Chapter 18 Triassic history

1997 ◽  
Vol 17 (1) ◽  
pp. 340-362 ◽  
Author(s):  
W. Brian Harland ◽  
Isobel Geddes
Keyword(s):  
Middle Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Early Triassic ◽  
Marked Contrast ◽  
Angular Unconformity ◽  
Triassic Period ◽  
Age Determinations

The Triassic Period of about 40 million years dutation spanned about a third of that of the Carboniferous and Permian interval. The Triassic rocks of Svalbard are easily distinguished from the underlying Permian strata because of a distinct desconformity between them and a marked contrast in facies from the resistant. pale coloured, cherls and siliciclastics of the Kapp Starostin Formation to the softer, darker areno-argillaceous Vardebukta and equivalent formations. Figure 18.1 shows the distribution of Triassic strata in Svalbard.The minor angular unconformity represents a hiatus mainly in the Permian rather than the Triassic record. The dominantly argillaceous facies constitute the Early Triassic to Late Middle Triassic Sassendalen Group. The rocks can be well dated from ammonoids, typically within calcareous concretions in the shales.The succeding Kapp Toscana Group is distinguished by a dominatly sandy deltaic facies in which age determinations are difficult. It spans both Late Triassic and Early Jurassic spoehs (roughly mid-Ladinian to mid-Bathonian). The Triassic-Jurassic boundary is not easy to estimate. Nevertheless towards the end of Triassic time (e.g. Rhaetian) the overall scene changed. Thus of the three formations of the Kapp Toscana Group the lower two (Tschermakfjellet and De Geerdalen) belong to the Triassic story. The overlying Wilhelmøya Formation may possibly range from Latest Triassic through Liassic time, and due to its complexity it is also discussed in the Jurassic-Crataceous chapter (19).The facies of the two groups reflect two distinct environmental configurations. The Sassendalen Group was deposited on a distal marine muddy shelf with a

scholarly journals New insights on the early Mesozoic evolution of multiple tectonic regimes in the northeastern North China Craton from the detrital zircon provenance of sedimentary strata

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1375-1397 ◽  
Author(s):  
Yi Ni Wang ◽  
Wen Liang Xu ◽  
Feng Wang ◽  
Xiao Bo Li
Keyword(s):  
North China Craton ◽  
North China ◽  
Early Jurassic ◽  
Orogenic Belt ◽  
Detrital Zircons ◽  
Late Triassic ◽  
Early Triassic ◽  
The South ◽  
The North ◽  
Early Mesozoic

Abstract. To investigate the timing of deposition and provenance of early Mesozoic strata in the northeastern North China Craton (NCC) and to understand the early Mesozoic paleotectonic evolution of the region, we combine stratigraphy, U–Pb zircon geochronology, and Hf isotopic analyses. Early Mesozoic strata include the Early Triassic Heisonggou, Late Triassic Changbai and Xiaoyingzi, and Early Jurassic Yihe formations. Detrital zircons in the Heisonggou Formation yield  ∼ 58 % Neoarchean to Paleoproterozoic ages and  ∼ 42 % Phanerozoic ages and were sourced from areas to the south and north of the basins within the NCC, respectively. This indicates that Early Triassic deposition was controlled primarily by the southward subduction of the Paleo-Asian oceanic plate beneath the NCC and collision between the NCC and the Yangtze Craton (YC). Approximately 88 % of the sediments within the Late Triassic Xiaoyingzi Formation were sourced from the NCC to the south, with the remaining  ∼ 12 % from the Xing'an–Mongolia Orogenic Belt (XMOB) to the north. This implies that Late Triassic deposition was related to the final closure of the Paleo-Asian Ocean during the Middle Triassic and the rapid exhumation of the Su–Lu Orogenic Belt between the NCC and YC. In contrast,  ∼ 88 % of sediments within the Early Jurassic Yihe Formation were sourced from the XMOB to the north, with the remaining  ∼ 12 % from the NCC to the south. We therefore infer that rapid uplift of the XMOB and the onset of the subduction of the Paleo-Pacific Plate beneath Eurasia occurred in the Early Jurassic.

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.

scholarly journals Anomalously high variation in postnatal development is ancestral for dinosaurs but lost in birds

2016 ◽  
Vol 113 (51) ◽  
pp. 14757-14762 ◽  
Author(s):  
Christopher T. Griffin ◽  
Sterling J. Nesbitt
Keyword(s):  
Postnatal Development ◽  
Intraspecific Variation ◽  
Early Jurassic ◽  
Late Triassic ◽  
Growth Trajectories ◽  
Low Levels ◽  
Triassic Period ◽  
Rates Of Growth

Compared with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development. It is now clear that birds inherited their high rates of growth from their dinosaurian ancestors, but the origin of the avian condition of low variation during development is poorly constrained. The most well-understood growth trajectories of later Mesozoic theropods (e.g.,Tyrannosaurus,Allosaurus) show similarly low variation to birds, contrasting with higher variation in extant crocodylians. Here, we show that deep within Dinosauria, among the earliest-diverging dinosaurs, anomalously high intraspecific variation is widespread but then is lost in more derived theropods. This style of development is ancestral for dinosaurs and their closest relatives, and, surprisingly, this level of variation is far higher than in living crocodylians. Among early dinosaurs, this variation is widespread across Pangaea in the Triassic and Early Jurassic, and among early-diverging theropods (ceratosaurs), this variation is maintained for 165 million years to the end of the Cretaceous. Because the Late Triassic environment across Pangaea was volatile and heterogeneous, this variation may have contributed to the rise of dinosaurian dominance through the end of the Triassic Period.

scholarly journals Comparative size evolution of marine clades from the Late Permian through Middle Triassic

Paleobiology ◽  
2015 ◽  
Vol 42 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Ellen K. Schaal ◽  
Matthew E. Clapham ◽  
Brianna L. Rego ◽  
Steve C. Wang ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Middle Triassic ◽  
Size Reduction ◽  
Late Triassic ◽  
Early Triassic ◽  
Large Species ◽  
Late Permian ◽  
Triassic Boundary ◽  
Median Size ◽  
Permian Extinction

AbstractThe small size of Early Triassic marine organisms has important implications for the ecological and environmental pressures operating during and after the end-Permian mass extinction. However, this “Lilliput Effect” has only been documented quantitatively in a few invertebrate clades. Moreover, the discovery of Early Triassic gastropod specimens larger than any previously known has called the extent and duration of the Early Triassic size reduction into question. Here, we document and compare Permian-Triassic body size trends globally in eight marine clades (gastropods, bivalves, calcitic and phosphatic brachiopods, ammonoids, ostracods, conodonts, and foraminiferans). Our database contains maximum size measurements for 11,224 specimens and 2,743 species spanning the Late Permian through the Middle to Late Triassic. The Permian/Triassic boundary (PTB) shows more size reduction among species than any other interval. For most higher taxa, maximum and median size among species decreased dramatically from the latest Permian (Changhsingian) to the earliest Triassic (Induan), and then increased during Olenekian (late Early Triassic) and Anisian (early Middle Triassic) time. During the Induan, the only higher taxon much larger than its long-term mean size was the ammonoids; they increased significantly in median size across the PTB, a response perhaps related to their comparatively rapid diversity recovery after the end-Permian extinction. The loss of large species in multiple clades across the PTB resulted from both selective extinction of larger species and evolution of surviving lineages toward smaller sizes. The within-lineage component of size decrease suggests that only part of the size decrease can be related to the end-Permian kill mechanism; in addition, Early Triassic environmental conditions or ecological pressures must have continued to favor small body size as well. After the end-Permian extinction, size decrease occurred across ecologically and physiologically disparate clades, but this size reduction was limited to the first part of the Early Triassic (Induan). Nektonic habitat or physiological buffering capacity may explain the contrast of Early Triassic size increase and diversification in ammonoids versus size reduction and slow recovery in benthic clades.

scholarly journals A Short-Snouted, Middle Triassic Phytosaur and its Implications for the Morphological Evolution and Biogeography of Phytosauria

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Michelle R. Stocker ◽  
Li-Jun Zhao ◽  
Sterling J. Nesbitt ◽  
Xiao-Chun Wu ◽  
Chun Li
Keyword(s):  
Middle Triassic ◽  
Prey Capture ◽  
General Trend ◽  
Morphological Evolution ◽  
Phylogenetic Analyses ◽  
Late Triassic ◽  
Early Triassic ◽  
Terrestrial Vertebrate ◽  
Nearshore Environments ◽  
Permian Extinction

Abstract Following the end-Permian extinction, terrestrial vertebrate diversity recovered by the Middle Triassic, and that diversity was now dominated by reptiles. However, those reptilian clades, including archosaurs and their closest relatives, are not commonly found until ~30 million years post-extinction in Late Triassic deposits despite time-calibrated phylogenetic analyses predicting an Early Triassic divergence for those clades. One of these groups from the Late Triassic, Phytosauria, is well known from a near-Pangean distribution, and this easily recognized clade bears an elongated rostrum with posteriorly retracted nares and numerous postcranial synapomorphies that are unique compared with all other contemporary reptiles. Here, we recognize the exquisitely preserved, nearly complete skeleton of Diandongosuchus fuyuanensis from the Middle Triassic of China as the oldest and basalmost phytosaur. The Middle Triassic age and lack of the characteristically-elongated rostrum fill a critical morphological and temporal gap in phytosaur evolution, indicating that the characteristic elongated rostrum of phytosaurs appeared subsequent to cranial and postcranial modifications associated with enhanced prey capture, predating that general trend of morphological evolution observed within Crocodyliformes. Additionally, Diandongosuchus supports that the clade was present across Pangea, suggesting early ecosystem exploration for Archosauriformes through nearshore environments and leading to ease of dispersal across the Tethys.

Review of Triassic insects in China

2021 ◽  
pp. SP521-2021-121
Author(s):  
Qianqi Zhang ◽  
Daran Zheng ◽  
Bo Wang ◽  
Haichun Zhang
Keyword(s):  
Yunnan Province ◽  
Middle Triassic ◽  
Southern China ◽  
Northern China ◽  
Guizhou Province ◽  
Late Triassic ◽  
Early Triassic ◽  
Incertae Sedis ◽  
Fossil Records ◽  
Existing Data

AbstractStudies of Triassic insects in China began in 1956, and so far, a total of 89 genera and 109 species have been found from the Triassic of China. The fossil records are from 17 provinces (or regions) in China are assigned to 11 orders except for two genera and species considered incertae sedis in Insecta. These Chinese Triassic insects including one Early Triassic, 53 Middle Triassic and 55 Late Triassic species are briefly reviewed in taxonomy and distribution, and listed here with detailed taxonomic and stratigraphic information. The Middle Triassic Tongchuan Entomofauna and Late Triassic Toksun Entomofauna are introduced much detailed from the perspectives of composition and taxonomy. Existing data indicate that the Chinese Triassic entomofauna is dominated by Hemiptera, Mecoptera and Coleoptera; the Chinese Early Triassic insects are only known from Fuyuan in Yunnan Province, Middle Triassic ones mainly known from northern China and sporadically from Guizhou Province, southern China, and Late Triassic ones widely seen in both northern and southern China; and the Middle and Late Triassic entomofaunas are similar in abundance but show a pattern of “more in northern China than in southern China”.

scholarly journals Middle Triassic (Anisian-Ladinian) Palynomorphs

1985 ◽  
Vol 4 (1) ◽  
pp. 107-111 ◽  
Author(s):  
W. A. Brugman ◽  
J. W. Eggink ◽  
H. Visscher
Keyword(s):  
Middle Triassic ◽  
Late Triassic ◽  
Early Triassic ◽  
Number Of Species ◽  
Deep Wells ◽  
Salt Range ◽  
Similar Development ◽  
Initial Results

Abstract. Initial results of the palynostratigraphical research in the Triassic of northeast Libya indicate the presence of Middle Triassic in several deep-wells. There is some evidence that the uppermost part of the Early Triassic (Late Scythian) as well as the early part of the Late Triassic (Karnian) may also be present. Additional palynological samples will need to be studied to confirm this view.Most Triassic assemblages in northeast Libya show a striking dominance of the monolete lycopodiophytic miospore Aratrisporites; this genus is represented by a large number of species (A. centratus, A. parvispinosus, A. strigosus, A. saturni, A. paenulatus, A. tenuispinosus, A. ovatus). A similar development is known to occur in the Middle Triassic of Australia and Pakistan. Bisaccate pollen is commonly present in the assemblages. Representatives of Triadispora and Lunatisporites are also frequently recorded.On the basis of a few additional forms, two palynologically distinctive intervals may be recognized within the Middle Triassic:Anisian interval. On the basis of Stellapollenites thiergartii, Strotersporites n. sp. of Visscher and Brugman 1981 (not illustrated) and Angustisulcites grandis, an Anisian age for the lower interval is indicated. The latter two species suggest the Early Anisian. The assemblages can be compared with similar assemblages from the Alpine Anisian in Europe (Visscher & Brugman, 1981; Brugman, in prep) and the Salt Range, Pakistan (Brugman & Baud, in prep).Ladinian interval. The upper part of the Libyan Middle Triassic is characterised by the absence of characteristic Anisian elements, and the incoming of rare representatives of the Circumpolles-group . . .

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.

scholarly journals Macroevolutionary patterns in the evolutionary radiation of archosaurs (Tetrapoda: Diapsida)

2010 ◽  
Vol 101 (3-4) ◽  
pp. 367-382 ◽  
Author(s):  
Stephen L. Brusatte ◽  
Michael J. Benton ◽  
Graeme T. Lloyd ◽  
Marcello Ruta ◽  
Steve C. Wang
Keyword(s):  
Strong Evidence ◽  
Fossil Record ◽  
Morphological Character ◽  
Middle Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Morphological Disparity ◽  
Faunal Abundance ◽  
Evolutionary Radiation ◽  
Early Middle Triassic

ABSTRACTThe rise of archosaurs during the Triassic and Early Jurassic has been treated as a classic example of an evolutionary radiation in the fossil record. This paper reviews published studies and provides new data on archosaur lineage origination, diversity and lineage evolution, morphological disparity, rates of morphological character change, and faunal abundance during the Triassic–Early Jurassic. The fundamental archosaur lineages originated early in the Triassic, in concert with the highest rates of character change. Disparity and diversity peaked later, during the Norian, but the most significant increase in disparity occurred before maximum diversity. Archosaurs were rare components of Early–Middle Triassic faunas, but were more abundant in the Late Triassic and pre-eminent globally by the Early Jurassic. The archosaur radiation was a drawn-out event and major components such as diversity and abundance were discordant from each other. Crurotarsans (crocodile-line archosaurs) were more disparate, diverse, and abundant than avemetatarsalians (bird-line archosaurs, including dinosaurs) during the Late Triassic, but these roles were reversed in the Early Jurassic. There is no strong evidence that dinosaurs outcompeted or gradually eclipsed crurotarsans during the Late Triassic. Instead, crurotarsan diversity decreased precipitously by the end-Triassic extinction, which helped usher in the age of dinosaurian dominance.

Diversity and distribution of Triassic bryozoans in the aftermath of the end-Permian mass extinction

2008 ◽  
Vol 82 (2) ◽  
pp. 362-371 ◽  
Author(s):  
Catherine M. Powers ◽  
Joseph F. Pachut
Keyword(s):  
Surface Area ◽  
Mass Extinction ◽  
Carbonate Rock ◽  
Middle Triassic ◽  
Late Triassic ◽  
Early Triassic ◽  
Diversity Pattern ◽  
Extinction Rates ◽  
Permian Mass Extinction ◽  
Early Late

Seventy-three species of stenolaemate bryozoans are documented worldwide from the Triassic. Stage-level diversity and paleogeographical analyses reveal that the recovery of bryozoans following the end-Permian mass extinction was delayed until the Middle Triassic. Early Triassic bryozoans faunas, dominated by members of the Order Trepostomida, were depauperate and geographically restricted. Bryozoan diversity increased during the Middle Triassic and diversity peaked in the Carnian (early Late Triassic). High extinction rates throughout the Late Triassic led to the extinction of all stenolaemate orders except the Cyclostomida by the end of the Triassic. Comparisons between global carbonate rock volume, outcrop surface area, and bryozoan diversity indicate that the documented diversity pattern for bryozoans may have been related, in part, to the availability of carbonate environments during the Triassic.

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