Modern Genera Research Articles

Diversification of almonds, peaches, plums and cherries – Molecular systematics and biogeographic history of Prunus (Rosaceae)

Most previous molecular phylogenetic studies of Prunus have been conducted primarily with crop species and their close relatives. As the center of crop diversity of the genus is in Eurasia, the geographic origin of Prunus has inevitably been inferred to be Eurasia as well. The lesser-known tropical Prunus species have not been well represented in previous phylogenetic reconstructions; therefore, their effects on inferences about the phylogenetic structure and geographic origin of Prunus are uncertain. In this study, we examined the phylogeny of Prunus, including an expanded sampling of species from tropical regions in Southeast Asia and the Americas, using sequences from four plastid markers and the nuclear ribosomal ITS region. A penalized likelihood method was used to estimate the absolute age of Prunus and the timing of infrageneric cladogenic events. The geographic origin of Prunus and ancestral sites of cladogenesis were inferred using the Bayes-DIVA approach. Our results indicate that the modern genus appeared ∼61Myr in eastern Asia and that diversification of all major lineages may have been triggered by the global warming period of the early Eocene. In addition, our molecular dating estimates suggest that the crown clade that includes the temperate deciduous crop species is older than the one that includes the tropical evergreen species, while incongruence between plastid and nuclear phylogenies suggests that the latter lineage originated via an ancient hybridization event. The most recent common ancestor (MRCA) of the temperate crop species was a component of the continuous boreotropical forests of the Northern Hemisphere, while the MRCA of the tropical species represented the last remains of the boreotropical elements and subsequently radiated throughout the Old and New World tropics from refugial areas at lower latitudes. Complex biogeographic histories leading to the present global distribution of the genus were driven by several geologic events, climatic oscillations, and independent dispersals across continents via the Bering and the North Atlantic Land Bridges during different geologic time periods.

A well-preserved isopod from the Middle Jurassic of southern Germany and implications for the isopod fossil record

A new isopod species, Eonatatolana geisingensis gen. et sp. nov., is described from Middle Jurassic shallow-water sediments of southern Germany. It shows not only the almost completely preserved dorsal morphology but, in addition, details of the cephalic appendages, the pereiopods, pleopods and uropods. The presence of ambulatory pereiopods I–VII of a wide tridentate mandibular incisor with prominently developed posteriormost tooth and a narrow frontal lamina indicates that the new species belongs to the subfamily Conilerinae of family Cirolanidae within the suborder Cymothoida. It is closer to the species of the modern genus NatatolanaBruce than to any fossil isopod hitherto described. The isopod fossil record as well as current practices of isopod taxonomy in palaeontology are discussed, and the facies distribution and fossilization of isopods is reviewed with examples from the Jurassic.

A fossil wood of Gluta L. (Anacardiaceae) from the Early Eocene sediments of Gujarat, western India

A fossil wood showing resemblance with the modern genus Gluta L. is described from the Rajpardi Lignite Mine of Bharuch District, Gujarat. The age of this mine has been considered as Early Eocene. The modern comparable species of the fossil, Gluta travancorica Bedd., is an evergreen element and presently growing in wet evergreen forests of Western Ghats, India. An account of the present distribution of its modern analogue, along with previously described fossils from the same locality indicates the existence of humid conditions and evergreen forest in and around the fossil locality during the Eocene as compared to arid to semi–arid climate in the area today.

A giant spider from the Jurassic of China reveals greater diversity of the orbicularian stem group

A large female spider, Nephila jurassica, was described from Middle Jurassic strata of north-east China and placed in the modern genus Nephila (family Nephilidae) on the basis of many morphological similarities, but, as with many ancient fossils, the single specimen lacked synapomorphies of the family (Selden et al. 2011). In order to test the placement within the nephilid phylogenetic tree, Kuntner et al. (2013) calibrated the molecular phylogeny using N. jurassica in three different scenarios based on inferred mitochondrial substitution rates. They concluded that N. jurassica fitted better as a stem orbicularian than a nephilid. Now, a giant male spider has been discovered at the same locality that yielded N. jurassica. The two sexes are considered conspecific based on their similar morphological features, size, and provenance. The male cannot be accommodated in Nephilidae because of its pedipalp morphology, so the new genus Mongolarachne and family Mongolarachnidae are erected for the species. Comparison with possibly related families show that Mongolarachnidae is most likely on the orbicularian stem, close to other cribellate orbicularians (e.g., Deinopoidea), which suggests a greater diversity of cribellate orbicularians during the Middle Jurassic.Electronic supplementary materialThe online version of this article (doi:10.1007/s00114-013-1121-7) contains supplementary material, which is available to authorized users.

Bimineralic bryozoan skeletons: a comparison of three modern genera

A combination of light microscopy, field-emission scanning electron microscopy (FE-SEM), electron microprobe, and Raman spectroscopic analysis is used here to study three cheilostome bryozoan taxa with bimineralic skeletons: Odontionella cyclops, Margaretta cereoides, and Pentapora spp. Typically for bimineralic bryozoans, all skeletal walls forming the box-like zooids are constructed primarily of calcite with only the outer layer of the frontal shield consisting of aragonite. The two minerals have characteristic lamellar (calcite) and fibrous (aragonite) ultrastructures visible in FE-SEM images. Similarities in skeletal ultrastructure between the three taxa are evident in the basal and vertical walls, which have almost the same thicknesses and fabrics. These calcitic walls consist of an inner layer with crystallites oriented parallel to the wall and an outer layer with crystallites perpendicular to the wall surface. The bimineralic frontal shields of Odontionella cyclops and Pentapora spp. are ca. 150 μm thick and Margaretta cereoides ca. 40–100 μm. Interfaces between calcite and aragonite layers in these walls are variable: in Odontionella cyclops the interface between the layers is relatively planar, while in the other two species it is undulose. In these bimineralic taxa frontal shields in the innermost parts of the calcite layer comprise low Mg-calcite with 3–4 mol% Mg, which increases to over 5 mol% Mg (intermediate Mg–calcite) near to the boundary with the overlying aragonite layer; Mg content drops to a minimal value of 0.2–0.3 mol% Mg in the aragonite. These findings are significant for our understanding of both biomineralization processes in bryozoans and the use of Mg skeletal chemistry as a temperature proxy.

A new species of Platydracus Thomson, 1858 (Coleoptera, Staphylinidae, Staphylininae) from the upper Eocene Florissant beds, Colorado, USA

Platydracus breviantennatus n. sp., is described and figured based on an impression fossil from the upper Eocene Florissant beds of Colorado, the United States. Based on the large and densely setose body, relatively small eyes, and robust mandibles (right mandible seemingly with one simple preapical tooth), tibiae and antennae, the new species is placed in the modern genus Platydracus Thomson, 1858. It differs from other species of Platydracus by its large body, small head, and distinctly short antennae.

Understanding morphological variation in the extant koala as a framework for identification of species boundaries in extinct koalas (Phascolarctidae; Marsupialia)

We document morphological variation (both geographical and sexual) in the dentition of the extant koala, Phascolarctos cinereus, in order to facilitate discrimination of species boundaries in extinct phascolarctids. Considerable variation is evident in dental structures previously used to diagnose several phascolarctid fossil species. Consistent patterns of morphological variation are not evident between sexes or geographic regions, with variation as great between samples as within them. Metric variation is evident between the sexes in upper molar dimensions with Victorian (southern) males significantly larger than Victorian females, although this is not reflected in lower molar dimensions or in the Queensland (northern) sample. Male koalas from southern populations generally display significantly larger molars than their northern counterparts; however this trend is not evident in female upper molar dimensions. In both males and females, some, but not all, lower molar dimensions are larger in southern populations than northern. In light of these results, a systematic revision of species of Litokoala suggests L. ‘dicktedfordi’ is a junior synonym of L. kutjamarpensis, and the poorly known L. thurmerae is regarded to be a nomen dubium. Further, we describe a partial cranium of a new species of koala from Early Miocene sediments in the Riversleigh World Heritage Area, northern Australia. Litokoala dicksmithi sp. nov. is the fifth koala species recorded from the diverse rainforest assemblages of Riversleigh and the third species referred to the Oligo-Miocene genus Litokoala. Aspects of cranial morphology, including a shortened robust rostrum and broad, irregular nasal aperture, confirm placement of Litokoala as sister taxon to the modern genus Phascolarctos. Relatively large orbits and small body size suggest the possibility that L. dicksmithi was nocturnal, had enhanced visual acuity, and was a more agile arboreal species than the relatively sedentary extant koala.http://zoobank.org/urn:lsid:zoobank.org:pub:EE5D13C1-47BB-4432-B281-16398A1781E1

Insect Fauna of the Late Miocene Locality of Öhningen (Germany) Less Diverse than Reported: An Example of the Hydrophilid Beetles (Coleoptera)

The fossils originally assigned to the family Hydrophilidae (Coleoptera, Polyphaga) from the late Miocene locality of Öhningen (southern Germany) are revised. Nine hydrophilid species are recognized, most of them representing the tribe Hydrophilini. Five species are reliably assigned to genera: Hydrochara noachica (Heer, 1847), n. comb. (=Hydrophilus rehmanni Heer, 1847, n. syn.), Hydrobiomorpha braunii (Heer, 1847), n. comb. (=Hydrous escheri Heer, 1862, n. syn.), Hydrobiomorpha heeri n. sp., Hydrophilus spectabilis Heer, 1847 (=Hydrophilus knorrii Heer, 1847, n. syn., =Hydrophilus giganteus Heer, 1862, n. syn.), and Hydrophilus vexatorius Heer, 1847. Two taxa are treated as Hydrophilini incertae sedis: Hydrophilopsis elongata Heer, 1862, and Hydrous ovalis Heer, 1862. Two species represent Hydrophilidae incertae sedis: Escheria ovalis Heer, 1847 and E. bella Heer, 1862. The fossil genus Hydrophilopsis Heer, 1862 likely represents the modern genera Sternolophus Solier, 1834 or Hydrobiomorpha Blackburn, 1888, the fossil genus Escheria Heer, 1847 likely represents some modern genus within the Hydrophilini or Hydrobiusini. Six taxa are excluded from the Hydrophiloidea: Helophorus magnus Heer, 1862, H. exilis Heer, 1862 (possibly belonging to Curculionidae), Hydrobius couloni Heer, 1862 and H. godeti Heer, 1862 (both possibly belonging to Curculionidae: Zygopinae), Hydrophilus braunii var. minor Heer, 1862, and Hydrophilus stenopterus Heer, 1862 (likely a leaf fossil). Our revision revealed a rather high amount of inaccurate family and genus assignments and a moderate amount of species-level synonymy in the original treatment of Öhnigen fauna by O. Heer. The diversity of the hydrophilid beetles in Öhningen is thus lower than previously reported, but still being slightly higher compared to other European Paleogene and Neogene localities.

Dabbling ducks (Aves: Anatidae) from the Middle Miocene of Mongolia

A new genus and two new species of ducks (Aves: Anatidae) from the Middle Miocene Sharga locality are described. Mioquerquedula minutissima gen. et sp. nov. is a very small duck. Anas velox Milne-Edwards, 1868 from the Middle Miocene of France is transferred to the genus Mioquerquedula. Aix praeclara sp. nov. described here is the oldest record of the modern genus Aix. A revision of the previously described small duck Anas soporata Kurochkin, 1976 shows that only the specimens from the Sharga locality should be referred to this species. The status of other small ducks from the Neogene of Europe and North America is discussed. The diversity of herbivorous and diving ducks in the Sharga locality indicates that Miocene Shargyn Govi Lake was rich in food resources.

Book review: Avian history is written by the winners

news and update book review Avian history is written by the winners Avian survivors: The history and biogeography of Palearctic birds, by Clive Finlayson, 2011, T & AD Poyser Ltd., 304 pp. £50 (Hardback) ISBN: 9780713688658; http://www.acblack.com/naturalhistory/ This is a difficult book to review fairly, because it is not a book to read through, nor is its intention easily discerned. It is a profound and deeply detailed compilation, assessing the climatic, historical and biogeographical attributes of the bird fauna of the Western Palaearctic. Its intention is to understand how this particular constellation of species survived through the climatic vicissitudes of the Tertiary Period, and especially the last 2 million years of the Pleistocene climatic fluctuations, to be combined as the extant fauna. Finlayson was inspired by the remarkably diverse faunas that appear in the caves of Gibraltar, at the extreme southern tip of the Western Palaearctic. At different times these included northern species such as Great Auk and Velvet Scoter, at others southern species such as Lammergeier and Crag Martin. Those that still occur in the Palaearctic are the survivors of his title. He starts with a short outline of the climatic, geographical and ecological changes that affected the region during the Tertiary, as Africa and India shifted north to collide with Europe and Asia, so closing the Mediterranean, and causing the uplift of the mountain ranges across central Europe and Asia that changed the climate, especially the strength and direction of rain-bearing winds. Grasses evolved in this period, and grasslands, replacing tropical forests, became more widespread. His analysis of the times of origin of bird genera that, at present, include migratory species, especially Trans-Saharan migrants, suggests that many of them evolved in the Miocene, as the grasslands appeared. Popular, perhaps superficial, opinion has assumed that the glacial-interglacial cycles of the Pleistocene prompted the evolution of the migratory habit, but this analysis strongly suggests that it was already well established. The majority of the book is a detailed examination of each family, genus and species that is currently represented in the Palaearctic. It assesses their climatic limits, habitat requirements and likely history. Much modern work on genetic phylogeny is used to assess the zoogeographic origins of such taxa, when they migrated into the Palaearctic, and how their climatic requirements have persisted, along with the taxa themselves. Each is assigned to its climatic and latitudinal tolerance ranges, and to its migratory group (sedentary, partial migrant, Trans-Saharan migrant). For instance, Finlayson interprets the history of the Corvidae as probably evolving in Australia, and migrating into the tropical forests of Southeast Asia, where a great diversity of basal genera still occur; but one, the Choughs (Pyrrhocorax) migrated out along the great mountain chain right across Asia and Europe in the Miocene, as mountain uplift created their drier upland habitat. However, most corvids remained essentially forest species, and migrated west along the forest belts south (mostly deciduous) or north (mostly coniferous) of the mountains. Corvids reside mostly in more humid climatic zones, and few show much migratory behaviour. Fossil corvids are represented in Europe by Middle Miocene times; two modern genera are present by the Early Pliocene (Pyrrhocorax, Pica, two more by Middle Pliocene (Garrulus, Nucifraga) and all by Early Pleistocene. Sometimes the detailed evidence on which such histories are based is clearly indicated. The fossil record is largely quoting the compilation by Mlikovský (2002), and the phylogenetic references are well cited. However, much of the story is informed speculation, of probable histories and probable spreads, based upon known climatic and geographical changes, and the known broad ecological requirements of the taxa. Given the number of taxa involved, this amounts to quite a lot of speculation accumulated over the book as a whole. This is not to suggest that it is wrong, nor does it deny its value. A lot of diverse information frontiers of biogeography 4.1, 2012 — © 2012 the authors; journal compilation © 2012 The International Biogeography Society

Fossil wood of Piceoxylon burejense sp. nov. (Pinaceae) from the Upper Cretaceous of Zeya-Bureya Basin, Amur Region (Russian Far East)

A new species, Piceoxylon burejense sp. nov. (Pinaceae), is described from the Middle Maastrichtian (Upper Cretaceous) of the Zeya-Bureya Basin, Amur Region (Russian Far East) based on the fossil wood anatomy. The new species is characterized by a combination of anatomical wood features of the modern genera Picea and Larix. The fossil wood of Pinaceae was found in the Cretaceous deposits of the Amur Region for the first time.

Meloneis Gen. Nov., a New Epipsammic Genus of Rhaphoneidaceae (Bacillariophyceae)

The diatom family Rhaphoneidaceae is characterized by high generic diversity and low species diversity with most genera known to have long stratigraphic ranges. The genera within this family are neritic marine, and mostly epipsammic. A new modern and epipsammic genus, Meloneis gen. nov., is described herein and is compared to all genera within Rhaphoneidaceae and especially to Rhaphoneis Ehrenberg s.l. Within Meloneis three new species and one variety are distinguished and described herein: M. mimallis sp. nov., M. mimallis var. zephyria var. nov., M. akytos sp. nov., and M. gorgis sp. nov.

Phylogenetic relationships of Paleotetra, a new characiform fish (Ostariophysi) with two new species from the Eocene-Oligocene of south-eastern Brazil

Paleotetra, a new characiform genus with two new species (P. entrecorregos and P. aiuruoca) from Palaeogene deposits of south-eastern Brazil is described. The fossil material is made up of two articulated specimens preserved as impressions in lateral view and including some bones and teeth. The new genus is hypothesized to be deeply inserted within the Characidae based on the apomorphic lack of a supraorbital bone, the low number of vertebrae (35), and the presence of four teeth in the inner series of the premaxilla; however, the new species cannot be assigned to any modern genus. Relationships of the two new species are further tested in a phylogenetic analysis along with 160 other characiform species using 360 morphological characters (150 coded for Paleotetra entrecorregos and 123 for P. aiuruoca), further supporting their recognition as characid characiforms. These results document the evolution of these characid lineages as early as the Eocene-Oligocene.

Cteniza bavincourti and the nomenclature of arachnid-related trace fossils

Abstract Sabella bavincourti Vaillant 1909 from the Eocene of northern France is a little-known trace fossil subsequently attributed – as Cteniza bavincourti – to the burrowing activities of a trapdoor spider. It is thus an ichnospecies name and not a body fossil. Its interpretation as the activity of a spider is questionable and its original assignment to a worm burrow seems intuitively more likely. Irrespective of the affinities of the producer, the ICZN also covers ichnotaxa such that classifying these structures under a modern genus name creates a homonym. It is here reassigned as the ichnotaxon Oichnus bavincourti comb. nov. Another problematic name is Theridium columbianum (Scudder 1878) from the Eocene of Canada and the USA, which is based on fossilized spider egg sacs. Under current ICZN rules fossil cocoons fall under the definition of “work of an animal”. We propose reassigning them here to Araneaovoidus igen. nov., as Araneaovoidus columbiae (Scudder 1878) comb. nov.; but stress that this is no...

Giants in a minute catfish genus: first description of fossil Mochokus (Siluriformes, Mochokidae) in the Late Miocene of Chad, including M. Gigas, sp. nov.

ABSTRACT The first Mochokus (Siluriformes, Mochokidae) remains of the fossil record are described, including a new species based on a sub-complete neurocranium discovered in the Late Miocene deposits of Toros-Menalla, Chad, Central Africa, dated to 7.0 Ma. Mochokus gigas, sp. nov., is the first fossil species described for the family Mochokidae, which is the largest family of African catfishes. The description is based on the comparison with the two living species of the genus, M. niloticus and M. brevis. Mochokus gigas, sp. nov., is a very large species presenting original features, notably on the pectoral spines and on the anterior part of the neurocranium. One of the apomorphies characterizing the modern genus Mochokus is found on the fossil: the root of the mesocoracoid arch is located on the posterior side of the vertical lamina of the coracoid and lacks any dorsally directed prominence. Several other Mochokus fossil remains, including nuchal plates, cleithra, and dorsal spines, are described and attributed to Mochokus, sp. indet., or Mochokus sp. Finally, and on the basis of preliminary observations of the fossil fish assemblages from different sites of Toros-Menalla, the lack of Mochokus fossil remains is discussed.

Faunistic similarity and endemism of earthworms in east mediterranean region

The analysis presents earthworm distribution in eight designated tectonic units (C—Cyprus, EP—East Pondites, ET—East Taurus block, Sc—Sakarya continent, Kb—Kirsehir block, L—the Levant, TM—Taurus–Menderes block, WP—West Pondites) in the East Mediterranean region (EM). It represents a full list of earthworm species (N = 81) of the region and reveals significant faunal similarities between Sc + WP, and between Kb + TM. The new Sc + WP unit is characterized by the presence of archaic (Spermophorodrilus) as well as modern earthworm fauna. In contrast, the second newly established Kb + TM unit is characterized by poorly presented earthworm autochthonous fauna and by a lack of endemic species. The analysis done on the species list (N = 73) representing the autochthonous family Lumbricidae showed statistically supported separation of L and EP between themselves and from other designated units. The Levant, part of the Arabian tectonic plate, is characterized by a high level of endemism in ancient (Healyella) and modern (Dendrobaena, Perelia) genera, and by the lack of archaic genera. The EP harbors unique species representing archaic (Eophila), ancient (Healyella), and modern (Allolobophora, Aporrectodea, Dendrobaena and Eisenia) earthworm genera in the EM. The analysis also indicates origin of earthworm fauna in TM and faunistic relationships among the designated units. Clearly, the present-day division of the EM earthworm fauna shows recognizable influences of tectonic history.

Gymnogeophagus eocenicus, n. sp. (Perciformes: Cichlidae), an Eocene cichlid from the Lumbrera Formation in Argentina

ABSTRACT A new cichlid referable to the extant genus Gymnogeophagus is described from the Eocene Lumbrera Formation of the Salta Group, northwestern Argentina. †Gymnogeophagus eocenicus, n. sp., presents the synapomorphies that support the genus: absence of supraneurals and a presence of a forward spine in the first dorsal pterygiophore. The existence of an early to middle Eocene–aged species presenting the synapomorphies and the appearance of a modern genus requires the acceptance of an extensive differentiation from the basal cichlid lineages. Extant Gymnogeophagus species are restricted to the La Plata drainage and a few coastal drainages of southern Brazil and Uruguay. The occurrence of an Eocene fossil in the geographical area corresponding to the present distribution of the genus suggests the patterns of distribution and endemism of the Neotropical fish fauna have a very old history in the continent.

Elucidating the affinities and habitat of ancient, widespread Cyperaceae: Volkeria messelensis gen. et sp. nov., a fossil mapanioid sedge from the Eocene of Europe

The sedges (family Cyperaceae) are an economically and ecologically important monocot group dating back at least to the Paleocene. While modern genera are mostly unknown before the Oligocene, several extinct taxa are recognized as the earliest sedges. Their affinities have been unclear until now, because they are found as isolated, often abraded fruits or endocarps. Exceptionally preserved sedge fossils from the Middle Eocene of Messel, Germany yield more characters for identification. Fossil cyperacean infructescences with in situ pollen are recognized for the first time and show features of the early-divergent mapanioid sedges. Pollen resembles that of tribe Hypolytreae. Comparisons with extant taxa suggest the closest affinities with Hypolytrum and Mapania. However, the Messel fossils represent a distinct taxon, Volkeria messelensis gen. et sp. nov. Without the additional characters of infructescence and pollen, the Messel fruits would have been placed in the extinct genus Caricoidea, a typical Eocene sedge that was widespread across Eurasia. Similarities of fruit structure suggest that Caricoidea was also a mapanioid sedge. Mapanioid sedges are found today in tropical wet forests and swamps, a distribution suggesting that early sedges occupied a similar habitat, unlike many modern sedges, and were not precursors to open grassland vegetation.

The Wasp Family Rhopalosomatidae in Mid-Cretaceous Amber from Myanmar (Hymenoptera: Vespoidea)

The first Cretaceous fossil of the wasp family Rhopalosomatidae (Aculeata: Euaculeata: Vespoidea) is described and figured from a male preserved in Burmese amber. Eorhopalosoma gorgyra Engel, new genus and species, is the first rhopalosomatid discovered in amber and the second—but first definitive—member of the family from the Cretaceous. The new species is distinguished from its modern counterparts. The modern genus Olixon Cameron is transferred to a separate new subfamily, Olixoninae.

Credneria and Platanus (Platanaceae) from the Late Cretaceous (Santonian) of Quedlinburg, Germany

Foliage and reproductive structures of Platanaceae from the Upper Cretaceous (Santonian) of Quedlinburg, Central Germany, were comparatively studied and their systematic affinities established. One type of foliage preserved in sandstone and rarely in clayish siltstone belongs to the extinct genus Credneria. The leaves are typically obovate with a pinnate-actinodromous venation and distinct suprabasal veins. In addition, a substantial number of leaves preserved in siltstone and rarely in sandstone are identical to modern Platanus based on leaf architecture and epidermal features. As in modern Platanus leaf margin and size were found to be of no systematic significance in both fossil leaf types. Further, staminate flower heads preserved as cleavage compressions in siltstone were found in association with Platanus leaves; they contain pollen that is identical to modern Platanus in size and type of tectum. In addition, a few three-dimensionally preserved staminate flower heads with ca. 50 flowers on a receptaculum are described. Each flower appears to have a two-whorled perianth and six or seven stamens. The organs of the outer perianth whorl show a distinct epidermal cell pattern different from the inner ones. All perianth organs have the same length as the stamens. Stamens are bithecate and contain pollen identical to that found in compression fossils. Pistillate heads preserved in siltstone consist of numerous achenes with persistent styles, which show close similarity to modern Platanus. It remains unclear, whether additional inflorescence heads of uncertain sex found in sandstone that are slightly larger than those preserved in siltstone belong to the leaves of Credneria. Association evidence links vegetative and reproductive structures preserved in siltstone and indicates the presence of the modern genus Platanus in the Santonian.