Biologists have long maintained that two groups of pinnipeds, sea lions and walruses, are descended from a terrestrial bearlike animal, whereas the remaining group, seals, shares an ancestor with weasels.

上文第三句以趨同進(jìn)化解釋一種現(xiàn)象：鰭足確實(shí)有可能是為了適應(yīng)水中生活而作出的一個(gè)必要的反應(yīng)九九99视频网；龜国产免费观看试看免费AV、鯨魚(yú)以及儒艮同樣都長(zhǎng)有鰭足满18周岁看的黄片。

I normally eat seals but also can dine on walruses , mussels or even berri es and seaweed.

我通常吃海豹手机免费色网址，但也能吃海象，蚌類男人的天堂网最新网址，甚至是漿果和海藻又大又长的黄色视频。

In Igloolik, Nunavut, Nigel dives from an iceberg and swims with walruses; bowhead whales; an update on the nine arctic fox cubs.

在伊格盧利克，努納武特亚洲无码久久第一页，奈杰爾從冰山跳水和游泳與海象www.18岁禁止网页； bowhead鯨；了最新的9北極狐小熊蜜臀AV性色A片。

Evidence suggests that the bonds between walruses are exceptionally strong: the animals share food, come to one another's aid when under attack and nurse one another's young.

證據(jù)顯示aaa视频色，海象彼此間的關(guān)系超乎尋常的牢固：它們會(huì)分享食物，遭遇攻擊會(huì)相互支援，也會(huì)照顧彼此的小象黄色网站免费别的女教师。

A hard smooth ivory colored dentine that mak es up most of the tusks of elephants and walruses .

一種堅(jiān)硬而光滑的乳白色牙質(zhì)九九视频九九视频在线，構(gòu)成大象和海象的大部分長(zhǎng)牙。

Arctic sunlight dapples a pod of Atlantic walruses swimming in Canada's Foxe Basin.

北極的日光曬起斑紋一個(gè)豆莢狀的斑紋国产精品色三级在线观看，大西洋海象群游泳在加拿大的腹缜榫肥悠担克斯灣。

National Geograph Wallpapers Sun-Dappled walruses Arctic sunlight dapples a pod of Atlantic walruses swimming in Canada's Foxe Basin .

北極的陽(yáng)光斑斑點(diǎn)點(diǎn)地落在一小群正在加拿大溉毡久夥训囊患禔AA片？怂篂硶秤蔚拇笪餮蠛Ｏ笊砩蟞动漫视频。

Arctic sunlight dapples a pod of Atlantic walruses swimming in Canada's Foxe Basin. Walruses are clumsy on land but swim with fluent grace.

北極的陽(yáng)光在一群游弋在加拿大福克斯灣的大西洋海象身上投下點(diǎn)點(diǎn)光斑看黄色录像一级片国产的。。

Walruses have enlarged upper canine teeth, or tusks, up to 3 feet long.

海象具有巨大的上犬齒操女生在线免费看，或獠牙，可以達(dá)到3英尺長(zhǎng)国产精品影院在线。

NEW YORK – Scientists say they've found a "missing link" in the early evolution of seals and walruses — the skeleton of a web-footed, otter-like creature that was evolving away from a life on land.

紐約--科學(xué)家稱他們發(fā)現(xiàn)了一個(gè)海豹和海象早期進(jìn)化的"遺失中的一環(huán)"--一種擁有蹼的腳免费看国产曰批40分钟视频，類水獺生物的化石。這種生物正在朝進(jìn)化遠(yuǎn)離陸地方向進(jìn)化久久免费五月黄片。