Occurrence of an in situ fern grove in the Aptian Douiret Formation, Tataouine area, South-Tunisia

A level with fern stumps was discovered in the Aptian Douiret Formation, South-Tunisia. These stumps are preserved as external moulds or casts, without any preservation of anatomical structures. These stumps are considered to be affiliated with the numerous fossil plants assigned to the fern genera Alstaettia and Piazopteris that are widely distributed in coeval strata from the same region, either as leaf imprints or as permineralized remains. The record of in situ fossil forests for the Southern Hemisphere reveals that their systematic components are different, i.e. mainly corystosperms and/or conifers, and rarely under tidal influence. The way this fern grove settled in a margino-littoral environment is discussed.     

Dinosaurs of Portugal

A synthesis on the state of art on dinosaur knowledge in Portugal is presented. The following genera have been recognized: Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoestesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. Pleurocoelus, Lusitanosaurus, Dacentrurus, Dracopelta, Phyllodon, Hypsilophodon, Alocodon, Trimucrodon, Draconyx, Iguanodon, and Taveirosaurus. Most are from Late Jurassic localities at the Lourinhã area and Guimarota. A new genus, Lusotitan, is here raised to include the Late Jurassic ‘Brachiosaurus’ atalaiensis. Lower Cretaceous until Cenomanian material is scarce, except for dinosaur footprints. An interesting Late-Cretaceous, mostly small dinosaur association has been collected between Aveiro and Taveiro. To cite this article: M.T. Antunes, O. Mateus, C. R. Palevol 2 (2003) 77–95.     

Recognising angiosperm clades in the Early Cretaceous fossil record

Studies of the earliest Cretaceous angiosperms in the 1970s made only broad comparisons with living taxa, but discoveries of fossil flowers and increasingly robust molecular phylogenies of living angiosperms allow more secure recognition of extant clades. The middle to late Albian rise of tricolpate pollen and the first local dominance of angiosperm leaves mark the influx of near-basal lines of eudicots. Associated flowers indicate that palmately lobed ‘platanoids’ and Sapindopsis are both stem relatives of Platanus, while Nelumbites was related to Nelumbo (also Proteales) and Spanomera to Buxaceae. Monocots are attested by Aptian Liliacidites pollen and Acaciaephyllum leaves and Albian araceous inflorescences. Several Albian–Cenomanian fossils belong to Magnoliidae in the revised monophyletic sense, including Archaeanthus in Magnoliales and Virginianthus and Mauldinia in Laurales, while late Barremian pollen tetrads (Walkeripollis) are related to Winteraceae. In the basal ANITA grade, Nymphaeales are represented by Aptian and Albian flowers and whole plants (Monetianthus, Carpestella and Pluricarpellatia). Epidermal similarities of lower Potomac leaves to woody members of the ANITA grade are consistent with Albian flowers assignable to Austrobaileyales (Anacostia). Aptian to Cenomanian mesofossils represent both crown group Chloranthaceae (Asteropollis plant) and stem relatives of Chloranthaceae and/or Ceratophyllum (Canrightia, Zlatkocarpus, Pennipollis plant and possibly Appomattoxia).     

Plant-dominated assemblage and invertebrates from the Lower Cenomanian of Jaunay-Clan,western France

Two fossil localities are reported on the “LGV SEA” railroad from the Lower Cenomanian of Jaunay-Clan (JC), near Poitiers, western France. The laminated mudstones yielded plant fossils including ferns (Cladophlebis, Osmundophyllum, Ruffordia goeppertii, Sphenopteris), conifers (Brachyphyllum, Dammarophyllum, Pagiophyllum), and terrestrial and aquatic freshwater angiosperms (Eucalyptolaurus depreii, Ploufolia). They are associated with a coleopteran insect that shows systematic affinities to the modern subfamily Chrysomelinae (Chrysomelidae). This assemblage suggests connections with arborescent vegetation growing in calm freshwater environment. Brackish to marine invertebrates also occur and include a dakoticancroid crab (Brachyura, Podotremata, Dakoticancroidea) and a few bivalves (Brachidontes). They suggest brackish episodes during pond sedimentation in a coastal environment. Lastly, vertebrates are represented by an isolated feather.     

On Mesopithecus habitat: Insights from late Miocene fossil vertebrate localities of Bulgaria

The aim of this study is to describe the environments where the cercopithecid Mesopithecus was found during latest Miocene in Europe. For this purpose, we investigate the paleoecology of the herbivorous ungulate mesofauna of three very rich late Miocene fossil localities from southwestern Bulgaria: Hadjidimovo, Kalimantsi and Strumyani. While Mesopithecus has been found in the two first localities, no primate remains have yet been identified in Strumyani. Comparison between localities with and without primates using the herbivore mesofauna allows the cross-corroboration of paleoenvironmental conditions where this primate did and did not live. A multi-parameter statistical approach involving 117 equid and 345 bovid fossil dental and postcranial (phalanges, metapodia, astragali) remains from these three localities provides species to generic-level diet and locomotor habit information in order to characterize the environment in which Mesopithecus evolved. The analysis of dental mesowear indicates that the bovids were mainly mixed feeders, while coeval equids were more engaged in grazing. Meanwhile, postcranial remains show that the ungulate species from Hadjidimovo and Kalimantsi evolved in dry environments with a continuum of habitats ranging from slightly wooded areas to relatively open landscapes, whereas the Mesopithecus-free Strumyani locality was in comparison reflecting a rather contrasted mosaic of environments with predominant open and some more closed and wet areas. Environments in which Mesopithecus is known during the late Miocene were not contrasted landscapes combining open grassy areas and dense forested patches, but instead rather restricted to slightly wooded and homogeneous landscapes including a developed grassy herbaceous layer.     

Early Cretaceous angiosperm invasion of Western Europe and major environmental changes

BACKGROUND AND AIMS: At the beginning of the Late Cretaceous, angiosperms already inhabited all the environments and overtopped previously gymnosperm-dominated floras, especially in disturbed freshwater-related environments. The aim of this paper is to define what fossil plant ecology occurred during the early Cretaceous in order to follow the early spread of angiosperm taxa. METHODS: Floristic lists and localities from the Barremian to the Albian of Europe are analysed with the Wagner's Parsimony Method. KEY RESULTS: The Wagner's Parsimony Method indicates that (a) during the Barremian, matoniaceous ferns formed a savannah-like vegetation, while angiosperms composed freshwater aquatic vegetation; (b) during the Late Aptian humid phase, conifers increased, while matoniaceous ferns decreased, reflecting the closure of the vegetation; and (c) from the Albian, warmer and drier conditions induced the recovery of the matoniaceous ferns, while core angiosperms first developed in floodplains. CONCLUSIONS: During the late Early Cretaceous (Barremian-Albian), angiosperms showed a stepwise widening of their ecological range, being recorded first during the Barremian as aquatic plant mega-remains and at the Cenomanian onwards occurred in all the environments.     

Ammoniten des Cenomans vom Südrand der westfälischen Kreide zwischen Unna und Möhnesee

Systematically collected ammonites from the different levels of the transgressive Cenomanian of the Haarstrang Mountains between Unna and Möhnesee (southern border of the westfalian Cretaceous, NW Germany) have been investigated. Twenty-one taxa (genera and species), partly previously unknown from this region, have been found and described. The fauna from the immediate transgression level is preserved as phosphoritic internal moulds (steinkerns). Fragmentary preservation and fossil condensation levels indicate reworking processes in these basal Cretaceous deposits. The age of the Cretaceous transgression in the area investigated can be precisely established as Lower Cenomanian (=carcitanensis subzone). The Cenomanian sequence, which is lithofacially very variable, can be, on the basis of the ammonite fauna, subdivided according to the modern Cretaceous stratigraphy for the boreal realm.     

L’ambre cénomanien d’Anjou : stratigraphie et paléontologie des carrières du Brouillard et de Hucheloup (Ecouflant,Maine-et-Loire)

The Ecouflant area (Maine-et-Loire, France) shows the last outcrops from the Anjou region that allow the study of early Cenomanian lignites and the associated amber. The quarry of Le Brouillard was historically the most studied locality, but it is now partly covered by bulky waste. No fossil arthropod has been found in the amber collected in this locality, and only a few bacterial filaments and plant fragments were detected among the microinclusions. The quarry of Hucheloup shows a wider exposure. Amber is poor, but fossil plants and bivalve are frequent. Based on the sedimentological series and the palaeontological contents of the lignitic clay, we suggest that it corresponds to estuarine to coastal depositional environments with variable salinity.     

Italian Cenozoic crocodilians: taxa, timing and palaeobiogeographic implications

Crocodylian remains are collected in 39 fossil-bearing localities but only in seven localities specimens with reliable taxonomic attributions, at least to genus level have been collected. Three species have been reported from the early Lutetian Purga di Bolca site: Pristichampsus cf. Pristichampsus rollinati, Asiatosuchus sp., Hassiacosuchus sp. (=Allognathosuchus sp.). The three crocodilians discovered at Purga di Bolca have been reported also from Geiseltal and Messel (Middle Eocene, Germany). Bolca at that time was part of a Tethysian archipelago and no mammals have been found there till now. Crocodilians and turtles clearly arrived from the European mainland across a marine water barrier. Among the other fossiliferous localities of Veneto, very interesting is the Monte Zuello site, of late Middle Eocene age, yielding a longirostrine crocodilian, Megadontosuchus arduini, a tomistomine species. Tomistomines are known in contemporaneous sediments of both Europe and Africa, but the European forms Dollosuchus and Kentisuchus seem the closest taxa. Remains of Oligocene age have been collected in Veneto and Liguria, but the fossils discovered in the second region are teeth or fragmented bones. The fossil crocodilians of Monteviale (Veneto), of Early Oligocene age, have been assigned to two species but they have been recently all identified as Diplocynodon ratelii, known from several European sites of Late Eocene, Oligocene and Miocene age. This species arrived in the Monteviale area from the European mainland across a narrow sea. Several crocodilian fossils of Miocene age are very fragmentary or represented by isolated teeth. In the Middle and Late Miocene of Sardinia, a well-established species, Tomistoma calaritanum is present. Remains of Tomistoma of the same age have been reported in some localities in Tuscany, Apulia, Sicily and Malta. In the Mediterranean area, the genus is known from European and African sites (of older age). The colonisation of Europe by this genus is the result of a dispersion from Africa (or less probably from Asia). During Late Miocene Sardinia and Tuscany belong to the same palaeobioprovince characterized by the Oreopithecus-Maremmia fauna. In Tuscany, a crocodilian identified as Crocodylus bambolii is present in the late Miocene site of Monte Bamboli. If the generic attribution of this form is correct, its ancestors must have arrived from Africa. Another fossil assemblage of Late Miocene age characterizes the Apulia-Abruzzi palaeobioprovince (Hoplitomeryx-Microtia fauna) and testifies complete isolation between the two palaeobioprovinces. In this last area, remains of Crocodylus sp. have been collected in coastal sandstones at Scontrone (Abruzzi) and in several fissure fillings of Gargano of slightly younger age. The ancestors of this species arrived from Africa while no African elements are present among the mammalian fauna. The dispersion of the genus Crocodylus in the Italian palaeoislands may have taken place once, with allopatric differentiation of the two populations (Tuscany-Sardinia and Apulia-Abruzzi) or twice with independent colonisation of each area.     

A NEW SPECIES OF MARSILEA FROM THE DAKOTA FORMATION IN CENTRAL KANSAS

Discovery of compression/impression megafossil material from the Cenomanian (mid-Cretaceous) in Kansas documents the occurrence of the genus Marsilea during this age. Only vegetative material has been found as complete plants; associated structures that may be fertile structures could belong to the genus also. This new fossil species extends the megafossil record of the genus back to the mid-Cretaceous when previously only megaspores attributed to the family occurred during this time. The fossil record of the heterosporous aquatic fern families is reviewed with emphasis on the Marsileaceae.     

Ecological distribution of Cenomanian terrestrial plants based on 13C/12C ratios

The Cenomanian lagoonal member of the `Argiles du Baugeois' (Anjou, France) yielded a rich and exceptionally well-preserved fossil leaf flora. Stable carbon isotope ratios of fossil plants were measured in order to investigate the presence of a palaeoenvironmental signal. The small intraspecies variations of δ<sup>13</sup>C values observed for most of the fossil leaves suggested that the isotopic signal had not been significantly altered. Hence, an isotopic approach was used as an attempt to assist in reconstructing the ecological distribution of the flora. The <sup>13</sup>C-enrichment of the fossil leaves suggested that the plants underwent water or salt stress. The occurrence of the conifer Frenelopsis suggested, at least locally, a saline environment such as a lagoon. According to their decreasing δ<sup>13</sup>C values, all the plants collected could have been distributed along a decreasing salinity transect from the lagoon to a flood plain. The predominant species, Eretmophyllum andegavense, a fossil ginkgo, exhibited a wide range of δ<sup>13</sup>C values. This could indicate that this taxon grew in a wide range of habitats with varying salinities. The origin of the organic matter appeared to be terrestrial with a major contribution from water-stressed plants such as Frenelopsis, as suggested by the similarity between δ<sup>13</sup>C values of the conifer and the sedimentary organic matter. δ<sup>13</sup>C values of the sediment indicated stable palaeoenvironmental conditions during the deposition of the `Argiles du Baugeois' member. Hence, while detailed palaeovegetation reconstructions are generally limited to the few deposits which present in-situ palaeoflora, the contribution of isotope geochemistry could allow reconstructions for a wider range of fossil plant deposits.     

Fossil evidence of eupolypod ferns in the mid-Cretaceous of Myanmar

Divergence time estimates based on DNA sequence variation of extant species suggest that eupolypod ferns were diverse already in the Cretaceous; however, fossil evidence to support this assumption remains exceedingly rare. Holttumopteris burmensis gen. et sp. nov., a fertile fern foliage fragment preserved in a piece of Albian–Cenomanian Burmese amber from Myanmar, is characterized by divided fertile leaves with catadromous, free lateral veins. Sporangia possess a vertical annulus interrupted by the sporangium stalk and contain monolete spores with a lophate perine. The sporangia occur clustered in discrete sori overarched by a laterally attached, reniform indusium. Reconstruction of ancestral character states suggests affinities of Holttumopteris to the Thelypteridaceae; however, several taxonomically relevant characters are not preserved. This discovery is nevertheless important because H. burmensis represents the first unequivocal fossil of a representative of the eupolypods from the middle Cretaceous.     

A new fossil record of Thyrsopteridaceae (Cyatheales) from the mid-Cretaceous amber of Myanmar

Paleopalynology evidence and megafossil records indicated that tree fern order Cyatheales, played an important role in Mesozoic terrestrial ecosystem. Few fossil records of the family Thyrsopteridaceae have been reported so far. In the present study, we describe a distinctive fertile pinnule segment of a fern plant preserved in a mid-Cretaceous amber from Myanmar. The well-preserved fertile pinnule is identified as a new species of the extant tree fern genus Thyrsopteris (Thyrsopteridaceae): Thyrsopteris cyathindusia n. sp. It represents the second fossil species of Thyrsopteridaceae found in the mid-Cretaceous amber from Myanmar. The new species shows distinctive characteristics of the sporophyll that are considered paleoecologically/paleobiogeographically significant for evolution of the Thyrsopteridaceae.     

Historical biogeography of the lineage Atopochara trivolvis PECK 1941 (Cretaceous Charophyta)

The evolutionary species Atopochara trivolvis represents a unique case of a charophyte with a well-documented, long-lasting fossil record of biostratigraphical interest and a worldwide distribution. This provides an excellent basis for analysing the historical biogeography of this important species. The origin of the lineage is recorded in the Early Berriasian of Western Europe, where an archipelago-like palaeogeography would have favoured allopatric speciation and small-sized original biogeographic ranges. The species first reached Eastern Europe during the Valanginian and expanded to China during the Hauterivian. It expanded worldwide during the Barremian–Aptian, first colonizing North Africa and South America through the Guinea Corridor and subsequently reaching North America. The Barremian–Aptian worldwide expansion was probably facilitated by the monoecious nature of A. trivolvis, which allowed for long-distance animal dispersal, as is the case with extant Chara. An initial fragmentation in the biogeographic range of A. trivolvis can be detected in the Albian–Cenomanian, when the species displayed up to 5 different morphotypes in scattered localities of Eurasia and North America. During the Turonian sea-level highstand A. trivolvis became extinct also from most of these localities, while, in the Latest Cretaceous plesiomorphic populations of A. trivolvis ulanensis survived in Mongolia and Northern China. The species became completely extinct near the K/T boundary.     

First record of the Late Cretaceous starfish Metopaster parkinsoni (Forbes, 1848) in Iran

A body fossil of the starfish Metopaster parkinsoni was collected from chalky rocks of the Coniacian – Santonian transition in the Abderaz Formation at the Padeha section, east of Mashhad (Kopet-Dagh, Iran). The species is common in the English Chalk and is well known from the Cenomanian to the Maastrichtian of Europe. The new Iranian occurrence of M. parkinsoni extends its geographical range of 700 km to the South and 2500 km to the East. The species proliferated in upper offshore environments of the North Tethyan continental shelves. The outstanding occurrence of many well-preserved specimens during the Coniacian – Santonian transition in Europe and Iran may be related to favorable taphonomic conditions driven by the Ocean Anoxic Event (OAE III).     

A new look at the Late Jurassic Canjuers conservation Lagerstätte (Tithonian,Var, France)

The Canjuers conservation Lagerstätte represents a Late Jurassic lagoonal environment. The sedimentology and stratigraphy of the locality show three different depositional sequences. Fossils are mainly found in the basalmost layers that correspond to the first phase of deposition in the lithographic limestones sensu stricto. The fossil biodiversity is rich. So far, more than 1000 specimens including 38 invertebrate and 18 vertebrate taxa have been recovered from the limestones. The depositional information suggests that most invertebrates and vertebrates were not autochthonous to the lagoon, but swept in during storm events from the open sea or nearby emerged reef environments.     

Dental remains of Lower Miocene small rodents from Napak (Uganda): Afrocricetodontidae,Myophiomyidae, Kenyamyidae and Sciuridae

The Early Miocene sites of Napak (Uganda), which have been prospected by the Uganda Palaeontology Expedition since 1985, have yielded abundant fossil remains, including a rich and diverse rodent fauna. Ever since the work of Lavocat (1973) on the East African Miocene rodents, which focused mainly on the Kenyan remains (but included some material from Napak discovered by Bishop during the 1950s and 1960s), few studies have been made on the Ugandan specimens. This lack provides motivation for further study of Napak micro-mammals, especially the abundant rodents, which were collected at five sites, Napak IV, V, XV, XXX and XXXI. The fossils described here are attributed to six species representing four families: Afrocricetodontidae (Afrocricetodon songhori, Protarsomys macinnesi), Myophiomyidae (Myophiomys arambourgi), Kenyamyidae (Simonimys genovefae, Kenyamys mariae) and Sciuridae (Vulcanisciurus africanus). Comparison of the dentition of extant and extinct taxa allows us to propose dietary hypotheses (granivory, herbivory and omnivory) for these rodents. In addition, the fossil rodents associated with other fauna from the same localities suggest a more-or-less dense forest environment with clearings, and the probable presence of a humid climate at the time of deposition.     

The rise to dominance of the angiosperm kingdom: dispersal,habitat widening and evolution during the Late Cretaceous of Europe

Coiffard, C. & Gomez, B. 2009: The rise to dominance of the angiosperm kingdom: dispersal, habitat widening and evolution during the Late Cretaceous of Europe. Lethaia, Vol. 43, pp. 164–169. The earliest fossil records of angiosperms in Europe occur in the Barremian and consist of freshwater wetland plants. From the Barremian onwards, angiosperms show a stepwise widening of their ecological range with the result that they inhabited most environments by the Cenomanian. Nevertheless, most angiosperms had still restricted habitats, while a few angiosperm trees were confined to disturbed environments, such as channel margins. A Wagner’s Parsimony Method analysis performed on a fossil plant and locality database from the Turonian to the Campanian of Europe indicates continued decrease in richness of ferns and gymnosperms compared with angiosperms, turnover between conifer and palm trees in freshwater‐related swamps at about the Cenomanian/Turonian boundary, and spreading of angiosperm trees through the floodplains. The ecological range of angiosperm trees was increased, being recorded in channel margins from the Cenomanian and spreading over floodplains (e.g. Platanaceae) and swamps (e.g. Arecaceae) by the Campanian. These new ecological ranges and successions went with innovative architectures, such as dicot trees and palm trees. Most living core angiosperm families had their earliest representatives in the Late Cretaceous, which should be considered as the dawn of modern angiosperm forests. □Core angiosperms, Europe, Late Cretaceous, palms, Wagner’s Parsimony Method.