Biometry, systematics and biogeography of the late Cambrian trilobite Maladioidella abdita

1995 ◽  
Vol 86 (4) ◽  
pp. 247-256 ◽  
Author(s):  
Adrian W. A. Rushton ◽  
Nigel C. Hughes
Keyword(s):  
Morphological Features ◽  
Dispersal Ability ◽  
Limited Extent ◽  
Late Cambrian ◽  
Cambrian Trilobite

ABSTRACTThe restoration of deformed specimens of the trilobite Conocoryphe abdita Salter from the late Cambrian of Wales allows a re-evaluation of their systematics, synonymy with other species described from Siberia and Iran, and assignment to the idahoiid genus Maladioidella. Maladioidella abdita is from the Parabolina spinulosa Biozone, and most species similar to it occur in equivalent strata near the lower part of the Iverian Stage. Widespread homeomorphy in primitive libristomates is documented and presents difficulties for assessing relationships within Maladioidella and among related taxa. Both the genus as a whole and the species M. abdita show a widespread peri-Gondwanan distribution that crosses a range of latitudes and lithofacies and, to a limited extent, oceanic basins. No morphological features were discerned that might account for its unusual dispersal ability.

scholarly journals Satunarcus, a new late Cambrian trilobite genus from southernmost Thailand and a reevaluation of the subfamily Mansuyiinae Hupé, 1955

2020 ◽  
Vol 94 (5) ◽  
pp. 867-880
Author(s):  
Shelly J. Wernette ◽  
Nigel C. Hughes ◽  
Paul M. Myrow ◽  
Apsorn Sardsud
Keyword(s):  
North China ◽  
New Genus ◽  
Sedimentary Rocks ◽  
Cladistic Analysis ◽  
New Genus And Species ◽  
Natural Group ◽  
Middle Cambrian ◽  
Current Definition ◽  
Late Cambrian ◽  
Cambrian Trilobite

AbstractThe Ao Mo Lae Formation of the Tarutao Group crops out on Thailand's Tarutao Island and contains a diverse assemblage of late Furongian trilobite taxa, including several endemic forms. This study presents a new genus and species, Satunarcus molaensis, discovered at two locations on the island. A cladistic analysis of the kaolishaniid subfamily Mansuyiinae in light of Satunarcus and similar genera known from across upper Cambrian equatorial Gondwanan rocks suggests that the subfamily is polyphyletic in its current definition, and thus is not a natural group. Separating Mansuyia Sun, 1924 from the other taxa conventionally placed in Mansuyiinae permits recognition of a previously unrecognized monophyletic subfamily Ceronocarinae new subfamily. As established herein, this kaolishaniid subfamily contains Satunarcus n. gen. and all genera previously recognized as Mansuyiinae. with the exception of Mansuyia itself. Ceronocarinae n. subfam. occur in middle Jiangshanian to middle Cambrian Stage 10 sedimentary rocks from Australia, South China, North China, and Sibumasu, with most genera endemic to Australia.UUID: http://zoobank.org/618c5136-73f0-4912-a7d3-e56559d2a76c

A NEW SUNWAPTAN (LATE CAMBRIAN) TRILOBITE FAUNA FROM THE UPPER MISSISSIPPI VALLEY

2005 ◽  
Vol 79 (1) ◽  
pp. 72-88 ◽  
Author(s):  
STEPHEN R. WESTROP ◽  
ALLISON R. PALMER ◽  
ANTHONY RUNKEL
Keyword(s):  
Mississippi Valley ◽  
Late Cambrian ◽  
Cambrian Trilobite

Classification of the Late Cambrian trilobite Idiomesus Raymond

1986 ◽  
Vol 23 (3) ◽  
pp. 300-307 ◽  
Author(s):  
Rolf Ludvigsen ◽  
Stephen R. Westrop
Keyword(s):  
New Species ◽  
Undescribed Species ◽  
Late Cambrian ◽  
New Material ◽  
Cambrian Trilobite

Idiomesus Raymond, 1924 has been considered to be a Late Cambrian member of the blind family Shumardiidae on the basis of its small size, absence of eyes, effacement, and marginal sutures. However, evaluation of new material, including previously undescribed species, demonstrates that Idiomesus is a member of the ptychaspidid subfamily Ptychaspidinae. The genus now includes both sighted and blind species, as well as furrowed and effaced species with both marginal and opisthoparian sutures. New species are Idiomesus granti, I. greggi, and I. ultimus.

Upper Cambrian trilobites and brachiopods from Severnaya Zemlya, Arctic Russia, and their implications for correlation and biogeography

2002 ◽  
Vol 139 (3) ◽  
pp. 281-290 ◽  
Author(s):  
A. W. A. RUSHTON ◽  
L. R. M. COCKS ◽  
R. A. FORTEY
Keyword(s):  
Northern Siberia ◽  
Upper Cambrian ◽  
Late Cambrian ◽  
Cambrian Trilobite ◽  
Brachiopod Fauna ◽  
The Baltic ◽  
Severnaya Zemlya ◽  
Arctic Russia

A new Late Cambrian trilobite–brachiopod fauna from the Kurchavinskaya Formation, Severnaya Zemlya, northern Siberia, allows correlation of the Ketyi Horizon of the NW Siberian succession with the praecursor Zone of the Baltic olenid zonation. The presence on Severnaya Zemlya of the typically Siberian trilobite Kujandaspis ketiensis indicates that even if Severnaya Zemlya lay on a separate plate, whether Kara or Arctida as postulated by other authors, then it was still probably not far from Siberia. However, the associated brachiopods are partly endemic to Severnaya Zemlya, thus giving some support to the independent palaeomagnetic evidence for their origin on a plate separate from Siberia.

Revision of the late Cambrian trilobite genus Archikainella

2021 ◽  
pp. 1-5
Author(s):  
Xuejian Zhu ◽  
Shanchi Peng ◽  
Tatyana V. Pegel ◽  
Jingxun Zuo
Keyword(s):  
Late Cambrian ◽  
Cambrian Trilobite

Cambrian–Ordovician boundary age and duration of the lowest Ordovician Tremadoc Series based on U–Pb zircon dates from Avalonian Wales

2000 ◽  
Vol 137 (5) ◽  
pp. 485-494 ◽  
Author(s):  
E. LANDING ◽  
S. A. BOWRING ◽  
K. L. DAVIDEK ◽  
A. W. A. RUSHTON ◽  
R. A. FORTEY ◽  
...  
Keyword(s):  
Average Duration ◽  
Early Cambrian ◽  
Late Cambrian ◽  
Road Section ◽  
North Wales ◽  
Cambrian Trilobite ◽  
Middle And Late Cambrian

Two thin volcaniclastic sandstone beds in the Bryn-llin-fawr road section in North Wales overlie an apparent sequence boundary within the uppermost Cambrian Acerocare Zone and are overlain by lowest Ordovician (lower Tremadoc) Rhabdinopora faunas. U–Pb geochronology of zircons from these sandstones yields a maximum Cambrian–Ordovician boundary age of 489±0.6 Ma. This age indicates both that the Tremadoc Series (lowest Ordovician) may be shorter in duration than was previously thought and that the duration of the Middle and Late Cambrian (c. 22 Ma) was much less than that of the Early Cambrian (c. 33 Ma). Cambrian trilobite zones locally had an average duration as short as 1 Ma.

scholarly journals The Current State of Eunicida (Annelida) Systematics and Biodiversity

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 74
Author(s):  
Joana Zanol ◽  
Luis F. Carrera-Parra ◽  
Tatiana Menchini Steiner ◽  
Antonia Cecilia Z. Amaral ◽  
Helena Wiklund ◽  
...  
Keyword(s):  
Distribution Patterns ◽  
Molecular Study ◽  
Molecular Data ◽  
Morphological Features ◽  
Valid Species ◽  
Dispersal Ability ◽  
Freshwater Species ◽  
Type Specimens ◽  
Local Diversity ◽  
Current State

In this study, we analyze the current state of knowledge on extant Eunicida systematics, morphology, feeding, life history, habitat, ecology, distribution patterns, local diversity and exploitation. Eunicida is an order of Errantia annelids characterized by the presence of ventral mandibles and dorsal maxillae in a ventral muscularized pharynx. The origin of Eunicida dates back to the late Cambrian, and the peaks of jaw morphology diversity and number of families are in the Ordovician. Species richness is heterogeneous among the seven recent families, with more than half of the valid species belonging to the Eunicidae + Onuphidae clade, one of the latest clades to diverge. Eunicidans inhabit soft and hard substrates from intertidal to deep waters in all oceans. The few freshwater species are restricted to Histriobdellidae, a family exclusively commensal/parasite of crustaceans. The reproductive biology, development and ecology of most families are poorly known and the information available suggests low dispersal ability. However, all families have records of widely distributed species. Scrutiny of these wide distributions has often revealed the presence of exotic species or more than one species. The exploration of the deep-sea and of new habitats has led to recent descriptions of new species. Furthermore, the revision of type specimens, the examination of new morphological features and the use of molecular data have revealed hidden biodiversity under unjustified synonyms, poor understanding of morphological features and incomplete descriptions. Molecular studies are still very few or nonexistent for the families Histriobdellidae, Hartmaniellidae, Lumbrineridae and Oenonidae. The integration of new methodologies for morphological and molecular study, along with information on biological and ecological traits appears to be the path to improve the knowledge on the diversity of Eunicida.

Kunmingaspis(Trilobita) putatively from the Yunling collage, and the Cambrian history of the eastern Himalayan syntaxial region

2002 ◽  
Vol 76 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Nigel C. Hughes ◽  
Peng Shanchi ◽  
Luo Huilin
Keyword(s):  
Structural Complexity ◽  
Yangtze Platform ◽  
Tectonic Event ◽  
Middle Cambrian ◽  
Late Cambrian ◽  
History Of ◽  
Cambrian Trilobite ◽  
Critical Constraints ◽  
The Himalaya ◽  
Tethyan Himalaya

Faunal data provide critical constraints upon tectonic models, particularly in such areas of extreme structural complexity as the region adjacent to the eastern syntaxis of the Himalaya. Trilobites reported to have been collected from the Yunling collage at Yinchangou, northwestern Yunnan, are here assigned toKunmingaspis yunnanensisChang, 1964, and the concept of the genusKunmingaspisis reconsidered. Although there is debate about to the paleogeographic affinities of the Yunling collage, the apparent presence of this species supports previous arguments for faunal links between the Yangtze platform and the Himalayan margin during Early and Middle Cambrian time. A significant tectonic event of Late Cambrian/Early Ordovician age present in the western central Himalayan margin suggests that the Lhasa block collided with India at that time, but the northward extent of that block remains unclear. The recently discovered Late Cambrian trilobite fauna of Bhutan may hold the key to establishing faunal relationships between the Tethyan Himalaya, Sibumasu, and the Yangtze platform during this interval. No Cambrian sedimentary rocks are yet known from the Lhasa or Qiangtang blocks of Tibet and so there is no direct evidence for the existence of Cimmeria during the Cambrian Period.

Sign in / Sign up

Export Citation Format

Share Document