Two new fossil flowers of magnoliid affinity from the Late Cretaceous of New Jersey

Two taxa of cupulate magnoliid fossil flowers, Cronquistiflora and Detrusandra, are described from the Late Cretaceous (Turonian, ∼90 million years before present [MYBP]) Raritan (or lower Magothy) Formation of New Jersey. The fossil taxa are represented by flowers at various stages of development, associated fragments of cup-shaped floral receptacles with attached anthers, and isolated anthers. Both taxa have laminar stamens with adaxial thecae and valvate dehiscence. Pollen is boat-shaped and foveolate in anthers associated with Cronquistiflora and spherical with reticulate ornamentation in Detrusandra. Cup-shaped receptacles are externally bracteose in both taxa. The receptacle of Cronquistiflora is broader than the campanulate one of Detrusandra. Cronquistiflora also has more carpels (∼50 in a spiral vs. ∼5 in a whorl or tight spiral). In Detrusandra the carpels are surrounded by dorsiventrally flattened structures (pistillodes?) that are remote from the attachment of the stamens near the distal rim of the receptacular cupule. Detrusandra stigmas are rounded and bilobed, while those of Cronquistiflora, although bilateral in symmetry, are somewhat peltate. The fossil taxa share prominent characters with extant cupulate magnoliids (e.g., Eupomatia, Calycanthus), but also share characters with other magnoliids including Winteraceae. These fossils represent taxa that are character mosaics relative to currently recognized families. Inclusion of these fossils in existing data matrices and ensuing phylogenetic analyses effect changes in tree topologies consistent with their mosaicism relative to modern taxa. But such analyses do not definitively demonstrate the affinities of the fossils other than illustrating that these fossils are generalized magnoliids. Additional analysis of modern and fossil magnoliids is necessary to fully appreciate the phylogenetic significance and positions of these fossil taxa. However, the results of the phylogenetic analyses do introduce the possibility that extinct taxa of Magnoliales with cupulate floral receptacles were transitional between basal angiosperms and those with tricolpate pollen. The fossils provide insights into the timing of evolution of character complexes now associated with coleopteran pollination.     

Chloranthaceous floral structures from the Late Cretaceous of Sweden

New chloranthaceous floral structures from the Late Cretaceous (Late Santonian/Early Campanian) of Scania, southern Sweden, have provided important new information on theChloranthistemon plants. The material includes well preserved fragments of inflorescence axes with flowers in situ documenting thatChloranthistemon flowers were bisexual and closely resembled those of extantChloranthus (Chloranthaceae). An emended diagnosis is given for the type species of the genus,Chloranthistemon endressii, and a new species,C. alatus, is described. The flowers ofChloranthistemon are small, perianthless and strongly zygomorphic, consisting of a tripartite and broadened androecium borne in an abaxial to lateral position on the monocarpellate ovary, and arranged in the axils of decussate bracts. Stamens are either completely free (C. alatus), or free at the base and coherent at the apex (C. endressii). The apical connective is extensive in both species; elaborated into conspicuous wing-like structures inC. alatus, or into a massive and shield-like structure inC. endressii. Pollen grains ofC. endressii are spheroidal, and reticulate and spiraperturate, while those ofC. alatus are ellipsoidal, tectate and foveolate with a unique combination of a distal colpus and a proximal furrow (colpus?) perpendicular to each other. Ovaries observed in well preserved flowers of both species are small and undifferentiated. Larger, dispersed fruits of chloranthaceous affinity are abundant and distinct, and probably represent at least two or three species, but cannot be linked with certainty to any of theChloranthistemon species described here.     

Female flowers and inflorescences of Didymelaceae

 In molecular analyses Didymelaceae together with Buxaceae form a fairly well-supported clade among families near the base of eudicots. Only little is known, however, about the flowers and inflorescences of Didymelaceae. In this study, the structure of the female flowers and inflorescences of Didymeles integrifolia was studied. Flowers are unicarpellate and orientation of the carpel is slightly deflected abaxially as in Proteaceae. Otherwise, Didymelaceae share many features of the gynoecium with Buxaceae and some other basal eudicots: the carpels are ascidiate in the lower half; anthetic carpels are completely closed by postgenital fusion; stigma is double-crested and widely decurrent; stigmatic papillae are unicellular and pear-shaped; the pollen tube transmitting tract is extensive and prominently differentiated; fruits are fleshy drupes with persistent stigma and style. However, the exceedingly elongate base of the integuments of Didymelaceae is an unusual feature among basal eudicots and even angiosperms. Received October 31, 2002; accepted December 17, 2002 Published online: March 31, 2003     

About some aporrhaid and strombid gastropods from the Late Cretaceous

Sixteen species of the Stromboidea (Gastropoda) from the Late Cretaceous are described in this study. One species belongs to the Strombidae, the others to eight genera and subgenera of the Aporrhaidae. Eight species are new. They have been found in the Cenomanian of Kassenberg in western Germany, the Coniacian of the Mungo River in Cameroon, the Santonian of the Eastern Cape Province of South Africa, the Santonian/Campanian of the Ariyalur area in southern India, the Campanian of northern Spain, and the Maastrichtian of the Western Desert in Egypt. Two species ofDrepanocheilus from South Africa are considered stem-group representatives of the aporrhaids which inhabited the Weddellian Province in the early Tertiary. One new species of the strombid genusHippocrenes is regarded as an early species of the evolutionary lineage leading to the Seraphsidae. The new species areLatiala? ponsi, Drepanocheilus herberti, Drepanocheilus triliratus, Drepanocheilus (Tulochilus) jouberti, Graciliala quaasi, Kaunhowenia catalanica, Kaunhowenia punctata andHippocrenes kussi.     

Fossil flowers of ericalean affinity from the Late Cretaceous of Southern Sweden

Charcoalified fossil flowers of a new genus and species (Paradinandra suecica) with affinities to Ericales s.l. (sensu lato) are described from the Late Cretaceous (Santonian-Campanian) from Southern Sweden. The flowers are pentamerous, hypogynous, and actinomorphic. Aestivation of sepals and petals is imbricate-quincuncial. The androecium consists of an outer whorl with single episepalous stamens and an inner whorl with paired epipetalous stamens. Pollen is small and probably tricolpate. Three carpels form a syncarpous ovary with numerous campylotropous ovules on parietal placentae. The styles are free for most of their length. The structure of mature fruits and seeds is unknown. Clear distinction of sepals and petals, possible dehiscence of anthers by restricted slits, presence of a nectary, and the general floral construction (salverform corolla) with a canalized access to the floral center clearly indicate insect pollination of the fossil flowers. Comparisons with extant taxa demonstrate that Paradinandra suecica shares many similarities with Ericales s.l. and in particular with members of Ternstroemiaceae, Theaceae, and Actinidiaceae. However, it is neither identical to any one genus of these families nor to any of the previously described ericalean taxa from the Cretaceous and thus provides further evidence of the diversity of Cretaceous ericalean plants.     

Cretaceous diversification of angiosperms in the western part of the Iberian Peninsula

The classic leaf fossil floras from the Cretaceous of the Lusitanian Basin, Portugal, which were first described more than one hundred years ago, have played an important role in the development of ideas on the early evolution of angiosperms. Insights into the nature of vegetational change in the Lusitanian Basin through the Cretaceous have also come from studies of fossil pollen and spores, but the discovery of a series of mesofossil floras containing well-preserved angiosperm reproductive structures has provided a new basis for understanding the systematic relationships and biology of angiosperms at several stratigraphic levels through the Cretaceous. In the earliest mesofossil floras from the Torres Vedras locality, which are of probable Late Barremian-Early Aptian age, angiosperms are surprisingly diverse with about 50 different taxa. In slightly later mesofossil floras, which are of probable Late Aptian-Early Albian age, the diversity of angiosperms is still more substantial with more than hundred different kinds of angiosperm reproductive structures recognized from the Famalicão locality alone. However, this early diversity is largely among angiosperm lineages that produced monoaperturate pollen (e.g., Chloranthaceae, Nymphaeales) and early diverging monocots (Alismatales). Eudicots are rare in these Early Cretaceous mesofossil floras, but already by the Late Cenomanian the vegetation of the western Iberian Peninsula is dominated by angiosperms belonging to various groups of core eudicots. The Normapolles complex is a particularly conspicuous element in both mesofossil floras and in palynological assemblages. In the Late Cretaceous mesofossil floras from Esgueira and Mira, which are of Campanian-Maastrichtian age, core eudicots are also floristically dominant and flowers show great organisational similarity to fossil flowers from other Late Cretaceous floras described from other localities in Asia, Europe and North America.     

Archamamelis,hamamelidalean flowers from the Upper Cretaceous of Sweden

Lignite fossil flowers (including pollen) and isolated stamens of probable hamamelidalean (possible hamamelidaceous) affinities from the upper Cretaceous (Late Santonian or Early Campanian) of Sweden are described. The flowers are 6–7-merous with probably a double perianth, one whorl of stamens and (2-?)3 carpels. The stamens are disporangiate; each theca opens by a valve towards the centre of the flower. Pollen is tricolpate, tectate-columellate and reticulate; the endexine is lamellated in the apertural region. The gynoecium has free styles and a syncarpous ovary. In the one flower that was serially sectioned the ovary is either non-functional or development of the few (2?) ovules is retarded.     

山西天镇晚白垩世一新鸭嘴龙超科恐龙（英文）

记述了山西天镇晚白垩世灰泉堡组发现的一鸭嘴龙超科恐龙新属种:天镇大同龙Datonglong tianzhenensis gen.et sp.nov.。标本为一保存较完好的右侧齿骨并带牙齿。与其他鸭嘴龙超科恐龙不同,大同龙每个齿槽有两个功能齿,而且舌面齿冠上嵴的发育也具有独特的特征组合(主嵴向远中方向偏移;次嵴发育;无其他附嵴;主嵴上半段略后弯)。对比研究发现,在较进步的非鸭嘴龙科鸭嘴龙超科类群中齿骨和牙齿的演化过程复杂,许多鸭嘴龙科的特征在这些类群中时而出现,如:巴克龙Bactrosaurus齿冠具有较大的高/宽比;吉尔摩龙Gilmoreosaurus齿冠上只有一个主嵴和纤弱的附嵴;张衡龙Zhanghenglong齿冠上主嵴中置;南宁龙Nanningosaurus下颌冠状突前倾;大同龙Datonglong每个齿槽有两个功能齿。这表明为了获得更有效的牙齿咀嚼方式,在鸭嘴龙科起源前它的姐妹群们曾进行过多种尝试;这也告诫我们,受大量趋同演化的影响,要厘清这些类群间的关系并非易事。     

Oxypetalum banksii subsp. banksii: a taxon of Asclepiadaceae with an extragynoecial compitum

 The floral morphology of seven Oxypetalum species and, in particular, the spatial relationship between the five stigmatic chambers and two separate ovaries of their flowers with respect to transmission of the pollen tube are studied. In all species, except O. banksii subsp. banksii, floral morphology is similar to that in other Asclepiadeae, and the flowers pollinated with one pollinium develop only one follicle, which means compitum absence. In O. banksii subsp. banksii flowers, the secretory interstaminal tissue lines the inner walls of the stigmatic chambers as in the other species studied, but it also reaches the upper part of the inner surface of the filament tube, where it surrounds the styles, an unprecedented feature for Asclepiadaceae. This tissue secretes nectar and mucilage; the latter acts as transmitting medium for the growth of pollen tubes from pollinia inserted and hydrated in stigmatic chambers (“hyperstigmas”). Mucilage also functions as an extragynoecial compitum: in flowers pollinated with one pollinium both carpels develop into a follicle. Received August 28, 2001; accepted April 9, 2002 Published online: October 14, 2002 Addresses of the authors: Milene Faria Vieira (e-mail: mfvieira@mail.ufv.br), Departamento de Biologia Vegetal, Universidade Federal de Vi?osa, 36571-000, Vi?osa, Minas Gerais, Brazil. George John Shepherd, Departamento de Botanica, Instituto de Biologia, Universidade Estadual de Campinas, C.P. 6109, 13083-970, Campinas, S?o Paulo, Brazil.     

The sweet jelly of Combretum lanceolatum flowers (Combretaceae): a cornucopia resource for bird pollinators in the Pantanal, western Brazil

 The pollination biology of the neotropical scandent shrub Combretum lanceolatum was studied in the seasonally-flooded Pantanal region in western Brazil. This plant bears horizontally oriented inflorescences, whose yellowish green flowers begin to expand at dusk and are fully open at dawn. Instead of fluid nectar the flowers produce sweet gelatinous secretion in form of pellets. The glandular complex of the flower is composed of the inner wall of the receptacle and its tubular extension, being equivalent to the nectariferous disk of the nectar-producing species within the genus. The jelly is produced at night, contains mannan and is imbibed by free hexoses. It originates by swelling and disintegration of the inner wall, after contact with the nectar generated concomitantly in the mesophyll. Combretum lanceolatum is unique within the genus in its production of jelly pellets instead of liquid nectar. A new term, the jelly-flower, is proposed for flowers with this kind of reward. The pellet is not replaced once removed by a bird, and thus resembles a fruit in its availability to consumers, another unique feature that distinguishes this species within the genus. The jelly pellets offered by the many flowered branches attract a great diversity of bird visitors (28 species from eight families), which feed on this copious food resource and pollinate the flowers. The most effective pollinators probably are thrushes, tanagers, and orioles. Flocking parakeets and macaws sometimes feed on the petals, thus acting as flower plunderers. Combretum lanceolatum presents a high fruit set under natural conditions, which likely favours its spreading and becoming a weed species. Received July 11, 2000 Accepted November 18, 2000     

A new nanhsiungchelyid turtle from the Late Cretaceous of Neixiang,Henan Province,China

A new genus and species of Nanhsiungchelyidae (Testudines: Cryptodira), Yuchelys nanyangensis n. g. n. sp., are described on the basis of a partial skeleton from the Late Cretaceous Gaogou Formation of Neixiang, Nanyang Basin, Henan Province. It is the first nanhsiungchelyid record in the east-central part of China and fills the geographical gap between the western (Uzbekistan, Mongolia, Northern and Southern China) and eastern (Japan) distribution areas of the family Nanhsiungchelyidae.     

Effect of rootstocks on floral nectar composition in apple cultivars

 Insect attraction of flowers in apple cultivars is an essential question from the viewpoint of fruit yield, since apple flowers are autosterile and entomogamous. Therefore, it is important to study the two most significant factors of primary attraction, pollen and nectar production. The composition of nectar in apple cultivars on different rootstocks was investigated, putting an emphasis on sugar components. It was stated that the composition of nectar and the ratio of mono- and disaccharides was almost identical and constant in trees on rootstock M.4, whereas on other rootstocks the effects of the season were more pronounced. In triploid cultivars on rootstocks M.9 and M.26 nectar can be characterised by the dominance of sucrose. Relationship was found between free fertilisation rate of cultivars and sugar amount of nectar. In triploid cultivars nectar sugar content was usually lower than in diploid ones, and reached the bee visitation threshold only in some years, influenced also by the effect of rootstocks. Received August 27, 2002; accepted November 16, 2002 Published online: June 2, 2003     

A second hadrosauroid dinosaur from the early Late Cretaceous of Zuoyun,Shanxi Province,China

A second basal hadrosauroid dinosaur, Zuoyunlong huangi gen. et sp. nov., is reported from the early Late Cretaceous Zhumapu Formation in Zuoyun County, Shanxi Province, northern China. Zuoyunlong preserves a partial right ilium and ischium and is unique in having a very short postacetabular process 50% as long as the iliac central plate. Our cladistic analysis recovers Zuoyunlong as the most basal Late Cretaceous hadrosauroid, with a sister taxon relationship with Probactrosaurus from the late Early Cretaceous of Inner Mongolia. Including Zuoyunlong, four Cenomanian basal hadrosauroids have been recorded, and the two taxa in North America (Eolambia and Protohadros) represent the earliest known hadrosauroids outside of Asia. In the light of the proposed phylogenetic topology and biogeographic data, the discovery of Zuoyunlong indicates that the first dispersal of hadrosauroids from Asia to North America probably happened around the boundary between the Early and Late Cretaceous.     

The urban heat island in a small city in coastal Portugal

This project arose from the need to study the phenomenon of the urban heat island, since only by recognising this phenomenon can we moderate it to improve the human and urban environments. Not only big cities develop urban heat islands. This study detected the presence and recorded the characteristics of an urban heat island in the small coastal city of Aveiro, Portugal. The study was developed through the scheduled measurements of air temperature and the analysis of the geographical, meteorological and urban conditions. The form and intensity of Aveiro’s heat island are a response to the interaction of three principal factors: the urban morphology (the hottest zones in the city are those with the tallest and the highest density of buildings, without green spaces and with intense generation of heat from traffic, commerce and services); the meteorological conditions (the intensity of the island is at its maximum when the sky is totally clear and there is no wind, and at its minimum in those situations when there is atmospheric instability, such as wind, cloud and precipitation); and the proximity of the coastal lagoon (which borders the city to the west and northwest and moderates seasonal temperatures. The urban heat island influences the comfort and health of its inhabitants, thus urban planning is very important in the moderation and prevention of this phenomenon. Received: 7 July 1999 / Revised: 24 April 2000 / Accepted: 26 April 2000     

Lindholmemydid turtles (Cryptodira: Testudinoidea) from the Late Cretaceous of Shandong Province,China

A new genus and new species of lindholmemydid turtle (Cryptodira: Testudinoidea), Shandongemys dongwuica n. g. and n. sp. are described on the basis of a partial skeleton with incomplete shell and skull, complete lower jaws and disarticulated limb bones from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China. Among Lindholmemydidae, the new species is closely related to Mongolemys elegans from the Late Cretaceous of Mongolia. An incomplete shell from the same locality is referred as Lindholmemydidae indet. Glyptops sp. from the Upper Cretaceous Wang Group of Jingangkou, Laiyang, Shandong is revised and assigned to Lindholmemydidae.     

The correlation between development of atypical bisexual flowers and phylogeny in the Aroideae (Araceae)

 In the intermediate zone of the inflorescence of genera of Aroideae one can find flowers with male and female characteristics. Until now, two types of developmental sequences of atypical bisexual flowers (ABFs) have been recognized: the Philodendron type and the Cercestis type. In the Philodendron type, bisexual flowers generally consist of functional carpels and staminodes inserted on the same whorl. In the Cercestis type, the gynoecium and stamens are inserted on two different whorls. These different ontogenetic patterns represent two different pathways in the evolution of unisexual flowers in this subfamily. A molecular phylogenetic analysis of 33 genera of Araceae, based on the chloroplast trnL intron and trnL–F intergenic spacer sequences was carried out. We use this phylogenetic analysis and those published by French et al. (1995) and Mayo et al. (1997) to examine the distribution of the two types of ABFs in selected genera. Our results suggest that the two developmental patterns of ABFs in Aroideae sensu Mayo et al. (1997) do not correspond to two separate evolutionary lineages but rather are more or less consistent within clades. Although this new molecular phylogeny does not include all aroid genera, it corroborates in general, at the subfamily level, the molecular analysis of French et al. (1995) based on chloroplast DNA restriction site data and the analysis of Mayo et al. (1997) based on morphological and anatomical data. Received March 15, 2001 Accepted October 11, 2001     

Ontogeny of pistillate flowers and inflorescences in Nothofagus subgenus Lophozonia (Nothofagaceae)

  Cupule and pistillate inflorescence morphology is described in detail for the first time for a number of species in Nothofagus subgenus Lophozonia. The architecture and temporal appearance of prophylls, flowers, and cupule valves is dichasial; the cupule valves are third and higher order shoot systems. Comparative studies demonstrate that the dorsal rows of appendages on the cupule valves have a similar arrangement, and each row exhibits the same temporal pattern of development. This suggests that the cupule valves in all species have a modular construction and consist of rows of homologous appendages. This study clearly demonstrates the uniform groundplan of the pistillate inflorescence in this subgenus. Received March 14, 2002; accepted May 8, 2002 Published online: September 13, 2002     

Compositional Properties of Homologous Coding Sequences from Plants

In this work, we investigated (1) the compositional distributions of all available nuclear coding sequences (and of their three codon positions) of six dicots and four Gramineae; this considerably expanded our knowledge about the differences previously seen between these two groups of plants; (2) the compositional correlations of homologous genes from dicots and from Gramineae, as well as from both groups; all correlations were characterized by very good coefficients, with slopes close to unity in the former two cases and very high in the last; (3) the compositional transition that accompanied the emergence of Gramineae from an ancestral monocot; (4) the compositional correlations between exons and introns, which were very good in Gramineae, but only poor to good in dicots; and (5) the compositional profiles of homologous genes from angiosperms, which were characterized by a series of peaks (exons) and valleys (introns) separated by 15–20% GC. The conservative and transitional modes of compositional evolution in plant genes and their general implications are discussed. Received: 24 June 1997 / Accepted: 20 August 1997     

New mammal remains from the Late Cretaceous Bostobe Formation (Northeast Aral Sea Region,Kazakhstan)

Four recently collected mammal specimens from the Upper Cretaceous (Santonian–?Campanian) Bostobe Formation in the northeastern Aral Sea Region, Kazakhstan are attributed to Asioryctitheria indet. (an edentulous dentary fragment) and the zhelestid Parazhelestes sp. cf. P. mynbulakensis (a maxillary fragment with a double-rooted canine, an M1, and a dentary fragment including m3). These new records double the known mammal fauna from this formation, which previously included the zhelestid Zhalmouzia bazhanovi and Zhelestidae indet. The taxonomic and ecological structure of the mammal assemblage from the Bostobe Formation can, on present evidence, be considered close to the other eutherian dominated Late Cretaceous mammal assemblages of Central Asia. This region is important in particular in the search for Late Cretaceous ancestors of crown-group eutherian mammal clades (Placentalia).     

Floral organogenesis of Chloranthus sessilifolius, with special emphasis on the morphological nature of the androecium of Chloranthus (Chloranthaceae)

 Floral organogenesis of Chloranthus sessilifolius K. F. Wu is described. The inflorescence primordium is dome-like in the beginning and then elongates, and bract primordia initiate almost decussately. Each floral primordium, arising from the axil of a bract, soon becomes a scale-like structure, with three primordia of androecial lobes originating from its abaxial part, and the gynoecial primordium in adaxial position. As the androecial lobes become more distinct, four thecae are already in differentiation, and the gynoecial primordium appears as a shallow disc. The androecial lobes do not extend their length until the thecae approach maturity and the stigma is differentiated. The androecial lobes are united at all the stages of development, and the entire androecium falls off as a unit at the end of anthesis. Based on these results, combined with published evidence from neobotany, palaeobotany and phylogenetic studies, the morphological nature of the androecium of Chloranthus is further discussed. Our studies support the viewpoint that the androecial structure of Chloranthus may have arisen by splitting of a single stamen with 2 marginal thecae. Received May 2, 2001 Accepted December 18, 2001