首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A new genus and species of lungfish with toothplates, Adelargo schultzei, is described from the Hunter Siltstone (Devonian, Late Famennian) near Grenfell, New South Wales. Materials assigned to Adelargo schultzei gen. et sp. nov., include a portion of the left side of the skull comprising B, I (postparietal) and J (parietal) bones, pterygoid and prearticular toothplates, a parasphenoid with a long posterior stalk, vertebrae, ribs, anal fin supports and scales. Toothplates are similar to Dipterus, although morphology of the skull, parasphenoid and postcranial elements is more derived. Biogeographic relationships of the Grenfell fauna were based on the presence of the antiarch group Sinolepidoidei, also present on Asian terranes during the Late Devonian. A small number of lungfish scales have been described from Asian sinolepid localities of this age, but differ from those of Adelargo schultzei, and other faunal similarities between these areas appear limited. Paucity of eastern Australian Devonian taxa on the North and South China blocks implies that strong biogeographic relationships between eastern Australia and Euramerican localities during the Late Devonian were not the result of Asian migration routes, but the closer proximity of these areas.  相似文献   

2.
3.
Cavanosteus, a new genus of homostiid arthrodire, with C. australis (McCoy) as type species, is erected for new material from the Early Devonian (Emsian) of the Burrinjuck area, NSW. This new material compares closely with the holotype from Buchan, Victoria, identified as the central plates from the skull; it includes lower jawbones (infragnathals) lacking denticulation also closely similar to those of Homostius from the Middle Devonian of the Baltic Province and Scotland. The only bone from the dermal trunk armour referred to the new genus is an anterior dorsolateral plate. Relationships of other large Early Devonian arthrodires assigned to the family Homostiidae are discussed. Cavanosteus gen. nov. is probably the closest relative to the type genus known from the Early Devonian.  相似文献   

4.
O’Gorman, J.P. &; Gasparini, Z., 2013. Revision of Sulcusuchus erraini (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina. Alcheringa 37, 161–174. ISSN 0311-5518.

Sulcusuchus erraini, from the upper Campanian–lower Maastrichtian of Patagonia, Argentina, is the only polycotylid from the Southern Hemisphere for which the skull and mandible are known. The diagnosis of the species and genus is emended based on new observations. Sulcusuchus is characterized by the following autapomorphies: (1) deep and broad rostral and mandibular grooves and (2) a wide notch on the posterior margin of the pterygoids that are combined with a part of the body of the basioccipital, forming a wide plate. Several hypotheses about the identity of the structures that could have been housed in the rostral and mandibular grooves are evaluated. Only two of several hypotheses were not discarded. The first is that the grooves may have accommodated oral glands (supralabial and sublabial), but the biological role of such glands could not be inferred. The second hypothesis is the presence of special structures of an electrosensitive and/or mechanosensitive nature, which might allow the detection of infaunal or semi-infaunal food in soft substrates, as is represented in modern analogues, such as dolphins.

José P. O’Gorman [joseogorman@fcnym.unlp.edu.ar] and Zulma Gasparini [zgaspari@fcnym.unlp.edu.ar], División Paleontología Vertebrados, Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n., B1900FWA La Plata, Argentina. Also affiliated with Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917 (C1033AAJ), Ciudad Autónoma de Buenos Aires, Argentina and CONICET: Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina Received 5.6.2012; revised 31.7.2012; accepted 4.9.2012.  相似文献   

5.
6.
7.
A new genus and species of lightly sclerotized arthropod with an Aglaspis-like tagmosis, Kwanyinaspis maotianshanensis, is described from the well-known Chengjiang Lagerstätte, Early Cambrian, Yunnan, South China, on the basis of a single exquisitely preserved specimen. The dorsal exoskeleton, showing a poorly defined axial region but lacking axial furrows, is composed of a cephalic shield, 12 trunk tergites with well-developed pleural spines and a tail spine. A pair of ventral eyes is present beneath the first quarter of the cephalic shield. Appendages are preserved in remarkable detail; the basis is a large, flat plate, and bears gnathobases ventrally; the endopod is articulated with the abaxial edge of the basis and comprises seven articles; the exopod is flap-like and articulated along the entire length of the dorsal margin of the basis. Kwanyinaspis is provisionally assigned to Aglaspidida due to its overall resemblance to Aglaspis.  相似文献   

8.
LI, Y.J., HAN, G., NEL, A. REN, D., PANG, H. & LIU. X.L., September 2012. A new fossil petalurid dragonfly (Odonata: Petaluroidea: Aktassiidae) from the Cretaceous of China. Alcheringa 36, 321–324. ISSN 0311-5518.

The new petalurid species Pseudocymatophlebia boda is described from Lower Cretaceous strata of Inner Mongolia, China. It provides additional morphological characters for this genus, which has been previously recorded from the Lower Cretaceous of England. Together with Aktassia, it is the second aktassiid genus with a very wide distribution, even though this family remains known only from Eurasia. Furthermore, a new name, Brachaktassia gen. nov., is proposed to replace the brachiopod genus Aktassia Popov, 1976.  相似文献   

9.
An occluded skull and dentaries, recovered from the Floraville Local Fauna, northern Queensland, is referred to Euowenia robusta De Vis, 1891. The specimen has distinctive zygomaturine features including a quinquetubercular upper third premolar and lower molars with cristids obliqua, directly challenging the synonymy of E. robusta with Nototherium inerme and N. mitchelli proposed by Woods (1968 Woods, J. T. 1968. The identity of the extinct marsupial genus Nototherium Owen. Memoirs of the Queensland Museum, 15: 111116.  [Google Scholar]). Comparison with the genotypic Euowenia grata (De Vis, 1887) has further confirmed that E. robusta does not belong within the Diprotodontinae. After examining all named zygomaturine genera, including a large data set of Zygomaturus trilobus Macleay, 1858, it is concluded that Euowenia robusta can not be placed within any known zygomaturine genus and, therefore, a new genus is proposed. It is perhaps the most derived of all the zygomaturines described to date from the Australian Cenozoic.  相似文献   

10.
We redescribe and interpret the postcranial elements of Allalmeia atalaensis Rusconi, found in the Divisadero Largo Formation, Mendoza, Argentina. Allalmeia is one of the few basal notoungulates with preserved postcranial remains. Rusconi initially documented a skull, several vertebrae and part of the appendicular skeleton but these specimens were subsequently lost. Recently though, distal components of the holotype humeri, the proximal portion of the right femur, several broken diaphyses and most of the left and right pes (MCNAM-PV 507), were relocated. Preparation of this material has revealed new details, especially from the plantar side of the feet. The calcaneum has a distal peroneal process with marked rugosity in the lateral end, a well-developed calcaneal plantar tubercle and a large sustentaculum tali. The naviculars exhibit a well-developed medial tuberosity and slightly contact the calcaneum on the dorsal side, a condition called a ‘reverse alternating tarsus’. The disposition and morphology of the cuneiforms are similar to those of more recent typotheres and the archaic ungulate Tetraclaenodon puercensis. The phalangeal rows are oblique to each other, as in some extant digitigrade mammals. The ungual phalanges are claw-like suggesting that they might have borne claws. Long bones are gracile in comparison with other notoungulates, but with well-developed muscle origins and insertions. The use of body-mass allometric equations and a comparison with extant analogues suggests that Allalmeia was a small, generalized, digitigrade animal. An estimated body mass of approximately 3 kg is consistent with oldfieldthomasiids and archaic ungulates.  相似文献   

11.
Pole, M., December, 2008. The record of Araucariaceae macrofossils in New Zealand. Alcheringa 32, 405–426. ISSN 0311-5518.

The Araucariaceae have a long record in New Zealand, extending back to the Jurassic at least, and Araucaria extends back to at least the Late Cretaceous. This paper reviews the macrofossil record of the family and presents new information based largely on the leaf cuticle record. Agathis, which is the only genus of the family currently growing in New Zealand, has no record before the Cenozoic. All specimens previously identified from pre-Cenozoic strata clearly belong to other taxa or do not show characteristic features of the genus. Araucariaceae macrofossils are virtually ubiquitous in the Cretaceous assemblages of New Zealand but are conspicuous by their absence or rarity in Palaeocene deposits. Their demise may be an expression of events at the Cretaceous–Palaeogene boundary.  相似文献   

12.
SHI, C.F., WANG, Y.J., YANG, Q. & REN, D., September 2012. Chorilingia (Neuroptera: Grammolingiidae): a new genus of lacewings with four species from the Middle Jurassic of Inner Mongolia, China. Alcheringa 36, 311–320. ISSN 0311-5518.

A new grammolingiid genus, Chorilingia containing four new species (C. euryptera, C. parvica, C. translucida and C. peregrina) is described and illustrated from the Jiulongshan Formation at Daohugou, Inner Mongolia, China. The new genus is differentiated mainly on the first branch of vein Rs (Rs1) separating distal to the forks of both CuA and CuP. A key to species of the genus is provided.  相似文献   

13.
Ni Yunan & Cooper, R. A., 1994:03:28. The graptolite Glossograptus Emmons and its proximal structure. Alcheringa 18, 161–167. ISSN 0311-5518.

New specimens of Glossograptus acanthus from the Ningkuo Shale of China, preserved in relief, help to resolve the much debated problem of the structure of Glossograptus. A model for the proximal structure of the genus is proposed, based on the new material and on Finney's (1978) Athens Shale specimens. The model confirms that Glossograptus has homologous structure and development with Pseudisograptus, and isograptid development type is primitive for the group containing both genera. A cladogram is presented in which the suborder Glossograptina Jaanusson (with families Glossograptidae and Cryptograptidae) together with family Corynoididae Bulman are subsumed within a redefined family Glossograptidae.  相似文献   

14.
Trilobites are common faunal elements in the Melbourne Formation, a unit of early Ludlow (upper nilssoni Biozone) age, which crops out extensively in the Darraweit Guim Province of the Melbourne Zone, central Victoria. New diagnoses are given for species previously described, including Maurotarion euryceps (McCoy, 1876; = Cyphaspis spryi Gregory, 1901), Raphiophorus jikaensis (Chapman, 1912; = Ampyx yarraensis Chapman, 1912), Cromus simpliciculus (Talent, 1964), Cromus spryi (Chapman, 1912), Sthenarocalymene kilmorensis (Gill, 1945; = Gravicalymene hetera Gill, 1945) and Trimerus harrisoni (McCoy, 1876). A new phacopid genus, Orygmatos is described, represented by the species O. yanyeani gen. et sp. nov. Other species newly described include Cromus melbournensis sp. nov., Arcticalymene australis sp. nov., “Ananaspis” woiwurrungi sp. nov. and Kettneraspis hollowayi sp. nov.

Species composition of the trilobite fauna varies spatially, and a number of distinct assemblages can be defined. Abundant trilobite moult configurations are conclusive for interpretation of the benthic fauna as autochthonous, inferring depth estimations based on benthic community distribution to be valid. A depth-related succession of communities is recognised and indicate the Melbourne Formation was deposited at relatively shallow depths on a broad, eastwardly deepening shelf, with deposition dominated by storm processes. The palaeoenvironment comprised a BA-1 community including the Arcticalymene australis trilobite assemblage, restricted to very shallow depths (~20 m) on the SW coastal margin of the shelf and preserved in proximal tempestite lithologies; and a BA-5 community group containing three distinct trilobite assemblages dominated by species of Cromus and a deeper water fauna, preserved in distal tempestite lithologies and ranging widely over the shelf at depths in the range of maximum storm wave base (~50 – 80 m).  相似文献   

15.
Kemp, A., December 2017. Adaptations to life in freshwater for Mioceratodus gregoryi, a lungfish from Redbank Plains, an Eocene locality in southeast Queensland, Australia. Alcheringa 42, 306–311. ISSN 0311-5518

Few Cenozoic lungfish fossils consist of articulated, associated bones and tooth plates. Mioceratodus gregoryi from the Paleogene (Eocene) deposit of the Redbank Plains Formation in southeast Queensland is unusual in this respect because the fossil includes tooth plates and elements of the skull. An analysis of the material and reconstruction of the skull and associated skeletal material provides new insights into the fish and its environment. The fish has a mandible with a wide separation between the lower tooth-bearing bones, and a strong ceratohyal bone. This suggests that, like the extant Australian lungfish, Neoceratodus forsteri, the fossil fish had a moveable basihyal that could be inserted between the prearticular bones to seal the oral cavity. This would have allowed the fish to draw food, air and water into the mouth, and dig holes by sucking mud into the oral cavity and blowing it out again, all useful attributes for a fish that lived in a shallow freshwater lake. The living Australian lungfish has similar structures in the mandible and hyoid apparatus, and performs comparable actions. The occipital ribs, also preserved in the Redbank Plains fossil, are embedded in hypaxial muscles and not moveable. It is unlikely that these ribs have any influence on the suctorial process in these two species.

Anne Kemp [] Environmental Futures Centre, Griffith University, 170 Kessels Road, Nathan, Brisbane, Queensland 4111, Australia.  相似文献   


16.
A new monotypic genus of cheirurine trilobite, Azyptyx, is described based on the new species A. toongabbiensis from Early Devonian (late Lochkovian) limestones of the Wurutwun Formation near Toongabbie, Victoria. A feature of the genus that is unusual for the subfamily is a continuous basal glabellar furrow (S1) that does not normally meet the occipital furrow medially.  相似文献   

17.
The genus Umkomasia, a megasporophyll, belonging to the pteridosperms (seed ferns) in the family Umkomasiaceae (Corystospermaceae), is reassessed comprehensively worldwide. All previous records are analysed. Certain fertile structures previously attributed are reclassified. Umkomasia is shown to be restricted to the Triassic of Gondwana where it is associated with the genus Pteruchus, a microsporophyll, and the genus Dicroidium, a vegetative leaf. It is well represented from Argentina, Australia and southern Africa where the Molteno Formation is by far the most comprehensively sampled with eight species described. Two specimens from the upper Permian of India attributed to Umkomasia are reclassified as cf. Arberiopsis sp. A whorled fertile structure from Antarctica, previously assigned to Umkomasia, is reclassified in a new genus as Axsmithia uniramia. Another compression fossil and the permineralized Umkomasia resinosa remain as valid records from Antarctica. The material described as Umkomasia from the Triassic of China is reclassified as Stenorachis asiatica. The Lower Jurassic record from Germany is placed in a new genus as Kirchmuellia franconica. The records of Umkomasia sp. from the Rhaetic of Germany are reclassified as cf. Kirchmuellia sp. and the single specimen from the Jurassic of Libya as genus et sp. indet. The Lower Cretaceous record from Mongolia has been reclassified by other researchers as Doylea mongolica. A pictorial key to Umkomasia species is provided, geographic and stratigraphic distributions are tabulated.  相似文献   

18.
Three specimens of silicified wood, two transported and one probably in situ, have been found in association with Early Miocene basaltic lavas in the upper Lachlan valley, N.S.W. On the basis of their preserved structure, the three specimens have been identified as belonging to Nothofagus, Acacia, and the family Myrtaceae, respectively. The specimen of Nothofagus (one of the transported specimens) constitutes the first identification of a macrofossil of this genus from this interval in southeastern mainland Australia, while its conjunction with the myrtaceous specimens (one probably in situ) may indicate vegetation zonation according to elevation, as proposed on pollen evidence from Kiandra. Such zonation is not demanded by the upper Lachlan evidence, however, but if it is favoured, reconstruction of the Early Miocene geography of the upper Lachlan constrains the maximum elevation above the locality of the myrtaceous fossils to be 350 m.  相似文献   

19.
The Jurassic dinoflagellate cyst genus Belowia Riding & Helby, 2001 is a junior homonym of Belowia Moquin-Tandon, 1849, a genus of the Chenopodiaceae. The new generic name Belowicysta is proposed here to replace Belowia Riding & Helby, 2001.  相似文献   

20.
I review the taxonomic history of two problematic mosasaur species, Clidastes liodontus and Clidastes moorevillensis. The genus Clidastes is thought to represent an early radiation of a diverse clade known as the Mosasaurinae. However, most phylogenetic analyses recover the genus as paraphyletic with respect to more highly nested mosasaurines such as Mosasaurus, Prognathodon, and Globidens. The fragmentary holotype of Clidastes liodontus was never figured or fully described, and was destroyed in World War II. Over 20 years after destruction of the holotype, relatively complete specimens were referred to Clidastes liodontus based upon a single, variable character. Another taxon, originally designated Clidastes liodontus moorevillensis in a master’s thesis and then elevated to Clidastes moorevillensis in a separate dissertation, has never been formally described and lacks definitive diagnostic characters that differentiate it from the contemporary concept of Clidastes liodontus. Clidastes provides an excellent example of how historical inertia in taxonomic nomenclature can build over decades and skew our interpretations of the diversity, paleobiology, biogeography, and biostratigraphy of a taxon. Clidastes liodontus is a nomen dubium and Clidastes moorevillensis a nomen nudum. I recommend that both names be abandoned. Removal of those names frees us from a burdensome taxonomy and eliminates cognitive biases that hinder objective understanding and exploration of early-diverging mosasaurines, and is a necessary first step toward a taxonomic revision of the lineage(s) involved.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号