Since the late 1990s, eight localities in volcanic shale-rich lacustrine deposits of Middle Jurassic through Early Cretaceous age in northern China (western Liaoning Province, northern Hebei ...Province, and southern Inner Mongolia) have yielded thousands of exceptionally well-preserved salamander specimens. With 10 species published and several new taxa yet to be named and described, the fossil samples from northern China represent the most species-diverse, individually abundant, and exquisitely preserved salamander fossil assemblage known from the Mesozoic Era. The stratigraphic range of the fossil record covers a geologic time span of roughly 40-45 million years from the Middle Jurassic (Bathonian) through the Early Cretaceous (Aptian). In contrast to the well-known stem-group salamanders Karaurus and Kokartus from the Middle to Late Jurassic of Middle Asia, the Chinese record contains the earliest known crown-group salamanders, including Jurassic representatives of both Cryptobranchoidea and Salamandroidea. The Chinese Mesozoic record includes numerous examples of virtually complete larval, juvenile, young adult, and fully grown adult individuals that collectively provide key information on the life histories and developmental patterns of the earliest known crown-group salamanders. Many specimens show preservation of soft tissue structures, including body outline, eye, liver, and external gill filaments. This kind of soft tissue preservation is unusual for fossil salamanders, so the Chinese Mesozoic specimens are important for furnishing otherwise unavailable information on the life history, diversity, and ecological adaptations of early crown-group salamanders.
Two Jurassic-Cretaceous anurans are described based on well-preserved specimens from the lower part of the Yixian Formation, western Liaoning Province, northeastern China. One specimen, from the ...Heitizigou site, documents a new genus and species, and the second, from the Sihetun site, is the holotype and only known specimen for the recently named Callobatrachus sanyanensis. Phylogenetic relationships of the major archaeobatrachian anuran clades are investigated with incorporation into the analysis of selected (well-established) early fossil taxa. The new taxon named and described in this paper is placed as the representative of a distinct archaic anuran clade, and Callobatrachus is considered to be an ingroup member of the Discoglossidae, constituting the earliest record of the family from Asia. The oldest known fossil anuran, Prosalirus from the Early Jurassic of Arizona, is grouped with Notobatrachus as sister taxa, and the two together form the most basal clade of Anura. Contradicting the widely accepted Leiopelmatidae-Discoglossidae sistergroup relationship, new evidence places the Leiopelmatidae as the most basal extant familial group and the sister group to other archaeobatrachian clades. The relationships and classification of the major archaic anuran clades are discussed, based on the phylogenetic results of this study.
To investigate whether there are aberrant acetylation modifications in global histone and monocyte chemoattractant protein-1 (MCP-1) promoter in monocytes from patients with coronary artery disease ...(CAD) and demonstrate the potential mechanisms.
CD14+ monocytes were isolated from 13 patients with CAD and 18 confirmed non-CAD controls using magnetic beads. Global histone H3/H4 acetylation and H3K4/H3K27 tri-methylation levels were measured with enzyme-linked immunosorbent assay. Quantitative real time-PCR was performed to detect the mRNA expression levels of MCP-1 and enzymes involved in histone modification processes. Histone modification levels in MCP-1 promoter were assessed by ChIP-qPCR assay.
Our results showed a markedly lower global histone H3 acetylation level in monocytes from CAD patients. Global H3K27 tri-methylation level was significantly increased in monocytes from CAD patients. Furthermore, the mRNA expression levels of epigenetic modification enzymes HDAC3, SIRT1, P300, JMJD3 and SUV39H1 were decreased significantly in monocytes from CAD patients, while HDAC7 mRNA expression level was markedly increased. MCP-1 mRNA expression level was increased histone H3/H4 acetylation levels in MCP-1 promoter were markedly increased in monocytes of CAD patients.
Aberrant histone modifications, including acetylation and tri-methylation, were found both in global histone and specific MCP-1 gene locos in monocytes from patients with CAD. Aberrant epigenetic modification enzymes expressions may be the regulatory mechanism responsible for aberrant histone modifications.
The discovery of a new specimen of
Monjurosuchus splendens, a taxon that has remained a taxonomic conundrum since the 1940s, from the Lower Cretaceous Yixian Formation in western Liaoning, has ...allowed a new and accurate interpretation of the skull roof. Comparison of the new fossil with several specimens of the same taxon from the type Lingyuan area clarifies several anatomical ambiguities, thus providing valuable information for assessment of the phylogenetic relationships within the Choristodera of this problematic taxon.
Monjurosuchus and its sister taxon
Philydrosaurus are the two known genera in the Monjurosuchidae, and the latter family occupies a basal position outside the Neochoristodera. Determination of the relationship of the Monjurosuchidae with another basal clade, the Hyphalosauridae, requires a better understanding of the cranial morphology of the latter group, and an extensive survey of character distribution among all other choristoderan clades.
We report here the first unequivocal record of a pre-Late Pleistocene lizard from the island of Madagascar, based on a nearly complete lower jaw, elements of both the pectoral and pelvic girdles, ...several vertebrae and ribs, and numerous osteoderms of what is presumed to be a single individual. The specimen, recovered from the Upper Cretaceous (Maastrichtian) Anembalemba Member, Maevarano Formation, Mahajanga Basin, northwestern Madagascar, is identified as a scincoid scincomorph and, more specifically, a new genus and species of ?Cordylidae (Cordyliformes), based on a combination of gnathic, dental, and postcranial characters. The new taxon is the first identifiable lizard from the Late Cretaceous of the African continent (sensu lato). If the new taxon is correctly attributed to the Cordylidae, it constitutes a significant temporal and geographic range extension for the clade since cordylids have no definite representatives in the fossil record and extant forms are restricted to the sub-Saharan portion of mainland Africa. This new record also indicates that cordylids, after their occurrence in the Maastrichtian, became extinct on Madagascar, leaving only zonosaurine Gerrhosauridae as extant representatives of Cordyliformes on the island. Owing to limited knowledge concerning the time of divergence for cordylids and gerrhosaurids relative to the tectonic separation of Africa and Madagascar, and in light of the paucity of Mesozoic lizard fossils in general, and from Gondwana in particular, the discovery of the new taxon in the Late Cretaceous of Madagascar does little to otherwise constrain scenarios concerning the biogeographic history of early cordyliforms. Finally, we document here the observation that lizards appear to have been much less speciose than snakes in Late Cretaceous faunas of Gondwana, whereas the reverse is true in Laurasia. Lizards do not appear to become common in Gondwana until the Early Tertiary.
Based on a nearly complete skeleton, an archaic frog is described from the Early Cretaceous Yixian Formation near Yixian, western Liaoning Province, China. The new frog shows several peculiar ...morphologies including the presence of a co-ossified parahyoid bone with a V-shaped configuration. Such a parahyoid was previously known only for the problematic taxon
Neusibatrachus from the Lower Cretaceous of Spain. A phylogenetic analysis was performed with the inclusion of the new taxon and
Neusibatrachus. This analysis suggests that the new taxon is a primitive archaeobatrachian closely related to
Notobatrachus and
Vieraella, while
Neusibatrachus is placed as a basal member of the Pipoidea. The suggested relationships of the new frog with South American forms reveal a biogeographic enigma that cannot be resolved until there is more fossil evidence and current phylogenetic hypotheses are further evaluated.
The remains of a choristodere recently discovered at Two Volcanoes, a new locality in the Gobi Desert of Mongolia, are described in this paper. Consisting of a fairly complete skull and partial ...postcranial skeleton, this specimen represents a new species of the genus Tchoiria. The new species differs from Tchoiria namsarai in having a much smaller number of teeth. Several elements preserved in this specimen are unknown in T. namsarai and thus provide new information about the genus. Phylogenetic analysis with the addition of data from the new specimen confirms the basal position of Tchoiria in Simoedosauridae.
A new trirachodontid eucynodont, Beishanodon youngi, is named and described based on a well-preserved skull from Triassic lacustrine deposits exposed in the Beishan Hills, northern Gansu Province, ...China. The new discovery documents the second record of trirachodontid eucynodonts known from China, along with Sinognathus gracilis from the Middle Triassic Ermaying Formation exposed in Shanxi Province. Cladistic analysis supports the placement of the new taxon as the sister group of Sinognathus, and the two together can be classified in Sinognathinae, a new subfamily differentiated from other trirachodontids by possession of several derived character states, including extremely short snout and strongly expanded temporal region. In addition, the stratigraphic and biogeographic significance of the new discovery are discussed. Because trirachodontids have a restricted stratigraphic range in the Triassic, as best documented by the Cynognathus Assemblage Zone of South Africa, discovery of the new fossil of this group from northern Gansu Province in China provides definitive evidence for a Triassic age of the fossil-bearing beds exposed in the Beishan Hills; moreover, the fossil beds are assessed as Early Triassic in age based on the evidence from the entire vertebrate fauna.
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