Fossil woods from the Late Cretaceous Aachen Formation

Silicified fossil woods from the Late Cretaceous (Santonian) Aachen Formation of northeast Belgium, southernmost Netherlands and adjacent Germany were investigated. Gymnosperms dominate this assemblage: Taxodioxylon gypsaceum, T. cf. gypsaceum, T. cf. albertense (all Taxodiaceae), Dammaroxylon aachenense sp. nov. (Araucariaceae), Pinuxylon sp. (Pinaceae), and Scalaroxylon sp. (Cycad or Cycadeoid). Angiosperms are minor constituents: Nyssoxylon sp. (Nyssaceae?, Cornaceae?), Mastixioxylon symplocoides sp. nov. (Mastixiaceae?, Symplocaceae?), Plataninium decipiens (Platanaceae) and Paraphyllanthoxylon cf. marylandense (Anacardiaceae?, Burseraceae?, Lauraceae?).The composition of this assemblage and the anatomy of the woods indicate a seasonal and humid warm-temperate to subtropical climate.     

Fossil Ponderosa-like Pine Wood from the Upper Cretaceous of North-east Mississippi

Petrified wood from the Lower Upper Cretaceous of north-easternMississippi (Eutaw Formation) in thin-section is most similarto extant Pinus woods of section Pinus, subsection Ponderosae.However, several features also suggest woods of subsection Australes.Based on anatomical detail, geologic age and geographic position,this fossil may represent an ancestral connection between thetwo subsections. Pinuxylon eutawense, silicified wood, Cretaceous, Mississippi, Pinus ponderosa, Pinus taeda     

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.     

Fossil flowers and pollen ofLauraceae from the Upper Cretaceous of New Jersey

A fossil trimerous flower from the Turonian (ca. 90 MYBP, Upper Cretaceous) of New Jersey is described as a new genus in the familyLauraceae. The fossil flower is charcoalified and preserved in exceptional detail. This fossil specimen is particularly remarkable in that several pollen grains have been preserved; pollen grains ofLauraceae generally have very thin exine and are rarely preserved in the fossil record. Although the specimen is incomplete and lacks anthers, there are sufficient structural details preserved to permit an assignment to theLauraceae, as well as comparisons with the tribePerseeae. This new genus provides an important addition to our knowledge of systematic and structural diversity in CretaceousLauraceae.     

The First Record of Fossil Wood of Winteraceae from the Upper Cretaceous of Antarctica

Fossil wood of the Winteraceae from the Upper Cretaceous sedimentsof James Ross Island, Antarctic Peninsula, is described herefor the first time. The specimen is characterized by the absenceof vessels, rays of two distinct sizes and tracheids with one–threerows of circular bordered pits, mainly on the radial walls,grading to horizontally elongate and scalariform. Despite anatomicalconformity to the family Winteraceae, the fossil wood is notidentical to any one extant genus and therefore has been assignedto the fossil organ genus Winteroxylon Gottwald with which thefossil shows greatest similarity. Copyright 2000 Annals of BotanyCompany Antarctica, Cretaceous, angiosperm, wood, anatomy, Winteraceae, Winteroxylon, fossil, palaeoclimate     

Fossil Flowers and Associated Plant Fossils from the Kamikitaba Locality (Ashizawa Formation, Futaba Group, Lower Coniacian, Upper Cretaceous) of Northeast Japan

in situ spores, and megaspores also document the presence of Selaginellaceae and Schizaeaceae. Received 8 February 1999/ Accepted in revised form 7 April 1999     

Fossil Evidence and the Origin of Bats

The phylogenetic and geographic origins of bats (Chiroptera) remain unknown. The earliest confirmed records of bats date from the early Eocene (approximately 51 Ma) in North America with other early Eocene bat taxa also being represented from Europe, Africa, and Australia. Where known, skeletons of these early taxa indicate that many of the anatomical specializations characteristic of bats had already been achieved by the early Eocene, including forelimb and manus elongation in conjunction with structural changes in the pectoral skeleton, hind limb reorientation, and the presence of rudimentary echolocating abilities. By the middle Eocene, the diversification of bats was well underway with many modern families being represented among fossil forms. A new phylogenetic analysis indicates that several early fossil bats are consecutive sister taxa to the extant crown group (including megabats), and suggests a single origin for the order, at least by the late Paleocene. Although morphological studies have long placed bats in the Grandorder Archonta, (along with primates dermopterans, and tree shrews), recent molecular studies have refuted this hypothesis, instead strongly supporting placement of bats in Laurasiatheria. Primitively, proto-bats were likely insectivorous, under-branch hangers and elementary gliders that exploited terminal branch habitats. Recent work has indicated that a number of other mammalian groups began to exploit similar arboreal, terminal branch habitats in the Paleocene, including multituberculates, eulipotyphlans, dermopterans, and plesiadapiforms. This may offer an ecological explanation for morphological convergences that led to the erroneous inclusion of bats within Archonta: ancestral archontan groups as well as proto-bats apparently were exploiting similar arboreal habitats, which may have led to concurrent development of homoplasic morphological attributes.     

High Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction

Background

Ichthyosaurs are reptiles that inhabited the marine realm during most of the Mesozoic. Their Cretaceous representatives have traditionally been considered as the last survivors of a group declining since the Jurassic. Recently, however, an unexpected diversity has been described in Upper Jurassic–Lower Cretaceous deposits, but is widely spread across time and space, giving small clues on the adaptive potential and ecosystem control of the last ichthyosaurs. The famous but little studied English Gault Formation and ‘greensands’ deposits (the Upper Greensand Formation and the Cambridge Greensand Member of the Lower Chalk Formation) offer an unprecedented opportunity to investigate this topic, containing thousands of ichthyosaur remains spanning the Early–Late Cretaceous boundary.

Methodology/Principal Findings

To assess the diversity of the ichthyosaur assemblage from these sedimentary bodies, we recognized morphotypes within each type of bones. We grouped these morphotypes together, when possible, by using articulated specimens from the same formations and from new localities in the Vocontian Basin (France); a revised taxonomic scheme is proposed. We recognize the following taxa in the ‘greensands’: the platypterygiines ‘Platypterygius’ sp. and Sisteronia seeleyi gen. et sp. nov., indeterminate ophthalmosaurines and the rare incertae sedis Cetarthrosaurus walkeri. The taxonomic diversity of late Albian ichthyosaurs now matches that of older, well-known intervals such as the Toarcian or the Tithonian. Contrasting tooth shapes and wear patterns suggest that these ichthyosaurs colonized three distinct feeding guilds, despite the presence of numerous plesiosaur taxa.

Conclusion/Significance

Western Europe was a diversity hot-spot for ichthyosaurs a few million years prior to their final extinction. By contrast, the low diversity in Australia and U.S.A. suggests strong geographical disparities in the diversity pattern of Albian–early Cenomanian ichthyosaurs. This provides a whole new context to investigate the extinction of these successful marine reptiles, at the end of the Cenomanian.     

Cephalopod and brachiopod fossils from the Pacific: Evidence from the Upper Cretaceous of the Magellan Seamounts

Maastrichtian cephalopods and a brachiopod were dredged from the Butakov, Fedorov, Kotsebu, Il’ichev, Govorov, Gelendzhik, and Ita-Mai-Tai guyots in the Magellan Seamounts. The ammonoids Hypophylloceras sp., Phyllopachiceras sp., Anagaudryceras? sp. A, Anagaudryceras? sp. B, Gaudryceras aff. propemite Marshall, Gaudryceras sp., and Pseudophyllites cf. indra (Forbes), and the single brachiopod Basiliolidae gen. and sp. indet. are a first discovery in this oceanic region, following earlier finds of belemnites (Dimitobelus? sp., Dimitobelidae gen. and sp. nov., and Belemnitella? sp.), and two ammonoid species (Zelandites aff. japonicus Matsumoto and Tetragonitidae gen. and sp. indet.). The Late Cretaceous Magellan Seamounts dimitobelid belemnite fauna shows affinities with southern high latitude forms (New Zealand) and the ammonoid fauna with northern, middle and high latitude ones (Hokkaido-Sakhalin and/or Kamchatka). This suggests by the end of the Cretaceous major surface palaeo-currents from S and N sides in direction of the central Palaeo-Pacific, a position coinciding with the plate tectonic reconstruction of the Magellan Seamounts.     

Lauraceous Fossil Flower from the Kamikitaba Locality (Lower Coniacian; Upper Cretaceous) in Northeastern Japan

Lauranthus futabensis , gen. et sp. nov. is assigned to the Lauraceae based on the regular trimerous organization of the perianth and androecium, and the valvate anthers. It provides the first detailed report of lauraceous flowers from the Cretaceous of Asia and adds significantly to our knowledge of the geographic distribution of Cretaceous Lauraceae and their systematic and structural diversity. Received 11 April 2001/ Accepted in revised form 30 August 2001     

Trends in the Evolution of Insect Parasitism by Nematodes as Inferred from Fossil Evidence

Fossil evidence can reveal a wealth of information regarding entomogenous nematodes. Amber is an excellent medium for the preservation of such fossils because it protects delicate organisms like nematodes, often along with their insect hosts. Such fossils establish a baseline for the appearance and continuation of parasite lineages as well as parasite-host associations. Thus far, fossil records of insect parasites have been discovered in the following nematode groups: terrestrial and aquatic Mermithidae, Tetradonematidae, Iotonchidae, Diplogasteridae, Allantonematidae, Sphaerulariidae, and Rhabditidae. Records date from 15 to 130 million years, demonstrating that these associations have existed for a considerable length of time.     

Systematic Placement of Dasypogonaceae Among Commelinid Monocots: Evidence from Flowers and Fruits

Despite progress in clarifying the relationships of Dasypogonaceae (four genera, Baxteria, Calectasia, Dasypogon, and Kingia), their infrafamilial relationships and precise affinities within the commelinid clade remain unsatisfactorily resolved. This paper reviews existing data on the systematic affinities of Dasypogonaceae. It also presents new data on floral structure in all four genera, and data on floral ontogeny in Dasypogon. In Dasypogon, Kingia, and Baxteria the ovary is trilocular and septal nectaries are present around the ovary base. In Calectasia, the ovary is unilocular and septal nectaries are entirely absent. Two subfamilial groupings within Dasypogonaceae (Calectasia–Dasypogon and Baxteria–Kingia) are proposed on the basis of leaf anatomy and ovule and ovary morphology. Many floral characters are plesiomorphic in Dasypogonaceae, but some morphological characters support a close relationship with the order Poales sensu lato, especially the epidermal location of the silica bodies. The unusual long-stalked “drumstick” inflorescences of Dasypogon and Kingia resemble those of some Poales, in which flowers are frequently borne on condensed inflorescences. A possible close relationship between Dasypogonaceae and some Poales such as Rapateaceae and Thurniaceae merits further exploration.     

Fossil evidence and phylogeny: the age of major angiosperm clades based on mesofossil and macrofossil evidence from Cretaceous deposits

The fossil record has played an important role in the history of evolutionary thought, has aided the determination of key relationships through mosaics, and has allowed an assessment of a number of ecological hypotheses. Nonetheless, expectations that it might accurately and precisely mirror the progression of taxa through time seem optimistic in light of the many factors potentially interfering with uniform preservation. In view of these limitations, attempts to use the fossil record to corroborate phylogenetic hypotheses based on extensive comparisons among extant taxa may be misplaced. Instead we suggest a method-minimum age node mapping-for combining reliable fossil evidence with hypotheses of phylogeny. We use this methodology in conjunction with a phylogeny for angiosperms to assess timing in the history of major angiosperm clades. This method places many clades both with and without fossil records in temporal perspective, reveals discrepancies among clades in propensities for preservation, and raises some interesting questions about angiosperm evolution. By providing a context for understanding the gaps in the angiosperm fossil record this technique lends credibility and support to the remainder of the angiosperm record and to its applications in understanding a variety of aspects of angiosperm history. In effect, this methodology empowers the fossil record.     

Development of agriculture in Europe and the near east: Evidence from quantitative studies

Quantitative methods of analysis of the data accumulated by European archaeobotanists over the last 30 years allow the agricultural history of Europe and the Near East to be seen in a new perspective. The histories of the major crop plants appear to be fairly simple, but there seem to have been at least two kinds of free-threshing wheat in cultivation at different times in prehistoric Europe. The evidence suggests that rye was a secondary crop associated with the later of these wheats. While the patterns of crop exploitation seem interpretable in terms of natural ecology only in the very earliest periods, they appear to have cultural correlations and may have some archaeological significance.     

Fossil representatives of the family Greenideidae (Hemiptera, Aphidoidea) from the Miocene of Europe

Four new aphid species (Hemiptera, Aphidoidea, Greenideidae) are described on the basis of imprints in oil-shales from the Miocene of Europe (Rubielos de Mora, Spain; Vishnevaya Balka ?Stavropol?, Russia): Eutrichosiphum europaeum nov. sp., Greenidea hispanica nov. sp., Greenideoida (Pentatrichosiphum) turolensis nov. sp. and Mollitrichosiphum rubusensis nov. sp. All the taxa are placed within recent genera of the subfamily Greenideinae. Miocene representatives of this subfamily have been found in the south of Europe. Later changes of climatic conditions limited its geographic range to south-eastern Asia, where it is now represented by over 130 species of seven genera.     

Sauropod diversity in the Late Cretaceous of southwestern Europe: The lessons of odontology

Recent discoveries in southern France and northern Spain suggest that the morphology of titanosaurian teeth shows much greater variations that previously thought. It is suggested that the different morphotypes are informative at specific or generic level and that titanosaurian genera may indeed be recognized by their isolated teeth. It is also confirmed that juvenile titanosaurian teeth have a rather uniform, cylindrical morphology. Four different morphotypes are described for the Ibero-Armorican Island in the Late Cretaceous.     

Crocodylomorph Trackways from the Jurassic to Early Cretaceous of North America and Europe: Implications for Ichnotaxonomy

Trackways described as Batrachopus (Batrachopodidae Lull, 1904 Lull, R. S. 1904. Fossil footprints of the Jura-Trias of North America. Memoirs of the Boston Society of Natural History, 5: 461–557.  [Google Scholar]) from the Lower Jurassic of Europe are rare and in some cases different from the type trackways from North America. Differences may be in part attributable to preservation, but current evidence suggests that there is inherent variability in Batrachopodidae morphotypes, beyond that attributable to differential preservation. Type Batrachopus is a stout-toed form, with minimal digit divarication (i.e., a long foot), whereas Antipus describes slender-toed forms with a wider foot and wider digit divarications.

Antipus is also similar to Crocodylopodus (ichnofamily Crocodylopodidae: Fuentes Vidarte and Meijide Calvo, 1999 Fuentes Vidarte, C. and Meijide Calvo, M. 1999. Primeras Huellas de Cocodrilo en el Weald de Cameros (Sria, Espana) Nueva Familia Crocodilopodidae: Nuevo icnogenero: Crocodylopodus Nueva icnoespecie: C. meijidei. Actas de las jornadas internacionales sobre paleontologia de dinosairios y su entorno. Sala de los infantes (Burgos, Espana). Collectivo Arqueologico-Paleontologico de Salas, : 329–338.  [Google Scholar]) from near the Jurassic-Cretaceous boundary in Spain. Crocodylopodus has a relatively large manus, and a less outwardly rotated trackway, but is not sufficiently different from Batrachopodidae to warrant its own ichnofamily. Manus-pes size (area) ratios (heteropody) may also be important in differentiating different crocodylomorph ichnotaxa, as is the case with other archosaurian ichnotaxa. However, heteropody may change with size, and be less pronounced in large individuals. Manus and pes rotation patterns, and trackway width are variable and may be of use for differentiation of ichnotaxa but may also be a function of speed.     

Scandianthus gen.nov., Angiosperm Flowers of Gaxifragalean Affinity from the Upper Cretaceous of Southern Sweden

Structurally preserved angiosperm flowers are described fromthe Upper Cretaceous of southern Sweden. They are found in fluviatiledeposits dated, on palynological evidence, as Upper Santonianor Lower Campanian. The material studied includes two speciesof Scandianthus gen.nov. and one unnamed, related taxon. Thefossil flowers represent the best-preserved Cretaceous floralstructures available and the preservation permits detailed studyof organization and arrangement of parts. Comparison with flowersof extant angiosperms indicates a close relationship with membersof the Saxifragales. Scandianthus gen.nov. fossil angiosperm, Upper Cretaceous     

Fossil amoebae (Hemiarcherellidae fam. nov.) from Albian (Cretaceous) amber of France

Abstract: Two extraordinarily well‐preserved testate amoebae are described from Late Albian age amber from south‐western France. The specimens are attributed to a new family, the Hemiarcherellidae fam. nov., and are described as Hemiarcherella christellae gen. et sp. nov. The amoebae described herein originate from highly fossiliferous amber pieces. Based on syninclusions, Hemiarcherella christellae was a soil‐dwelling organism, probably an active bacterivore. This taxon represents the third species of testate amoebae described from mid‐Cretaceous French amber. Analysis of this fossil amoeba fauna illustrates the uniqueness of mid‐Cretaceous French amber deposits. Indeed, most amoebae found in amber have been assigned to modern species, corroborating the hypothesis of morphological stasis in different microbial lineages. However, the well‐preserved amoebae fauna found in French amber can be distinguished clearly from modern species and help us to better understand the fossil record of these organisms.