科学家给两种新角龙命名
文章来源:未知 文章作者:enread 发布时间:2012-03-13 04:57 字体: [ ]  进入论坛
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Two new horned dinosaurs2 have been named based on fossils collected from Alberta, Canada. The new species, Unescopceratops koppelhusae and Gryphoceratops morrisoni, are from the Leptoceratopsidae family of horned dinosaurs. The herbivores(食草动物) lived during the Late Cretaceous period between 75 to 83 million years ago. The specimens4 are described in research published in the Jan. 24, 2012, online issue of the journal Cretaceous Research. "These dinosaurs fill important gaps in the evolutionary5 history of small-bodied horned dinosaurs that lack the large horns and frills of relatives like Triceratops from North America," said Michael Ryan, Ph.D., curator of vertebrate paleontology at The Cleveland Museum of Natural History, lead author on the research. "Although horned dinosaurs originated in Asia, our analysis suggests that leptoceratopsids radiated to North America and diversified6(多样化) here, since the new species, Gryphoceratops, is the earliest record of the group on this continent."

Unescoceratops koppelhusae lived approximately 75 million years ago. It measured about one to two meters (6.5 feet) in length and weighed less than 91 kilograms (200 pounds). It had a short frill extending from behind its head but did not have ornamentation(装饰物) on its skull7. It had a parrot-like beak8. Its teeth were lower and rounder than those of any other leptoceratopsid. In addition, its hatchet-shaped jaw9 had a distinct portion of bone that projected below the jaw like a small chin.

The lower left jaw fragment of Unescoceratops was discovered in 1995 in Dinosaur1 Provincial10 Park, a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site by Philip Currie, Ph.D., now of the University of Alberta. Originally described in 1998 by Ryan and Currie, the dinosaur was referred to as Leptoceratops. Subsequent research by Ryan and David Evans, Ph.D., of the Royal Ontario Museum in Toronto, Canada, determined11 the specimen3 was a new genus and species. The genus is named to honor the UNESCO World Heritage Site designation for the locality where the specimen was found and from the Greek "ceratops(角龙) ," which means "horned face." The species is named for Eva Koppelhus, Ph.D., a palynologist at the University of Alberta and wife of Currie.

Gryphoceratops morrisoni lived about 83 million years ago. It had a shorter and deeper jaw shape than any other leptoceratopsid. Researchers believe the individual was a full-grown adult. Based on unique characteristics of the jaw and its size, the researchers believe that Gryphoceratops was an adult that did not exceed one-half meter in length. This means it is the smallest adult-sized horned dinosaur in North America and one of the smallest adult-sized plant-eating dinosaurs known.

Lower right jaw fragments of Gryphoceratops were discovered in southern Alberta in 1950 by Levi Sternberg while he worked for the Royal Ontario Museum. The genus is named for "Gryphon," a mythological12 Greek figure with the body of a lion and the head of an eagle, which is a reference to the animal's beaked13(有喙的) face. The species name honors Ian Morrison, a Royal Ontario Museum technician, who discovered how the bones fit together.

Second author Evans, associate curator of vertebrate palaeontology at the Royal Ontario Museum and assistant professor at the University of Toronto, said, "Small-bodied dinosaurs are typically poorly represented in the fossil record, which is why fragmentary remains14 like these new leptoceratopsids can make a big contribution to our understanding of dinosaur ecology and evolution."

Contributing authors are Philip Currie, Ph.D., of the University of Alberta; Caleb Brown of the University of Toronto; and Don Brinkman, Ph.D., of the Royal Tyrrell Museum of Palaeontology.



点击收听单词发音收听单词发音  

1 dinosaur xuSxp     
n.恐龙
参考例句:
  • Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击?
  • He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。
2 dinosaurs 87f9c39b9e3f358174d58a584c2727b4     
n.恐龙( dinosaur的名词复数 );守旧落伍的人,过时落后的东西
参考例句:
  • The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
  • Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
3 specimen Xvtwm     
n.样本,标本
参考例句:
  • You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。
  • This specimen is richly variegated in colour.这件标本上有很多颜色。
4 specimens 91fc365099a256001af897127174fcce     
n.样品( specimen的名词复数 );范例;(化验的)抽样;某种类型的人
参考例句:
  • Astronauts have brought back specimens of rock from the moon. 宇航员从月球带回了岩石标本。
  • The traveler brought back some specimens of the rocks from the mountains. 那位旅行者从山上带回了一些岩石标本。 来自《简明英汉词典》
5 evolutionary Ctqz7m     
adj.进化的;演化的,演变的;[生]进化论的
参考例句:
  • Life has its own evolutionary process.生命有其自身的进化过程。
  • These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
6 diversified eumz2W     
adj.多样化的,多种经营的v.使多样化,多样化( diversify的过去式和过去分词 );进入新的商业领域
参考例句:
  • The college biology department has diversified by adding new courses in biotechnology. 该学院生物系通过增加生物技术方面的新课程而变得多样化。 来自《简明英汉词典》
  • Take grain as the key link, develop a diversified economy and ensure an all-round development. 以粮为纲,多种经营,全面发展。 来自《现代汉英综合大词典》
7 skull CETyO     
n.头骨;颅骨
参考例句:
  • The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
  • He fell out of the window and cracked his skull.他从窗子摔了出去,跌裂了颅骨。
8 beak 8y1zGA     
n.鸟嘴,茶壶嘴,钩形鼻
参考例句:
  • The bird had a worm in its beak.鸟儿嘴里叼着一条虫。
  • This bird employs its beak as a weapon.这种鸟用嘴作武器。
9 jaw 5xgy9     
n.颚,颌,说教,流言蜚语;v.喋喋不休,教训
参考例句:
  • He delivered a right hook to his opponent's jaw.他给了对方下巴一记右钩拳。
  • A strong square jaw is a sign of firm character.强健的方下巴是刚毅性格的标志。
10 provincial Nt8ye     
adj.省的,地方的;n.外省人,乡下人
参考例句:
  • City dwellers think country folk have provincial attitudes.城里人以为乡下人思想迂腐。
  • Two leading cadres came down from the provincial capital yesterday.昨天从省里下来了两位领导干部。
11 determined duszmP     
adj.坚定的;有决心的
参考例句:
  • I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
  • He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
12 mythological BFaxL     
adj.神话的
参考例句:
  • He is remembered for his historical and mythological works. 他以其带有历史感和神话色彩的作品而著称。
  • But even so, the cumulative process had for most Americans a deep, almost mythological significance. 不过即使如此,移民渐增的过程,对于大部分美国人,还是意味深长的,几乎有不可思议的影响。
13 beaked 42b0b2b670f3394bbb13dd099d16f8ae     
adj.有喙的,鸟嘴状的
参考例句:
  • A Fox invited a long-beaked Stork to have dinner with him. 狐狸请长嘴鹳同他一起吃饭。 来自互联网
  • Most of the other fossils come from rhynchosaurs (parrot-beaked reptiles). 其他大部分化石来自剪嘴龙(嘴像鹦鹉的爬行动物)。 来自互联网
14 remains 1kMzTy     
n.剩余物,残留物;遗体,遗迹
参考例句:
  • He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
  • The remains of the meal were fed to the dog.残羹剩饭喂狗了。
TAG标签: species dinosaurs horned
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