Lichidae (Trilobita): Morphology and classification

2002 ◽  
Vol 76 (2) ◽  
pp. 306-320 ◽  
Author(s):  
H. B. Whittington
Keyword(s):  
Special Reference ◽  
External Surface ◽  
Surface Form ◽  
Type Specimens ◽  
Middle Ordovician ◽  
Strongly Convex ◽  
Early Diversification

Morphology is reviewed with special reference to the doublure and thoracic characters; a reconstruction of Richterarges aquilonius is used to suggest possible lichid anatomy. The relatively large hypostome and wide doublure, and the thorax with, or without, the strongly convex posterior pleural bands characterize lichids, in addition to the distinctive glabellar morphology. Relatively shallow furrows on the external surface form strong ridges on the visceral surface of the exoskeleton; apodemes are absent. Type specimens of species described by Schmidt, recently traced in Russian museums, are figured. Lichids differ from odontopleurids in morphology and anatomy, and are unlike Scutelluinae; accepted subfamilial divisions of Lichidae are reinforced by thoracic characters. A single lichid species is known in the early Tremadoc, in the early Middle Ordovician the main four subfamilies are recognised and are widespread; their ancestry and early diversification remain unknown.

Redescription of the giant mud worm Paraleonnates uschakovi Khlebovich and Wu, 1962 (Polychaeta: Nereididae) with special reference to the synonymy of Periserrula leucophryna Paik, 1977 and the difference from Paraleonnates bolus (Hutchings and Reid, 1991)

Zootaxa ◽  
2012 ◽  
Vol 3490 (1) ◽  
pp. 49 ◽  
Author(s):  
JAE-SANG HONG ◽  
BYUNG-MEE CHOI ◽  
AKI KUBO ◽  
MASANORI SATO
Keyword(s):  
Special Reference ◽  
Junior Synonym ◽  
Monotypic Genus ◽  
Type Specimens ◽  
Taxonomic Confusion ◽  
The Difference

There has been a long-standing taxonomic confusion over the name of a giant nereidid worm living in Asian intertidalmud flats. To clear up the confusion, we examined the type specimens of Paraleonnates uschakovi Khlebovich and Wu,1962 described from China as well as Periserrula leucophryna Paik, 1977 described from Korea (Polychaeta: Nereididae),together with additional non-type materials newly collected from Korea, China, Taiwan, and Thailand. Our results con-firmed that Periserrula leucophryna should be reduced to a junior synonym of Paraleonnates uschakovi as previouslynoted, and that this species is widely distributed in Asia, newly recorded from Taiwan and Thailand. We also present newinformation about the arrangement of three kinds of chaetae in the parapodia as a characteristic of this species. We alsocompared this species with Paraleonnates bolus (Hutchings and Reid, 1991) described from Australia and concluded thatthese are different species. Based on our examination, we propose the amended diagnosis of the genus ParaleonnatesKhlebovich and Wu, 1962. Paraleonnates Amoureux, 1985 erected as a monotypic genus for P. guadalupensis Amoureux,1985 was judged as a junior homonym of Paraleonnates Khlebovich and Wu, 1962, and P. guadalupensis is transferred to the genus Leonnates Kinberg, 1865.

Early Diversification

1980 ◽  
Vol 3 ◽  
pp. 86-93
Author(s):  
James Sprinkle
Keyword(s):  
Adaptive Radiation ◽  
Fossil Record ◽  
Early Cambrian ◽  
Early Paleozoic ◽  
Two Stage ◽  
Evolutionary Pattern ◽  
Middle Ordovician ◽  
Early Diversification ◽  
Initial Radiation

The initial explosive radiation of echinoderms in the Cambrian and Ordovician is very likely the single most spectacular evolutionary pattern shown by echinoderms during their long fossil record. This radiation involved 19–20 echinoderm classes and lasted from the Early Cambrian (perhaps latest Precambrian) to the end of the Middle Ordovician. It is important because in many ways this initial radiation determined the entire Paleozoic record for echinoderms. In addition, it is almost a textbook example of a major adaptive radiation (Raup and Stanley, 1978, p. 307, 357–360), and also fits nicely the two-stage metazoan diversification model for the Early Paleozoic outlined by Sepkoski (1979).

scholarly journals The first Ordovician cyclocystoid (Echinodermata) from Gondwana and its morphology, paleoecology, taphonomy, and paleogeography

2017 ◽  
Vol 91 (4) ◽  
pp. 735-754 ◽  
Author(s):  
Mike Reich ◽  
James Sprinkle ◽  
Bertrand Lefebvre ◽  
Gertrud E. Rössner ◽  
Samuel Zamora
Keyword(s):  
Early Ontogeny ◽  
New Taxon ◽  
Time Of Death ◽  
X Ray ◽  
Middle Ordovician ◽  
New Family ◽  
Early Diversification ◽  
Mode Of Life ◽  
X Ray Computed ◽  
Oral Surface

AbstractMoroccodiscus smithirepresents a new cyclocystoid genus and species based on moldic specimens from the Middle Ordovician Taddrist Formation (Darriwilian) of SE Morocco. This represents the earliest articulated member of the Cyclocystoidea and is the first complete cyclocystoid described from the Ordovician of Gondwana, as well as the first cyclocystoid ever recorded from Africa. The anatomy and morphology of this new species were studied using a combination of conventional paleontological methods and nondestructive X-ray computed tomography. BecauseMoroccodiscusdiffers from other cyclocystoids, in particular by lacking cupules attached to the marginal ossicles, it is assigned to the new family Moroccodiscidae. This new taxon illustrates the relatively poorly known early diversification of these enigmatic extinct echinoderms and sheds light on the mode of life of cyclocystoids, including injuries to plate circlets during early ontogeny and folding of these disk-like specimens at the time of death. The overall thecal shape was very similar in cyclocystoids and many domal edrioasteroids, probably because they were both sessile or attached, benthic, suspension feeders. However, many oral surface, ambulacral, and marginal ring features had become very different, indicating that these two groups had either converged because of similar life modes or were only distantly related sister groups.

On the mammals collected by Friedrich Sellow in Brazil and Uruguay (1814–1831), with special reference to the types and their provenance 

Zootaxa ◽  
2017 ◽  
Vol 4221 (2) ◽  
pp. 172 ◽  
Author(s):  
GUILHERME S. T. GARBINO ◽  
MARCELO R. NOGUEIRA
Keyword(s):  
Special Reference ◽  
Sao Paulo ◽  
Type Locality ◽  
Zoological Museum ◽  
Species Occurrence ◽  
Type Specimens ◽  
Eastern Brazil ◽  
Northern Brazil ◽  
Locality Information ◽  
Occurrence Records

From 1814 to 1831, the Prussian naturalist Friedrich Sellow collected 263 mammals in Brazil and Uruguay. Upon receiving the specimens, the curator of the Berlin Zoological Museum, Martin Lichtenstein, removed the original labels and replaced with ones containing more generalized locations. As a consequence, several type specimens have now dubious type localities. We examined these types as well as geographically restricted mammals collected by Sellow. In some cases, there are inconsistencies between the specimen label and the collection catalog regarding the collecting locality. We conclude that the locality information on the lectotype of the tent-making bat Uroderma bilobatum is mistakenly identified, and therefore, we restrict it to “eastern Brazil”. We designate a lectoype for Azara’s agouti, Dasyprocta azarae, and restrict its type locality to the region travelled by Sellow in São Paulo. Although there are no recent records of the woolly giant rat, Kunsia tomentosus, from its type locality, the species may have been recently extirpated from the area. Two primate specimens supposedly collected by Sellow, a silvery marmoset, Mico argentatus, and a black tamarin, Saguinus niger, occur only in the Amazonia of northern Brazil, outside the route travelled by the naturalist, and are more likely to have been collected by Sieber. Our investigations stress the importance of collecting vouchers for verifying species occurrence records and establishing a solid taxonomy.  

Lower and Middle Ordovician Lithistid Demosponges from the Mingan Islands, Gulf of St. Lawrence, Quebec, Canada

1995 ◽  
Vol 69 (S41) ◽  
pp. 1-35 ◽  
Author(s):  
J. Keith Rigby ◽  
Andre Desrochers
Keyword(s):  
New Species ◽  
North America ◽  
Type Material ◽  
Eastern North America ◽  
Type Specimens ◽  
Middle Ordovician ◽  
First Time ◽  
Original Type

New collections, as well as original type material, of Lower and Middle Ordovician sponges from the Mingan Island Archipelago are described and figured from the Mingan and Romaine Formations. Archaeoscyphia minganensis (Billings, 1859), Hudsonospongia minganensis Raymond and Okulitch, 1940, H. irregularis Raymond and Okulitch, 1940, H. duplicata Raymond and Okulitch, 1940, Zittelella varians (Billings, 1861a), and Eospongia roemeri Billings, 1861, are redescribed from original type specimens and new collections. The species Archaeoscyphia pulchra (Bassler, 1927), Rhopalocoelia clarkii Raymond and Okulitch, 1940, Psarodictyum magnificum Raymond and Okulitch, 1940, and Lissocoelia ramosa Bassler, 1927 are reported and described from the Mingan Islands for the first time. To these sponges are added the new species Anthaspidella amplia, Archaeoscyphia undulata, Hudsonospongia nodosa, and Zittelella grossa, which are described from type specimens from the Mingan Formation.The assemblage from 12 localities from the Mingan Formation, and one from the Romaine Formation, represents one of the most diverse demosponge faunas from eastern North America. Sponges in most of the localities accumulated as transported debris or lag gravels, but locally, some grew in small reefoidal mounds and also accumulated as adjacent debris.

A revision of the genus Pachygrapsus Randall, 1840 (Crustacea: Decapoda: Brachyura, Grapsidae), with special reference to the Southwest Pacific species

Zootaxa ◽  
2005 ◽  
Vol 1015 (1) ◽  
pp. 1 ◽  
Author(s):  
JOSEPH POUPIN ◽  
PETER J.F. DAVIE ◽  
JEAN CHRISTOPHE CEXUS
Keyword(s):  
Special Reference ◽  
Junior Synonym ◽  
Type Locality ◽  
Type Specimens ◽  
Separate Species ◽  
Southwest Pacific ◽  
New Material ◽  
De Man ◽  
Pacific Species

The genus Pachygrapsus Randall, 1840 is revised with particular attention to the five Southwest Pacific species: P. fakaravensis Rathbun, 1907, P. laevimanus Stimpson, 1858, P. minutus A. MilneEdwards, 1873, P. planifrons De Man, 1888, and P. plicatus (H. Milne Edwards, 1837). Pachygrapsus laevimanus Stimpson, 1858 is redescribed and a neotype is designated because of confusion of this species with P. transversus (Gibbes, 1850). Seven other species were examined: P. corrugatus (von Martens, 1872), P. crassipes Randall, 1840, P. gracilis (de Saussure, 1858), P. loveridgei Chace, 1966, P. marmoratus (Fabricius, 1787), P. maurus (Lucas, 1846), and P. transversus (Gibbes, 1850). The type specimens of P. striatus A. Milne-Edwards, 1873, and P. laevis Borradaile, 1900, were re-examined and found to be junior synonyms of P. plicatus (H. Milne Edwards, 1837), and P. planifrons De Man, 1888, respectively. Pachygrapsus kraussii (Dana, 1852) is considered a junior synonym of P. plicatus H. Milne Edwards, 1837. Pachygrapsus polyodous Stebbing, 1921, is excluded from Pachygrapsus and provisionally placed in Euchirograpsus H. Milne Edwards, 1853. Pachygrapsus propinquus De Man, 1908, is probably a junior synonym of P. minutus A. MilneEdwards, 1873, but its status needs to be confirmed with the collection of new material from the type locality. Pachygrapsus now includes twelve species, thirteen if P. propinquus De Man, 1908, proves to be a separate species. A key to all thirteen species is given.

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