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Lycopodiaceae are one of three surviving families of lycopsids, a lineage of vascular plants with a fossil history dating to at least the Early Devonian or perhaps the Late Silurian (c. 415 Ma). Many fossils have been linked to crown Lycopodiaceae, but the lack of well-preserved material has hindered definitive recognition of this group in the paleobotanical record. New, exceptionally well-preserved permineralized lycopsid fossils from the Early Cretaceous (125.6 ± 1.0 Ma) of Inner Mongolia, China, were examined in detail using acetate peel and micro-computed tomography techniques. The anatomy of extant Lycopodiaceae was analyzed for comparison using fluorescence microscopy. Phylogenetic relationships of the new fossil to extant Lycopodiaceae were evaluated using parsimony and maximum likelihood analyses. Lycopodicaulis oellgaardii gen. et sp. nov. provides the earliest unequivocal and best-documented evidence of crown Lycopodiaceae and Lycopodioideae, based on anatomically-preserved fossil material. Recognition of Lycopodicaulis in Asia during the Early Cretaceous indicates the presence of crown Lycopodiaceae at this time, and striking similarities of stem anatomy with extant species provide a framework for the understanding of the interaction of branching and vascular anatomy in crown-group lycopsids.

PREMISE Seed cones of extant Pinaceae exhibit two mechanisms of seed release. In "flexers" the cone scales remain attached to the central axis, while flexing and separating from each other to release the seeds. In "shedders" scales are shed from the axis, with the seeds either remaining attached to the scale or becoming detached. The early fossil history of Pinaceae from the Jurassic to Early Cretaceous is dominated by flexing seed cones, while the systematic information provided by shedding fossil cones has been overlooked and rarely integrated with data based on compression and permineralized specimens. We describe the earliest and best-documented evidence of a "shedder" seed cone from the Aptian-Albian of Mongolia. METHODS Lignite samples from Tevshiin Govi locality were disaggregated in water, washed, and dried in air. Fossils were compared to material of extant Pinaceae using LM and CT scans. RESULTS Lepidocasus mellonae gen. et sp. nov. is characterized by a seed cone that disarticulated at maturity and shed obovate bract-scale complexes that have a distinctive ribbed surface and an abaxial surface covered with abundant trichomes. The ovuliferous scale has ca. 30-40 resin canals, but only scarce xylem near the attachment to the cone axis. Resin vesicles are present in the seed integument. Phylogenetic analysis places Lepidocasus as sister to extant Cedrus within the abietoid grade. CONCLUSIONS The exquisite preservation of the trichomes in L. mellonae raises questions about their potential ecological function in the cones of fossil and living Pinaceae. Lepidocasus mellonae also shows that a shedding dispersal syndrome, a feature that has often been overlooked, evolved early in the history of Pinaceae during the Early Cretaceous.

Premise of research. The extinct conifer genus Schizolepidopsis is characterized by deeply bilobed ovuliferous scales bearing two adaxial seeds. Although it is frequently placed in Pinaceae, the ev...

Premise of research. Melastomataceae are a diverse and primarily tropical family with a particularly sparse fossil record. Various biogeographic interpretations based on phylogenies, extant distrib...

The second integument of the angiosperm ovule is unique among seed plants, with developmental genetics that are distinct from those of the inner integument1. Understanding how the second integument should be compared to structures in other seed plants is therefore crucial to resolving the long-standing question of the origin of angiosperms2–6. Attention has focused on several extinct plants with recurved cupules that are reminiscent of the anatropous organization of the basic bitegmic ovules of angiosperms1–6, but interpretations have been hampered by inadequate information on the relevant fossils. Here we describe abundant exceptionally well-preserved recurved cupules from a newly discovered silicified peat dating to the Early Cretaceous epoch (around 125.6 million years ago) in Inner Mongolia, China. The new material, combined with re-examination of potentially related fossils, indicates that the recurved cupules of several groups of Mesozoic plants are all fundamentally comparable, and that their structure is consistent with the recurved form and development of the second integument in the bitegmic anatropous ovules of angiosperms. Recognition of these angiosperm relatives (angiophytes) provides a partial answer to the question of angiosperm origins, will help to focus future work on seed plant phylogenetics and has important implications for ideas on the origin of the angiosperm carpel. Analysis of recurved cupules from a newly discovered Early Cretaceous silicified peat in Inner Mongolia, China and comparison with other potentially related Mesozoic plant fossils provides insight into the origins of angiosperms.

The birth of modern rainforestsThe origin of modern rainforests can be traced to the aftermath of the bolide impact at the end of the Cretaceous. Carvalhoet al.used fossilized pollen and leaves to characterize the changes that took place in northern South American forests at this time (see the Perspective by Jacobs and Currano). They not only found changes in species composition but were also able to infer changes in forest structure. Extinctions were widespread, especially among gymnosperms. Angiosperm taxa came to dominate the forests over the 6 million years of recovery, when the flora began to resemble that of modern lowland neotropical forest. The leaf data also imply that the forest canopy evolved from relatively open to closed and layered, leading to increased vertical stratification and a greater diversity of plant growth forms.Science, this issue p.63; see also p.28

Leguminosae are one of the most diverse flowering-plant groups today, but the evolutionary history of the family remains obscure because of the scarce early fossil record, particularly from lowland tropics. Here, we report ~500 compression or impression specimens with distinctive legume features collected from the Cerrejón and Bogotá Formations, Middle to Late Paleocene of Colombia. The specimens were segregated into eight fruit and six leaf morphotypes. Two bipinnate leaf morphotypes are confidently placed in the Caesalpinioideae and are the earliest record of this subfamily. Two of the fruit morphotypes are placed in the Detarioideae and Dialioideae. All other fruit and leaf morphotypes show similarities with more than one subfamily or their affinities remain uncertain. The abundant fossil fruits and leaves described here show that Leguminosae was the most important component of the earliest rainforests in northern South America c. 60–58 million years ago.

While modern forests have their origin in the diversification and expansion of angiosperms in the Late Cretaceous and early Cenozoic, it is unclear whether the rise of closed-canopy tropical rainforests preceded or followed the end-Cretaceous extinction. The “canopy effect” is a strong vertical gradient in the carbon isotope (δ13C) composition of leaves in modern closed-canopy forests that could serve as a proxy signature for canopy structure in ancient forests. To test this, we report measurements of the carbon isotope composition of nearly 200 fossil angiosperm leaves from two localities in the Paleocene Cerrejón Formation and one locality in the Maastrichtian Guaduas Formation of Colombia. Leaves from one Cerrejón fossil assemblage deposited in a small fluvial channel exhibited a 6.3‰ range in δ13C, consistent with a closed-canopy forest. Carbon isotope values from lacustrine sediments in the Cerrejón Formation had a range of 3.3‰, consistent with vegetation along a lake edge. An even-narrower range of δ13C values (2.7‰) was observed for a leaf assemblage recovered from the Cretaceous Guaduas Formation, and suggests vegetation with an open canopy structure. Carbon isotope fractionation by Late Cretaceous and early Paleogene leaves was in all cases similar to that by modern relatives, consistent with estimates of low atmospheric CO2 during this time period. This study confirms other lines of evidence suggesting that closed-canopy forests in tropical South America existed by the late Paleocene, and fails to find isotopic evidence for a closed-canopy forest in the Cretaceous.

Premise of research. Recent classifications of Anacardiaceae recognize two subfamilies, Anacardioideae and Spondioideae. Most genera within Spondioideae are still recognized for having drupes with ...

Premise of research. Fossil leaves from the early Eocene Green River Formation of Wyoming and late Eocene Florissant Formation of Colorado have been studied and described here as two species in the...

International audience; Since 2012, we have investigated a stratigraphic section encompassing the late Eocene–earliest Oligocene interval at Shapaja (Tarapoto area, Peruvian Amazonia, ca. 7°S), through paleontological and geological fieldwork. The measured sedimentary series (120 m-thick [West] plus 90 m-thick [East]), assigned to the upper member of the Pozo Formation, records fluvial micro-conglomeratic lenses intercalated with floodplain and evaporite-rich fine red deposits, estuarine/coastal-plain tidally-influenced fine sandstones, and oxbow lake nodule-rich blue clays. This sedimentary shift coincides locally with the demise of the large Eocene coastal-plain wetland known as Pozo System. The late Eocene–early Oligocene Shapaja section was extensively sampled for chemostratigraphy (δ13C on dispersed organic matter and pedogenic carbonate nodules), which in turn allowed for refining the location of the Eocene-Oligocene Transition (EOT) and other climatic events recognized at a global scale (i.e., Oi-1 and Oi-1a). The section has yielded nine fossil localities with plant remains (leaves, wood, charophytes, and palynomorphs), mollusks, decapods, and/or vertebrates (selachians, actinopterygians, lungfishes, amphibians, sauropsids, and mammals), documenting ~130 distinct taxa. Four localities of the upper member of the Pozo Formation at Shapaja predate the EOT, one is clearly within the EOT, while four are earliest/early Oligocene in age. The small leaf impressions found along the Shapaja section could be indicative of dry and/or seasonal conditions for this region throughout and after the EOT. Monkeys, indicative of tropical rainforest environments, are only recorded in a latest Eocene locality (TAR-21). Two biotic turnovers are perceptible in the selachian, metatherian, and rodent communities, well before the EOT [~35–36 Ma] and a few hundred thousand years after the EOT [~33 Ma]. The latter turnover seems to be primarily related to a global sea-level drop (ichthyofauna: marine-littoral elements replaced by obligate freshwater taxa) and/or the onset of a drier and more seasonal climate in early Oligocene times (terrestrial components). Changes in the structure of the Shapaja paleocommunities were mostly driven by the flexural subsidence during the late Eocene, and then globally driven by the earliest Oligocene climatic deterioration.

Plant predation by insects is a major driver of high plant diversity in modern tropical forests. Previous reports of leaf damage in middle–late Paleocene Neotropical rainforests of Cerrejon, Colombia, show that leaf herbivory was abundant but of low diversity, mainly inflicted by generalized feeders. Here, we present and describe plant-insect associations in leaf fossils from the middle–late Paleocene Bogota Formation, central Colombia, to test whether the high abundance and low richness of insect damage typified early evolving Neotropical rainforests. The Bogota flora records the highest richness and frequency of insect-damage associations among comparable Paleocene floras in North America, Patagonia, and Europe, as well as the highest number of leaf mines and galling associations. These results indicate that by the middle–late Paleocene, plant-insect herbivore interactions were much more intense and host-specialized in Neotropical rainforests of the Bogota region than elsewhere. The rich and frequent galling associations, a distinctive feature of the Bogota flora, are consistent with the preferential use of canopy leaves by galling insects seen in modern Neotropical rainforests. Our results also indicate differences in plant-insect associations among Paleocene Neotropical rainforests, perhaps reflecting a geographically heterogeneous ecological recovery from the end-Cretaceous ecological crisis. Plant insect-associations in the Bogota flora also suggest a deep historical context for negative density-dependence as a potential driver (and maintainer) of the high plant diversity observed in modern Neotropical rainforests.

— Fossil fruits of Symplocos (Ericales: Symplocaceae) are here recognized from the Pliocene of Guasca, Colombia, based on specimens formerly attributed to Cordia (Cordiaceae, Boraginales). Symplocos vera (Berry) comb. nov. is represented by 19 lignitized fruits. The fossils are recognized as belonging to Symplocos primarily by their woody endocarps that are apically truncate and that possess 3 to 5 apical germination pores and locules, and a central vascular canal extending the length of the endocarp. In several key characters they are highly congruent with the endocarps of the extant Neotropical clade S. ser. Symplocos. Some of the extant species in the series are variably 3- to 5-locular; 4-locular endocarps are otherwise rare in Symplocos, and 5-locular endocarps appear to be unique to this series. Symplocos vera is the only specifically named record of fossil Symplocos fruits with accessible voucher specimens from South America. The younger Neogene age of the fossils relative to those attributed to S. ser. Symplocos from the late Eocene of Texas, along with a report of Colombian fossil endocarps from the middle Miocene, supports the North America to South America migration inferred for this clade from molecular phylogenetic data.

The second integument of the angiosperm ovule is unique among seed plants, with developmental genetics that are distinct from those of the inner integument

New discoveries of corystosperm seed-bearing structures from the Tevshiin Govi locality, Mongolia, which is of Early Cretaceous (Aptian–Albian) age, show that the individual seed-bearing units of U...

The Spondioideae subfamily of the Anacardiaceae is widely distributed today in tropical regions. Recent molecular phylogenetic investigations indicate that the Spondioideae are not monophyletic, but rather comprise at least two separate clades that are difficult to distinguish using vegetative and floral characters. Nevertheless, the syndrome of fruit characters traditionally used in identifying the subfamily is useful in discriminating genera of these clades and for identification of both modern and fossil anacardiaceous fruits. Here we document the morphology and anatomy of endocarps for representatives of all extant genera traditionally treated as Spondioideae, plus two genera that have been placed close to them in molecular investigations, Buchanania and Campnosperma. All genera are characterized by drupe-like fruits with sclerified stones that vary from uni- to multilocular depending on the genus. Germination modes vary throughout the Spondioideae. Some have characteristic plug-like opercula; others have recessed bilabiate germination valves, and still others open by apical flaps or simple slits. Although most currently recognized genera appear to be monophyletic, fruit morphology indicates that current circumscriptions of Cyrtocarpa, Poupartia and Tapirira are in need of revision.

espanolPara entender el origen de la diversidad de los bosques de America Central, se necesita integrar estudios de plantas actuales y fosiles. En este trabajo, describimos fosiles de Humiriaceae, excavados de dos nuevas secuencias sedimentarias en la Peninsula de Azuero, Panama. Los fosiles fueron encontrados en depositos marinos-marginales del Oligoceno (una localidad) y del Mioceno temprano (dos localidades). Describimos nuevos especimenes y aumentamos la descripcion morfologica de Lacunofructus cuatrecasana Herrera, Manchester et Jaramillo para las localidades del Oligoceno y Mioceno temprano y presentamos un nuevo registro de Sacoglottis sp., para el Mioceno temprano. Estos nuevos registros expanden los rangos de distribucion geografica y temporal para ambos taxones, y ademas demuestran que la familia Humiriaceae fue un importante constituyente de los primeros bosques en America Central. La evidencia presentada tambien sugiere que hubo dispersiones de especies de Humiriaceae entre Centro y Sur America mucho antes del cierre del Istmo de Panama. Se necesitan mas estudios para establecer con claridad si el origen de Humiriaceae se dio en America Central o Sur America. EnglishUnderstanding the origin of the diversity in Central American forests requires the integration of both extant and fossil taxa. Here, we provide a description of Humiriaceae fossils from two new sedimentary sequences in the Azuero Peninsula, Panama. Fossils were recovered from Oligocene (one locality) and Early Miocene (two localities) marginal marine deposits. We describe new specimens and augment the generic description of Lacunofructus cuatrecasana Herrera, Manchester et Jaramillo, and present a new record of Sacoglottis sp. Our results expand the temporal and geographical distribution of both taxa and show that Humiriaceae was an important constituent of early Central American forests, and that this family was dispersed in between Central and South America before the final closure of the Central American Seaway. Further studies are necessary to establish whether the origin of this family was in Central or South America.

Salvinia is a pantropical aquatic fern that has the highest species diversity in tropical America. Its evolutionary history and biogeography is still poorly understood. Contrasting its almost modern pantropical distribution, fossils of Salvinia have been found worldwide, including North America, Europe and Asia. Here, we describe fossils of Salvinia from four Paleogene localities of Colombia. Based on comparative morphological analyses of sterile organs, we describe two new species: Salvinia magdalenensis sp. nov. and Salvinia bogotensis sp. nov and assign the fossils from the other two localities to Salvinia sp. Available fossil data, together with these new records indicate that Salvinia was distributed in tropical latitudes as well as in temperate latitudes of the Northern Hemisphere throughout most of the Cenozoic. Its modern pantropical distribution could be the result of Pleistocene extinction of Salvinia in temperate regions due to global cooling climate trend.

Premise of the study Hymenophyllaceae ("filmy ferns") are a widely distributed group of predominantly tropical, epiphytic ferns that also include some temperate and terrestrial species. Hymenophyllaceae are one of the earliest-diverging lineages within leptosporangiate ferns, but their fossil record is sparse, most likely because of their low fossilization potential and commonly poor preservation of their delicate, membranaceous fronds. A new species of unequivocal fossil Hymenophyllaceae, Hymenophyllum iwatsukii sp. nov., is described from the Early Cretaceous of Mongolia based on abundant and exceptionally well-preserved material. Methods Bulk lignite samples collected from Tevshiin Govi and Tugrug localities in Mongolia, were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. Fossils were examined and compared to material of extant Hymenophyllaceae using LM and SEM. Key results The fossil fern specimens are assigned to the Hymenophyllaceae based on their membranaceous laminae with marginal sori that have sessile to short-stalked sporangia with oblique, complete annuli, and trilete, tetrahedral-globose spores. Within the family, the fossil material is assigned to the extant genus Hymenophyllum on the basis of bivalvate indusia and short, included receptacles. Conclusions Hymenophyllum iwatsukii was likely an epiphyte based on the sedimentary environment in which the fossils are preserved, the associated fossil flora, and the growth habit of extant species of Hymenophyllum. The new fossil species underlines the extent to which morphological characters in Hymenophyllum have been conserved despite significant tectonic, climatic, ecological, and floristic changes since the Early Cretaceous.

Previously unrecognized anatomical features of the cone scales of the enigmatic Early Cretaceous conifer Krassilovia mongolica include the presence of transversely oriented paracytic stomata, which is unusual for all other extinct and extant conifers. Identical stomata arepresent on co-occurring broad, linear, multiveined leaves assigned to Podozamites harrisii, providing evidence that K. mongolica and P. harrisii are the seed cones and leaves of the same extinct plant. Phylogenetic analyses of the relationships of the reconstructed Krassilovia plant place it in an informal clade that we name the Krassilovia Clade, which also includes Swedenborgia cryptomerioides–Podozamites schenkii, and Cycadocarpidium erdmanni–Podozamites schenkii. All three of these plants have linear leaves that are relatively broad compared to most living conifers, and that are also multiveined with transversely oriented paracytic stomata. We propose that these may be general features of the Krassilovia Clade. Paracytic stomata, and other features of this new group, recall features of extant and fossil Gnetales, raising questions about the phylogenetic homogeneity of the conifer clade similar to those raised by phylogenetic analyses of molecular data. Funding for this work was provided by National Science Foundation grants DEB-1748286 to P.S.H., P.R.C. and F.H., and 1348456 to P.R.C. and P.S.H., the Oak Spring Garden Foundation to F.H., and Grants-in-Aid for Scientific Research (21405010 and 24405015) from the Japan Society.

Strap-shaped, parallel-veined leaves of Podozamites and Pseudotorellia are among the most common fossils in Late Triassic to Early Cretaceous floras from the Northern Hemisphere. Podozamites is considered to be the leaf of a voltzian conifer, but its cuticle is poorly known, whereas Pseudotorellia, with a thick cuticle and haplocheilic stomata, is commonly considered to be the leaf of a ginkgoalean. Here we describe the leaf morphology, cuticle and stomata of Podozamites and Pseudotorellia based on excellently preserved material from the Early Cretaceous of central Mongolia. Podozamites harrisii sp. nov. has transversely oriented, paracytic (probably syndetocheilic) stomata that are regularly arranged in longitudinal files. Pseudotorellia resinosa sp. nov. and Pseudotorellia palustris sp. nov. have scattered, longitudinally oriented stomata in which the two guard cells are sunken and surrounded by 2–5 specialized lateral subsidiary cells and 1–3 unspecialized polar cells. Association evidence and similari...

Premise of research. The two living species of Cunninghamia form a clade that is sister to the rest of the Cupressaceae sensu lato, within which the monotypic extant genus Taiwania is sister to all Cupressaceae except Cunninghamia. Seed cones of both Cunninghamia and Taiwania bear helically arranged bract-scale complexes, but a free ovuliferous scale is present only in Cunninghamia. Here, we describe two new genera of fossil seed cones similar to those of Cunninghamia and Taiwania.Methodology. Early Cretaceous (Aptian-Albian) bulk lignite samples collected from the Tevshiin Govi locality were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air.Pivotal results. Pentakonos gen. nov. has seed cones that are up to 7 mm long with ca. 25–30 helically arranged, papery bract-scale complexes that have minute teeth. Adaxially, the free tip of the membranous ovuliferous scale is denticulate, and the scale bears five small, thin-winged seeds. Pentakonos adds to the diver...

Pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian; England) in the NHMUK are stored in silicone oil to retard decay processes. X-ray micro-computed tomography (micro-CT) has revealed internal morphology for multiple holotypes (including severely cracked and encrusted specimens) scanned in the protective fluid. Silicone oil alone has a similar X-ray attenuation to parts of the specimens, causing minor uncertainty for digitally rendered surfaces, but key systematic characters are readily visualized. Further work is needed to optimize visualization of fine-scale cellular detail. Labelling and segmentation to visualize important structures is achievable with these micro-CT datasets. However, manual labelling of individual slices is required, and defining boundaries between features can be difficult due to differential pyritization and silicone oil permeation. Digital sections through specimens can be made in any orientation and digital locule casts can be produced for studies in virtual taphonomy. These achievements have been accomplished with minimal risk to specimens, which remained in silicone oil and were studied within the museum. The datasets provide a potentially permanent record of at-risk specimens, can be made widely available to researchers unable to visit the collections and to other interested parties, and they enable monitoring for future conservation.

Choerospondias (Anacardiaceae) is a monospecific genus that is mainly distributed in the subtropics and tropics of eastern Asia today. Fossil records suggest that the genus was widely distributed throughout Eurasia during the Oligocene and Miocene. In this paper, we describe a new species of Choerospondias based on three-dimensionally preserved endocarps from the middle Miocene of Fujian, Southeast China. The internal structures and anatomical details of the fossils were studied using Micro-CT and physical sections. Choerospondias fujianensis sp. nov. is characterized by having five or seven radially arranged germination pores at the subapical region of endocarp. Fossils indicate that Choerospondias was more diverse in the Miocene than today. The genus has a nearly continuous fossil record in East Asia since the Oligocene. Fossil evidence also indicates that Choerospondias was a minor component in several different types of evergreen forests along river channels in subtropical to probably tropical climates since its early history. The relatively wide range of adaption of Choerospondias may play an essential role in its current survival in East Asia.

Corystosperms, a key extinct group of Late Permian to Early Cretaceous plants, are important for understanding seed plant phylogeny, including the evolution of the angiosperm carpel and anatropous bitegmic ovule. Here, we describe a new species of corystosperm seed-bearing organ, Umkomasia mongolica sp. nov., based on hundreds of three-dimensionally preserved mesofossils from the Early Cretaceous of Mongolia. Individual seed-bearing units of U. mongolica consist of a bract subtending an axis that bifurcates, with each fork (cupule stalk) bearing a cupule near the tip. Each cupule is formed by the strongly reflexed cupule stalk and two lateral flaps that partially enclose an erect seed. The seed is borne at, or close to, the tip of the reflexed cupule stalk, with the micropyle oriented towards the stalk base. The corystosperm cupule is generally interpreted as a modified leaf that bears a seed on its abaxial surface. However, U. mongolica suggests that an earlier interpretation, in which the seed is borne directly on an axis (shoot), is equally likely. The 'axial' interpretation suggests a possible relationship of corystosperms to Ginkgo. It also suggests that the cupules of corystosperms may be less distinct from those of Caytonia than has previously been supposed.

PREMISE OF THE STUDY Chrysobalanaceae are woody plants with over 500 species in 20 genera. They are among the most common trees in tropical forests, but a sparse fossil record has limited our ability to test evolutionary and biogeographic hypotheses, and several previous reports of Chrysobalanaceae megafossils are doubtful. METHODS We prepared fossil endocarps and wood collected from the lower Miocene beds along the Panama Canal using the cellulose acetate peel technique and examined them using light microscopy. We compared the fossil endocarps with previously published fossils and with fruits from herbarium specimens. We compared the fossil wood with photographs and descriptions of extant species. KEY RESULTS Parinari endocarps can be distinguished from other genera within Chrysobalanaceae by a suite of features, i.e., thick wall, a secondary septum, seminal cavities lined with dense, woolly trichomes, and two ovate to lingulate basal germination plugs. Fossil endocarps from the Cucaracha, Culebra, and La Boca Formations confirm that Parinari was present in the neotropics by the early Miocene. CONCLUSIONS The earliest unequivocal evidence of crown-group Chrysobalanaceae is late Oligocene-early Miocene, and the genus Parinari was distinct by at least 19 million years ago. Parinari and other Chrysobalanaceae likely reached the neotropics via long-distance dispersal rather than vicariance. The presence of Parinari in the Cucaracha flora supports the interpretation of a riparian, moist tropical forest environment. Parinari was probably a canopy-dominant tree in the Cucaracha forest and took advantage of the local megafauna for seed dispersal.

Premise of research. Abundant fossil and molecular evidence suggests that all extant conifer families were established by the Early Cretaceous. However, the recognition and understanding of the lineages that lead to the evolution of these extant families remain incomplete. Late Paleozoic to Early Mesozoic Voltziales conifers—also known as transitional conifers, usually with multilobed ovuliferous scales—have been hypothesized to be among the stem lineages of modern crown conifers. This article describes an exquisitely preserved voltzian seed cone from the Aptian-Albian of Mongolia that introduces new taxonomic diversity and morphological data into the complex pattern of conifer evolution.Methodology. Bulk lignite samples collected from the Tevshiin Govi locality were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. Fossils were examined using LM, SEM, and X-ray microtomography.Pivotal results. Krassilovia mongolica gen. et sp. nov. has seed cones with hel...

Pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian, England) in the NHMUK are stored in silicone oil to retard decay processes. X-ray micro-computed tomography (micro-CT) has revealed internal morphology for multiple holotypes (including severely cracked and encrusted specimens) scanned in the protective fluid. Silicone oil alone has a similar X-ray attenuation to parts of the specimens, causing minor uncertainty for digitally rendered surfaces, but key systematic characters are readily visualised. Further work is needed to optimise visualization of fine-scale cellular detail. Labelling and segmentation to visualise important structures is achievable with these micro-CT datasets. However, manual labelling of individual slices is required and defining boundaries between features can be difficult due to differential pyritization and silicone oil permeation. Digital sections through specimens can be made in any orientation and digital locule casts can be produced for studies in virtual taphonomy. These achievements have been accomplished with minimal risk to specimens, which remained in silicone oil and were studied within the museum. The datasets provide a potentially permanent record of at-risk specimens, can be made widely available to researchers unable to visit the collections and to other interested parties, and they enable monitoring for future conservation.

Understanding the origins of the five groups of living seed plants requires well-supported hypotheses of their relationships to extinct groups, many of which are poorly understood. New information from the Early Cretaceous of Mongolia on the enigmatic extinct plant Umaltolepis shows that its leaves are similar to those of Ginkgo, but its seed-bearing structures are unique, and more comparable to those of certain extinct Peltaspermales and Umkomasiales. Umaltolepis provides new data for understanding relationships among living and fossil seed plants and supports previous ideas that Ginkgo biloba may be the sole surviving relict of a once very diverse group of Mesozoic seed plants.

The origins of the five groups of living seed plants, including the single relictual species Ginkgo biloba, are poorly understood, in large part because of very imperfect knowledge of extinct seed plant diversity. Here we describe well-preserved material from the Early Cretaceous of Mongolia of the previously enigmatic Mesozoic seed plant reproductive structure Umaltolepis, which has been presumed to be a ginkgophyte. Abundant new material shows that Umaltolepis is a seed-bearing cupule that was borne on a stalk at the tip of a short shoot. Each cupule is umbrella-like with a central column that bears a thick, resinous, four-lobed outer covering, which opens from below. Four, pendulous, winged seeds are attached to the upper part of the column and are enclosed by the cupule. Evidence from morphology, anatomy, and field association suggests that the short shoots bore simple, elongate Pseudotorellia leaves that have similar venation and resin ducts to leaves of living GinkgoUmaltolepis seed-bearing structures are very different from those of Ginkgo but very similar to fossils described previously as Vladimaria. Umaltolepis and Vladimaria do not closely resemble the seed-bearing structures of any living or extinct plant, but are comparable in some respects to those of certain Peltaspermales and Umkomasiales (corystosperms). Vegetative similarities of the Umaltolepis plant to Ginkgo, and reproductive similarities to extinct peltasperms and corystosperms, support previous ideas that Ginkgo may be the last survivor of a once highly diverse group of extinct plants, several of which exhibited various degrees of ovule enclosure.

Extant Neotropical rainforests are well known for their remarkable diversity of fruit and seed types. Biotic agents disperse most of these disseminules, whereas wind dispersal is less common. Although wind-dispersed fruits and seeds are greatly overshadowed in closed rainforests, many important families in the Neotropics (e.g., Bignoniaceae, Fabaceae, Malvaceae, Orchidaceae, Sapindaceae) show numerous morphological adaptations for anemochory (i.e. wings, accessory hairs). Most of these living groups have high to moderate levels of plant diversity in the upper levels of the canopy. Little is known about the fossil record of wind-dispersed fruits and seeds in the Neotropics. Six new species of disseminules with varied adaptations for wind dispersal are documented here. These fossils, representing extinct genera of Ulmaceae, Malvaceae, and some uncertain families, indicate that wind-dispersed fruit and seed syndromes were already common in the Neotropics by the Paleocene, coinciding with the early development of multistratal rainforests. Although the major families known to include most of the wind-dispersed disseminules in extant rainforests are still missing from the Paleogene fossil record of South and Central America, the new fossils imply that anemochory was a relatively important product and/or mechanism of plant evolution and diversification in early Neotropical rainforests.

Premise of research. Humiriaceae occupy predominantly Neotropical lowland rainforests, with only a single Old World species in western Africa. Molecular divergence time estimates suggest that the family might have originated during the middle Cretaceous; however, fossil occurrences are lacking prior to the Paleocene. Here we provide new fossil evidence that expands our understanding of the paleobiogeographic history and evolution of this family.Methodology. Fossil endocarps and wood were compared with extant relatives of the family. Transverse and longitudinal sections of fossil and modern fruits were studied anatomically and morphologically.Pivotal results. Fruits of the new species, Duckesia berryi sp. n., from the Oligocene of Pacific coastal Peru (ca. 30–28.5 Ma), provide the earliest fossil evidence of Duckesia—the genus is now confined to Amazonia. We also document the earliest fossil fruit record for Sacoglottis tertiaria, from the early Oligocene (ca. 33.9–28.4 Ma) of Puerto Rico, and a new occurr...

The Phytocreneae (Icacinaceae) are a tribe of scrambling shrubs and lianas presently distributed in tropical Africa, Madagascar, and Indo-Malesia. We describe the oldest known fossils of this tribe and provide the first recognition of this group in the Neotropical fossil record based on distinctive fruit remains. Palaeophytocrene piggae sp. nov., from the late Paleocene of western North America, and Palaeophytocrene hammenii sp. nov. and cf. Phytocrene sp., from the middle-late Paleocene of Colombia, constitute the oldest confirmed records of this tribe. Pyrenacantha austroamericana sp. nov., from the Oligocene of Peru, represents an extant Old World genus known also from the Eocene fossil record of North America and Europe. Collectively, these fossils indicate that the Phytocreneae were previously established in the Neotropics, despite their current absence from the region, and may provide evidence for Paleogene floristic exchange between North and South America.

The Belen flora, in north coastal Peru, is the most diverse fruit and seed assemblage yet known from the Paleogene of South America. Little original paleobotanical work has been performed on this assemblage since the pioneering treatments published by E. W. Berry in the 1920s, and the precise age has not been determined. Nevertheless, the flora has been regarded as a focal point in understanding the vegetational, orogenic, and climatic history of northern South America, and in recent literature it has been assumed to be early Eocene. In order to tighten this age assignment, which has varied from early Eocene to early Oligocene in the opinions of different authors, we revisited the Belen site, measured the stratigraphic section, and processed the fruit- and seed-containing sediment for age-diagnostic microfossils. Although pollen and foraminifera were not recovered, the sediment is rich in diatoms. The diatom assemblage includes Lisitzinia ornata and Rocella vigilans, among others, indicating a lat...

Central American rainforests are among the most diverse biomes in the world today. However, we know little about their history because of a poor fossil record. Here, we augment previous studies based on fossil pollen of Panama with an investigation of eight species of endocarps and seeds from an upper Eocene locality near Tonosi on the Pacific coast of central Panama. Affinities at the family/order level include: Arecaceae, Vitaceae, Humiriaceae, Anacardiaceae, and Lamiales. Biogeographically, two of the Tonosi fossil taxa, Dracontomelon and cf. Leea , are interesting because they occur today only in lowland rainforests of the Old World. The new fossil genus Saxuva , together with cf. Leea , are the earliest evidence of Vitaceae (the grape family) in the Neotropics. The new genus Lacunofructus is the oldest record for Humiriaceae and supports the previously suggested Neotropical origin for the family. We interpret the Tonosi macroflora as a record of the vegetation which colonized land that emerged as part of the Eocene volcanic arc in southern Central America.

 Premise of the study: Fossil leaves of Menispermaceae were previously described from the Paleocene of Colombia. Because of strong homoplasy of leaf characters, the fossils could not be placed more specifi cally within recognized clades, and additional data were needed to specify intrafamilial and paleogeographic relationships during the Paleocene.  Methods: Fossil endocarps of Menispermaceae were collected from the Cerrej o n Formation, the recently discovered Bogot a fl ora, and Wyoming (~60 Ma). We surveyed the endocarp morphology of almost all extant genera, conducted character optimization, a molecular scaffold analysis, and critically reviewed the related fossil genera.  Key results: Parallel syndromes of fruit characters have appeared in unrelated clades of the family according to current phylogenetic reconstructions. However, mapping selected endocarp characters across those clades that contain horseshoe-shaped endocarps facilitates identifi cation and phylogenetic assessment of the fossils. Three fossil species are recognized. One of them belongs to the extant genus Stephania , which today grows only in Africa and Australasia. Palaeoluna gen. nov. is placed within the pantropical clade composed of extant Stephania , Cissampelos , and Cyclea ; this morphogenus is also recognized from the Paleocene of Wyoming. Menispina gen. nov. shows similarity with several unrelated clades.  Conclusions: The new fossils from Colombia reveal a complex paleobiogeographic history of the recognized clades within Menispermaceae, suggesting a more active exchange among neotropical, paleotropical, North American, and European paleoforests than previously recognized. In addition, the new fossils indicate that neotropical forests were an important biome for the radiation and dispersal of derived lineages in Menispermaceae after the Cretaceous – Paleogene boundary.

To place a new fossil occurrence of Sacoglottis in a broader context, we surveyed the fruit morphology of all extant genera of the Humiriaceae, conducted a cladistic analysis, and critically reviewed the fossil record for this family. Living and fossil fruits of Humiriaceae are recognized by a woody endocarp, germination valves, and, in some genera, wall cavities. The phylogenetic analysis based on 40 morphological characters yielded two most parsimonious trees indicating Vantanea as sister taxon to all genera among Humiriaceae. Schistostemon is indistinguishable from Sacoglottis in fruit morphology and is recovered as sister to Sacoglottis in the topology; we recommend restoring Schistostemon to the rank of subgenus within Sacoglottis. A review of prior published reports of fossil fruits attributed to Humiriaceae led to the rejection and/or reattribution of some records but supports recognition of Vantanea, Humiria, Humiriastrum, and Sacoglottis. The available characters do not support recognition of mul...

Neotropical rainforests have a very poor fossil record, making hypotheses concerning their origins difficult to evaluate. Nevertheless, some of their most important characteristics can be preserved in the fossil record: high plant diversity, dominance by a distinctive combination of angiosperm families, a preponderance of plant species with large, smooth-margined leaves, and evidence for a high diversity of herbivorous insects. Here, we report on an approximately 58-my-old flora from the Cerrejón Formation of Colombia (paleolatitude approximately 5 degrees N) that is the earliest megafossil record of Neotropical rainforest. The flora has abundant, diverse palms and legumes and similar family composition to extant Neotropical rainforest. Three-quarters of the leaf types are large and entire-margined, indicating rainfall2,500 mm/year and mean annual temperature25 degrees C. Despite modern family composition and tropical paleoclimate, the diversity of fossil pollen and leaf samples is 60-80% that of comparable samples from extant and Quaternary Neotropical rainforest from similar climates. Insect feeding damage on Cerrejón fossil leaves, representing primary consumers, is abundant, but also of low diversity, and overwhelmingly made by generalist feeders rather than specialized herbivores. Cerrejón megafossils provide strong evidence that the same Neotropical rainforest families have characterized the biome since the Paleocene, maintaining their importance through climatic phases warmer and cooler than present. The low diversity of both plants and herbivorous insects in this Paleocene Neotropical rainforest may reflect an early stage in the diversification of the lineages that inhabit this biome, and/or a long recovery period from the terminal Cretaceous extinction.