New Early Triassic coelacanth in the family Laugiidae (Sarcopterygii: Actinistia) from the Sulphur Mountain Formation near Wapiti Lake, British Columbia, Canada

2013 ◽  
Vol 50 (9) ◽  
pp. 904-910 ◽  
Author(s):  
Andrew J. Wendruff ◽  
Mark V.H. Wilson
Keyword(s):  
British Columbia ◽  
Late Jurassic ◽  
Evolutionary Relationships ◽  
Early Triassic ◽  
Dorsal Lobe ◽  
Caudal Fin ◽  
Size And Shape ◽  
Fin Ray ◽  
The Family ◽  
The Asymmetry

A new Early Triassic coelacanth, Belemnocerca prolata, gen. et sp. nov., is described as a new member of the family Laugiidae. Although only one incomplete specimen is known, much can be deduced about its evolutionary relationships. In particular, the new coelacanth is most similar to one member of its family, Laugia groenlandica, in the asymmetry (dorsal lobe longer than ventral) and the gradually tapering shape of its caudal fin, though it differs in caudal fin ray count and anal fin position as well as in the size and shape of the supplementary lobe. Belemnocerca prolata is the westernmost occurrence of the family Laugiidae and only member of this family known to inhabit Panthalassa, west of the supercontinent Pangaea. The family Laugiidae has a temporal range from the Early Triassic to the Late Jurassic, and its members have been described from both Greenland and Germany.

Helmolepis cyphognathus, sp. nov., a new platysiagid actinopterygian from the Lower Triassic Sulphur Mountain Formation (British Columbia, Canada)

2005 ◽  
Vol 42 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Andrew G Neuman ◽  
Raoul J Mutter
Keyword(s):  
British Columbia ◽  
New Species ◽  
Central Europe ◽  
Middle Triassic ◽  
Lower Triassic ◽  
Western Canada ◽  
Early Triassic ◽  
East Greenland ◽  
The Family ◽  
A New Species

A new species of stem actinopterygian, Helmolepis cyphognatus sp. nov., is reported from the Lower Triassic Sulphur Mountain Formation of western Canada (probably Smithian). This taxon differs from the only other known Early Triassic platysiagid, H. gracilis from the Lower Triassic Wordie Creek Formation of East Greenland (Griesbachian), in counts of branchiostegal rays, shape of the maxilla, shape (and possibly counts) of extrascapulars, and the size ratio of major opercular bones. In spite of their overall unfavorable preservation, the numerous available specimens amend our knowledge of the little known genus Helmolepis considerably: it has become evident that the morphology of Helmolepis cyphognatus sp. nov. comes closest to Platysiagum minus (Middle Triassic Besano Formation of central Europe). This study suggests placement of the two genera in the family Platysiagidae. Investigation of this new species also shows certain features of the cheek and the caudal fin are more primitive than previously believed, whereas the snout region is probably derived but of yet uncertain affinities in Helmolepis.

scholarly journals Phylogeny and divergence estimates for the gasteruptiid wasps (Hymenoptera : Evanioidea) reveals a correlation with hosts

2020 ◽  
Author(s):  
Ben A. Parslow ◽  
John T. Jennings ◽  
Michael P. Schwarz ◽  
Mark I. Stevens
Keyword(s):  
Late Jurassic ◽  
Divergence Times ◽  
Evolutionary Relationships ◽  
Taxon Sampling ◽  
Early Eocene ◽  
Molecular Fragments ◽  
Nuclear Markers ◽  
The Family ◽  
Divergence Estimates ◽  
Solitary Bees And Wasps

The Gasteruptiidae are an easily recognised family of wasps whose larvae are considered predator-inquilines in the nests of solitary bees and wasps. There has been minimal molecular research on the family and as a result little understanding of the evolutionary relationships within the group. We present the first molecular phylogeny focused on Gasteruptiidae, generated using three molecular fragments (mitochondrial C01 and nuclear markers EF1-α and 28s) and estimate the divergence times of Evanioidea based on three secondary calibration points. The analyses included 142 specimens of Gasteruptiidae and 5 outgroup taxa from Aulacidae and Evaniidae. The monophyly of the Gasteruptiidae and its subfamilies Gasteruptiinae (Gasteruption) and Hyptiogastrinae (Hyptiogaster and Pseudofoenus) are confirmed. Our results indicate that Evanioidea diverged during the late Jurassic at 151.3 (171.99–136.15)Ma with Evaniidae during the early Cretaceous at 137.33 (140.86–133.67)Ma, and Gasteruptiidae during the Palaeocene at 60.23 (83.78–40.02)Ma. The crown age of Hyptiogastrinae was estimated to be during the mid-Eocene 40.72 (60.9–22.57)Ma and for Gasteruption during the early Eocene at 47.46 (64.7–31.75)Ma, which corresponded to their host divergence ages. We anticipate that more extensive taxon sampling combined with the use of phylogenomic data will help resolve low support within the Gasteruption clade.

Redescription of †Yanosteus longidorsalis Jin et al., (Chondrostei, Acipenseriformes, †Peipiaosteidae) from the Early Cretaceous of China

2020 ◽  
Vol 95 (1) ◽  
pp. 170-183
Author(s):  
Eric J. Hilton ◽  
Lance Grande ◽  
Fan Jin
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Monotypic Genus ◽  
Pectoral Fin ◽  
Caudal Fin ◽  
Anterior Process ◽  
Dorsal Fin ◽  
The Family ◽  
Fin Rays ◽  
Cretaceous Deposits

AbstractThe family †Peipiaosteidae contains the genera †Peipiaosteus, †Stichopterus, †Spherosteus, †Yanosteus, and †Liaosteus, all from Late Jurassic to Early Cretaceous deposits of China, Russia, Kazakhstan, and Mongolia. Although the family has taxonomically expanded since it was first established for †P. pani Liu and Zhou, 1965, the amount of detailed comparative data for many of the taxa involved is lacking. In this paper, we describe the osteology of the monotypic genus †Yanosteus from the Yixian Formation (Early Cretaceous) of China largely on the basis of a newly prepared, well-preserved specimen. †Yanosteus is characterized by a series of infraorbital ossicles (a characteristic of the family), a broad, rounded palatopterygoid, a robust dentary, an extremely small opercle and a subopercle with distinctly long and rounded anterior process and a posteriorly scalloped margin, a broad and weakly forked caudal fin, an elongate dorsal fin with more than 160–178 fin rays (diagnostic for the genus), and a short but well-formed pectoral fin spine. We use the results of this study to discuss the characters of the †Peipiaosteioidei and the diversity of †peipiaosteioids.

Ichthyosaurs (Reptilia, Ichthyosauria) from the Lower and Middle Triassic Sulphur Mountain Formation, Wapiti Lake area, British Columbia, Canada

1989 ◽  
Vol 26 (7) ◽  
pp. 1491-1500 ◽  
Author(s):  
Jack M. Callaway ◽  
Donald B. Brinkman
Keyword(s):  
British Columbia ◽  
North America ◽  
Middle Triassic ◽  
Lower Triassic ◽  
Early Triassic ◽  
Lake Area ◽  
New Information ◽  
The Family

Ichthyosaurs are found in the Lower and Middle Triassic members of the Sulphur Mountain Formation in the Wapiti Lake area, British Columbia. Three species are recognized: Pessosaurus sp. in the family Shastasauridae from the Middle Triassic, Mixosaurus cf. M. nordenskioeldii in the family Mixosauridae from the Lower and Middle Triassic, and Phalarodon cf. P. fraasi in the family Omphalosauridae from the Middle Triassic. Other ichthyosaur material in the Lower Triassic (Smithian) member is the oldest known from North America and coeval with the oldest known elsewhere but cannot be identified confidently at this time. This material provides new information relative to the paleobiogeography of early ichthyosaurs and additional confirmation that ichthyosaurs were already highly specialized and quite diverse by the Early Triassic.

Effects of Median-Fin Amputation on Fast-Start Performance of Rainbow Trout (Salmo Gairdneri)

1977 ◽  
Vol 68 (1) ◽  
pp. 123-135 ◽  
Author(s):  
P. W. WEBB
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Ventral Lobe ◽  
Dorsal Lobe ◽  
Progressive Reduction ◽  
Caudal Fin ◽  
Lateral Body ◽  
Fin Ray ◽  
Fast Start ◽  
Major Variation

Fast-start performance of eight groups of rainbow trout with various finrays removed was measured to test the hydromechanical theory (Weihs, 1973) that large fins are required for acceleration. A trend towards decreasing performance was found for the following sequence of fin-ray amputations: control (pelvic rays amputated); dorsal fin; anal fin; dorsal lobe of caudal fin and ventral lobe of caudal fin; ventral lobe of caudal fin and anal fin; dorsal and ventral lobes of caudal fin; both caudal-fin lobes and anal fin. The series represents progressive reduction in fin and body area, as well as reduction in these areas where lateral movements are largest. Effects of fin amputation on performance were statistically significant (P > 0.05) in comparison with controls only for the last three groups lacking the caudal fin. The results confirm the hydromechanical theory, and lead to the conclusion that mechanically optimum lateral body profiles for faststart and for steady (cruising and sprint) performance are mutually exclusive. This mechanical restriction can be circumvented only in bony fish, with the evolution of flexible, collapsible fins that permit major variation in lateral body profile.

New species of Rineloricaria (Siluriformes: Loricariidae) from the Paranaíba River basin, Brazil

Zootaxa ◽  
2021 ◽  
Vol 5072 (6) ◽  
pp. 531-540
Author(s):  
GUILHERME JOSÉ DA COSTA-SILVA ◽  
CLAUDIO OLIVEIRA ◽  
GABRIEL DE SOUZA DA COSTA E SILVA
Keyword(s):  
New Species ◽  
River Basin ◽  
Color Pattern ◽  
Neotropical Region ◽  
Valid Species ◽  
Southeastern Brazil ◽  
Dark Spot ◽  
Caudal Fin ◽  
Fin Ray ◽  
First Ray

Rineloricaria is a genus of armored catfish encompassing 67 valid species that are widely distributed throughout the Neotropical region. A new species of Rineloricaria is described from the Paranaíba River, Upper Paraná River basin, southeastern Brazil. Rineloricaria rodriquezae sp. n. is distinguished from its congeners by the combination of the following characters: caudal-fin color pattern with basal dark spot and subterminal dark bar on branched rays interspersed with a hyaline area; five series of lateral plates with two keeled in the mid-dorsal series around the insertion of the first ray of dorsal fin; and unbranched caudal-fin ray extended as long filaments.  

Two new species of stalked crinoids from the northeastern Pacific in the genera Gephyrocrinus and Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae). Effects of ontogeny and variability on hyocrinid taxonomy

Zootaxa ◽  
2011 ◽  
Vol 2825 (1) ◽  
pp. 1 ◽  
Author(s):  
MICHEL ROUX ◽  
PHILIP LAMBERT
Keyword(s):  
British Columbia ◽  
New Species ◽  
Single Species ◽  
Depth Range ◽  
Evolutionary Trend ◽  
Exceptional Collection ◽  
The Family ◽  
Two New Species ◽  
Northeastern Pacific ◽  
Stalked Crinoids

Two new species of deep-sea stalked crinoids belonging to the family Hyocrinidae were collected in the northeastern Pacific. The descriptions contain detailed information on character variations and ontogeny. The five specimens of Gephyrocrinus messingi n. sp. lived at depths ranging from 1,777 m to 2,110 m off British Columbia and California. This new species is the first record of the genus Gephyrocrinus in the Pacific Ocean, which was previously known from only a single species, G. grimaldii, from the northeastern Atlantic at the same depth range. The two species illustrate opposing phenotypes within the same genus. Fifty-eight specimens of the second new species, Ptilocrinus clarki n. sp., were dredged off British Columbia close to the type-locality of P. pinnatus, the type species of the genus Ptilocrinus, but at shallower depths ranging from 1,178 to 1,986 m. This exceptional collection provides significant data on intraspecific variation in the main morphological characters, especially arm pattern. The ontogeny of stalk articulations and the main traits of adoral plate differentiation are described in detail. A complementary investigation on P. pinnatus was conducted using specimens collected by the “Albatross” expedition at a depth of 2,906 m. Despite similarities in external morphology, tegmen and cover plates, the two ptilocrinid species display significant differences in pinnule architecture, aboral cup and stalk articulations. From comparison with Gephyrocrinus messingi n. sp. and Ptilocrinus clarki n. sp., G. grimaldii and P. pinnatus are interpreted as the result of heterochronic development by paedomorphy after ecological or geographic isolation. Pinnule architecture in the two new species suggests first steps in an evolutionary trend toward a rigid box which protects gonad inflation in the proximal part of the pinnule. These new data on Ptilocrinus and Gephyrocrinus create problems in the current taxonomy of the family Hyocrinidae. The main derived characters, especially in pinnule and arm pattern, are used to propose new hypotheses for hyocrinid phylogeny.

scholarly journals A review of Palaeozoic and Mesozoic tetrapods from Greenland

2018 ◽  
Vol 66 ◽  
pp. 21-46 ◽  
Author(s):  
Marco Marzola ◽  
Octávio Mateus ◽  
Jesper Milàn ◽  
Lars B. Clemmensen
Keyword(s):  
Late Jurassic ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Late Triassic ◽  
Late Devonian ◽  
Early Triassic ◽  
Shallow Marine ◽  
East Greenland ◽  
Marine Deposits ◽  
Theropod Dinosaurs

This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

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