Spiracarneyella, a new carneyellid edrioasteroid from the Upper Ordovician (Katian) of Kentucky and Ohio and comments on carneyellid heterochrony

2020 ◽  
pp. 1-6
Author(s):  
Colin D. Sumrall ◽  
Daniel Phelps

Abstract A new genus and species of carneyellid edrioasteroid, Spiracarneyella florencei n. gen. n. sp., is described from the Upper Ordovician (Kaitian) Point Pleasant Formation of northern Kentucky and southern Ohio. Spiracarneyella n. gen. is characterized by having all five ambulacra curving clockwise around the theca, having small node-bearing interambulacral plates in the distal interambulacra, and having the periproct placement slightly offset to the right side of the CD interambulacrum. The oral area of carneyellids evolved by paedomorphosis of the oral plates covering the mouth. The straight ambulacra of Cryptogoleus and the spiraling ambulacra of Spiracarneyella n. gen. evolved by paedomorphosis and peramorphosis, respectively. UUID: http://zoobank.org/79733c8f-0bc8-4e7e-8f77-8508f576755c

1998 ◽  
Vol 72 (5) ◽  
pp. 927-932 ◽  
Author(s):  
Markes E. Johnson ◽  
Mu Xi-Nan ◽  
Rong Jia-Yu

Storeacolumnella hudsonensis is described as a new genus and species of encrusting, colonial organism that lived in an intertidal, rocky-shore environment. The fossil was discovered in the basal beds of the Upper Ordovician Port Nelson Formation at a coastal outcrop on Hudson Bay near Churchill, Manitoba. Showing some possible characteristics of sponges and other possible characteristics of calcaerous green algae, this matlike organism is considered nonetheless to have uncertain taxonomic affinities. It consists of cylinder-shaped columns, each with an internal system of star-shaped filaments or spicules as viewed in transverse section. The cylinders stand vertical in longitudinal section and are densely packed together to form a mat. The hard substrate to which the mat is attached consists of a boulder eroded from the Precambrian Churchill Quartzite. Maximum colony size observed in a single example exhibits a diameter of not less than 80 mm and maximum thickness of 5.85 mm.


Remains of a fossil amphibian have been recovered from an ironstone layer in the Upper Evergreen Formation, dated as late Liassic, of southeast Queensland. Extraction of the skeleton from the very hard matrix has presented a number of problem s which are discussed. The find is an almost complete skull and mandible connected to an articulated postcranial skeleton which is missing only some ribs, the right hind leg and the distal portions of the other limbs and tail. The remains are those of a temnospondyl labyrinthodont described as a new genus and species of the family Chigutisauridae. The new form is notable for its very large size (total length estimated to be in excess of 2.5 m), relatively large marginal dentition, with unique lance-shaped tooth tips, the presence of minute denticles associated with the palate and mandible, a well developed atlas showing a strong link with the axis, neorhachitomous vertebrae that lack ossified pleurocentra and have low, heavily built neural spines, a neck region and a narrow dermal pectoral girdle associated with unreduced limbs. The discovery of this chigutisaur provides the first unequivocal evidence that labyrinthodonts survived beyond the end of the Triassic. T he status of two previously described doubtful Jurassic forms is reviewed. Austropelor Longman, 1941, from the Early Jurassic Marburg Sandstone of southeast Queensland, is confirmed as a fragm ent of temnospondyl lower jaw , probably attributable to the superfamily Brachyopoidea, and there is no longer any reason to consider the earlier suggestion that it is a reworked Triassic fossil. Cyrtura Jaekel, 1904, from the Late Jurassic Solnhofen Shale of Germany, is considered not to be a labyrinthodont, but its exact relationships are uncertain. The unsatisfactory nature of the higher taxonomy of the Temnospondyli is noted. The superfamily Brachyopoidea is reviewed and the family Kourerpetontidae is removed from it, membership of the superfamily thereby being restricted to the Brachyopidae (Late Permian to Middle Triassic) and Chigutisauridae (Early Triassic to Early Jurassic). Diagnoses for the superfamily and its two included families are provided. The relationships of the better characterized members of the two families are examined and a phylogeny based on shared derived character states is proposed. The analysis of relationships indicates that Brachyops allos Howie, 1972 shares few of the characters diagnostic of the type of Brachyops (B. laticeps Owen, 1855), and a new genus is proposed. The diversity of Australia’s brachyopoids, including the presence of the most primitive and earliest-known members of each of the included families, suggests that the superfamily originated in Australia.


2003 ◽  
Vol 77 (5) ◽  
pp. 949-957 ◽  
Author(s):  
Alexander Glass ◽  
William I. Ausich ◽  
Paul Copper

Nicholsodiscus anticostiensisnew genus and species (Mill Bay Member, Vauréal Formation, Rawtheyan, Upper Ordovician) is described from Anticosti Island, Quebec, Canada.Nicholsodiscus anticostiensisn. gen. and sp. is known from two complete specimens preserved in situ with the cupule-bearing side facing toward the bedding surface. Sedimentological, petrographic, and trace fossil evidence suggest that this bedding surface had the consistency of a hardground during the lifetime of the cyclocystoids. This provides the first unequivocal evidence that cyclocystoids lived with their cupule-bearing side (ventral) toward the substratum. A cupules-down orientation results in the ambulacral grooves facing the substratum. Such an orientation excludes suspension-feeding from being a possible feeding mode of the Cyclocystoidea as discussed by Henderson and Shergold (1971).A third Anticosti Island cyclocystoid specimen of unknown affinities is described from the same locality. Furthermore, a re-examination of the holotype of“Cyclocystoides” raymondiFoerste for purposes of comparison withNicholsodiscus anticostiensisn. gen. and sp. provided evidence that it is a member ofZygocycloides, albeit with missing interseptal plates.


Zootaxa ◽  
2006 ◽  
Vol 1368 (1) ◽  
pp. 1 ◽  
Author(s):  
ELENA L. MARKHASEVA ◽  
KNUD SCHULZ

Sensiava longiseta gen. et sp. nov. is described from male specimens collected at abyssal depths above the seabed in the Weddell Sea (Southern Ocean). Segmentation and setation of the swimming legs of the new species are typical of the superfamily Clausocalanoidea. Although the new genus shares the presence of sensory setae on the maxilla with the Bradfordian families of the Clausocalanoidea, it does not fit the diagnosis of any of these families. Sensiava longiseta shares with the ancestral group of Bradfordian genera a 1,2,3 setal pattern on the praecoxal endites of the maxilliped and, therefore is provisionally placed within Diaixidae. Sensiava longiseta shows marked asymmetry in the antennule; the right limb is geniculated with ancestral segments XIX–XXIII morphologically modified. The presence of this well pronounced, geniculated antennule is up to now the most striking example of this feature and regarded as an ancestral character in the advanced superfamily Clausocalanoidea.


2019 ◽  
Vol 21 ◽  
pp. 86-89
Author(s):  
Jozef Grego ◽  
Peter Glöer

A new genus and species of hydorbiid gastropod is described from a small karst spring at the right bank of Trebišnjica River in Gorica near Trebinje in Hercegovina. The taxon is clearly distinguished by the unique morphology of its male copulatory organ.


2022 ◽  
Vol 787 ◽  
Author(s):  
Sukonthip Savatenalinton

A new genus, Thaicypris gen. nov., in the tribe Herpetocypridini Kaufmann, 1900 of the subfamily Herpetocypridinae Kaufmann, 1900 is established to accommodate a new species from Thailand. The present contribution deals with the description of a new genus and species, Thaicypris panhai gen. et sp. nov., which is mainly characterized by the distinctive and raised, inwardly displaced selvage at the postero-ventral part of the right valve (RV) that is not parallel to the valve margin, the absence of an anterior inner list on the RV, the prominent and elevated double inner list on the posterior part of the left valve, the small and three-segmented Rome organ on the first antenna (A1), the spatulated terminal segment of the maxillular (Mx1) palp, the slender caudal ramus (CR) with long and thin Sp seta, the presence of basal triangle on the CR attachment, and the pointed projection at the terminal segment base of the prehensile palps. The hemipenis of the new genus and species is outstanding, especially the medial lateral shield which has a long, beak-shaped protrusion on the distal part. The discovery of this Thai taxon is the first record of the tribe Herpetocypridini in Thailand and the second species of the tribe in Southeast Asia.


2001 ◽  
Vol 92 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Andrew B. Smith ◽  
Jeremy J. Savill

ABSTRACTA new genus and species of primitive echinozoan, Bromidechinus rimaporus, is described from the Upper Ordovician of Oklahoma, USA. This has a unique plate arrangement. There is a single perradial series of imperforate plates bounded on either side by a column of perforate ambulacral plates. A double column of interambulacral plates separates ambulacral zones. The sparse record of Ordovician echinozoans is reviewed and cladistic analysis suggests that Bromidechinus represents a lineage that diverged prior to the split between bothriocidarids and main-line echinoids. This leads to a revised interpretation of the earliest stages of morphological evolution of echinoids.


2010 ◽  
Vol 47 (8) ◽  
pp. 1037-1053 ◽  
Author(s):  
Patrick S. Druckenmiller ◽  
Erin E. Maxwell

A new, articulated skeleton of an ichthyosaur from the Lower Cretaceous (lower Albian) Wabiskaw Member of the Clearwater Formation near Fort McMurray, Alberta, is the most complete and stratigraphically oldest known ichthyosaur from the Cretaceous of North America and represents a new genus and species of ophthalmosaurian, Athabascasaurus bitumineus . The specimen consists of a nearly complete, dorsoventrally compressed skull, a complete and articulated presacral and partial caudal vertebral series, portions of the right pectoral girdle, and the right pelvic girdle and femur. The new taxon is characterized by the lack of a robust supranarial process of the premaxilla, an elongate maxilla that has its tallest point (in lateral view) posterior to the external naris, a wide postorbital region, the presence of a rectangular squamosal, an angular with greater lateral exposure on the posterior jaw ramus than the surangular, a dentition with extremely light enameled ridges, and a reduced presacral count of 42 vertebrae. The first species-level phylogenetic analysis of Ophthalmosauria reveals that Athabascasaurus is neither the sister taxon of, nor nests within Platypterygius , a geographically widespread, geologically long-lived, and taxonomically problematic genus. Athabascasaurus adds important new data on the morphology of Cretaceous ichthyosaurs and expands our knowledge of the palaeoecology and marine tetrapod diversity of the early Albian Boreal Sea.


2000 ◽  
Vol 74 (1) ◽  
pp. 179-180 ◽  
Author(s):  
Robert J. Elias ◽  
Graham A. Young

An enigmatic encruster from the Upper Ordovician rocky shore exposed near Churchill, Manitoba, was recently described by Johnson et al. (1998). The specimen was found attached to a quartzite boulder enclosed in carbonate matrix. The matlike, calcareous fossil consists of densely packed, vertical, cylindrical columns with upward-radiating structures issuing from their centers. It was identified as a new genus and species, Storeacolumnella hudsonensis, of uncertain taxonomic affinity but with possible characteristics of sponges and calcareous green algae. In particular, the radiating structures within columns were compared with spicules of a sclerosponge and with the siphon system of siphonous green algae.


2017 ◽  
Vol 284 (1862) ◽  
pp. 20171189 ◽  
Author(s):  
Derek E. G. Briggs ◽  
Derek J. Siveter ◽  
David J. Siveter ◽  
Mark D. Sutton ◽  
Imran A. Rahman

Echinoderms are unique in having a water vascular system with tube feet, which perform a variety of functions in living forms. Here, we report the first example of preserved tube feet in an extinct group of echinoderms. The material, from the Silurian Herefordshire Lagerstätte, UK, is assigned to a new genus and species of rhenopyrgid edrioasteroid, Heropyrgus disterminus . The tube feet attach to the inner surface of compound interradial plates and form two sets, an upper and a lower, an arrangement never reported previously in an extant or extinct echinoderm. Cover plates are absent and floor plates are separated creating a large permanent entrance to the interior of the oral area. The tube feet may have captured food particles that entered the oral area and/or enhanced respiration. The pentameral symmetry of the oral surface transitions to eight columns in which the plates are vertically offset resulting in a spiral appearance. This change in symmetry may reflect flexibility in the evolutionary development of the axial and extraxial zones in early echinoderm evolution.


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