阿拉(la)摩(mo)龍(long)(Alamosaurus),又譯阿拉(la)莫龍(long),是(shi)薩(sa)爾塔龍(long)科(ke)下(xia)的一(yi)阿拉(la)摩(mo)龍(long)阿拉(la)摩(mo)龍(long)個屬(shu),生活(huo)于上(shang)白(bai)堊(e)紀的北美(mei)洲。它(ta)是(shi)一(yi)種大型的四足的植食(shi)(shi)性恐龍(long),而它(ta)所屬(shu)的泰坦(tan)巨龍(long)家(jia)族(zu),也(ye)是(shi)這個世界上(shang)存在的最后的植食(shi)(shi)恐龍(long)家(jia)族(zu)。身(shen)長超(chao)過30米,體重(zhong)可達75噸。阿拉(la)摩(mo)龍(long)與其他(ta)蜥腳(jiao)下(xia)目(mu)的恐龍(long)相(xiang)似,有(you)著(zhu)長的頸部(bu)及尾巴,末端有(you)著(zhu)鞭(bian)索(suo)結構。阿拉(la)摩(mo)龍(long)和很多大型蜥腳(jiao)類(lei)植食(shi)(shi)恐龍(long)一(yi)樣是(shi)大個子(zi)(zi),它(ta)也(ye)有(you)長長的脖子(zi)(zi)和尾巴。
阿(a)拉(la)(la)摩(mo)龍(long)(long)(long)明(ming)顯是(shi)泰坦巨龍(long)(long)(long)類的(de)(de)派生成員,但是(shi)它(ta)在該科內的(de)(de)關(guan)系卻不甚(shen)清楚。一個主(zhu)(zhu)要的(de)(de)分(fen)(fen)(fen)析將阿(a)拉(la)(la)摩(mo)龍(long)(long)(long)與后凹(ao)尾龍(long)(long)(long)分(fen)(fen)(fen)類于薩(sa)爾塔龍(long)(long)(long)科的(de)(de)后凹(ao)尾龍(long)(long)(long)亞科。另一個主(zhu)(zhu)要爭(zheng)論的(de)(de)分(fen)(fen)(fen)析則指阿(a)拉(la)(la)摩(mo)龍(long)(long)(long)是(shi)柏(bo)利連尼龍(long)(long)(long)的(de)(de)姊妹分(fen)(fen)(fen)類,只是(shi)它(ta)們都(dou)是(shi)被分(fen)(fen)(fen)類在薩(sa)爾塔龍(long)(long)(long)科之外。其他(ta)科學家亦發現,在分(fen)(fen)(fen)支系統學及形態學上(shang),阿(a)拉(la)(la)摩(mo)龍(long)(long)(long)與內烏肯龍(long)(long)(long)及巴(ba)西的(de)(de)三角區龍(long)(long)(long)有獨(du)特的(de)(de)相似性。
阿拉摩(mo)(mo)龍(long)是(shi)北美(mei)(mei)洲(zhou)(zhou)晚白堊世唯(wei)一的泰坦龍(long)類,關于它的起源(yuan)也一直個存在(zai)爭(zheng)議的話(hua)題。以往的觀點認為(wei)阿拉摩(mo)(mo)龍(long)可(ke)(ke)能從南(nan)(nan)美(mei)(mei)州或者(zhe)亞洲(zhou)(zhou)的路(lu)橋遷徙而來,但也有(you)可(ke)(ke)能起源(yuan)于北美(mei)(mei)洲(zhou)(zhou)本土。我們(men)對阿拉摩(mo)(mo)龍(long)的研究(jiu)大多源(yuan)于未發(fa)育成(cheng)熟(shu)的個體(ti),近(jin)年(nian)對阿拉摩(mo)(mo)龍(long)成(cheng)年(nian)標(biao)本的研究(jiu)后得(de)知(zhi),阿拉摩(mo)(mo)龍(long)其(qi)實與南(nan)(nan)美(mei)(mei)洲(zhou)(zhou)的隆柯(ke)龍(long)類關系更近(jin),所以阿拉摩(mo)(mo)龍(long)更有(you)可(ke)(ke)能是(shi)由南(nan)(nan)美(mei)(mei)洲(zhou)(zhou)遷徙至北美(mei)(mei)州的。主要分布(bu)在(zai)今天的美(mei)(mei)國南(nan)(nan)部。
阿拉(la)摩(mo)龍是(shi)最(zui)后的(de)蜥腳類恐龍之一(yi),成(cheng)(cheng)年阿拉(la)摩(mo)龍體長超過30米,重(zhong)達75噸(dun)(dun)。因(yin)為它們身體龐大,所以它們一(yi)天(tian)可吃下一(yi)噸(dun)(dun)重(zhong)的(de)樹(shu)葉。十(shi)幾(ji)只(zhi)阿拉(la)摩(mo)龍幾(ji)小時(shi)就能吃光一(yi)片樹(shu)林。阿拉(la)摩(mo)龍每天(tian)都必(bi)須四處(chu)遷(qian)徙尋找食物,因(yin)此(ci),科學家推測雌性(xing)阿拉(la)摩(mo)龍從(cong)不筑(zhu)巢(chao)生蛋(dan),而(er)是(shi)每次只(zhi)下5,6只(zhi)蛋(dan),從(cong)而(er)提高后代(dai)的(de)存活率(lv)。通常(chang)情(qing)況下,每3000枚蛋(dan)中,只(zhi)有一(yi)個可以順利活到成(cheng)(cheng)年。
阿拉(la)摩(mo)龍(long)(long)(long)有許多骨骼和散骨化(hua)(hua)(hua)石(shi)的(de)(de)發(fa)(fa)現(xian),意味著阿拉(la)摩(mo)龍(long)(long)(long)分布(bu)很廣,是(shi)一(yi)個成功的(de)(de)物種(zhong)。頭骨化(hua)(hua)(hua)石(shi)仍沒有發(fa)(fa)現(xian)。保存最(zui)完(wan)整的(de)(de)化(hua)(hua)(hua)石(shi)來自于亞成年(nian)的(de)(de)阿拉(la)摩(mo)龍(long)(long)(long),通過這(zhe)些化(hua)(hua)(hua)石(shi)可以推算出成年(nian)阿拉(la)摩(mo)龍(long)(long)(long)的(de)(de)大小(xiao)。這(zhe)些龐大的(de)(de)植食(shi)(shi)(shi)恐龍(long)(long)(long)可能是(shi)以群體生活(huo)(huo),以高(gao)大樹(shu)木上的(de)(de)葉子(zi)為(wei)食(shi)(shi)(shi),然后用(yong)胃里的(de)(de)胃石(shi)幫助消化(hua)(hua)(hua)。它們和掠食(shi)(shi)(shi)性的(de)(de)暴龍(long)(long)(long)類恐龍(long)(long)(long)及其他獸腳類恐龍(long)(long)(long)生活(huo)(huo)在同一(yi)片土地上很可能是(shi)最(zui)后滅亡(wang)的(de)(de)非鳥類恐龍(long)(long)(long)之一(yi)。
成年阿(a)(a)拉(la)摩龍(long)(long)體型巨(ju)大,沒有天(tian)敵,但霸(ba)王(wang)龍(long)(long)會攻擊小個(ge)(ge)體阿(a)(a)拉(la)摩龍(long)(long),一塊小個(ge)(ge)體的(de)(de)阿(a)(a)拉(la)摩龍(long)(long)頸骨化石(shi)(shi),因為上(shang)面還(huan)保存有霸(ba)王(wang)龍(long)(long)的(de)(de)牙齒化石(shi)(shi),而在另一具小個(ge)(ge)體阿(a)(a)拉(la)摩龍(long)(long)的(de)(de)前肢(zhi)化石(shi)(shi)上(shang)也發現過霸(ba)王(wang)龍(long)(long)的(de)(de)咬痕。可以想(xiang)象(xiang)當(dang)時(shi)霸(ba)王(wang)龍(long)(long)襲(xi)擊阿(a)(a)拉(la)摩龍(long)(long)時(shi)的(de)(de)場景。