scholarly journals New material and revision ofMelanorosaurus thabanensis, a basal sauropodomorph from the Upper Triassic of Lesotho

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1639 ◽  
Author(s):  
Claire Peyre de Fabrègues ◽  
Ronan Allain
Keyword(s):  
Phylogenetic Analysis ◽  
Southern Africa ◽  
Upper Triassic ◽  
Early Jurassic ◽  
Type Locality ◽  
Late Triassic ◽  
Original Publication ◽  
Stratigraphic Position ◽  
New Material

Melanorosaurusis a genus of basal sauropodomorph that currently includes two species from Southern Africa. In this paper, we redescribe the holotype femur ofMelanorosaurus thabanensisfrom the Elliot Formation of Lesotho, as well as associated remains. The stratigraphic position of this taxon is reviewed, and it is clear that it comes from the Lower Elliot Formation being, therefore, Late Triassic in age, and not Early Jurassic as originally described. The knowledge of the anatomy of the basal sauropodomorph of Thabana Morena is enhanced by the description of six new skeletal elements from the type locality. The femur and the ilium from Thabana Morena are diagnostic and characterized by unusual proportions. The first phylogenetic analysis including both this specimen andMelanorosaurusis conducted. This analysis leads to the conclusion that the femur described in the original publication ofMelanorosaurus thabanensiscan no longer be referred toMelanorosaurus. For these reasons, we hereby createMeroktenosgen. nov. to encompassMeroktenos thabanensiscomb. nov.

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 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 A revision of the early neotheropod genus Sarcosaurus from the Early Jurassic (Hettangian–Sinemurian) of central England

2020 ◽  
Vol 191 (1) ◽  
pp. 113-149 ◽  
Author(s):  
Martín D Ezcurra ◽  
Richard J Butler ◽  
Susannah C R Maidment ◽  
Ivan J Sansom ◽  
Luke E Meade ◽  
...  
Keyword(s):  
Type Species ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Valid Species ◽  
Character State ◽  
New Information ◽  
Evolutionary Radiation ◽  
Nomina Dubia

Abstract Neotheropoda represents the main evolutionary radiation of predatory dinosaurs and its oldest records come from Upper Triassic rocks (c. 219 Mya). The Early Jurassic record of Neotheropoda is taxonomically richer and geographically more widespread than that of the Late Triassic. The Lower Jurassic (upper Hettangian–lower Sinemurian) rocks of central England have yielded three neotheropod specimens that have been assigned to two species within the genus Sarcosaurus, S. woodi (type species) and S. andrewsi. These species have received little attention in discussions of the early evolution of Neotheropoda and recently have been considered as nomina dubia. Here, we provide a detailed redescription of one of these specimens (WARMS G667–690) and reassess the taxonomy and phylogenetic relationships of the genus Sarcosaurus. We propose that the three neotheropod specimens from the Early Jurassic of central England represent a single valid species, S. woodi. The second species of the genus, ‘S. andrewsi’, is a subjective junior synonym of the former. A quantitative phylogenetic analysis of early theropods recovered S. woodi as one of the closest sister-taxa to Averostra and provides new information on the sequence of character state transformations in the lead up to the phylogenetic split between Ceratosauria and Tetanurae.

scholarly journals A new sphenodontian (Lepidosauria: Rhynchocephalia) from the Late Triassic of Argentina and the early origin of the herbivore opisthodontians

2013 ◽  
Vol 280 (1772) ◽  
pp. 20132057 ◽  
Author(s):  
Ricardo N. Martínez ◽  
Cecilia Apaldetti ◽  
Carina E. Colombi ◽  
Angel Praderio ◽  
Eliana Fernandez ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
South America ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Late Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
Northwestern Argentina ◽  
Successful Group ◽  
Early Origin

Sphenodontians were a successful group of rhynchocephalian reptiles that dominated the fossil record of Lepidosauria during the Triassic and Jurassic. Although evidence of extinction is seen at the end of the Laurasian Early Cretaceous, they appeared to remain numerically abundant in South America until the end of the period. Most of the known Late Cretaceous record in South America is composed of opisthodontians, the herbivorous branch of Sphenodontia, whose oldest members were until recently reported to be from the Kimmeridgian–Tithonian (Late Jurassic). Here, we report a new sphenodontian, Sphenotitan leyesi gen. et sp. nov., collected from the Upper Triassic Quebrada del Barro Formation of northwestern Argentina. Phylogenetic analysis identifies Sphenotitan as a basal member of Opisthodontia, extending the known record of opisthodontians and the origin of herbivory in this group by 50 Myr.

Shastasaurus altispinus(Ichthyosauria, Shastasauridae) from the Upper Triassic of the El Antimonio district, northwestern Sonora, Mexico

1989 ◽  
Vol 63 (6) ◽  
pp. 930-939 ◽  
Author(s):  
Jack M. Callaway ◽  
Judy A. Massare
Keyword(s):  
Upper Triassic ◽  
Current Understanding ◽  
Type Locality ◽  
Lower Jaw ◽  
First Occurrence ◽  
New Material ◽  
Shasta County ◽  
Early Late

New specimens ofShastasaurus altispinusMerriam are recognized from the Upper Triassic Antimonio Formation in the El Antimonio district of northwestern Sonora, Mexico. This represents the first occurrence of the species outside of its type locality in Shasta County, California, and the first known occurrence of Triassic ichthyosaurs from Mexico. Some remains are well preserved, but in general they are fragmented, structurally distorted, and incomplete; however, they enhance the current understanding of the morphology of a species that has been known hitherto only from an even more incomplete holotype. The material is the first from anyShastasaurusthat preserves the anterior portions of the skull and lower jaw and implanted teeth. Revised diagnoses for the genus and species are given on the basis of the new material. Biostratigraphic zonation furnishes an early Late Carnian age for the specimens, which is in accord with that for the holotype.

scholarly journals A reevaluation of the basal turtle Indochelys spatulata from the Early–Middle Jurassic (Toarcian–Aalenian) of India, with descriptions of new material

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8542
Author(s):  
Walter G. Joyce ◽  
Saswati Bandyopadhyay
Keyword(s):  
Phylogenetic Analysis ◽  
Middle Jurassic ◽  
Phylogenetic Analyses ◽  
Type Locality ◽  
Recent Analysis ◽  
New Material

Background Indochelys spatulata is an extinct turtle from the Early to Middle Jurassic Kota Formation of the Pranhita–Godavari Gondwana basin, India. The holotype and previously only known specimen is a partially eroded shell that had been collected near Kota village, north of Sironcha, in Maharashtra State. Phylogenetic analyses have consistently suggested placement at the base of the clade Mesochelydia. Methods We here figure and describe the holotype of Indochelys spatulata and two new specimens, which were collected from the Kota Formation near Kistapur village, Telengana State, about 60 km NW from the type locality. We furthermore explore the relationships of this fossil turtle by updating its scoring based on all available material in the most recent analysis of basal turtle relationships. Results The revision of the holotype of Indochelys spatulata provides minor adjustments to the morphology of this specimen, in particular recognition of a transverse break across the carapace, presence of only eight neurals, of which the eight is octagonal, and presence of a pathological element located between neurals VII and VIII. The new material provides new anatomical insights, in particular presence of a broad cervical, a vertebral V that inserts deeply into vertebral IV, narrow pleurals within increasingly short posteromedial contacts with the vertebrals towards the posterior, at least three pairs of musk duct foramina, and numerous insights into the morphology of the girdles and stylopodium. In combination, all material allows affirming the validity of Indochelys spatulata with confidence. The phylogenetic analysis affirms the placement of Indochelys spatulata as a basal mesochelydian, but cannot resolve its relationships relative to the roughly coeval Condorchelys antiqua and Kayentachelys aprix.

Redescription of the archosaur Parringtonia gracilis from the Middle Triassic Manda beds of Tanzania, and the antiquity of Erpetosuchidae

2012 ◽  
Vol 150 (2) ◽  
pp. 225-238 ◽  
Author(s):  
STERLING J. NESBITT ◽  
RICHARD J. BUTLER
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Middle Triassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
Dorsal Margin ◽  
Posterior Portion ◽  
Anterior Half

AbstractParringtonia gracilis Huene, 1939 is represented by both cranial and postcranial material collected from the lower Middle Triassic (Anisian) Lifua Member of the Manda beds in southwestern Tanzania. This aberrant taxon was previously proposed to have affinities with pseudosuchian archosaurs, and specifically with the enigmatic Erpetosuchus granti from the Upper Triassic of Scotland. Here, we confirm the close affinities of Parringtonia gracilis and Erpetosuchus granti based on the following unambiguous synapomorphies: mediolaterally expanded posterior portion of the maxilla, alveoli present only in the anterior half of the maxilla, and absence of tooth serrations. Furthermore, the two taxa share osteoderms with deep sculpturing, a deep fossa on the dorsal margin of the neural spines and a heavily waisted shaft of the scapula. We added both Parringtonia gracilis and Erpetosuchus granti into a comprehensive phylogenetic analysis of early archosaurs and found that these taxa are clearly referable to Archosauria but that relationships are poorly resolved at the base of this clade. However, our analysis demonstrates that Erpetosuchus granti is not closely related to Crocodylomorpha, as has been hypothesized previously. The Erpetosuchidae are a clade of small-bodied archosaurs that have a poor fossil record but have members from both northern and southern Pangaea, ranging temporally from the Middle to Late Triassic. Thus, Erpetosuchidae is part of the early archosaurian radiation.

scholarly journals Phylogenetic and ecomorphologic diversifications of spiriferinid brachiopods after the end-Permian extinction

Paleobiology ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 495-510
Author(s):  
Zhen Guo ◽  
Zhong-Qiang Chen ◽  
David A. T. Harper
Keyword(s):  
Phylogenetic Analysis ◽  
Small Group ◽  
Phylogenetic Trees ◽  
Early Jurassic ◽  
Late Triassic ◽  
Evolutionary Relationships ◽  
Early Triassic ◽  
Permian Extinction ◽  
Recovery Dynamics

AbstractThe Order Spiriferinida spanning the latest Ordovician to Early Jurassic is a small group of brachiopods overshadowed by other taxon-rich clades during the Paleozoic. It diversified significantly after the end-Permian extinction and became one of the four major clades of Triassic brachiopods. However, the phylogeny and recovery dynamics of this clade during the Triassic still remain unknown. Here, we present a higher-level parsimony-based phylogenetic analysis of Mesozoic spiriferinids to reveal their evolutionary relationships. Ecologically related characters are analyzed to indicate the variances in ecomorphospace occupation and disparity of spiriferinids through the Permian–Triassic (P-Tr) transition. For comparison with potential competitors of the spiriferinids, the pre-extinction spiriferids are also included in the analysis. Phylogenetic trees demonstrate that about half of the Mesozoic families appeared during the Anisian, indicating the greatest phylogenetic diversification at that time. Triassic spiriferinids reoccupied a large part of the ecomorphospace released by its competitor spiriferids during the end-Permian extinction; they also fully exploited the cyrtiniform region and developed novel lifestyles. Ecomorphologic disparity of the spiriferinids dropped greatly in the Early Triassic, but it rebounded rapidly and reached the level attained by the pre-extinction spiriferids in the Late Triassic. The replacement in ecomorphospace occupation between spiriferids and spiriferinids during the P-Tr transition clearly indicates that the empty ecomorphospace released by the extinction of Permian spiriferids was one of the important drivers for the diversification of the Triassic spiriferinids. The Spiriferinida took over the empty ecomorphospace and had the opportunity to flourish.

A coral reef in the Telkwa Range, British Columbia: the earliest Jurassic example

1993 ◽  
Vol 30 (4) ◽  
pp. 819-831 ◽  
Author(s):  
George D. Stanley Jr ◽  
Christopher A. McRoberts
Keyword(s):  
British Columbia ◽  
Mass Extinction ◽  
Upper Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Stages Of Growth ◽  
The World ◽  
Extinction Event ◽  
Three Stages ◽  
Sponge Reefs

An end-Triassic mass extinction profoundly affected reef ecosystems that flourished in the Late Triassic Tethys seaway. The collapse of Late Triassic coral–sponge reefs was followed by an Early Jurassic (Hettangian–Sinemurian) perturbation interval with a near-global absence of reefs and sharp reductions in diversity. A Jurassic (Sinemurian) reef in the Hazelton Group of central British Columbia appears to fill the gap. Its paleoecology and composition show it to be the first large-framework example in North America and perhaps the world. It demonstrates that the reef-building Triassic coral, Phacelostylophyllum, survived the extinction event and was constructing reefs in Early Jurassic time during a global reef eclipse. The reef is a 48 m thick bioherm that grew within the island-arc complex of Stikinia. Following a decrease in volcanism, reef building began with bivalves growing upon water-lain tuffs. The reef was dominated by large dendroid–phaceloid corals, primarily Phacelostylophyllum rugosum, a species known from the Upper Triassic of Italy, which produced extensive constructional framework. Other fossils include bivalves, solitary and colonial corals, and a variety of dwellers and reef destroyers. Three stages of growth are present. During siliciclastic deposition, the reef mound grew into a bioherm with steep relief and flanking beds. Two intervals of arrested growth marked by pyroclastic lenses and hard grounds punctuated the reef's history. The reef was finally overwhelmed by volcaniclastic sediment, was uplifted, and developed paleokarst. The reef is unique in understanding the dynamics of recovery after the end-Triassic mass extinction.

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