Biostratigraphy of Lower Cretaceous microfossils from the Araripe basin, northeastern Brazil

A biostratigraphic study was carried out in the Lower Cretaceous Araripe basin, northeastern Brazil, allowing the recognition of several chronostratigraphic units: the Dom João (Jurassic?-Lower Cretaceous?), the Rio da Serra (Neocomian) and the Alagoas (Aptian/Albian) local stages. For the first time a large hiatus between the Rio da Serra and Alagoas local stages is carefully documented. The palynomorphs and the ostracode associations throughout the Jurassic?-Aptian/Albian sequence allow the interpretation of the paleoenvironmental evolution of the Araripe basin which otherwise confirms that a polycyclical sedimentation occurred in the basin, being one of the controlling factors on the distribution of ostracodes and palynomorphes.     

A pterosaurian notarium from the Lower Cretaceous of Brazil

A pterosaur vertebral column consisting of the last cervical vertebra, the first five dorsals fused to a notarium, and the following four dorsal vertebrae, is figured and described from the Aptian Santana Formation of the Chapada do Araripe in northeastern Brazil. The specimen is tentatively referred toSantanadactylus brasilensis de Buisonjé. It is the best preserved and most complete pterosaurian notarium known. Its functional significance is discussed.     

First Mesozoic Scutigeromorph Centipede, from the Lower Cretaceous of Brazil

The first Mesozoic scutigeromorph centipede (Myriapoda: Chilopoda), Fulmenocursor tenax gen. et sp. nov., is described from the Lower Cretaceous (Aptian) Crato Formation of north-east Brazil. Previously described fossil Scutigeromorpha are known from Dominican and Baltic amber, the Carboniferous (Westphalian D) Francis Creek Shale of Mazon Creek, Illinois, the Silurian and Devonian of Britain, and the Devonian of New York State.     

New triconodontids (Mammalia) from the Lower Cretaceous Shahai and Fuxin formations, northeastern China

The first triconodontids from Asia have been discovered from the Lower Cretaceous (Aptian to Albian) Shahai and Fuxin formations in Liaoning Province, northeastern China: Meiconodon lii gen. and sp. nov. and M. setoguchii gen. and sp. nov. M. lii is characterized by molariform teeth with a developed cusp d, an m3 with taller cusp a, an m4 with three primary cusps of subequal height, the posteriorly decreasing transverse width of the m4, and a considerably reduced m5. M. setoguchii is slightly larger than M. lii, and characterized by a sharp labial cingulum on the m4, and a less developed cusp d on the molariform teeth than M. lii. The extensive interlocking system between molariforms, posteriorly recumbent primary molariform cusps, and their great degree of asymmetry in occlusal view with rounded labial faces and more angulate lingual faces in lateral view, indicate that Meiconodon belongs to the triconodontid subfamily Alticonodontinae. These new taxa are the first record of Triconodontidae from Asia, and of Alticonodontinae outside North America, suggesting the occurrence of mammalian faunal exchange between North America and Asia during or before the Aptian-Albian.     

A whole-plant monocot from the Lower Cretaceous

The Yixian Formation (the Lower Cretaceous) of China is world famous for its fossils of early angiosperms. Despite their great diversity, few of these fossils are preserved as whole plants, making our understanding of early angiosperms incomplete. Here, we report a fossil angiosperm, Sinoherba ningchengensis n. gen. n. sp. (Sinoherbaceae n. fam.), from the Yixian Formation of China. The fossil is of a whole plant, including physically connected root with fibrous rootlets, a stem with branches and nodes, leaves with parallel-reticulate veins, and a panicle of female flowers with an ovary surrounded by perianth. Morphological and phylogenetic analyses reveal that Sinoherba is an herbaceous monocot. This fossil underscores the great diversity of angiosperms in the Lower Cretaceous Yixian Formation and an earlier, pre-Cretaceous origin of angiosperms.     

An epiphyllous fungus from the Lower Cretaceous

A fungus believed to be a member of the Microthyriales is described from the English Wealden. It occurs on the shoots of an undescribed conifer resembling Frenelopsis Schenk. From the structure of the thyrothecium and the presence of an epicuticular mycelium, the fungus is classified in the family Micropeltaceae, subfamily Stomiopeltoideae, and is described under the name Stomiopeltites cretacea gen. et sp. nov. It is the earliest fossil record of the Microthyriales.     

An epiphyllous fungus from the Lower Cretaceous

A fungus believed to be a member of the Microthyriales is described from the English Wealden. It occurs on the shoots of an undescribed conifer resembling Frenelopsis Schenk. From the structure of the thyrothecium and the presence of an epicuticular mycelium, the fungus is classified in the family Micropeltaceae, subfamily Stomiopeltoideae, and is described under the name Stomiopeltites cretacea gen. et sp. nov. It is the earliest fossil record of the Microthyriales.     

Potential oilseed crops from the semiarid region of northeastern Brazil

The caatinga semi-arid ecosystem of northeastern Brazil is characterized by a dry, spiny and predominantly deciduous shrub/forest vegetation, and many species there are potential sources of renewable resources for the oleochemical industry. The present research determined the oil content and fatty acid profiles of seeds from eight caatinga species. Seed oils were extracted in a Soxhlet system, and their fatty acid content identified by GC–MS. Oil content varied between 20.2% in Tabebuia impetiginosa (Mart.) Standl. (Bignoniaceae) and 46.4% in Barnebya harleyi (W.R. Anderson & B. Gates) Malpighiaceae. Anemopaegma laeve DC. (Bignoniaceae) had the highest oleic acid content (63.4%), while high levels of linoleic acid were found in Banisteriopsis pubipetala (Juss.) Cuatrec. (42.8%) and B. harleyi (31.9%) (both Malpighiaceae). Palmitic acid was the major fatty acid (50%) in Hippocratea volubilis (L.) (Celastraceae). High levels of linoleic and linolenic acids were found in Croton adamantinus Mull. Arg. (Euphorbiaceae), averaging 44.2% and 45.2% respectively. Gadoleic acid in was the most abundant fatty acid in the oil produced by Serjania lethalis A. St. Hill. (Sapindaceae), averaging 69.6%. B. pubipetala, B. harleyi, C. adamantinus, and H. volubilis were identified as promising species for cultivation.     

The gonorynchiform fish Dastilbe from the lower Cretaceous of Brazil

We examine the preservation, autecology and morphological variation for several characters of the Cretaceous gonorynchiform fish Dastilbe from the Lower Cretaceous of Brazil and Africa. More than 83 specimens were examined. We test species validity using characters of the caudal endoskeleton and meristic counts of fin-rays vs length. Evidence provided by fossilized soft tissues and slabs containing large individuals 'freeze framed' in the process of swallowing smaller prey meals, show that Dastilbe was predatory, at least as adults, as well as cannibalistic. Dastilbe was probably an anadromous fish tolerant of hypersalinity and in Araripe was subjected to frequent mass mortality events. Observations of the otic region indicate that the lagenar statolith is consistently larger than the saccular statolith, hence revealing a primitive actinopterygian condition. For the first time, a lagenar statolith from Dastilbe has been cleaved to expose putative annuli-like ridges. Our results clearly show that there is a wide degree of morphological plasticity of the endoskeleton coupled with wide meristic variation, and as such, overall length, fin-ray count and even absence or presence of caudal diastema are not suitable criteria for species recognition in Dastilbe . New specimens from the Crato Formation (Aptian) and statistical tests suggest rejection of all species of Dastilbe erected subsequent to Jordan (1910). All Brazilian specimens of Lower Cretaceous Dastilbe can be assigned to the single species D. crandalli Jordan. The African D. batai Gayet is also placed within D. crandalli     

Anatomical features of species of Cyperaceae from northeastern Brazil

Seventy-three species from 17 genera of Cyperaceae were studied with the aim of identifying and confirming those species with Kranz anatomy. Among the species studied, 36 exhibited Kranz anatomy; 37 did not. Of the four types of Kranz anatomy recognized in Cyperaceae, three were encountered: the chlorocyperoid type in the genera Cyperus, Kyllinga, Lipocarpha, Pycreus, and Remirea; the fimbristyloid type in Abildgaardia, Bulbostylis, and Fimbristylis; and the rhynchosporoid type in Rhynchospora. Non-Kranz anatomy was confirmed in species of the following genera: Becquerelia, Calyptrocarya, Cyperus, Diplacrum, Eleocharis, Fuirena, Hypolytrum, Pleurostachys, Rhynchospora, and Scleria. The anatomical data obtained corroborate earlier studies of species of Cyperaceae as to the presence of Kranz anatomy and the anatomical types in several species and the “Kranzkette” pattern in Cyperus ligularis and Cyperus pohlli.     

First record ofColoborhynchus (Pterosauria) from the Santana Formation (Lower Cretaceous) of the Chapada do Araripe, Brazil

The anterior tips of associated upper and lower jaws of a pterosaur from the Lower Cretaceous of Brazil are described and assigned to the taxonColoborhynchus in the family Ornithocheiridae. It is characterized by the shape and position of the sagittal crest on the upper and lower jaw, the arrangement and length of the teeth and the spoon-like lateral expansion of the anterior parts of the jaws. It closely resemblesColoborhynchus wadleighi from North America andColoborhynchus clavirostris from England. Diagnostic anatomical characteristics permit a revision of the genusTropeognathus, which is shown here to be a junior synonym of other described taxa.Tropeognathus mesembrinus is referred toCriorhynchus andT. robustus toColoboryhnchus. Consistent anatomical features enable the new jaw fragment to be assigned toColoborhynchus robustus.      

A clupeomorph fish from the Gault (Lower Cretaceous)

A primitive clupeomorph fish, Spratticepsgaultinus gen. et sp. nov., is described on the basis of incomplete braincases from the Gault (Albian) of Folkestone, Kent. This is the earliest clupeomorph in which any details of cranial structure are known. Spratticeps is more primitive than living clupeomorphs in having no recessus lateralis, auditory fenestra, pterotic bulla or sinus temporalis, and in having a heavily ornamented, entire skull roof, with the sensory canals bone enclosed and the post-temporal fossa roofed. The fish is too primitive to be placed in either suborder of Clupeomorpha, and is left incertae sedis. The primary characters of the Clupeomorpha are discussed.     

Orthid brachiopods from the Lower and Middle Devonian of northeastern Russia

Brachiopods of the order Orthida from the Lower and Middle Devonian of northeastern Russia: Skenidium diversus Baranov (family Skenidiidae); Datnia gen. nov., with the type species D. asiatica sp. nov. (subfamily Prokopiinae); Janzhinshinia gen. nov., with the type species J. datnensis sp. nov. (subfamily Isorthinae); Cortezorthis chobotchalensis (Alekseeva) (subfamily Cortezorthinae); Elenia gen. nov., with the type species E. gerensis sp. nov. (family Dicoelosiidae); Seimtchania communis (family Seimtchaniidae); Simakovia gen. nov., with the type species S. rara sp. nov. (family Draboviidae); Schizophoria distenta sp. nov., S. grande Baranov, S. striatula (Schlotheim) (family Schizophoriinae); and Hypsomionia sinsera Baranov (family Hypsomioniidae) are described.     

Asteroid and Ophiuroid Trace Fossils from the Lower Cretaceous of Chile

Abundant asterozoan trace fossils in the Lower Cretaceous Apeleg Formation of southern Chile were produced by the infilling of traces made by asteroids and ophiuroids on a muddy surface. Most are preserved as hypichnial ridges formed as casts on the bottom of fine-grained sandstone laminae. Star-shaped Asteriacites lumbricalis are interpreted as the infillings of shallow excavations made by asteroids. Hook-shaped and sinuous ridges of the newly defined ichnogenus and ichnospecies Ophioichnus aysenensis are interpreted as the casts of imprints made by the walking action of the arms of ophiuroids. Deposition probably took place in an offshore tide-swept marine shelf environment. In life the animals formed an assemblage equivalent to echinoderm aggregations on the modern sea floor.     

Ostracoda of the subfamilies Protocytherinae and Trachyleberidinae from the British Lower Cretaceous

The distribution and range of the members of these two subfamilies are given for material of Hauterivian, Barremian, Aptian and Albian age from the Speeton Clay in Yorkshire, England. Eleven species are described and figured of whichProtocythere gaultina, Protocythere intermedia, Protocythere mertensi, Protocythere speetonensis, Homocythere reticulata, Cythereis blanda andCythereis lamplughi are new. The genusHomocythere is described for the first time. An ontogenetic study ofProtocythere triplicata (F. A. Roemer) is undertaken.     

Double fossilization in eukaryotic microorganisms from Lower Cretaceous amber

Background  

Microfossils are not only useful for elucidating biological macro- and microevolution but also the biogeochemical history of our planet. Pyritization is the most important and extensive mode of preservation of animals and especially of plants. Entrapping in amber, a fossilized resin, is considered an alternative mode of biological preservation. For the first time, the internal organization of 114-million-year-old microfossils entrapped in Lower Cretaceous amber is described and analyzed, using adapted scanning electron microscopy in backscattered electron mode in association with energy dispersive X-ray spectroscopy microanalysis. Double fossilization of several protists included in diverse taxonomical groups and some vegetal debris is described and analyzed.     

Vertebral lesions in a titanosaurian dinosaur from the Lower-Upper Cretaceous of Brazil

In this paper we describe macroscopically two types of bone lesions on a caudal vertebra of an indeterminate titanosaur recovered from the Lower-Upper Cretaceous (Albian-Cenomanian) Açu Formation in the Potiguar Basin, Brazil. The first type of lesion corresponds to cystic lesions on cranial and caudal joint surfaces of the vertebral body, which are identified as subchondral cysts. The second type of lesion corresponds to an irregular bone overgrowth located on longitudinal ligament insertion points. This ossification can be associated with an axial spondyloarthropathy or diffuse idiopathic skeletal hyperostosis (DISH). Bone overgrowth on vertebrae is well documented in the dinosaur fossil record, whereas this is only the second case recorded of subchondral cysts.     

A new species of Sinningia (Gesneriaceae) from northeastern Brazil

Sinningia nordestina is described and illustrated. Morphological and molecular characters are discussed. It is a new species endemic to northeastern Brazil and is distinguished from other members of the genus by its vestigial tubers, ascending pedicels with pendent flowers, small corollas, and deviating flowering period.