Nailed It: Scientists Describe Weird Ancient Hammerhead Reptile
VOA News
Last updated on: May 06, 2016 9:08 PM (source)
Nailed It: Scientists Describe Weird Ancient Hammerhead Reptile
找到了！科學家描述奇特的遠古錘頭型爬蟲類
VOA News
May 06, 2016 9:08 PM
It was a creature so outlandish that scientists say it reminds them of the fanciful beasts conjured up by Dr. Seuss. But would the famous children's book author have thought up a marine reptile with a hammerhead snout it used to snack on algae?
Scientists on Friday announced the discovery in southern China of new fossils of a reptile from 242 million years ago called Atopodentatus that clarify the nature of this strange crocodile-sized, plant-eating sea-dweller.
When the first fossils of Atopodentatus were found in 2014, scientists thought, based on its poorly preserved skull, it had a down-turned snout resembling a flamingo's beak with a vertical, zipper-like mouth. But two new fossil specimens, described in research published in the journal Science Advances, resolved the matter.
"On a scale of weirdness, I think this is up there with the best. It kind of reminds me of some of the Dr. Seuss creations," National Museums Scotland paleontologist Nicholas Fraser said.
Atopodentatus is the earliest-known herbivorous marine reptile, said paleontologist Olivier Rieppel of the Field Museum in Chicago.
Atopodentatus apparently used chisel-like teeth along the edge of its blunt, hammer-shaped snout to scrape algae off hard underwater surfaces. It then quickly opened its mouth to create suction before closing its jaws to filter the plant material through densely packed and needle-shaped teeth, much like baleen whales strain tiny shrimp-like krill from seawater.
Atopodentatus, about 9 feet (2.75 meters) long, lived in a shallow sea in China's Yunnan province alongside fish and other marine reptiles, said paleontologist Chun Li of the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology.
When thinking of hammerhead creatures, sharks may come to mind. But Atopodentatus' hammerhead feature differed in location and function from the sharks, whose eyes are on the end of lateral extensions on their head.
Atopodentatus appeared during the Triassic Period relatively soon after the biggest mass extinction of species in Earth's history, illustrating that life was bouncing back nicely. Other oddball creatures also swam the seas at the time, including a reptile called Dinocephalosaurus whose neck comprised half of its 17-foot (5.25 meters) length.
"If you saw this reptile [Atopodentatus] in isolation cruising around with some of the fishes of the day, I think you would say it was really quite absurd," Fraser said. "But alongside some of its fellow denizens of the deep, I think it would just appear as one more oddity in a mesmerizing world."
這個古怪的(outlandish)生物讓科學家想到童書作家蘇斯博士(Dr. Seuss)筆下召喚出(conjure up)的那些天馬行空的野獸。但世界上居然有這種錘頭型口鼻(snout)，把藻類(algae)當小點心的海洋爬蟲類生物(reptile)，這位童書名作家大概也想像不到吧！
上週五科學家宣布在中國南方發現了新的化石(fossil)，是兩億四千兩百年前名為「奇異濾齒龍」(Atopodentatus) 的爬蟲類生物，這能釐清(clarity)這種奇特的，如鱷魚般大小、以植物為食的海洋居民的特性。
（編按：Atopodentatus 這個名字是由古希臘字根 atopos 與拉丁字根 dentatus 組合而來，前者是指「怪異的、古怪的、奇特的」等意思，後者指「長有牙齒的」；再加上新聞中對此物種進食方式的描述，中文將之譯為「奇異濾齒龍」。）
奇異濾齒龍的化石首次在2014年時被發現，科學家當時依據這個保存並不完好的頭骨(skull)認為，它的口鼻下彎，類似火鶴(flamingo)的鳥喙(beak)，其嘴部直立並有如拉鍊般。但此次出現的兩個新的化石標本(specimen)，解開了這個謎團，其特徵描述的研究則發表於期刊《科學進展》(Science Advances)中。
蘇格蘭國家博物館的古生物學家(paleontologist)尼古拉斯‧弗雷澤(Nicholas Fraser)說：「若將古怪程度當作量表來參照，我想它大概會落在最古怪的那一端。它會讓我想起蘇斯博士的那些創作。」
芝加哥菲爾德博物館(Field Museum)的古生物學家奧利維爾‧瑞芃(Olivier Rieppel)表示，奇異濾齒龍是目前已知中最早的草食性的(herbivorous)海洋爬蟲類。
沿著奇異濾齒龍鈍圓錘頭型的口鼻部邊緣，有一排鑿子型的牙齒，很顯然是用來刮落(scrape off)水中堅硬物表面上的藻類。之後牠再快速張嘴，在上下顎闔上前製造出吸力，用排列密集，如針型般的牙齒來過濾出植物性物質，這很像鬚鯨從海水中過濾出微小的磷蝦(krill)一樣。
依據中國科學院古脊椎動物與古人類研究所的古生物學家李淳的說法，奇異濾齒龍身長約9英尺（2.75公尺），與其他魚類和海洋爬蟲類動物一起生長在中國雲南省的淺海中。
當我們想到錘頭型的生物時，鯊魚可能很快就會浮現心頭。但奇異濾齒龍的錘頭型特徵，其位置和功能都與鯊魚不同。鯊魚的雙眼是長在橫向(lateral)延展的頭部的末端。
奇異濾齒龍出現在地球史上物種大滅絕後不久的三疊紀(the Triassic)，這表示地球在大滅絕後很快速地恢復了生機。許多古怪的(oddball)生物也在當時的大海中，其中有一種名為「恐頭龍」(Dinocephalosaurus)的爬蟲類動物，其脖子的長度就構成了(comprise)體長17英尺（5.25公尺）的一半。
「如果你看到奇異濾齒龍單獨和魚類混游在一起，我想你大概也會覺得這個場景很突兀(absurd)」，古生物學家弗雷澤如此說著。「但伴隨著其他海洋中特有的棲息生物(denizen)的同夥們，我想牠看起來只會是那奇異迷人的(mesmerizing)世界裡的另一個怪胎(oddity)而已。」
Language Notes
outlandish (a) 異國風格的；古怪的
conjure up (v) 令人回想起；召喚出
snout [riθ] (n) 口鼻部
dweller [`dwɛlɚ] (n) 居民
* dwell [dwɛl] (v) 居住；生活於
flamingo [flə`mɪŋgo] (n) 火鶴
specimen [`spɛsəmən] (n) 標本；樣本
paleontologist [͵pelɪɑn`tɑlədʒɪst] (n)古生物學者
* paleontology [͵pelɪɑn`tɑlədʒɪ] (n) 古生物學
herbivorous [hɚ`bɪvərəs] (a) 草食性的
* herbivore [`hɝbə͵vɔr] (n) 草食動物 [cf.] carnivore [`kɑrnə͵vɔr] (n) 肉食動物；carnivorous [kɑr`nɪvərəs] (a) 肉食性的
scrape something off (v phr) 刮落，擦除
* scrape (v) 擦傷；刮破
lateral (a) 側面的；橫的，橫向的
oddball (a) 古怪的
mesmerize [`mɛsmə͵raɪz] (v) 對. . . . . .施催眠術；迷住
Check your vocabulary!
Fill in the blanks with a word or phrase from the list above. Make necessary changes. After you finish, highlight the blanks to reveal the hidden answers.
I'll have to scrape the ice off the windscreen before we set off.
Dieting always seems to conjure up images of endless salads.
They dwelt in London for two years.
She came to the party wearing an outlandish costume and blond wig.
My father is a world renowned paleontologist.
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A fossil of Atopodentatus unicus is seen alongside a reconstruction showing what it would have looked like in life is shown in this image released May 6, 2016. (Courtesy: Nick Fraser/National Museums Scotland). 
