scholarly journals An archaic crested plesiosaur in opal from the Lower Cretaceous high-latitude deposits of Australia

2006 ◽  
Vol 2 (4) ◽  
pp. 615-619 ◽  
Author(s):  
Benjamin P Kear ◽  
Natalie I Schroeder ◽  
Michael S.Y Lee
Keyword(s):  
High Latitude ◽  
Lower Cretaceous ◽  
Convergent Evolution ◽  
Cold Water ◽  
Extreme Environment ◽  
Climatic Conditions ◽  
Short Neck ◽  
Diverse Range ◽  
Marine Reptiles ◽  
Large Head

Umoonasaurus demoscyllus gen. et sp. nov. is a new small-bodied (approx. 2.5 m) pliosauroid plesiosaur from the Lower Cretaceous (Aptian–Albian) of southern Australia. It is represented by several partial skeletons (one with a near complete skull is the most complete opalized vertebrate fossil yet known), and is unique in having large crests on the skull midline and above the orbits. Umoonasaurus is surprisingly archaic despite its relatively late age (approx. 115 Myr ago)—being simultaneously the most basal (primitive) and last surviving rhomaleosaurid. Notably, it lacks the ‘pliosauromorph’ features (large head, short neck, gigantism) typically characterizing many more derived Jurassic rhomaleosaurids; thus, reinforcing the suspected convergent evolution of the ‘pliosauromorph’ hypercarnivore body plan. Umoonasaurus inhabited an Early Cretaceous high-latitude (approx. 70° S) inland seaway subject to seasonally near-freezing climatic conditions. This extreme environment supported a diverse range of plesiosaur taxa, suggesting that these marine reptiles might have possessed adaptations (e.g. heightened metabolic levels) to cope with cold-water temperatures. Indeed, survival of ancient endemic lineages such as Umoonasaurus is a common phenomenon in Australian Cretaceous vertebrate assemblages and might have been facilitated by isolation in low-temperature high-latitude regions.

Biological features of guests and requirements for their containment

2020 ◽  
pp. 22-27
Author(s):  
V. M. Poliakovskyi ◽  
◽  
V. M. Mykhalska ◽  
L. V. Shevchenko ◽  
М. S. Gruntkovskyi ◽  
...  
Keyword(s):  
Guinea Fowl ◽  
Climatic Conditions ◽  
Short Neck ◽  
High Quality ◽  
Biological Features ◽  
Potato Beetle ◽  
Large Head ◽  
Production Area ◽  
Feed Costs ◽  
Oval Body

This article reveals the biological features of guinea fowl and methods of keeping them. Guinea fowl are raised and bred to produce dietary meat, high-quality eggs, and to control pests of crops: snails, insects, including the Colorado potato beetle. The main direction of growing guinea fowl is meat, in terms of meat yield guinea fowl are not inferior to chickens. The taste of guinea fowl resembles game, but it is more tender, juicy and not fibrous. Guinea fowl have a horizontally placed oval body, short neck, large head with a strong growth in the crest, short, lowered tail. Guinea fowl are unpretentious, easily acclimatized to any natural and climatic conditions. The disadvantages of this species of bird include a poorly developed hatching instinct and aggression during capture. With age, the aggression of guinea fowl increases. This bird is also known to make unpleasant shrill sounds, which is why they are sometimes refused to breed. When keeping guinea fowl, it should be borne in mind that domestic guinea fowl inherited from the wild the ability to fly well. They are mobile, timid, reluctant to go to the nest and often lay eggs in hidden, cozy places. After isolating males from the herd, females are able to lay fertilized eggs for more than 10 days. This species of birds is quite well acclimatized and shows a fairly high egg productivity in different methods of cultivation. There are several ways to keep guinea fowl. The most common walking method, which involves keeping guinea fowl during the day on pasture, and at night — indoors. Keeping on the floor (on deep litter) is used when it is not possible to give the bird exercise. The cage method allows to increase the efficiency of production area, reduce feed costs by 15%, to mechanize the care and maintenance of poultry houses.

scholarly journals Paleocene-Eocene volcanic segmentation of the Norwegian-Greenland seaway reorganized high-latitude ocean circulation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jussi Hovikoski ◽  
Michael B. W. Fyhn ◽  
Henrik Nøhr-Hansen ◽  
John R. Hopper ◽  
Steven Andrews ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Seismic Reflection ◽  
Arctic Region ◽  
Climatic Conditions ◽  
The Arctic ◽  
Early Eocene ◽  
Subaerial Exposure ◽  
Thermal Maximum ◽  
Volcanic Facies

AbstractThe paleoenvironmental and paleogeographic development of the Norwegian–Greenland seaway remains poorly understood, despite its importance for the oceanographic and climatic conditions of the Paleocene–Eocene greenhouse world. Here we present analyses of the sedimentological and paleontological characteristics of Paleocene–Eocene deposits (between 63 and 47 million years old) in northeast Greenland, and investigate key unconformities and volcanic facies observed through seismic reflection imaging in offshore basins. We identify Paleocene–Eocene uplift that culminated in widespread regression, volcanism, and subaerial exposure during the Ypresian. We reconstruct the paleogeography of the northeast Atlantic–Arctic region and propose that this uplift led to fragmentation of the Norwegian–Greenland seaway during this period. We suggest that the seaway became severely restricted between about 56 and 53 million years ago, effectively isolating the Arctic from the Atlantic ocean during the Paleocene–Eocene thermal maximum and the early Eocene.

scholarly journals Convergent evolution of ramified antennae in insect lineages from the Early Cretaceous of Northeastern China

2016 ◽  
Vol 283 (1839) ◽  
pp. 20161448 ◽  
Author(s):  
Taiping Gao ◽  
Chungkun Shih ◽  
Conrad C. Labandeira ◽  
Jorge A. Santiago-Blay ◽  
Yunzhi Yao ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Motion Detection ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Convergent Evolution ◽  
Chemical Cues ◽  
Northeastern China ◽  
Environmental Cues ◽  
Key Innovation ◽  
Temperature Levels

Antennae are important, insect sensory organs that are used principally for communication with other insects and the detection of environmental cues. Some insects independently evolved ramified (branched) antennae, which house several types of sensilla for motion detection, sensing olfactory and chemical cues, and determining humidity and temperature levels. Though ramified antennae are common in living insects, occasionally they are present in the Mesozoic fossil record. Here, we present the first caddisflies with ramified antennae, the earliest known fossil sawfly, and a scorpionfly also with ramified antennae from the mid-Lower Cretaceous Yixian Formation of Northeastern China, dated at 125 million years ago (Ma). These three insect taxa with ramified antennae consist of three unrelated lineages and provide evidence for broad structural convergence that historically has been best demonstrated by features such as convergent mouthparts. In addition, ramified antennae in these Mid-Mesozoic lineages likely do not constitute a key innovation, as they are not associated with significantly increased diversification compared with closely related lineages lacking this trait, and nor are they ecologically isolated from numerous, co-occurring insect species with unmodified antennae.

A late Cisuralian (early Permian) brachiopod fauna from the Taungnyo Group in the Zwekabin Range, eastern Myanmar and its biostratigraphic, paleobiogeographic, and tectonic implications

2021 ◽  
pp. 1-31
Author(s):  
Hai-peng Xu ◽  
Kyi Pyar Aung ◽  
Yi-chun Zhang ◽  
G.R. Shi ◽  
Fu-long Cai ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Cold Water ◽  
Water Environment ◽  
Climatic Conditions ◽  
Early Permian ◽  
The North ◽  
Southern Thailand ◽  
Brachiopod Fauna ◽  
Insight Into ◽  
Different Parts

Abstract The tectonic evolution of the Sibumasu Block during the Permian remains controversial, and Permian faunas and their paleobiogeographic affinities provide some insight into its paleogeographic and tectonic evolutionary histories. In this paper, a new brachiopod fauna dominated by Spinomartinia prolifica Waterhouse, 1981 is described from the uppermost part of the Taungnyo Group in the Zwekabin Range, eastern Myanmar. This brachiopod fauna includes 23 species and its age is well constrained as late Kungurian by the associated conodonts, i.e., Vjalovognathus nicolli Yuan et al., 2016 and Mesogondolella idahoensis (Youngquist, Hawley, and Miller, 1951), contrary to the late Sakmarian age given to the same brachiopod faunas previously reported from southern Thailand and Malaysia. Based on comprehensive comparisons of the Cisuralian brachiopod faunas and other data in different parts of the Sibumasu Block, we consider that they are better subdivided into two independent stratigraphic assemblages, i.e., the lower (earlier) Bandoproductus monticulus-Spirelytha petaliformis Assemblage of a Sakmarian to probably early Artinskian age, and the upper (younger) Spinomartinia prolifica-Retimarginifera alata Assemblage of a late Kungurian age. The former assemblage is a typical cold-water fauna, mainly composed of Gondwanan-type genera, e.g., Bandoproductus Jin and Sun, 1981, Spirelytha Fredericks, 1924, and Sulciplica Waterhouse, 1968. The latter assemblage is strongly characterized by an admixture of both Cathaysian and Gondwanan elements, as well as some genera restricted to the Cimmerian continents. Notably, the spatial distribution pattern of these two separate brachiopod assemblages varies distinctly. The Sakmarian cold-water brachiopod faunas have been found in association with glacial-marine diamictites throughout the Sibumasu Block including both the Irrawaddy and Sibuma blocks. In contrast, the Kungurian biogeographically mixed brachiopod faunas are only recorded in the Irrawaddy Block, unlike the Sibuma Block that contains a contemporaneous paleotropical Tethyan fusuline fauna. Thus, it appears likely that by the end of Cisuralian (early Permian), the Sibumasu Block comprised the Irrawaddy Block in the south with cool climatic conditions, and the Sibuma Block in the north with a temperate to warm-water environment, separated by the incipient Thai-Myanmar Mesotethys.

scholarly journals Geology of the Upper Jurassic to Lower Cretaceous geothermal aquifers in the West Netherlands Basin – an overview

2020 ◽  
Vol 99 ◽  
Author(s):  
Cees J.L. Willems ◽  
Andrea Vondrak ◽  
Harmen F. Mijnlieff ◽  
Marinus E. Donselaar ◽  
Bart M.M. van Kempen
Keyword(s):  
Lower Cretaceous ◽  
Cold Water ◽  
Upper Jurassic ◽  
The West ◽  
Geothermal Heat ◽  
Sequence Stratigraphic ◽  
Tectonic History ◽  
Water Breakthrough ◽  
Hydrocarbon Fields ◽  
Sedimentary Aquifer

Abstract In the past 10 years the mature hydrocarbon province the West Netherlands Basin has hosted rapidly expanding geothermal development. Upper Jurassic to Lower Cretaceous strata from which gas and oil had been produced since the 1950s became targets for geothermal exploitation. The extensive publicly available subsurface data including seismic surveys, several cores and logs from hundreds of hydrocarbon wells, combined with understanding of the geology after decades of hydrocarbon exploitation, facilitated the offtake of geothermal exploitation. Whilst the first geothermal projects proved the suitability of the permeable Upper Jurassic to Lower Cretaceous sandstones for geothermal heat production, they also made clear that much detail of the aquifer geology is not yet fully understood. The aquifer architecture varies significantly across the basin because of the syn-tectonic sedimentation. The graben fault blocks that contain the geothermal targets experienced a different tectonic history compared to the horst and pop-up structures that host the hydrocarbon fields from which most subsurface data are derived. Accurate prediction of the continuity and thickness of aquifers is a prerequisite for efficient geothermal well deployment that aims at increasing heat recovery while avoiding the risk of early cold-water breakthrough. The potential recoverable heat and the current challenges to enhance further expansion of heat exploitation from this basin are evident. This paper presents an overview of the current understanding and uncertainties of the aquifer geology of the Upper Jurassic to Lower Cretaceous strata and discusses new sequence-stratigraphic updates of the regional sedimentary aquifer architecture.

First plesiosaur remains from the lower Cretaceous of the Neuquén Basin, Argentina

2003 ◽  
Vol 77 (4) ◽  
pp. 784-789 ◽  
Author(s):  
Dario G. Lazo ◽  
Marcela Cichowolski
Keyword(s):  
Lower Cretaceous ◽  
Sister Group ◽  
Monophyletic Group ◽  
Phylogenetic Position ◽  
Crown Group ◽  
Marine Reptiles ◽  
Stem Group ◽  
Neuquen Basin ◽  
Neuquén Basin

Plesiosaurs constitute a monophyletic group whose stratigraphical range is uppermost Triassic to uppermost Cretaceous (Brown, 1981). They were large predatory marine reptiles, highly adapted for submarine locomotion, with powerful paddle-like limbs and heavily reinforced limb girdles (Saint-Seine, 1955; Romer, 1966; Carroll, 1988; Benton, 1990). The Plesiosauria clade belongs to the Sauropterygia, which has recently been hypothesized as the sister-group of the Ichthyosauria. Together with that clade they form the Euryapsida (Caldwell, 1997). The Sauropterygia can be subdivided into relatively plesiomorphic stem-group taxa from the Triassic (Placodonts, Nothosauroids, and Pistosauroids), and the obligatorily marine crown-group Plesiosauria (Rieppel, 1999). Plesiosaurs are traditionally divided into two superfamilies: Plesiosauroidea, with usually small heads and long necks; and Pliosauroidea, with larger heads and shorter necks (Welles, 1943; Persson, 1963; Brown, 1981). Plesiosauroidea contains three families: Plesiosauridae, Cryptoclididae, and Elasmosauridae (Brown, 1981; Brown and Cruickshank, 1994). The validity of the Polycotylidae Cope, 1869, has long been questioned and its phylogenetic position among Plesiosauria debated, as many consider it to be related to the Pliosauridae or to be a sister-group of the Elasmosauridae (Sato and Storrs, 2000; O'Keefe, 2001).

Heat Sink Issue: A Specific Safety Issue for NPP Site Selection and Evaluation in the Warm Countries With Extreme Climatic Conditions

2013 ◽  
Author(s):  
Andrei Rodionov ◽  
Jean-Marie Mattei
Keyword(s):  
Site Selection ◽  
Heat Sink ◽  
Cold Water ◽  
Safety Issue ◽  
Cooling Water ◽  
Water Source ◽  
Climatic Conditions ◽  
Spent Fuel ◽  
Regulatory Review ◽  
Human Environment

One of the major issues during the site selection and design of a NPP is the heat sink issue, i.e. installation and availability of reliable and efficient recipient of heat (air, water or both of them) in relation in particular with: • waste the heat removed from the condenser of the turbines during normal operational state, • waste the heat removed from all of the safety-related and non-safety-related equipment and systems during normal operational state, • waste the residual heat removed from nuclear reactor fuel (situated in reactor vessel or tubes), the decay heat removed from nuclear spent fuel (situated in spent fuel pool), and the heat removed from all of the safety-related equipment and systems during abnormal operational state and accident conditions. There are several “newcomer” countries that are situated in warm climate zones. In such countries, the cooling water design could be a challenge with regards to extreme water and air temperatures, air humidity, absence of an important reliable cold water source inside the country, etc. In addition, some specific items related to natural, industrial and human environment should be considered during the site evaluation, as for example, risk of intensive biota development, oil spills, siltation, low water level events, etc. This requires particular consideration of the heat sink issue for the site regulatory review during the licensing process. The article discusses the methodology for site regulatory review with regards to the heat sink issue and provides some practical advises on safety assessment and acceptance criteria to be considered.

Evidence for a second species of the ichthyosaur Platypterygius in North America: a new record from the Loon River Formation (Lower Cretaceous) of northwestern Canada

2006 ◽  
Vol 43 (9) ◽  
pp. 1291-1295 ◽  
Author(s):  
E E Maxwell ◽  
M W Caldwell
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Lower Cretaceous ◽  
New Record ◽  
Taxonomic Diversity ◽  
Pectoral Girdle ◽  
Western Interior Seaway ◽  
Anterior Portion ◽  
Australian Species ◽  
Marine Reptiles

To date, all Cretaceous ichthyosaur material from North America has been referred to the species Platypterygius americanus. This species is generally identified based on skull and paddle morphology, but all non-diagnostic material from North America has been assigned to this species. A new Lower Cretaceous ichthyosaur from the Loon River Formation at Hay River, Northwest Territories, Canada, is described here. The specimen in question consists of the anterior portion of a large ichthyosaur, of which only the pectoral girdle is well preserved. It is assignable to Platypterygius, but is inconsistent with P. americanus based on paddle morphology. It shares most similarities with European and Australian species; unfortunately, it cannot be definitively assigned to any one taxon because of poor preservation of the skull. This specimen increases our knowledge of the diversity of North American Cretaceous ichthyosaurs, and suggests that the Cretaceous Western Interior Seaway was capable of sustaining a large taxonomic diversity of these marine reptiles, similar to the high numbers of Platypterygius species known from Europe.

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