The palaeobiology of the Malay Archipelago region remains poorly documented, despite its present-day significance as a modern global marine biodiversity hotspot. The Togopi Formation of the Dent Peninsula, situated in Borneo on the western Sulu Sea and eastern coast of Sabah, Malaysia, preserves Plio-Pleistocene sedimentary sequences interpreted to represent localized transgressive episodes, and which have a relatively high coral diversity. Fossil corals were sampled from three available quarries on the Dent Peninsula, the sediments of which have been previously dated as 4.5–3.4?Ma in age based on foraminiferal data and radiometric analyses. These Pliocene corals are identified here based on their macromorphology, micromorphology and microstructural characteristics. In total, this study describes 28 fossil coral taxa, with 16 genera recognized and 22 taxa identified to species level, 21 of which can be confidently assigned to extant species. These new data have resulted in revised stratigraphic ranges for eight of these species. As the most comprehensive systematic survey of corals from the Pliocene of the Indo-Pacific to date, this study indicates a high diversity of corals on the margin of the Sabah Sea, Borneo, at this time, including taxa found today, thus casting doubt on the local impact of the Plio-Pleistocene extinction previously reported from faunal analyses of the central Indo-Pacific.
Jasmin V.M. Saw [varnmay@yahoo.
Mourasuchus is one of the most peculiar crocodylians of all time, showing an unusual ‘duck-faced’ rostrum with thin, gracile mandibles. It includes four species restricted to the South American Miocene. Here, we describe ten late Miocene specimens of Mourasuchus, nine from the Solimões Formation of Brazil and one from Bolivia. All specimens are assigned to M. arendsi, but this assignment may change as the diversity and relationships within Mourasuchus are better understood. We also discuss several issues pertinent to the morphology of Mourasuchus: the presence of a braincase neomorph (the laterocaudal bridge), hypotheses about sexual dimorphism, the function of the squamosal ‘horns’ the presence of possible thermoregulatory functions in the genus. Additionally, the paleogeographic distribution of Mourasuchus in the Miocene of South America is also discussed.
Giovanne M. Cidade* [giovannecidade@hotmail.
Ana Andruchow-Colombo [aandruchow@mef.
The original holotype and paratypes of the stylophoran mitrate Placocystella langei (Echinodermata) are definitively lost. A neotype is designated here, based on new material collected in the marine Devonian strata of the Apucarana Sub-basin, Paraná, Brazil. Placocystella langei was the first species of Stylophora to be identified in Devonian basins from Brazil. Its range extends from the late Emsian to early Givetian. Taphonomic data indicate that P. langei specimens were preserved in a storm-influenced, transitional offshore environment, and that skeletal remains were few exposed at the water–sediment surface. Considering that the specimens do not exhibit evidence of reworking, it is possible that their final burial was rapid and definitive, which facilitated their almost complete preservation. Finally, taphonomic, diagenetic and sedimentologic data all suggest a shallow infaunal habit for Placocystella langei.
Sandro Marcelo Scheffler [schefflersm@mn.
A number of hyolith fragments (including one operculum), found in Early Devonian marine turbidites at Mt Pleasant, near Alexandra, central Victoria, are described as Costulatotheca schleigeri gen. et sp. nov., the first confirmed record of the order Orthothecida in the Devonian of Australia. Index fossils found at this locality (Uncinatograptus sp. cf. U. thomasi and Nowakia sp. ex gr. N. acuaria) indicate an age of Pragian or earliest Emsian. The taphonomy of rare rafted shelly fossils indicates that flysch deposition occurred in a very-low-energy environment into which there were occasional bursts of high-energy turbidites carrying allochthonous fossils from shallower water.
Clement Earp [omaiosys@yahoo.
Extensive bulk sampling over the past 20 years and greatly improved stratigraphic control permitted a meaningful revision of previously described anacoracid sharks from the ‘upper’ Gearle Siltstone and lower Haycock Marl in the lower Murchison River area, Western Australia. Isolated teeth of anacoracids are rare in the lower three (Beds 1–3) of four stratigraphic units of the ‘upper’ Gearle Siltstone but relatively common in the uppermost layer (Bed 4) and in the lower part of the overlying Haycock Marl. On the basis of calcareous nannofossils, Beds 1 and 2 of the ‘upper’ Gearle Siltstone can be placed in the uppermost upper Albian calcareous nannofossil Subzone CC9b whereas Bed 3 can be referred to the lowermost Cenomanian CC9c Subzone. Bed 1 yielded fragments of strongly serrated anacoracid teeth as well as a single, smooth-edged tooth. The samples from Beds 2 and 3 contained a few small fragments of serrated anacoracid teeth. Bed 4 is barren of calcareous nannofossils but the presence of a dentally advanced tooth of the cosmopolitan lamniform genus Cretoxyrhina in combination with the age of the overlying Haycock Marl indicate deposition within the younger half of the Cenomanian. The unit produced teeth of two anacoracids; Squalicorax acutus sp. nov. and S. bazzii sp. nov. The basal, laminated part of the Haycock Marl is placed in the uppermost upper Cenomanian part of CC10b. It yielded Squalicorax mutabilis sp. nov. and S. aff. S. bernardezi. Exceptionally well-preserved teeth of the former species span a 5:1 size ratio range for teeth of comparable jaw position. The teeth reveal strong ontogenetic heterodonty with a large increase in the relative size of the main cusp with age and the transition from a vertical distal heel of the crown in very young juveniles to a sub-horizontal, well demarcated heel in ‘adult’ teeth. An isolated phosphatic lens in the lower part of the Haycock Marl produced calcareous nannofossils indicative of the CC10b SubZone, most likely the lowermost lower Turonian part. It contains teeth of Squalicorax mutabilis sp. nov., S. aff. S. bernardezi, and S. sp. C.
Mikael Siversson* [mikael.
http://zoobank.org/urn:lsid:zoobank.org:pub:97D5131F-C0D5-4A7E-9C9A-0FDF13BFCBBB
http://zoobank.org/urn:lsid:zoobank.org:act:5977DCC2-355C-4732-8B0A-4BD0EABBA8DE
http://zoobank.org/urn:lsid:zoobank.org:act:2D7C4147-B756-4434-847A-B0C1C6D167DF
http://zoobank.org/urn:lsid:zoobank.org:act:33F3B55E-41E0-45B3-8296-A3B95C17B41D 相似文献
Enigmaptera magnifica gen. et sp. nov., type genus and species of the new odonatopteran family Enigmapteridae, is described from the Moscovian of Avion (northern France). It is the sister group of the major clade Neodonatoptera, placed together in the new clade Paneodonatoptera. Its wing venation has characters never found in other Odonatoptera. It is a further case of convergent wing petiolation in this superorder. Enigmaptera magnifica, like the protozygopteran Jacquesoudardia magnifica from the same outcrop, probably lived like the extant damselflies along the shores of lakes and rivers, hunting the small insects found in the same deposits. These discoveries show that very small insects were significant elements of the entomofaunal diversity and trophic chains of the Late Carboniferous ecosystems.
Romain Garrouste [garroust@mnhn.
Newly identified hyoliths from early Cambrian ‘Small Shelly Fossil’ assemblages in New York State and Quebec extend the geographical ranges of hyolith taxa, otherwise known only from Baltica and Siberia, into eastern Laurentian North America, and in some cases, are accompanied by significant stratigraphical range extensions. The newly recognized taxa from this region include the hyolithids Hexitheca washingtonensis sp. nov., Aimitus sp., A. sp. cf. A. communis, Anabaricornus sp., Similotheca americana, Grantitheca glenisteri, and the orthothecids Decoritheca sp., Contitheca sp., two species of Holmitheca, and two hyolith species that can not be confidently assigned to an order at this time. Early Cambrian limestone clasts within the Lower Ordovician of Quebec have produced the hyolithids Similotheca americana and Nevadotheca princeps. The occurrences of Aimitus, Anabaricornus, and Holmitheca provide a palaeobiogeographical link with hyolith assemblages in Siberia, and Hexitheca to Baltica. Contitheca not only is known from these areas, but also has been found in west Laurentia, Morocco, Korea and Antarctica. A review of previously named species demonstrates that none of their type materials can be confidently referred to genus or species level because of poor preservation.
John M. Malinky [jmalinky@sbcglobal.
Fossil Arachnida from New Zealand are extremely rare and represented by some unidentifiable amber inclusions only. The first fossil arachnids from New Zealand to be described in detail are presented here, based on four compression fossils from the earliest Miocene Fossil-Lagerstätte at Foulden Maar, South Island. Two specimens are referred to Arachnida incertae sedis and Araneomorpha incertae sedis, respectively, whereas two specimens are mygalomorph spiders. One of these is placed in the Rastelloidina clade of Mygalomorphae, probably in the Idiopidae, which is represented in New Zealand by the extant Cantuaria.
P.A. Selden* [selden@ku.
A new fossil genus with three species of Sinoalidae, Parasinoala daohugouensis gen. et sp. nov., Parasinoala minuta gen. et sp. nov., Parasinoala magnus gen. et sp. nov., from the Middle to Upper Jurassic Haifanggou Formation at Daohugou, Inner Mongolia, northeastern China, is described and illustrated. The new genus differs from other sinoalids by the tegmen with RA having 2–3 branches, MP with 3–4 branches and MP of hind wings with two branches, which indicates the terminal branches of RA and MP are highly variable within Sinoalidae. The new discovery greatly increases the palaeodiversity of sinoalids in the early assemblage of the Yanliao biota from the Daohugou beds.
Yanzhe Fu [yzfu@nigpas.
Dragonflies (odonatans) are comparatively rare as amber inclusions, and most are not well preserved on account of their size. Here, we report a single piece of Mexican amber with one complete dragonfly and two damselflies. The dragonfly is attributed to the extant gomphid Erpetogomphus Selys Longchamps, and the damselflies belong to the extant coenagrionid Argia Rambur. Both genera are nowadays distributed widely in Mexico. The new discovery dates the origins of these two genera to the Miocene at least.
Daran Zheng [dranzheng@gmail.
A comparison of 29 identifiable vascular plant species in litter beneath Eucalyptus woodland with at least 74 species living nearby showed that the litter is a poor representation of standing vegetation. The leaf litter is dominated by sclerophyll leaves, which are a factor of 6.2 over-represented in litter for Angophora costata, factor of 5.7 for Melaleuca linariifolia, of 3.6 for Eucalyptus spp., of 3.5 for Pteridium esculentum and of 2.1 for Acacia linifolia. Angophora leaves are favored by lignification, with denser venation than Eucalyptus leaves. Sparse emergent oil glands of Angophora also provide fewer entry points for bacteria than rotted internal oil glands of Eucalyptus. The myrtaceous taxa Angophora, Eucalyptus, Melaleuca and Kunzea all have oils dominantly of preservative terpene. Melaleuca linariifolia and Acacia linifolia also have leaves and phyllodes (respectively) that are narrow with a thick lignin midrib. Thickly cuticled, succulent, hirsute, pubescent, and pinnate leaves, and green stems are not favored for preservation, because they rot from the inside out. Conspicuously absent in the leaf litter are nonsclerophyll leaves, most grasses and low herbs. This modern sclerophyll leaf litter matches Sydney Basin Permian and Triassic fossil plant localities above nutrient-poor siliceous paleosols, which may have had much more diversity than the preserved fossil flora. Clayey calcareous paleosol leaf litters and lake deposits may record a truer record of local floristic diversity in deep time than sclerophyll leaf litters.
Gregory J. Retallack [gregr@uoregon.
A new grylloblattid (Permoshurabia argentina sp. nov.: Geinitziidae) is described and illustrated from the Upper Triassic of Argentina. The material represents the first record of this family from Argentina and expands the geographic distribution of this group during the Triassic.
María Belén Lara [lara.
An isolated turtle xiphiplastron similar to that of Puppigerus sp. is described from the upper Oligocene (27.3–25.2 Ma) Pomahaka Formation near Tapanui, Otago, New Zealand. The bone is unlike any previously described turtle from the Cenozoic of New Zealand and is from a newly recognized estuarine vertebrate locality. It represents the first Oligocene cheloniid turtle bone described from the southwest Pacific.
Henry J. L. Gard [henrygard@hotmail.
Howchinia Cushman is a useful biostratigraphic marker for Mississippian rocks. In South China, Howchinia has been reported from four sections: the Bei’an, Baping, Naqing and Yashui sections; with high species diversity in the Bei’an section. Ten species from the Mississippian Bei’an Formation in the Bei’an section are described in this paper: Howchinia bradyana, H. beleutensis, H. gibba, H. plana, H. convexa, H. subconica, H. subplana, Howchinia sp. A, Howchinia sp. B. and Howchinia beianensis sp. nov. Howchinia ranges from late Visean to early Bashkirian in South China. Howchinia species inhabited both shallow-water and relatively deep-water environments.
Yang Shen [shenybj@126.
The ‘tuning-fork’ didymograptid previously referred to as Didymograpt(ell)us protobifidus is common in Victoria where it is confined to the Chewtonian (mid-Floian). Biometric differences indicate that the mid-Floian form is not conspecific with the holotype of the Darriwilian Didymograptus protobifidus Elles, 1933 and the Floian form is thus renamed Didymograptellus kremastus n. sp. Study of the Valhallfonna Formation faunas on Spitsbergen indicated that the Floian form of D. ‘protobifidus’ differs from Didymograptellus bifidus (Hall) in both its morphology and stratigraphic distribution but a later study of the Cow Head Group on Newfoundland concluded that they are one species. My study, of more than 50 specimens of Didymograptellus from the Floian of Victoria, Australia, shows that the two are different and that similar differences exist in the Cow Head Group populations of Didymograptellus. The Chewtonian (Ch1) Didymograptellus protobifidus Biozone is renamed D. kremastus Biozone.
Alfons H.M. Vandenberg, [lanceolatus@hotmail.
Numerous small specimens of hypercalcified sponges of the genus Plectroninia (Jurassic to Recent) are recorded from deep water in the Atlantic, Indian and Pacific oceans, where they are attached to diverse hard substrata, mostly scleractinian skeletons. Being represented as skeletons of linked calcareous tetractines with an incomplete free spicule complement, the specimens could not be identified at the species level. These observations show that Plectroninia spp. have a wide distribution in the bathyal zone of the Recent World Ocean, where they may be the most common calcareous sponges.
Jean Vacelet* [jean.
A new dasyuromorphian, Barinya kutjamarpensis sp. nov., is described on the basis of a partial dentary recovered from the Miocene Wipajiri Formation of northern South Australia. Although about the same size as the only other species of this genus, B. wangala from the Miocene faunal assemblages of the Riversleigh World Heritage Area, northwestern Queensland, it has significant differences in morphology including a very reduced talonid on M4 and proportionately wider molars. Based on the structural differences and the more extensive wear on its teeth, the central Australian species might have consumed harder or more abrasive prey in a more silt-rich environment than its congener, which hunted in the wet early to middle Miocene forests of Riversleigh.
Pippa Binfield [pippa.