First record of the early Mesozoic sphenodontian Clevosaurus (Lepidosauria: Rhynchocephalia) from the Southern Hemisphere

1995 ◽  
Vol 69 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Hans-Dieter Sues ◽  
Robert R. Reisz
Keyword(s):  
Nova Scotia ◽  
Southern Hemisphere ◽  
Southern Africa ◽  
First Record ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Red Beds ◽  
Early Mesozoic

An incomplete skull of a small sphenodontian lepidosaur from the upper part of the Stormberg Group of southern Africa is referable to Clevosaurus Swinton, 1939. It is most closely related to C. bairdi from the McCoy Brook Formation (Lower Jurassic) of Nova Scotia (Canada) and C. mcgilli from the Dark Red Beds of the Lower Lufeng Formation (Lower Jurassic) of Yunnan (China). The new specimen is important because it represents the first record of Clevosaurus from the Southern Hemisphere. Like many other taxa of Early Jurassic continental tetrapods (crocodylomorph archosaurs, dinosaurs, synapsids), Clevosaurus had an apparently Pangaean distribution.

First record of the tritylodontid cynodont Oligokyphus and cynodont postcranial bones from the McCoy Brook Formation of Nova Scotia, Canada

2015 ◽  
Vol 52 (4) ◽  
pp. 244-249 ◽  
Author(s):  
Tim J. Fedak ◽  
Hans-Dieter Sues ◽  
Paul E. Olsen
Keyword(s):  
Nova Scotia ◽  
North America ◽  
Geographic Distribution ◽  
First Record ◽  
Upper Triassic ◽  
Early Jurassic ◽  
Eastern North America ◽  
Taxonomic Identification ◽  
Early Mesozoic ◽  
Wide Geographic Distribution

A fragment of a right dentary with one postcanine tooth from the Upper Triassic (Rhaetian) Scots Bay Member of the McCoy Brook Formation at Wasson Bluff, Nova Scotia, Canada, represents the first record of the tritylodontid cynodont Oligokyphus from the early Mesozoic of eastern North America. In addition, three dissociated postcranial bones from the same horizon and locality are referable to derived cynodont therapsids. One of these elements, a nearly complete right humerus, can be assigned to Tritylodontidae. Two other bones, an ulna and incomplete ischium, belong to indeterminate derived cynodonts but show no features allowing more precise taxonomic identification. The presence of Oligokyphus in the McCoy Brook Formation provides additional evidence for the remarkably wide geographic distribution of many latest Triassic and Early Jurassic continental tetrapods.

scholarly journals Upper Karoo vertebrate assemblages (Late Triassic/Early Jurassic) of the Lake Kariba region, Zimbabwe

2017 ◽  
Author(s):  
Paul M Barrett ◽  
Tim Broderick ◽  
Kimberley Chapelle ◽  
Jonah Choiniere ◽  
Steve Edwards ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Southern Africa ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Type Locality ◽  
Late Triassic ◽  
Lake Kariba ◽  
Aquatic Fauna ◽  
Mudstone Facies

Southern Africa provides critical information on Late Triassic–Early Jurassic terrestrial tetrapod faunas. Most of the localities in this region are in South Africa and Lesotho, but preliminary work in Zimbabwe has revealed significant potential. Early Jurassic Zimbabwean localities have yielded the basal sauropodomorph Massospondylus, the early sauropod Vulcanodon and theropod material. Late Triassic localities are also known, but have yielded only fragmentary specimens thus far. In early 2017, a joint South African-Zimbabwean-UK team conducted fieldwork in the upper Karoo-aged deposits along the shores of Lake Kariba, northern Zimbabwe (Mid-Zambesi Basin). We relocated the Vulcanodon type locality on Island 126/127 and found that, contrary to previous reports suggesting a Toarcian age, the quarry was in a horizon pre-dating the onset of Drakensburg volcanism (= Batoka Basalts). It is situated instead within the earlier Lower Jurassic Forest Sandstone. This indicates that Vulcanodon is 10–15 million years older than thought previously, recalibrating several nodes within Sauropoda and indicating extensive overlap between true sauropods and 'prosauropods'. Other new vertebrate localities show that sauropodomorphs are present in the Forest Sandstone and upper Tashinga (Late Triassic) formations, but a grey mudstone facies within the Pebbly Arkose Member of the latter unit yields a more aquatic fauna, including lungfish and phytosaurs, but lacking sauropodomorphs. The phytosaur occurrence is the first in Africa south of the Sahara. Faunal and sedimentological evidence indicates that the Late Triassic and Early Jurassic sites in this region were deposited under more mesic environments than their lateral equivalents in South Africa.

scholarly journals Upper Karoo vertebrate assemblages (Late Triassic/Early Jurassic) of the Late Kariba region, Zimbabwe

2017 ◽  
Author(s):  
Paul M Barrett ◽  
Tim Broderick ◽  
Kimberley Chapelle ◽  
Jonah Choiniere ◽  
Steve Edwards ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Southern Africa ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Type Locality ◽  
Late Triassic ◽  
Lake Kariba ◽  
Aquatic Fauna ◽  
Mudstone Facies

Southern Africa provides critical information on Late Triassic–Early Jurassic terrestrial tetrapod faunas. Most of the localities in this region are in South Africa and Lesotho, but preliminary work in Zimbabwe has revealed significant potential. Early Jurassic Zimbabwean localities have yielded the basal sauropodomorph Massospondylus, the early sauropod Vulcanodon and theropod material. Late Triassic localities are also known, but have yielded only fragmentary specimens thus far. In early 2017, a joint South African-Zimbabwean-UK team conducted fieldwork in the upper Karoo-aged deposits along the shores of Lake Kariba, northern Zimbabwe (Mid-Zambesi Basin). We relocated the Vulcanodon type locality on Island 126/127 and found that, contrary to previous reports suggesting a Toarcian age, the quarry was in a horizon pre-dating the onset of Drakensburg volcanism (= Batoka Basalts). It is situated instead within the earlier Lower Jurassic Forest Sandstone. This indicates that Vulcanodon is 10–15 million years older than thought previously, recalibrating several nodes within Sauropoda and indicating extensive overlap between true sauropods and 'prosauropods'. Other new vertebrate localities show that sauropodomorphs are present in the Forest Sandstone and upper Tashinga (Late Triassic) formations, but a grey mudstone facies within the Pebbly Arkose Member of the latter unit yields a more aquatic fauna, including lungfish and phytosaurs, but lacking sauropodomorphs. The phytosaur occurrence is the first in Africa south of the Sahara. Faunal and sedimentological evidence indicates that the Late Triassic and Early Jurassic sites in this region were deposited under more mesic environments than their lateral equivalents in South Africa.

scholarly journals The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5976 ◽  
Author(s):  
Cristiano Dal Sasso ◽  
Simone Maganuco ◽  
Andrea Cau
Keyword(s):  
Marine Invertebrates ◽  
First Record ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Ancestral State ◽  
Theropod Dinosaurs ◽  
Sea Bottom ◽  
Fourth Finger ◽  
Primary Axis ◽  
Digit Position

The homology of the tridactyl hand of birds is a still debated subject, with both paleontological and developmental evidence used in support of alternative identity patterns in the avian fingers. With its simplified phalangeal morphology, the Late Jurassic ceratosaurian Limusaurus has been argued to support a II–III–IV digital identity in birds and a complex pattern of homeotic transformations in three-fingered (tetanuran) theropods. We report a new large-bodied theropod, Saltriovenator zanellai gen. et sp. nov., based on a partial skeleton from the marine Saltrio Formation (Sinemurian, lowermost Jurassic) of Lombardy (Northern Italy). Taphonomical analyses show bone bioerosion by marine invertebrates (first record for dinosaurian remains) and suggest a complex history for the carcass before being deposited on a well-oxygenated and well-illuminated sea bottom. Saltriovenator shows a mosaic of features seen in four-fingered theropods and in basal tetanurans. Phylogenetic analysis supports sister taxon relationships between the new Italian theropod and the younger Early Jurassic Berberosaurus from Morocco, in a lineage which is the basalmost of Ceratosauria. Compared to the atrophied hand of later members of Ceratosauria, Saltriovenator demonstrates that a fully functional hand, well-adapted for struggling and grasping, was primitively present in ceratosaurians. Ancestral state reconstruction along the avian stem supports 2-3-4-1-X and 2-3-4-0-X as the manual phalangeal formulae at the roots of Ceratosauria and Tetanurae, confirming the I–II–III pattern in the homology of the avian fingers. Accordingly, the peculiar hand of Limusaurus represents a derived condition restricted to late-diverging ceratosaurians and cannot help in elucidating the origin of the three-fingered condition of tetanurans. The evolution of the tridactyl hand of birds is explained by step-wise lateral simplification among non-tetanuran theropod dinosaurs, followed by a single primary axis shift from digit position 4 to 3 at the root of Tetanurae once the fourth finger was completely lost, which allowed independent losses of the vestigial fourth metacarpal among allosaurians, tyrannosauroids, and maniraptoromorphs. With an estimated body length of 7.5 m, Saltriovenator is the largest and most robust theropod from the Early Jurassic, pre-dating the occurrence in theropods of a body mass approaching 1,000 Kg by over 25 My. The radiation of larger and relatively stockier averostran theropods earlier than previously known may represent one of the factors that ignited the trend toward gigantism in Early Jurassic sauropods.

scholarly journals Upper Karoo vertebrate assemblages (Late Triassic/Early Jurassic) of the Lake Kariba region, Zimbabwe

2017 ◽  
Author(s):  
Paul M Barrett ◽  
Tim Broderick ◽  
Kimberley Chapelle ◽  
Jonah Choiniere ◽  
Steve Edwards ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Southern Africa ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Type Locality ◽  
Late Triassic ◽  
Lake Kariba ◽  
Aquatic Fauna ◽  
Mudstone Facies

Southern Africa provides critical information on Late Triassic–Early Jurassic terrestrial tetrapod faunas. Most of the localities in this region are in South Africa and Lesotho, but preliminary work in Zimbabwe has revealed significant potential. Early Jurassic Zimbabwean localities have yielded the basal sauropodomorph Massospondylus, the early sauropod Vulcanodon and theropod material. Late Triassic localities are also known, but have yielded only fragmentary specimens thus far. In early 2017, a joint South African-Zimbabwean-UK team conducted fieldwork in the upper Karoo-aged deposits along the shores of Lake Kariba, northern Zimbabwe (Mid-Zambesi Basin). We relocated the Vulcanodon type locality on Island 126/127 and found that, contrary to previous reports suggesting a Toarcian age, the quarry was in a horizon pre-dating the onset of Drakensburg volcanism (= Batoka Basalts). It is situated instead within the earlier Lower Jurassic Forest Sandstone. This indicates that Vulcanodon is 10–15 million years older than thought previously, recalibrating several nodes within Sauropoda and indicating extensive overlap between true sauropods and 'prosauropods'. Other new vertebrate localities show that sauropodomorphs are present in the Forest Sandstone and upper Tashinga (Late Triassic) formations, but a grey mudstone facies within the Pebbly Arkose Member of the latter unit yields a more aquatic fauna, including lungfish and phytosaurs, but lacking sauropodomorphs. The phytosaur occurrence is the first in Africa south of the Sahara. Faunal and sedimentological evidence indicates that the Late Triassic and Early Jurassic sites in this region were deposited under more mesic environments than their lateral equivalents in South Africa.

Lithostratigraphy of volcanic and sedimentary sequences in central Livingston Island, South Shetland Islands

1995 ◽  
Vol 7 (1) ◽  
pp. 99-113 ◽  
Author(s):  
J.L. Smellie ◽  
M. Liesa ◽  
J.A. Muñoz ◽  
F. Sàbat ◽  
R. Pallàs ◽  
...  
Keyword(s):  
Debris Flows ◽  
Lower Jurassic ◽  
South Shetland Islands ◽  
Polyphase Deformation ◽  
Magmatic Arc ◽  
Shetland Islands ◽  
Sedimentary Sequences ◽  
Early Mesozoic ◽  
Livingston Island ◽  
Volcaniclastic Rocks

Livingston Island contains several, distinctive sedimentary and volcanic sequences, which document the history and evolution of an important part of the South Shetland Islands magmatic arc. The turbiditic, late Palaeozoic–early Mesozoic Miers Bluff Formation (MBF) is divided into the Johnsons Dock and Napier Peak members, which may represent sedimentation in upper and lower mid-fan settings, respectively, prior to pre-late Jurassic polyphase deformation (dominated by open folding). The Moores Peak breccias are formed largely of coarse clasts reworked from the MBF. The breccias may be part of the MBF, a separate unit, or part of the Mount Bowles Formation. The structural position is similar to the terrigenous Lower Jurassic Botany Bay Group in the northern Antarctic Peninsula, but the precise stratigraphical relationships and age are unknown. The (?) Cretaceous Mount Bowles Formation is largely volcanic. Detritus in the volcaniclastic rocks was formed mainly during phreatomagmatic eruptions and redeposited by debris flows (lahars), whereas rare sandstone interbeds are arkosic and reflect a local provenance rooted in the MBF. The Pleistocene–Recent Inott Point Formation is dominated by multiple, basaltic tuff cone relicts in which distinctive vent and flank sequences are recognized. The geographical distribution of the Edinburgh Hill Formation is closely associated with faults, which may have been reactivated as dip-slip structures during Late Cenozoic extension (arc splitting).

Provenance of Jurassic sedimentary rocks of south-central Quesnellia, British Columbia: implications for paleogeography

2004 ◽  
Vol 41 (1) ◽  
pp. 103-125 ◽  
Author(s):  
Nathan T Petersen ◽  
Paul L Smith ◽  
James K Mortensen ◽  
Robert A Creaser ◽  
Howard W Tipper
Keyword(s):  
Detrital Zircon ◽  
Middle Jurassic ◽  
Sedimentary Rocks ◽  
Source Area ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Nd Isotopes ◽  
South Central ◽  
History Of

Jurassic sedimentary rocks of southern to central Quesnellia record the history of the Quesnellian magmatic arc and reflect increasing continental influence throughout the Jurassic history of the terrane. Standard petrographic point counts, geochemistry, Sm–Nd isotopes and detrital zircon geochronology, were employed to study provenance of rocks obtained from three areas of the terrane. Lower Jurassic sedimentary rocks, classified by inferred proximity to their source areas as proximal or proximal basin are derived from an arc source area. Sandstones of this age are immature. The rocks are geochemically and isotopically primitive. Detrital zircon populations, based on a limited number of analyses, have homogeneous Late Triassic or Early Jurassic ages, reflecting local derivation from Quesnellian arc sources. Middle Jurassic proximal and proximal basin sedimentary rocks show a trend toward more evolved mature sediments and evolved geochemical characteristics. The sandstones show a change to more mature grain components when compared with Lower Jurassic sedimentary rocks. There is a decrease in εNdT values of the sedimentary rocks and Proterozoic detrital zircon grains are present. This change is probably due to a combination of two factors: (1) pre-Middle Jurassic erosion of the Late Triassic – Early Jurassic arc of Quesnellia, making it a less dominant source, and (2) the increase in importance of the eastern parts of Quesnellia and the pericratonic terranes, such as Kootenay Terrane, both with characteristically more evolved isotopic values. Basin shale environments throughout the Jurassic show continental influence that is reflected in the evolved geochemistry and Sm–Nd isotopes of the sedimentary rocks. The data suggest southern Quesnellia received material from the North American continent throughout the Jurassic but that this continental influence was diluted by proximal arc sources in the rocks of proximal derivation. The presence of continent-derived material in the distal sedimentary rocks of this study suggests that southern Quesnellia is comparable to known pericratonic terranes.

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