Note on a second occurrence of thalattosaur remains (Reptilia: Neodiapsida) in British Columbia

1991 ◽  
Vol 28 (12) ◽  
pp. 2065-2068 ◽  
Author(s):  
Glenn W. Storrs
Keyword(s):  
British Columbia ◽  
Geographic Range ◽  
Range Extension ◽  
Late Triassic

A fragmentary thalattosaur specimen from the Late Triassic Pardonet Formation of northeastern British Columbia is the second reported occurrence of such animals in Canada. The group was previously known with certainty only from the Hosselkus Limestone of California, the Monte San Giorgio region shales of Italy and Switzerland, the Natchez Pass Formation of Nevada, and most recently, the Sulphur Mountain Formation of British Columbia. As such, the described material, which is indeterminate to genus, represents a slight geographic range extension of the Thalattosauria. The Norian age of this material represents a significant temporal range extension for the Thalattosauria, and it is the geologically youngest material known of this taxon.

scholarly journals Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Teresa A. Newsome ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Geographic Range ◽  
Regression Analyses ◽  
Relative Height ◽  
Trembling Aspen ◽  
Ecosystem Productivity ◽  
Height Ratio ◽  
Critical Height ◽  
South Central

Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximizedR2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. MaximumR2values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

scholarly journals The first occurrence of the enigmatic archosaur Crosbysaurus (Heckert 2004) from the Chinle Formation of Southern Utah

2014 ◽  
Author(s):  
Robert J Gay ◽  
Isabella St. Aude
Keyword(s):  
New Mexico ◽  
Close Association ◽  
First Record ◽  
Geographic Range ◽  
Type Locality ◽  
Late Triassic ◽  
Southern Area ◽  
Chinle Formation ◽  
First Occurrence ◽  
Unique Compound

Originally identified as an ornithisichian dinosaur, Crosbysaurus has been found in New Mexico, Arizona, and the type locality in Texas. The genus has been reassessed by other workers in light of revelations about the postcrania of another putative Triassic ornithischian, Revueltosaurus. The understanding of Triassic dental faunas has become more complicated by the extreme convergence between pseudosuchian archosaurus and ornithichian dinosaur dental morphologies. We report here on a new specimen of Crosbysaurus from the Petrified Forest Member of the Chinle Formation at Comb Ridge in southeastern Utah. This new specimen is assigned to Crosbysaurus on the basis of the unique compound posterior denticles, mediolateral width, and curvature. While this specimen, MNA V10666, does not help resolve the affinities of Crosbysaurus it does represent an approximately 250 kilometer extension of the geographic range of this taxon. This is the first record of this taxon in Utah and as such it represents the northernmost known record of Crosbysaurus. This indicates that Crosbysaurus was not limited to the southern area of Chinle/Dockum deposition but instead was widespread across the paleoriver systems of the Late Triassic in western Pangea. The specimen we report on here was found in close association with a typical Late Triassic Chinle fauna, including phytosaurs, metoposaurs, and dinosauromorphs.

scholarly journals New records and range extension of Black-goggled Tanager, Trichothraupis melanops (Vieillot, 1818) (Passeriformes, Thraupidae), in extreme southern Brazil

Check List ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 67-73
Author(s):  
Gustavo Crizel Gomes ◽  
Thales Castilhos de Freitas ◽  
Henrique Noguez da Cunha ◽  
Fernando Jacobs ◽  
Michele Spenst Wall
Keyword(s):  
New Records ◽  
Rio Grande ◽  
Geographic Range ◽  
Range Extension ◽  
Direct Visualization ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Vocal Recognition ◽  
Resident Populations

We describe new records of Trichothraupis melanops in five municipalities of Rio Grande do Sul, Brazil. The birds were detected in sporadic expeditions in the Serra do Sudeste and Campanha Gaúcha regions by direct visualization and vocal recognition. One of these records, next to the border with Uruguay, is the southernmost known location for the species in Brazil. This record expands the geographic range of the species in Brazil south by 170 km. We believe that these occurrences are seasonal displacements and do not represent a colonization front with resident populations.

A new genus of ichthyosaur from the Late Triassic Pardonet Formation of British Columbia: bridging the Triassic Jurassic gap

2001 ◽  
Vol 38 (6) ◽  
pp. 983-1002 ◽  
Author(s):  
Elizabeth L Nicholls ◽  
Makoto Manabe
Keyword(s):  
British Columbia ◽  
Type Species ◽  
New Genus ◽  
Late Triassic ◽  
Unique Combination ◽  
Type Specimens ◽  
Nomen Dubium ◽  
The Family ◽  
Large Diamond

Both the genus Shastasaurus and the family Shastasauridae have long been hard to define due to the fragmentary nature of the type specimens. Consequently, recent interpretations of the genus have been based almost entirely on Shastasaurus neoscapularis from the Late Triassic Pardonet Formation of British Columbia. Two new specimens of this taxon, from Pink Mountain, British Columbia, demonstrate that it does not belong in the genus Shastasaurus. This paper describes the new specimens, and refers the species to Metashastasaurus gen nov. Post-cranially, the skeleton of Metashastasaurus resembles that of shastasaurids, differing primarily only in the shape of the scapula and fibula. However, the skull has a unique combination of characters, including large diamond-shaped frontals that enter the supratemporal fenestrae, and very narrow posterior extensions of the nasals, which contact the postfrontals. It also differs from the skull of Shastasaurus in the presence of both a parietal ridge and postparietal shelf. This is a combination of derived characters previously known only in Jurassic forms. The front limb has four proximal carpals and four digits, indicating that previous reconstructions were based on incomplete material. Shastasaurus pacificus Merriam 1895, the type species of the genus Shastasaurus, must be considered a nomen dubium, making the genus Shastasaurus invalid. Until this problem is clarified, the use of the generic name Shastasaurus should be restricted to Merriam's type specimens, of which only Shastasaurus alexandrae and Shastasaurus osmonti are based on adequate material.

Structural and metamorphic relationships between the Mount Ida and Monashee Groups at Mara Lake, British Columbia

1982 ◽  
Vol 19 (2) ◽  
pp. 288-307 ◽  
Author(s):  
Kent C. Nielsen
Keyword(s):  
British Columbia ◽  
Large Scale ◽  
Ductile Deformation ◽  
Late Triassic ◽  
Second Phase ◽  
The West ◽  
Late Mesozoic ◽  
The North ◽  
Phase Deformation ◽  
Metamorphic Core

Mara Lake, British Columbia straddles the boundary between the Monashee Group on the east and the Mount Ida Group on the west. Correlation of units across the southern end of Mara Lake indicates lithologic continuity between parts of the groups. Both groups have experienced four phases of deformation. Phases one and two are tight and recumbent, trending to the north and to the west, respectively. Phases three and four are open to closed and upright, trending northwest and northeast, respectively. Second-phase deformation includes large-scale tectonic slides that separate areas of consistent vergence. Slide surfaces are folded by third- and fourth-phase structures and outline domal outcrop patterns. Metamorphic grade increases from north to south along the west side of Mara Lake. Calc-silicate reactions involving the formation of diopside are characteristic. From west to east increasing grade is evident in the reaction of muscovite + quartz producing sillimanite + K-feldspar + water. These prograde reactions are related to relative position in the second-phase structure. The highest grade is located near the lowest slide surface. Greenschist conditions accompanied phase-three deformation. Fourth phase is characterized by hydrothermal alteration, brittle fracturing, and local faulting. First-phase deformation appears to be pre-Late Triassic whereas second and third phases are post-Late Triassic and pre-Cretaceous. The fourth phase is part of a regional Tertiary event. The third folding event is correlated with the development of the Chase antiform and the second-phase folding is related to the pervasive east–west fabric of the Shuswap Complex. The timing of these events indicates that the metamorphic core zone of the eastern Cordillera was relatively rigid during the late Mesozoic foreland thrust development. Ductile deformation significantly preceded thrusting and developed a fabric almost at right angles to the trend of the thrust belt.

Regional implications of Upper Triassic metavolcanic and metasedimentary rocks on the Chilkat Peninsula, southeastern Alaska

1980 ◽  
Vol 17 (6) ◽  
pp. 681-689 ◽  
Author(s):  
George Plafker ◽  
Travis Hudson
Keyword(s):  
British Columbia ◽  
Volcanic Rocks ◽  
Upper Triassic ◽  
Late Triassic ◽  
Low Grade ◽  
Lake Area ◽  
Metasedimentary Rocks

A low-grade metamorphic sequence consisting of thick mafic volcanic rocks overlain by calcareous flysch with very minor limestone underlies much of the Chilkat Peninsula. Fossils collected from both units are of Triassic age, probably late Karnian. This sequence appears to be part of the Taku terrane, a linear tectono-stratigraphic belt that now can be traced for almost 700 km through southeastern Alaska to the Kelsall Lake area of British Columbia. The age and gross lithology of the Chilkat Peninsula sequence are comparable to Upper Triassic rocks that characterize the allochthonous tectono-stratigraphic terrane named Wrangellia. This suggests either that the two terranes are related in their history or that they are allochthonous with respect to one another and coincidentally evolved somewhat similar sequences in Late Triassic time.

Extension of the Known Range of the Masked Greenling, Hexagrammos octogrammus, to British Columbia

1971 ◽  
Vol 28 (6) ◽  
pp. 927-928
Author(s):  
Alex E. Peden
Keyword(s):  
British Columbia ◽  
Geographic Range

Previously, the known geographic range of the masked greenling, Hexagrammos octogrammus (Pallas), extended north and west of Sitka, Alaska. The capture of four juvenile specimens from Stephens Island near Prince Rupert extends the known range by more than 200 miles and provides the first records of this species from British Columbia.

Revised stratigraphy of the Takla Group, north-central British Columbia

1977 ◽  
Vol 14 (2) ◽  
pp. 318-326 ◽  
Author(s):  
J. W. H. Monger ◽  
B. N. Church
Keyword(s):  
British Columbia ◽  
Sedimentary Rocks ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
North Central ◽  
Volcaniclastic Rocks ◽  
Jurassic Rocks

The Takla Group of north-central British Columbia as originally defined contained volcanic and sedimentary rocks of Late Triassic and Jurassic ages. As redefined herein, it consists of three formations in the McConnell Creek map-area. Lowest is the Dewar Formation, composed of argillite and volcanic sandstone that is largely the distal equivalent of basic flows and coarse volcaniclastic rocks of the Savage Mountain Formation. These formations are overlain by the volcaniclastic, basic to intermediate Moosevale Formation. These rocks are Upper Triassic (upper Karnian and lower Norian). They are unconformably overlain by Lower Jurassic rocks of the Hazelton Group.

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