scholarly journals An Older and Exceptionally Large Adult Specimen of Tyrannosaurus rex

2019 ◽  
Vol 303 (4) ◽  
pp. 656-672 ◽  
Author(s):  
W. Scott Persons ◽  
Philip J. Currie ◽  
Gregory M. Erickson
Keyword(s):  
2011 ◽  
Vol 1 (5) ◽  
pp. 164-165
Author(s):  
Dr. Yavalkar PA Dr. Yavalkar PA ◽  
◽  
Dr. Naik AM Dr. Naik AM

Our Nature ◽  
1970 ◽  
Vol 2 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Kalu Ram Rai

Tangting River originates from southern slope of Murtidanda of Mahabharat range and forms a very narrow v-shaped agriculturally fertile valley in lower parts of Chure hills. It has three main tributaries merging from east and west. Water is clear with rocky bed and margin is covered with thick bushes of semi-shrubs (Eupatorium adenophorum). During the herpetological survey, a live juvenile specimen of Cyclemys oldhamii (Gray, 1983) was collected from the periphery of Banmare Khola, an eastern tributory of the river. It was found hiding in the paddy field in the flood plain of Tangting river (280 m), and another adult specimen was collected from Dhobi Khola (450 m), a western tributory of the river. Empty shells were also collected from Garuwa and Mai valleys, respectively. Tangting and Garuwa river valleys are the favourable habitats for Cyclemys oldhamii. The main reason of discontinued distribution is habitat loss by deforestation. Key words: Cyclemys, Morphology, Ecological habitats, Distributiondoi:10.3126/on.v2i1.317Our Nature (2004) 2: 7-12


2004 ◽  
Vol 55 (3) ◽  
pp. 295 ◽  
Author(s):  
A. J. Richardson ◽  
J. E. Growns ◽  
R. A. Cook

Caridean shrimps are an integral component of lowland river ecosystems in south-eastern Australia, but their distributions may be affected by flow alteration. Monthly shrimp samples were collected from slackwaters in three hydrologically distinct sections of the heavily regulated Campaspe River and the less regulated Broken River for three consecutive years. The distributions of Paratya australiensis, Caridina mccullochi and Macrobrachium australiense, along with their life history in river sections with different hydrology are outlined. Paratya australiensis and M. australiense occurred in all sections, but C. mccullochi was absent from sections of the Campaspe River that received irrigation flows during summer/autumn. Shrimp larvae were most abundant in summer (December–February) and juvenile recruitment continued through to mid autumn (April). Breeding and recruitment of P. australiensis occurred for longer than other shrimps. Apart from large adult and berried M. australiense, all life stages of shrimps commonly occurred in slackwaters, particularly the larval and juvenile stages. Irrigation flows in summer/autumn probably adversely affect the size, extent and arrangement of slackwaters, at a time when they may be critical habitats for C. mccullochi larval development and recruitment. Dams and weirs in the Campaspe River may have influenced shrimp abundance and the timing of breeding.


1952 ◽  
Vol s3-93 (24) ◽  
pp. 427-434
Author(s):  
MONICA TAYLOR

Material collected in Loch Tannoch was allowed to macerate in a chemical nutrient. A rich crop of Euglena gracilis as well as other infusoria resulted. Eight months later, when the Euglena had encysted, many amoebae were found at the bottom of the receptacle. They constitute a new species, here named Amoeba hugonis. An average adult specimen, when extended, measures about 104x52·2µ. The nucleus consists of a central karyosome lying in the nuclear sap, separated from the cytoplasm by a wellmarked nuclear membrane. Between the latter and the karyosome is situated an achromatic ‘collar’ with chromatin particles embedded in it. Fission is described, but a study of mitosis has been deferred. The life-history of this small amoeba is very similar to that of the large A. proteus, &c. The cycle occupies two months. Chromidia begin to appear in the cytoplasm of the early adult. They give rise to spores, out of which amoebulae hatch.


Crustaceana ◽  
1995 ◽  
Vol 68 (3) ◽  
pp. 382-389
Author(s):  
Katsushi Sakai

AbstractAn adult specimen of Upogebia pugnax is described, and the occurrence of the species in Japan is confirmed. New Caledonian specimens previously assigned to U. pugnax probably belong to a new species.


2003 ◽  
Vol 94 (2) ◽  
pp. 115-143 ◽  
Author(s):  
Euan N. K. Clarkson ◽  
John Ahlgren ◽  
Cecilia M. Taylor

ABSTRACTThis paper completes the description of intact and three-dimensional Ctenopyge species from the upper Cambrian Peltura minor Zone in Västergötland, central Sweden. All these species are present together, on the same bedding planes. The most abundant species, Ctenopyge (Eoctenopyge) angusta Westergård, 1922 has previously been described, and an almost complete ontogeny worked out. C. (Ctenopyge) gracilis Henningsmoen, 1957 is a small trilobite with nine thoracic segments and very long, thin curving and subparallel thoracic spines; the genal spines partially encircle the body. Two axial spines at the rear are of considerable length. When reconstructed in side view, the posterior thoracic spines rise upwards as an inclined fan, but when relaxed the tips of all the thoracic and axial spines come to lie in the same plane as the horizontal genal spines. An almost complete ontogeny is described for this species, and individuals show an evident spinosity from an early stage, but the body size at which thoracic segments are liberated is highly variable. C. (Ctenopyge) ahlbergi n. sp. is a larger, robust and broad species distinguished by long, stout genal spines, ten thoracic segments, and a very spiny body with the first three to four spines expanded into lateral flanges. A degree 6 meraspis shows these flanges already developing. C. (Ctenopyge) rushtoni n. sp has likewise ten thoracic segments, and has stout, broad-based and tapering spines. Incomplete meraspides 6 and 7 are known for this species. In both C. (Ctenopyge) ahlbergi and C. (Ctenopyge) rushtoni there are also two axial spines at the rear, and the extended body would have had a similar rising tail fan to that of C. (Ctenopyge) gracilis. C. (Mesoctenopyge) tumida is also present as a single large adult and several smaller holaspides. In this species the first thoracic segment is confirmed as bearing a pair of long curving spines, somewhat smaller than the encircling genal spines. The remaining thoracic spines are straight and sharp, and evidently longer in young holaspides. There is a single long axial spine on the last segment. No adult pygidium has been found.Some comments on the diversity of the fauna as a whole and the range of functional types are appended.


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