scholarly journals Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11800
Author(s):  
Xuejian Zhu ◽  
Rudy Lerosey-Aubril ◽  
Javier Ortega-Hernández
Keyword(s):  
South China ◽  
Fossil Record ◽  
Marine Ecosystems ◽  
Middle Cambrian ◽  
Early Devonian ◽  
Early Ordovician ◽  
Marine Life ◽  
Oral Cone ◽  
The Family ◽  
Sandstone Formation

The Furongian period represents an important gap in the fossil record of most groups of non-biomineralizing organisms, owing to a scarcity of Konservat-Lagerstätten of that age. The most significant of these deposits, the Jiangshanian strata of the Sandu Formation near Guole Township (Guangxi, South China), have yielded a moderately abundant, but taxonomically diverse soft-bodied fossil assemblage, which provides rare insights into the evolution of marine life at that time. In this contribution, we report the first discovery of a radiodont fossil from the Guole Konservat-Lagerstätte. The specimen is an incomplete frontal appendage of a possibly new representative of the family Hurdiidae. It is tentatively interpreted as composed of seven podomeres, six of which bearing laminiform endites. The best preserved of these endites is especially long, and it bears short auxiliary spines that greatly vary in size. This is the second occurrence of hurdiids and more generally radiodonts in the Furongian, the first being the external mould of an oral cone from Jiangshanian strata of the Wiśniówka Sandstone Formation in Poland. Restudy of this Polish specimen confirms that it belongs to a hurdiid radiodont and best compares to Peytoia. The family Hurdiidae includes the oldest (basal Cambrian Epoch 2) and youngest (Early Ordovician, possibly Early Devonian) representatives of the Radiodonta and as such, has the longest stratigraphical range of the group. Yet, hurdiids only became prominent components of marine ecosystems during the middle Cambrian (Miaolingian), and their fossil record in younger strata remains limited.

Revision of lyracystid eocrinoids from the Middle Cambrian of South China and Western Laurentia

2011 ◽  
Vol 85 (2) ◽  
pp. 250-255 ◽  
Author(s):  
James Sprinkle ◽  
Ronald L. Parsley ◽  
Yuanlong Zhao ◽  
Jin Peng
Keyword(s):  
South China ◽  
Short Distance ◽  
Outer Shelf ◽  
Muddy Sediment ◽  
Middle Cambrian ◽  
Sea Floor ◽  
Suspension Feeders ◽  
The Family ◽  
Upper Slope

The Middle Cambrian eocrinoid genera Lyracystis Sprinkle and Collins, 2006, from western Laurentia and Balangicystis Parsley and Zhao, 2006, from South China, described in the same year, have turned out to be closely related genera assigned to the Family Lyracystidae. Both have erect, lyre-shaped, arm-like, brachiolebearing, feeding appendages, here termed exothecal ambulacra, that are not homologous to crinoid arms. They also have a long, multiplated stalk to elevate the theca and feeding appendages well above the sea floor, making them among the highest tiered echinoderm suspension feeders known from the Middle Cambrian. The long stalk was either inserted a short distance into the muddy sediment, or attached to rare skeletal fragments lying on the sea floor. Both genera seem well adapted to quiet-water or slow-current conditions in deeper water (150-200 m) on the outer shelf or upper slope of their respective continents.

scholarly journals A horseshoe crab (Arthropoda: Chelicerata: Xiphosura) from the Lower Devonian (Lochkovian) of Yunnan, China

2012 ◽  
Vol 150 (2) ◽  
pp. 367-370 ◽  
Author(s):  
JAMES C. LAMSDELL ◽  
JINZHUANG XUE ◽  
PAUL A. SELDEN
Keyword(s):  
New Species ◽  
South China ◽  
Yunnan Province ◽  
Lower Devonian ◽  
Horseshoe Crab ◽  
Single Specimen ◽  
Early Devonian ◽  
The Family ◽  
A New Species ◽  
Stratigraphic Range

AbstractA single specimen of a new species of the synziphosurine Kasibelinurus Pickett, 1993 is described from the Lower Devonian (Lochkovian) Xiaxishancun Formation of Yunnan Province, China. The new species, K. yueya sp. nov., extends the geographic extent of the family Kasibelinuridae from the Australian palaeocontinent to the South China palaeocontinent, and the stratigraphic range back some 50 Ma from Late to Early Devonian.

Molecular phylogeny and divergence time estimates of Penaeid Shrimp Lineages (Decapoda: Penaeidae)

Zootaxa ◽  
2009 ◽  
Vol 2107 (1) ◽  
pp. 41-52 ◽  
Author(s):  
CAROLINA M VOLOCH ◽  
PABLO R FREIRE ◽  
CLAUDIA A M RUSSO
Keyword(s):  
Fossil Record ◽  
Divergence Time ◽  
Penaeid Shrimp ◽  
Divergence Time Estimates ◽  
Time Estimates ◽  
Global Clock ◽  
Late Tertiary ◽  
The Family ◽  
Molecular Studies ◽  
Triassic Period

Fossil record of penaeids indicates that the family exists since the Triassic period, but extant genera appeared only recently in Tertiary strata. Molecular based divergence time estimates on the matter of penaeid radiation were never properly addressed, due to shortcomings of the global molecular clock assumptions. Here, we studied the diversification patterns of the family, uncovering, more specifically, a correlation between fossil and extant Penaeid fauna. For this, we have used a Bayesian framework that does not assume a global clock. Our results suggest that Penaeid genera originated between 20 million years ago and 43 million years ago, much earlier than expected by previous molecular studies. Altogether, these results promptly discard late Tertiary or even Quaternary hypotheses that presumed a major glaciations influence on the diversification patterns of the family.

Early Paleozoic Hyolitha from North America: reexamination of Walcott's and Resser's type specimens

1988 ◽  
Vol 62 (2) ◽  
pp. 218-233 ◽  
Author(s):  
John Mark Malinky
Keyword(s):  
North America ◽  
Lower Cambrian ◽  
Type Species ◽  
New Genus ◽  
Early Paleozoic ◽  
Type Specimens ◽  
Middle Cambrian ◽  
Upper Cambrian ◽  
New Family ◽  
The Family

Concepts of the family Hyolithidae Nicholson fide Fisher and the genera Hyolithes Eichwald and Orthotheca Novak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated. Hyolithes encompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept of Orthotheca includes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.Eighteen species of Hyolithes and one species of Orthotheca from the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens of H. similis Walcott from the Lower Cambrian of Newfoundland, H. whitei Resser from the Lower Cambrian of Nevada, H. billingsi Walcott from the Lower Cambrian of Nevada, H. gallatinensis Resser from the Upper Cambrian of Wyoming, and H. partitus Resser from the Middle Cambrian of Alabama indicates that none of these species represents Hyolithes. Hyolithes similis is here included under the new genus Similotheca, in the new family Similothecidae. Hyolithes whitei is designated as the type species of the new genus Nevadotheca, to which H. billingsi may also belong. Hyolithes gallatinensis is referred to Burithes Missarzhevsky with question, and H. partitus may represent Joachimilites Marek. The type or types of H. attenuatus Walcott, H. cecrops Walcott, H. comptus Howell, H. cowanensis Resser, H. curticei Resser, H. idahoensis Resser, H. prolixus Resser, H. resseri Howell, H. shaleri Walcott, H. terranovicus Walcott, and H. wanneri Resser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types of H.? corrugatus Walcott and “Orthotheca” sola Resser does not support placement in the Hyolitha; the affinities of these species are uncertain.

Palaeonema phyticum gen. n., sp. n. (Nematoda: Palaeonematidae fam. n.), a Devonian nematode associated with early land plants

Nematology ◽  
2008 ◽  
Vol 10 (1) ◽  
pp. 9-14 ◽  
Author(s):  
George Poinar Jr ◽  
Hans Kerp ◽  
Hagen Hass
Keyword(s):  
Early Stage ◽  
Land Plant ◽  
Terrestrial Plants ◽  
Early Devonian ◽  
Plant Parasitism ◽  
New Family ◽  
The Earth ◽  
The Family ◽  
The Face ◽  
Early Land

AbstractNematodes are one of the most abundant groups of invertebrates on the face of the earth. Their extremely poor fossil record hinders our ability to assess just when members of this group invaded land and first became associated with plants. This study reports fossil nematodes from the stomatal chambers of the Early Devonian (396 mya) land plant, Aglaophyton major. These nematodes, which are tentatively assigned to the order Enoplia, are described as Palaeonema phyticum gen. n., sp. n. in the new family Palaeonematidae fam. n. Diagnostic characters of the family are: i) cuticular striations; ii) uniform, cylindrical pharynx with the terminal portion only slightly set off from the remainder; and iii) a two-portioned buccal cavity with the upper portion bearing protuberances. The presence of eggs, juveniles and adults in family clusters within the plant tissues provide the earliest evidence of an association between terrestrial plants and animals and may represent an early stage in the evolution of plant parasitism by nematodes.

Two Ordovician asterozoans (Echinodermata) of problematic affinities

2014 ◽  
Vol 88 (6) ◽  
pp. 1163-1173 ◽  
Author(s):  
Daniel B. Blake
Keyword(s):  
New Species ◽  
New Genus ◽  
Early Period ◽  
Early Ordovician ◽  
Class Level ◽  
The Family ◽  
Evolutionary Radiation ◽  
Frame Construction

Phragmactis grayaeSpencer andSwataria derstlerinew genus new species are early (Ordovician) asterozoans (Echinodermata) that comprise the Phragmactinidae. Asterozoans are complexly varied, but as is true for other echinoderms, ambulacral construction is critical to interpretation. Phragmactinids share plesiomorphic aspects of ambulacral form and articulation with basal somasteroids and stenuroids whereas the apomorphic ambulacral expressions of asteroids and ophiuroids are lacking. Phragmactinids, like asteroids and ophiuroids, have only one virgal-series ossicle associated with each ambulacral, unlike the multiple ossicles of somasteroids and stenuroids. Virgal morphology of phragmactinids is reminiscent of expressions in somasteroids and stenuroids. Aspects of phragmactinid mouth frame construction are apomorphic. Morphologies of other ossicular series are similarly varied, and as a result, the family cannot be easily fitted into a recently proposed class-level taxonomy of early asterozoans; it is left in open nomenclature. Phragmactinid morphology does not indicate behavior significantly different from that of other early asterozaons. Asterozoan diversity suggests an early period of rapid evolutionary radiation.

Marine Biology. Biodiversity and Functioning of Marine Ecosystems: Scientific Advancements and New Perspectives for Preserving Marine Life

2020 ◽  
pp. 447-462
Author(s):  
Cecilia Maria Totti ◽  
Stefano Accoroni ◽  
Marco Barucca ◽  
Silvia Bianchelli ◽  
Maria Assunta Biscotti ◽  
...  
Keyword(s):  
Marine Biology ◽  
Marine Ecosystems ◽  
Marine Life

scholarly journals Diversity of the Crinocheta (Crustacea, Isopoda, Oniscidea) from Early Miocene Chiapas amber, Mexico

2018 ◽  
Vol 35 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Pierre Broly ◽  
María De Lourdes Serrano-Sánchez ◽  
Francisco J. Vega
Keyword(s):  
New Species ◽  
Brackish Water ◽  
Fossil Record ◽  
Early Miocene ◽  
Paleoenvironmental Reconstruction ◽  
New Genera ◽  
Terrestrial Isopods ◽  
Water Influence ◽  
The Family

Currently, the Onisicdea (terrestrial isopods) is a massive Crustacea suborder of more than 3 700 species, but our knowledge of their paleodiversity is poor. In this paper, we present ten fossils of Crinocheta, the largest clade within the Onisicdea, discovered in Early Miocene (23 Ma) amber of Chiapas. We described three new genera and six new species including Palaeolibrinus spinicornis gen. nov. sp. nov., Armadilloniscus miocaenicus sp. nov., Archeostenoniscus robustus gen. nov. sp. nov., Archeostenoniscus mexicanus sp. nov., Palaeospherarmadillo mazanticus gen. nov. sp. nov., and Palaeospherarmadillo rotundus sp. nov. This study represents the first fossil record of the family Detonidae, Olibrinidae, and “Stenoniscidae”. From a paleoenvironmental reconstruction perspective, the oniscidean fauna presented here supports a particularly wet paleoenvironment, under brackish water influence, similar to an estuary.

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