nov., along with Compsostrobus neotericus and Voltzia andrewsii, reflects considerable diversity among conifer ovulate cones during the Upper Triassic.     

A new genus of male cones of voltzialean affinity,Uralostrobus voltzioides nov. gen., nov. sp., from the Lower Permian of the Urals (Russia)

A new genus and species of male cones of coniferophyte from the Lower Permian (Artinskian and Kungurian) deposits of the Urals, Russia is described: Uralostrobus voltzioides Naugolnykh nov. gen., nov. sp. The cone shows characters typical of some representatives of conifers belonging to the order Voltziales: more or less isometrical bracts of rhombic shape, prolonged sporangia with attenuate apices, and bisaccate pollen of Illinites-type. General information on the associated female seed scales and vegetative leafy shoots is given as well.     

A NEW STRUCTURALLY PRESERVED PENNSYLVANIAN CORDAITEAN POLLEN ORGAN

Permineralized specimens of the pollen organ Gothania (Hirmer) consist of a primary axis bearing pollen cones in the axils of bracts that are four ranked. The bilaterally symmetrical primary axis consists of a uniform parenchymatous pith surrounded by up to 15 endarch-mesarch axile bundles. The cortex is two-parted and consists of an inner zone of subepidermal fibers. Bract traces arise from the ends of the ellipsoid stele. Traces to the cones are derived from the open ends of the stele, and at higher levels form a centrarch-medullated vascular system. Each pollen cone is constructed of up to 25 helically arranged scales, each vascularized by a single trace that may dichotomize. Scales are elongate and broad, and histologically composed of mesophyll parenchyma and fibrous layers. Stomata are restricted to the adaxial surface between rows of fibers. Up to 10 distal scales may be fertile, each with 4 elongate pollen sacs at the tip. Large monosaccate grains of the Felixipollenites-type are densely packed in each pollen sac. The well-preserved specimens of Gothania provide an opportunity to compare this genus with pollen cones assigned to the genus Cordaianthus, and to relate isolated plant organs to the Cordaitales.     

A new genus of Early Devonian plants with novel strobilar structures and vegetative appendages from the Posongchong Formation of Yunnan,China

A new plant, Dibracophyton acrovatum gen. et sp. nov., is described from the Lower Devonian (Pragian) Posongchong Formation of Wenshan District, southeastern Yunnan, China. The plant has creeping axes from which arise vegetative and fertile axes. The vegetative axes helically bear lateral dichotomous appendages with curved or round tips. The fertile axes possess terminal strobili with numerous fertile units arranged in irregular helices. Each fertile unit consists of a stalked long-elliptical sporangium, with dehiscence into two equal valves, and two discrete long-ovate bracts covering sporangium from above–below directions. A new genus and species is thus established based on these characters and is temporarily regarded as incertae sedis of Tracheophyta, although it perhaps closes to the barinophytes in affinity. Detailed comparisons with other plants having a similar architecture, i.e., sporangia closely associated with modified vegetative structures, are made. The discovery of D. acrovatum further enriches the composition of the Posongchong flora and demonstrates great morphological disparity of the Early Devonian vascular plants.     

Late Paleocene Phaeodaria (Radiolaria) from Denmark

The article reports the finding of some late Paleocene (Thanetian) species of Phaeodarian Radiolaria in phosphorite concretions occurring in the Holmehus Formation of Denmark. These species are associated with a rich assemblage of diatoms and sparse spherical radiolarians. Phaeodarians are very well-preserved in celestobarite (BaSrSO₄) and consist of representatives of the families Challengeridae (Challengerebium triangulovum nov. sp. and Challengerebium sp.) and particularly Medusettidae (Medusetta danica nov. sp. and M. densicostata nov. sp.), which are the most frequent. A new genus of medusettid phaeodarians (Pseudochallengeranium nov. gen.) is also described.     

Two early eudicot fossil flowers from the Kamikitaba assemblage (Coniacian,Late Cretaceous) in northeastern Japan

Two new fossil taxa referable to the basal eudicot grade are described from the Kamikitaba locality (ca. 89 MYBP, early Coniacian: Late Cretaceous) of the Futaba Group in Japan. These charcoalified mesofossils exhibit well-preserved three-dimensional structure and were analyzed using synchrotron-radiation X-ray microtomography to document their composition and internal structure. Cathiaria japonica sp. nov. is represented by infructescence segments that consist of an axis bearing three to four fruits. The capsular fruits are sessile and dehiscent and consist of a gynoecium subtended by a bract. No perianth parts are present. The gynoecium is monocarpellate containing two pendulous seeds. The carpel is ascidiate in the lower half and conduplicate in the upper part, and the style is deflected abaxially with a large, obliquely decurrent stigma. Pollen grains are tricolpate with a reticulate exine. The morphological features of Cathiaria are consistent with an assignment to the Buxaceae s. l. (including Didymelaceae). Archaestella verticillatus gen. et sp. nov. is represented by flowers that are small, actinomorphic, pedicellate, bisexual, semi-inferior, and multicarpellate. The floral receptacle is cup shaped with a perigynous perianth consisting of several tepals inserted around the rim. The gynoecium consists of a whorl of ten conduplicate, laterally connate but distally distinct carpels with a conspicuous dorsal bulge, including a central cavity. The styles are short, becoming recurved with a ventrally decurrent stigma. Seeds are ca. 10 per carpel, marginal, pendulous from the broad, oblique summit of the locule. Pollen grains are tricolpate with a reticulate exine pattern, suggesting a relationship to eudicots. The morphological features of Archaestella indicate a possible relationship to Trochodendraceae in the basal grade of eudicots. The fossil currently provides the earliest record of the family and documents the presence of Trochodendraceae in eastern Eurasia during the middle part of the Late Cretaceous.     

Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond

Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and bilateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules.     

A novel lycopsid from the Upper Devonian of Jiangsu, China

A new lycopsid, Monilistrobus yixingensis gen. et sp. nov., is described from the Wutung Formation (Famennian, Upper Devonian) of Jiangsu, China. The plant has many features typical of other Upper Devonian lycopsids, including dichotomous branching, helically arranged obovate expanded leaf bases, linear leaves with spiny appendages along the lateral margins, sporophylls widened proximally, and one elliptical sporangium attached to the adaxial surface. The most distinctive novel feature of the plant is that the modified sporophylls are arranged tightly into fertile zones or cone-like structures that are separated by lengths of axes with more lax sterile microphylls only: therefore the cone-like structures are strung along the branches like beads on a necklace.     

Yuhania: a unique angiosperm from the Middle Jurassic of Inner Mongolia,China

Despite increasing claims of pre-Cretaceous angiosperms, whether there really are angiosperms in the Jurassic is apparently still an open question for many people before further evidence is available. This question can only be answered by studying more Jurassic plant fossils. Here we report a fossil angiosperm, Yuhania daohugouensis gen. et sp. nov, from the Middle Jurassic of Inner Mongolia, China. The plant includes connected stem, leaves, flowers, aggregate fruits, fruitlets, and seeds within fruitlets. The leaves are helically arranged along the curving stem, linear in shape, with 5–6 parallel veins. The aggregate fruit is pedicellate, composed of over 20 carpels/fruitlets helically arranged. Each fruitlet encloses a seed. The reproductive organs in various stages are found in the same plant, allowing us to understand the development of Yuhania. The occurrence of Yuhania in the Middle Jurassic re-confirms the Jurassic history for angiosperms that has been suggested by other independent research and adds to the on-going study on the early evolution of angiosperms.     

New evidence of the reproductive organs of Glossopteris based on permineralized fossils from Queensland,Australia. II: pollen-bearing organ Ediea gen. nov

Ediea homevalensis H. Nishida, Kudo, Pigg & Rigby gen. et sp. nov. is proposed for permineralized pollen-bearing structures from the Late Permian Homevale Station locality of the Bowen Basin, Queensland, Australia. The taxon represents unisexual fertile shoots bearing helically arranged leaves on a central axis. The more apical leaves are fertile microsporophylls bearing a pair of multi-branched stalks on their adaxial surfaces that each supports a cluster of terminally borne pollen sacs. Proximal to the fertile leaves there are several rows of sterile scale-like leaves. The pollen sacs (microsporangia) have thickened and dark, striate walls that are typical of the Arberiella type found in most pollen organs presumed to be of glossopterid affinity. An examination of pollen organs at several developmental stages, including those containing in situ pollen of the Protohaploxypinus type, provides the basis for a detailed analysis of these types of structures, which bear similarities to both compression/impression Eretmonia-type glossopterid microsporangiate organs and permineralized Eretmonia macloughlinii from Antarctica. These fossils demonstrate that at least some Late Permian pollen organs were simple microsporophyll-bearing shoot systems and not borne directly on Glossopteris leaves.     

Clevelandodendron ohioensis,gen. et sp. nov., a slender upright lycopsid from the late Devonian Cleveland Shale of Ohio

Clevelandodendron ohioensis Chitaley & Pigg gen. et sp. nov. is an almost entire lycopsid plant known from a single compressed specimen from the Cleveland Shale member of the Upper Devonian Ohio Shale. This unique specimen is 125 cm long, consisting of an unbranched, slender, monopodial axis with a partially preserved plant base bearing thick appendages at one end, and a compact, terminal ovoid bisporangiate strobilus at the other. The stem is 2 cm wide for most of its length. Visible on the decorticated stem surface are helically arranged, elongate leaf traces and laterally compressed, slender leaves along the stem margin. The plant base bears 4-6 thick appendages. The terminal strobilus is compact, ovoid, 9 cm long and up to 6 cm wide, morphologically similar to those of some Lepidodendrales, and bears helically arranged sporophyll/sporangium complexes with narrow bases and distal laminae up to 18 mm long, turned upward. Megaspores are 320-360 μm, trilete and laevigate, lacking a gula; microspores are 30-42 μm, trilete, indistinctly punctate and possibly assignable to Calamospora or Punctatisporites. Clevelandodendron demonstrates that slender unbranched lycopsids with an isoetalean plant habit similar to the Carboniferous genera Chaloneria and Sporangiostrobus and Triassic Pleuromeia-like forms were present as early as the Late Devonian. The early occurrence of this unique habit suggests that diversification within the isoetalean clade sensu Rothwell and Erwin (including both Isoetales and Lepidodendrales) was well established prior to the Carboniferous.     

STRUCTURE AND AFFINITIES OF ATHROTAXITES BERRYI BELL,AN EARLY CRETACEOUS CONIFER

Compressions and impressions of leafy twigs, pollen cones, and seed cones of Athrotaxites berryi are abundant in certain layers of the Kootenai Formation (Aptian) in Montana and the Lower Blairmore Formation in adjacent Alberta. The twigs are densely covered by helically arranged leaves that are about 2 mm long and wide. Pollen cones are borne laterally on ultimate branch segments. Some are sessile, while others terminate a minute lateral branch. The cones are 3–4 mm in diam and about 10 mm long. Each sporophyll has a stalk that is about 0.7 mm long and an upturned laminar tip that is 1–1.5 mm long by 1 mm wide. At least two pollen sacs are attached to the abaxial side of each sporophyll. Seed cones are borne terminally on lateral branches that are often curved. These cones are about 10 mm at their widest diameter and about 15 mm long. Each bract and associated ovuliferous scale are fused to form a wedge-shaped complex that is 4–5 mm long. The complex is 0.7 mm wide at its base and expands to about 2.5 mm wide and thick near its apex. The tip of the complex narrows abruptly to a point and terminates in a spine that is about 0.5 mm long. At least one seed occurs on the adaxial side of each complex. Athrotaxites berryi belongs to the Taxodiaceae. It resembles modern Athrotaxis cupressoides but differs from it in too many aspects to be included in the modern genus.     

SVALBARDIA BANKSII SP. NOV. FROM THE UPPER DEVONIAN (FRASNIAN) OF NEW YORK STATE

Svalbardia banksii sp. nov., is described from the Upper Devonian (Frasnian) Fish Cabin Creek locality near Pond Eddy, New York. The compression consists of ultimate branches bearing spirally arranged, unwebbed leaves. The unwebbed leaves are up to 3.2 cm long, are somewhat flexuous, and dichotomize in more than one plane. The new species is similar to the reconstruction of Actinoxylon banksii from the Middle Devonian (Givetian) of New York and strengthens the supposed relationship between Svalbardia polymorpha and Actinopodium nathorstii from Mimerdalen, Spitzbergen.     

A male cone of Pseudofrenelopsis dalatzensis with in situ pollen grains from the Lower Cretaceous of Northeast China

A Classopollis-containing male cone found in close association with Pseudofrenelopsis dalatzensis from the Lower Cretaceous Dalazi Formation of Yanji Basin, eastern Jilin, China was studied using scanning electron microscopy and described as Classostrobus dalatzensis sp. nov. The small oval cone, borne on the top of a stalk (fertile short shoot), consists of helically arranged microsporophylls, each with a rhomboid and expanded distal head. The short shoot is divided into indistinct nodes and internodes with fine longitudinal striations. Cuticles of the microsporophyll and the internode of the short shoot are generally similar to Pseudofrenelopsis dalatzensis internode cuticles, all of them having papillate outer surfaces. Stomata are similar in structure and arrangement, with papillae of subsidiary cells overhanging the stomatal pit. Epidermal cells are rectangular or isodiametrical, each with a robust papilla on the periclinal wall. Hypodermal cells are present between the stomatal files. The internal structure of the in situ Classopollis pollen grains was studied in detail. Pollen grain is small, with thin sexine, poorly developed nexine and may be immature. This is the first record of in situ pollen grains Classopollis in China of which the internal structure is known in detail.