Ordovician Of China Research Articles

The oldest iocrinid crinoids from the Early/Middle Ordovician of China: Possible paleogeographic implications

This study reports new crinoid material, which is identified as Muicrinus dawanensis new genus and new species from South China, representing the oldest known iocrinid in the world. These new fossils, which are characterized by bearing simple primibrachials and a helically coiled column, are from the lower-middle part of the Dawan Formation, which ranges from the upper Floian (Lower Ordovician) to the lower Dapingian (Middle Ordovician) (∼470 Ma). A total of 11 related taxa with 80 characters were selected to conduct phylogenetic analyses. Our results indicated that South China specimens are closely related to ones that are endemic to Laurentia. Synapomorphies shared between species in those two cratons include elongate supraradial plates and isotomous arm branching. Furthermore, the phylogenetic closeness of endemic taxa that only occurred in two cratons leads us to suggest a geographic connection between those regions during deep time. Combining biogeographic evidence reported from Cambrian studies, this study supports the “missing-link” configuration of Rodinia during the breakup phase. Based on the crinoid global biodiversity pattern updated here, the potential for discovery of new Paleozoic crinoid faunas in China is very high.

A three-dimensionally preserved aglaspidid euarthropod with a calcitic cuticle from the Ordovician of China

AbstractAglaspidid euarthropods are usually preserved as flattened carapaces. We here describe a new species and genus,Gogglops ensifer, from the Ordovician Shaanxi Province, China, which shows the best three-dimensional (3D) preservation yet discovered. We show that the cuticle was originally composed of calcium carbonate, except for the visual surfaces of the eyes which were probably originally organic but have been selectively phosphatized. A review is given of the problems pertaining to the original nature of the aglaspidid cuticle.Gogglopsis probably closely related to certain poorly known aglaspidid genera from Ordovician deposits of the Siberian Platform. Phylogenetic analysis indicates that the new genus is closely related toAglaspisitself, and securely nested within the clade Aglaspidida.

New material from the Ordovician of China indicates that Inocaulis is a graptolite

Muir, L.A., Zhang, Y.-D. & Lin, J.-P. 2012. New material from the Ordovician of China indicates that Inocaulis is a graptolite. Alcheringa 37, 558–559. ISSN 0311-5518.The problematic Early Palaeozoic fossil Inocaulis has been regarded as an alga, a graptolite and a hydroid by different authors. A new specimen from the Ordovician (late Darriwilian) of Guizhou Province (China) shows fusellar banding, confirming that it is a benthic graptolite.Lucy A Muir [lucy@asoldasthehills.org], Yuan-dong Zhang [ydzhang@nigpas.ac.cn], Jih-Pai Lin [jplin@nigpas.ac.cn] (corresponding author), State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, No. 39 East Beijing Road, Nanjing 210008, PR China. Received 13.12.2012; revised 10.5.2013; accepted 13.5.2013.

Probable advanced hydroid from the Early Ordovician of China

A fossil of a colonial organism with pyritized soft tissues of elongated fusiform zooids, found in the middle part of the early Floian Fenxiang Formation in Hubei Province of China, probably represents the oldest reliable record of a hydroid cnidarian. The preservation of the fossil is sufficiently different from that of associated carbonized skeletons of graptolites to exclude affinities with this group. The fossil is unlikely to be a bryozoan because of the mode of budding from proximal, not distal, parts of parent zooids, which is typical rather of hydroids. Although no thecae are preserved, the fossil, named Sino- bryon elongatum gen. et sp. nov., is suggested to be a thecate hydroid, possibly related to the Haleciidae. The apparent presence of an advanced member of the thec- aphoran Macrocolonia clade in strata 470 Ma old means that much of the hydroid (and cnidarian) diversification preceded the Middle Ordovician.

Preservation of soft tissues in an Ordovician linguloid brachiopod from China

The findings of preserved soft body parts including pedicle in the linguloid brachiopods are extremely rare in the fossil record of which the early Cambrian Chengjiang (southern China) and Burgess Shale (British Columbia) faunas are the most important. However, these characteristic Cambrian soft-bodied faunas largely disappeared from the fossil record well before the end of the Cambrian. Here we describe the first record of the pedicle in a linguloid brachiopod from the post-Cambrian strata, preserved with remarkable fidelity. Contrary to the Chengjiang and Burgess Shale-type faunas which are commonly preserved as essentially two-dimensional aluminosilicate or degraded organic carbon films or pyritized compressed fossils, the specimens now recovered from the Ordovician of China show a three-dimensional, pyritized pedicle with preserved external morphology, in detail. The presence of streamlined shell shape and burrowing shell sculpture in our specimens supports an assumption for infaunal mode of life of t...

First documentation of the Ordovician Guttenberg δ13C excursion (GICE) in Asia: chemostratigraphy of the Pagoda and Yanwashan formations in southeastern China

AbstractThe only published δ13C data from the Ordovician of China are from the Lower and Upper Ordovician, and only the latter records include a significant excursion, namely the Hirnantian excursion (HICE). Our recent chemostratigraphic work on the Upper Ordovician (Sandbian–Katian) Pagoda and Yanwashan formations at several localities on the Yangtze Platform and Chiangnan (Jiangnan) slope belt has resulted in the recognition of a positive δ13C excursion that has values of ~+1.5‰ above baseline values. This excursion starts a few metres above a stratigraphic interval withB. alobatusSubzone conodonts as well as graptolites of theN. gracilisZone. The distinctive conodontsAmorphognathusaff.Am. ventilatusandHamarodus europaeusfirst occur at, or very near, the excursion interval. Because these conodonts appear in the stratigraphic interval of the Guttenberg δ13C excursion (GICE) in Estonia, we identify the Chinese excursion as the GICE. This is the first record of the GICE in the entire Asian continent. It confirms that GICE is a global excursion and provides an illustration of how δ13C chemostratigraphy, combined with new biostratigraphic data, solves the problem of the previously controversial age of the Pagoda Formation and how this classical stratigraphic unit correlates with the Baltoscandian and North American successions.

Tubular phosphatic microproblematica from the Early Ordovician of China

Fenhsiangia zhangwentangi gen. et sp. nov., is named for an animal represented by a phosphatic tube-like exoskeleton with the internal walls ornamented by stellate-based rounded tubercles. As vertebrates are the only animals known to possess stellate tubercles of phosphatic material in the dermal skeleton, yet our remains do not show any morphological or histological similarity to primitive fish bone, we suggest that Fenhsiangia was an ancestral protovertebrate, possibly an ascidian or related form. A second form, here referred to as Fenhsiangia sp. differs in that the tubercles are flat-topped or concave, and the external walls are deeply pitted with lines of small pustules bordering the depressions. The Upper Cambrian and Ordovician could have been a time of great diversity and radiation for protovertebrates. with the evolution of the first true vertebrates resulting from this radiation. □Ordovician, China, phosphatic microproblematica, protovertebrate.

Clathrodictyid stromatoporoids from the Ordovician of China

Six species of clathrodictyid stromatoporoids are described from the Upper Ordovician successions of China. They come from localities in north China (Qinghai and Shaanxi Provinces, and Nei Monggol Autonomous Region), and SE China (Zhejiang and Jiangxi Provinces), and mainly from horizons of early- middle Ashgill age. Only a single occurrence of Ecclimadictyon is known from an earlier (late Caradoc) horizon. The zoogeographical relationships of the fauna are also discussed.

ALLOGRAPTUS CANADENSIS N. SP.; ITS SIGNIFICANCE TO LOWER ORDOVICIAN CORRELATION

A declined four-branched graptoloid is referred to a new species of Allograptus, a genus of the family Sinograptidae described from the uppermost Lower Ordovician of China. This new Canadian species has been discovered from the upper Lévis Formation at Lévis, Québec, and is the first representative of Allograptus in North America. A description of A. canadensis n. sp. is presented with a discussion on its possible significance for international stratigraphic correlation.