scholarly journals China and the lost worlds of the dinosaurian era

1992 ◽  
Vol 6 ◽  
pp. 257-257
Author(s):  
Dale A. Russell

What is known of dinosaurian biogeography suggests a centre of evolution first on a fragmenting Pangea-Gondwana and then on a consolidating Laurasia. By Cretaceous time members of Gondwanan low-latitude abelisaur-titanosaur assemblages often bore “back-fans,” while those in polar latitudes were relictual and/or highly derived. The time of last contact between South America and Africa is not well constrained, but links to Antarctica continued beyond the end of the Cretaceous. Many Gondwanan tetrapods appear to have waif-dispersed to Laurasia across southern Europe; few crossed in the opposite direction until the end of the period. Laurasian assemblages were then typically dominated by tyrannosaurids and hadrosaurids.Land masses (“lost worlds”) periodically became isolated from Gondwana-Laurasia. (1) Eastern Asia was isolated between middle Jurassic through Neocomian time, although related temnospondyls and carnosaurs may have co-existed in Austral regions. Mamenchisaurs were the dominant giant terrestrial herbivores, while whip-tailed diplodocids filled the same role in Pangea. Groups of European-North American affinity then replaced many Asian endemics in a manner reminiscent of the Neogene mammalian turnover in South America. (2) In North America. Late Jurassic dinosaur assemblages exhibited Gondwana affinities, but by Late Cretaceous time they were dominated by forms of Asian ancestry. The apparent low diversity of Aptian-Albian dinosaur assemblages and absence of well-marked endemism may have been the result of a brief period of isolation. (3) European archipelagos were a filter bridge between northern lands and Gondwana analogous to the East Indies, which separate comparably different modern biotas in southeast Asia and Australia. (4) During Barremian time India probably hosted an polar dinosaurian assemblage, but low-latitude Gondwana forms (abelisaurids, titanosaurids) were present during at least part of this interval. Isolation ended with the immigration of northern taxa in Maestrichtian time.Underexplored Mesozoic horizons of great biogeographic interest include (1) the Middle Jurassic-Neocomian of China for microvertebrate materials, (2) the pre-Maestrichtian Cretaceous of India, and (3) the post-Cenomanian of Africa, Australia and Antarctica. Paradoxically, the two recently discovered dinosaurian specimens of the latter age in Antarctica, which represent about as much biogeographic information as all described materials of similar age from Africa combined (none are known from Australia), are presently referred to families with Laurasian distributions.

2019 ◽  
Author(s):  
Walter G. Joyce ◽  
Jérémy Anquetin

The fossil record of non-baenid paracryptodires ranges from the Late Jurassic (Kimmeridgian) tothe Paleocene of North America and Europe only. Earlier remains may be present as early as the Middle Jurassic (Bathonian). Only a single dispersal event is documented between the two continents following their breakup during the Cretaceous in the form of the appearance of the Compsemys lineage in the Paleocene of France. Non-baenid paracryptodires were restricted to freshwater aquatic environments, but display adaptations to diverse feeding strategies consistent with generalist, gape-and-suction, and hypercarnivorous feeding. Current phylogenies recognize two species rich subclades within Paracryptodira, Baenidae and Pleurosternidae, which jointly form the clade Baenoidea. A taxonomic review of non-baenid paracryptodires concludes that of 34 named taxa, 11 are nomina valida, 15 nomina invalida, and 8 nomina dubia.


1992 ◽  
Vol 6 ◽  
pp. 132-132
Author(s):  
Thomas R. Holtz

It has often been assumed that the intensively studied dinosaur faunal assemblages of western North America and the Gobi Desert of Mongolia and China represent “typical” Late Cretaceous terrestrial vertebrate communities. This assumption has led to a paleoecological scenario in which a global ecological shift occurs from the dominance of high-browsing saurischian (i.e., sauropod) to low-browsing ornithischian (i.e., iguanodontian, marginocephalian, ankylosaurian) herbivore communities. Furthermore, the assumption that the Asiamerican dinosaur faunas are communities “typical” of the Late Cretaceous has forced the conclusion that the sauropod-dominated Argentine population must have been an isolated relict ecosystem of primitive taxa (i.e., titanosaurid sauropods, abelisaurid ceratosaurs). Recent discoveries and reinterpretations of other Late Cretaceous assemblages, however, seriously challenge these assumptions.Paleogeography and paleobiogeography have demonstrated that terrestrial landmasses became progressively fractionated from the Late Jurassic (Kimmeridgian-Tithonian) to the Late Cretaceous (Campanian), owing to continental drift and the development of large epicontinental seas (the Western Interior Seaway, the Turgai Sea, etc.). The Maastrichtian regressions resulted in the reestablishment of land connection between long isolated regions (for example, western and eastern North America). These geographic changes are reflected in changes in the dinosaurian faunas. These assemblages were rather cosmopolitan in the Late Jurassic (Morrison, Tendaguru, and Upper Shaximiao Formations) but became more provincialized throughout the Cretaceous.Cluster analysis of presence/absence data for the theropod, sauropod, and ornithischian clades indicates that previous assumptions for Late Cretaceous dinosaurian paleoecology are largely in error. These analyses instead suggest that sauropod lineages remained a major faunal component in both Laurasia (Europe, Asia) and Gondwana (South America, Africa, India, and Australia). Only the pre-Maastrichtian Senonian deposits of North America were lacking sauropodomorphs. Furthermore, the abelisaurid/titanosaurid fauna of Argentina is, in fact, probably more typical of Late Cretaceous dinosaurian communities. Rather, it is the coelurosaurian/ornithischian communities of Asiamerica (and particularly North America) that are composed primarily of dinosaurs of small geographic distribution. Thus, the Judithian, Edmontonian, and Lancian faunas, rather than being typical of the Late Cretaceous, most likely represent an isolated island-continent terrestrial vertebrate population, perhaps analogous to the extremely isolated vertebrate communities of Tertiary South America. Furthermore, the shift from high-browsing to low-browsing herbivore “dynasties” more likely represents a local event in Senonian North America and does not represent a global paleoecological transformation of Late Cretaceous dinosaur community structure.


2010 ◽  
Vol 29 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Benjamin Sames ◽  
Robin Whatley ◽  
Michael E. Schudack

Abstract. The genus Praecypridea gen. nov. (Cypridoidea, Family Cyprideidae Martin, 1940) is described and thus far comprises four species: the type species Praecypridea acuticyatha (Schudack, 1998) comb. nov., Praecypridea postelongata (Oertli, 1957) comb. nov., Praecypridea suprajurassica (Mojon, Haddoumi & Charriére, 2009) comb. nov. and Praecypridea acuta (Moos, 1959 in Wicher, 1959) comb. nov. Representatives of the new genus have been described from the Middle to Late Jurassic of Europe, North America and Africa and the Early Cretaceous of South America, with other presumed representatives also occurring in the Early Cretaceous. Species of Praecypridea are considered to represent members of the ancestral lineage of the extinct genus Cypridea Bosquet, representatives of which flourished in non-marine habitats of latest Jurassic to Early Cretaceous age and account for the first period of abundance of the non-marine Cypridoidea.


Author(s):  
P. M. Kirk

Abstract A description is provided for Pseudocercospora abelmoschi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On species of Hibiscus, especially H. esculentus. DISEASE: Causes a leaf spot or blight on Hibiscus spp. GEOGRAPHICAL DISTRIBUTION: Africa (Gabon, Ghana, Guinea, Kenya, Malawi, Nigeria, Sierra Leone, Sudan, Tanzania, Togo, Uganda), Asia (Burma, India, Nepal, Pakistan), East Indies (Brunei, Malaya, New Hebrides, Philippines, Sarawak, Taiwan), Middle East (Yemen), Europe (Italy: San Domingo), North America (USA), West Indies (Antigua, Grenada, Jamaica, St. Vincent, Trinidad), South America (Venezuela). TRANSMISSION: By air-borne conidia.


1883 ◽  
Vol 15 (4) ◽  
pp. 69-72 ◽  
Author(s):  
S. W. Williston

The family of Nemistrinidæ comprises throughout the world one hundred and ten described species, six or seven of which are from Southern Europe and three from North America; the remainder nearly equally distributed in Asia, Africa, Australia and South America. In their habits, so far as known, the species approach the Bombylidæ most closely, as also do many in their general appearance. Structurally they are of interest to the Dipterologist, on account of their intricate and diverse neuration, which in some species is almost Neuropter-like in the reticulation.Doubtless the number of our species will be augmented by future discoveries, but yet we can never expect a very material increase.


2014 ◽  
Vol 41 (4) ◽  
pp. 379 ◽  
Author(s):  
Jim W.H. Monger

The boundary between rocks assigned to the Intermontane superterrane in the interior of the Canadian Cordillera and those of the Insular superterrane in the westernmost Cordillera of British Columbia and southeastern Alaska lies within/along the Coast Mountains, in which is exposed the core of an orogen that emerged as a discrete tectonic entity between 105 and 45 million years ago. Evidence from the Coast Mountains and flanking areas indicates that parts of the Intermontane superterrane (in Stikinia and Yukon-Tanana terranes) were near those of the Insular superterrane (Wrangellia and Alexander terranes) by the Early Jurassic (~180 Ma). This timing, as well as paleobiogeographic and paleomagnetic considerations, appears to discount a recent hypothesis that proposes westward-dipping subduction beneath an intra-oceanic arc on Insular superterrane resulted in arc-continent collision and inaugurated Cordilleran orogenesis in the Late Jurassic (~146 Ma). The hypothesis also relates the subducted ocean that had separated the superterranes to a massive, faster-than-average-velocity seismic anomaly in the lower mantle below the eastern seaboard of North America. To create such an anomaly, subduction of the floor of a large ocean was needed. The only surface record of such an ocean in the interior of the Canadian Cordillera is the Cache Creek terrane, which lies within the Intermontane superterrane but is no younger than Middle Jurassic (~174 Ma). This terrane, together with the probably related Bridge River terrane in the southeastern Coast Mountains, which is as young as latest Middle Jurassic (164 Ma) and possibly as young as earliest Cretaceous (≥ 130 Ma), appear to be the only candidates in Canada for the possible surface record of the seismic anomaly.  SOMMAIRELa limite entre les roches assignées au Superterrane d’intermont de l’intérieur des Cordillères canadiennes et celles du Superterrane insulaire dans la portion la plus à l’ouest de la Cordillère de Colombie-Britannique et du sud-est de l’Alaska se trouvent dans et au long de la Chaîne côtière, au sein de laquelle affleure le noyau d’un orogène qui est apparu comme entité tectonique distincte entre 105 et 45 millions d’années.  Des indices de la Chaîne côtière et des régions environnantes montrent que des portions du Superterrane d’intermont (dans les terranes de Stikinia et de Yukon-Tanana) se trouvaient alors près de celles du Superterrane insulaire (terranes de Wrangellia et d’Alexander) au début du Jurassique (~180 Ma).  Cette chronologie, ajoutée à certains facteurs paléobiogéographiques et paléomagnétiques semblent discréditer une hypothèse récente voulant qu’une subduction à pendage ouest sous un arc intra-océanique sur le Superterrane insulaire résultait d’une collision entre un arc et le continent, initiant ainsi l’orogénèse de la Cordillère à la fin du Jurassique (~146 Ma).  Cette hypothèse relie aussi l’océan subduit qui séparait les superterranes à une anomalie de vitesse sismique plus rapide que la normale dans le manteau inférieur sous le littoral maritime oriental de l’Amérique du Nord.  Pour créer une telle anomalie, la subduction du plancher d’un grand océan était nécessaire.  La seule indication de surface de l’existence d’un tel océan à l’intérieur de la Cordillère canadienne est le terrane de Cache Creek qui, bien qu’il se trouve dans le Superterrane d’intermont, est plus ancien que le Jurassique moyen (~174 Ma).  Ce terrane, avec son équivalent probable de Bridge River dans le sud-est de la Chaîne côtière, qui est aussi jeune que la fin du Jurassique (164 Ma) et peut-être aussi jeune que le début du Crétacé (≥ 130 Ma), semblent être les seuls candidats au Canada offrant des vestiges en surface de cette anomalie sismique. 


Acarologia ◽  
2019 ◽  
Vol 59 (2) ◽  
pp. 226-241
Author(s):  
Valerie M. Behan-Pelletier ◽  
Wayne Knee

The oribatid mite family Zetomotrichidae is represented in warm regions of world, including Australia, South Africa, Mexico, South America and across the Palaearctic from southern Europe to Asia, but has been unreported from the USA and Canada. We describe a new zetomotrichid species, Ghilarovus robisoni n. sp., on the basis of adults, the first record of the genus and family from temperate North America. Specimens were collected from dry, usually rocky, vertical microhabitats in forests in southern USA. We provide a revised and expanded diagnosis for adults of Ghilarovus, discuss characters in Zetomotrichidae unique to the family, and provide a key to world Ghilarovus species.


1993 ◽  
Vol 30 (10) ◽  
pp. 2002-2012 ◽  
Author(s):  
Dale A. Russell

Dinosaurian biogeography may have been largely controlled by the Mesozoic fragmentation of Pangea and the reassembly of its fragments into a new, boreal supercontinent (Laurasia). Although Late Triassic and Early Jurassic dinosaurs were globally distributed, Chinese assemblages were dominated by endemic forms from Middle Jurassic into Early Cretaceous time. The affinities of Aptian – Albian immigrants to Asia were strongest with North America and Europe rather than Gondwana, indicating that the northern and southern hemispheres had by then attained their biogeographic identity. This distinctiveness was maintained through Cretaceous time. Europe seems to have been a buffer area between Paleolaurasia and Gondwana; of the northern continents it was the most strongly influenced by Gondwana dispersants. Late Jurassic dinosaur assemblages in North America exhibited Gondwana affinities, but by Late Cretaceous time they were dominated by forms of Asian ancestry.


1973 ◽  
Vol 105 (1) ◽  
pp. 105-111 ◽  
Author(s):  
J. F. McAlpine

AbstractCretonomyia pristina new genus and new species, a fossil fly in amber from Cedar Lake, Manitoba, is described and assigned to the Ironomyiidae. This fossil establishes that the family, heretofore known from a single Australian species, Ironomyia nigromaculata White, existed during Mesozoic times in North America. Comparison of the extinct species with the living species shows that the family appeared little different 73 million years ago than it does today. In points of difference, the fossil species usually shows the more primitive conditions. It is postulated that the family arose in North America in late Jurassic – early Cretaceous times, dispersed to South America late in the Cretaceous Period and thence to Australia via Antarctica while the latter three were contiguous — 43 million years ago.


Paleobiology ◽  
1995 ◽  
Vol 21 (4) ◽  
pp. 479-495 ◽  
Author(s):  
Michael R. Sandy

Distributions of brachiopods from low-latitude paleogeographic settings, primarily in the Tethyan Ocean of southern Europe, with additional data from North America allow some observations on the bathymetric distribution of early Mesozoic brachiopod orders. Norian and latest Triassic (Rhaetian) brachiopod biofacies are dominated in shallowest waters by short-looped terebratulids (Terebratulidina) while spire-bearing athyrids (Athyrida) are common components of deeper-water environments in the latest Triassic. In the late Early Jurassic (Pliensbachian), shallow-water brachiopod faunas are dominated by rhynchonellids, short-looped terebratulids are commoner in relatively deeper shelf waters, and spiriferids and long-looped terebratulids (Terebratellidina) are abundant in deeper-water shelf environments.Following the end-Triassic extinction event there appears to be niche-replacement in deep-water shelf environments of Late Triassic athyrids by spiriferids and long-looped terebratulids in the Early Jurassic. Rhynchonellids appear to have diversified into shallowest water environments; specialized short-looped terebratulids may have occupied deeper-water niches that resulted ultimately in the success of the enigmatic Pygopidae later in the Jurassic and Cretaceous.


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