Fossil Record最新文献

Globacrochordiceras transpacificum gen. et sp. nov. is an ammonoid (Ammonoidea, Cephalopoda) with a shell characterized by plicate ribbing (rounded and undulating ribs strengthening on the venter without interruption), increasing involution through ontogeny, overhanging and deep umbilical wall, absence of tuberculation, subtriangular whorl section, globose adult shape with a closed umbilicus followed by an abrupt egressive coiling, and a subammonitic adult suture line. This new taxon occurs in Nevada (USA) and in Guangxi (South China). It has its typical occurrence within the Neopopanoceras haugi Zone of late Spathian age (Early Triassic). The plicate ribbing, suture line and general shell shape are diagnostic of the family Acrochordiceratidae. The large adult size, high degree of involution and subammonitic suture line of Globacrochordiceras markedly contrast with the next younger genus of the family (Paracrochordiceras of early Anisian age, Middle Triassic), which is evolute and displays a ceratitic suture shape. Shell coiling and suture line of Globacrochordiceras are closer to that of the youngest member of the family: Acrochordiceras carolinae (late middle Anisian). The latter is the end-member of a long-term morphological evolutionary trend of the family during the early and middle Anisian. This trend composed of classical increases in adult size (Cope's rule), shell involution and suture indentation, lasted ca. four Myr. The sudden morphological evolutionary jump between Globacrochordiceras and Paracrochordiceras at the Spathian/Anisian (Early/Middle Triassic) boundary may correspond to a generalized morphological reset of long-term trends, a process that differs from classic paedomorphic transformations. A dramatic global sea level change and carbon isotope positive excursion at the Early/Middle Triassic boundary both indicate stressful environmental changes that may have triggered this evolutionary jump. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The fourth complete skull of the marine crocodilian Machimosaurus von Meyer, 1837 is hereby described together with an associated complete mandible and disarticulated postcranial elements from the Kimmeridgian of Neuffen, Germany. Although the genus has been described fairly recently on the basis of two nearly complete skulls, their state of preservation did not allow a thorough examination of the entire skull anatomy. Here, we add new information with the description of nicely preserved cranial and mandibular elements of a single individual attributable to Machimosaurus hugii von Meyer, 1837. The diagnosis is updated for the genus and for the species M. hugii and challenges the validity of the second species M. mosae (Liénard, 1876). Moreover, previous assumption that Steneosaurus obtusidens Andrews, 1913 is a junior synonym of Machimosaurus hugii is not supported by our observations. Notably, M. hugii differs from S. obtusidens by a lower tooth count, the morphology of the dentition, the shape of the supratemporal fenestrae and the absence of an antorbital fenestra. Comparative anatomy and a phylogenetic analysis show that Machimosaurus is more closely related to the genus Steneosaurus than to Teleosaurus cadomensis (Lamouroux, 1820). (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Three new species and two new genera are described within the wasp family Ichneumonidae from Late Cretaceous (Campanian) amber collected at the Grassy Lake locality in Alberta, Canada. New taxa include Pareubaeus rasnitsyni n. gen. et sp. and P. incertus n. sp. within the subfamily Labenopimplinae, and Albertocryptus dossenus n. gen. et sp. within the subfamily Labeninae. The presence of a labenopimpline genus closely related to Eubaeus Townes within Canadian amber further supports faunal similarity between the Canadian assemblage and that recovered from Siberian amber. The records of Labeninae are the first from Mesozoic amber, and demonstrate that the subfamily was present in the Northern Hemisphere in the Late Cretaceous, as opposed to their modern, predominantly austral distribution. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Three new species, Grammolingia uniserialis n. sp., Grammolingia binervis n. sp., and Grammolingia sticta n. sp. are described from the Jiulongshan Formation of northeastern China. G. uniserialis n. sp. exhibits a single row of cells in the costal area almost along the entire wing length except the basal part, which is rare in the family and firstly found in this genus. G. binervis n. sp. and G. sticta n. sp. add two new patterns of wing markings to the family. A key to the species of Grammolingia Ren, 2002 is provided. All types of wing markings present in this family are classified. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A new trigonotarbid (Arachnida: Trigonotarbida) is described as Permotarbus schuberti n. gen., n. sp. from the Early Permian Petrified Forest (Rotliegend) of Chemnitz in Saxony (Germany). At ca. 290 Ma it represents the youngest record of this extinct arachnid order discovered to date. Its familial affinities are uncertain, but may lie close to the Aphantomartidae. The distribution of the trigonotarbid genera through time is summarised, together with a list of their seventy-seven fossil-yielding localities. Together they offer a broad overview of the group's fossil record, which is heavily biased towards the Moscovian Stage (ca. 307–312 Ma) of the Late Carboniferous in Europe and North America. This is due in no small part to numerous localities associated with coal mining districts, and trigonotarbids are found less frequently after this stage. While it is tempting to associate this with biological events – such as a putative ‘Carboniferous Rainforest Collapse' dating to ca. 305 Ma – it is difficult to differentiate the effects of genuine extinction patterns from artefacts caused by fewer appropriate localities in the economically less relevant latest Carboniferous and Early Permian strata. Nevertheless, trigonotarbids became extinct at some point after the Early Permian and loss of the Coal Measures forests remains one of the most likely possible causes. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)