阿(a)拉(la)摩龍(long)(long)(long)(Alamosaurus),又譯阿(a)拉(la)莫(mo)龍(long)(long)(long),是(shi)薩爾塔龍(long)(long)(long)科下的(de)一(yi)阿(a)拉(la)摩龍(long)(long)(long)阿(a)拉(la)摩龍(long)(long)(long)個(ge)屬,生活(huo)于上白堊(e)紀的(de)北(bei)美洲。它(ta)是(shi)一(yi)種(zhong)大型的(de)四足的(de)植(zhi)(zhi)食(shi)(shi)性恐龍(long)(long)(long),而它(ta)所屬的(de)泰坦巨龍(long)(long)(long)家(jia)族,也(ye)(ye)是(shi)這個(ge)世界上存在(zai)的(de)最后的(de)植(zhi)(zhi)食(shi)(shi)恐龍(long)(long)(long)家(jia)族。身長(chang)超(chao)過30米,體(ti)重可達75噸。阿(a)拉(la)摩龍(long)(long)(long)與其(qi)他蜥(xi)腳(jiao)下目的(de)恐龍(long)(long)(long)相似,有著長(chang)的(de)頸部及尾巴(ba),末端有著鞭索(suo)結(jie)構(gou)。阿(a)拉(la)摩龍(long)(long)(long)和很(hen)多大型蜥(xi)腳(jiao)類植(zhi)(zhi)食(shi)(shi)恐龍(long)(long)(long)一(yi)樣是(shi)大個(ge)子,它(ta)也(ye)(ye)有長(chang)長(chang)的(de)脖子和尾巴(ba)。
阿(a)拉(la)(la)摩(mo)(mo)龍(long)(long)明顯是(shi)泰坦巨龍(long)(long)類的派生成員,但是(shi)它在該科(ke)(ke)(ke)內(nei)的關系卻不甚清楚。一個主(zhu)要(yao)的分析將阿(a)拉(la)(la)摩(mo)(mo)龍(long)(long)與后(hou)凹(ao)尾(wei)龍(long)(long)分類于(yu)薩爾塔龍(long)(long)科(ke)(ke)(ke)的后(hou)凹(ao)尾(wei)龍(long)(long)亞科(ke)(ke)(ke)。另一個主(zhu)要(yao)爭(zheng)論的分析則指阿(a)拉(la)(la)摩(mo)(mo)龍(long)(long)是(shi)柏利連尼龍(long)(long)的姊妹分類,只是(shi)它們都是(shi)被分類在薩爾塔龍(long)(long)科(ke)(ke)(ke)之外。其他科(ke)(ke)(ke)學(xue)(xue)(xue)家(jia)亦發(fa)現,在分支系統學(xue)(xue)(xue)及形態(tai)學(xue)(xue)(xue)上,阿(a)拉(la)(la)摩(mo)(mo)龍(long)(long)與內(nei)烏(wu)肯龍(long)(long)及巴(ba)西的三角區龍(long)(long)有獨特的相似性。
阿拉(la)摩(mo)龍(long)(long)是(shi)北美(mei)(mei)(mei)洲(zhou)晚白堊世唯一的(de)(de)泰坦(tan)龍(long)(long)類(lei),關于(yu)它的(de)(de)起源(yuan)也一直個(ge)存在爭議的(de)(de)話題(ti)。以往(wang)的(de)(de)觀(guan)點(dian)認為阿拉(la)摩(mo)龍(long)(long)可能(neng)從南美(mei)(mei)(mei)州(zhou)或者亞洲(zhou)的(de)(de)路橋遷(qian)徙(xi)而來,但也有可能(neng)起源(yuan)于(yu)北美(mei)(mei)(mei)洲(zhou)本土。我們(men)對(dui)阿拉(la)摩(mo)龍(long)(long)的(de)(de)研究(jiu)大多(duo)源(yuan)于(yu)未(wei)發育(yu)成(cheng)熟(shu)的(de)(de)個(ge)體(ti),近年(nian)對(dui)阿拉(la)摩(mo)龍(long)(long)成(cheng)年(nian)標本的(de)(de)研究(jiu)后得(de)知,阿拉(la)摩(mo)龍(long)(long)其實與南美(mei)(mei)(mei)洲(zhou)的(de)(de)隆柯龍(long)(long)類(lei)關系(xi)更近,所以阿拉(la)摩(mo)龍(long)(long)更有可能(neng)是(shi)由(you)南美(mei)(mei)(mei)洲(zhou)遷(qian)徙(xi)至北美(mei)(mei)(mei)州(zhou)的(de)(de)。主要分(fen)布在今天的(de)(de)美(mei)(mei)(mei)國(guo)南部。
阿(a)拉摩(mo)龍(long)(long)是最后(hou)的(de)(de)蜥腳(jiao)類恐龍(long)(long)之一,成年阿(a)拉摩(mo)龍(long)(long)體(ti)長超(chao)過30米,重(zhong)(zhong)達75噸。因為(wei)它們身體(ti)龐大,所(suo)以(yi)(yi)它們一天可吃(chi)下一噸重(zhong)(zhong)的(de)(de)樹(shu)葉(xie)。十幾只(zhi)(zhi)阿(a)拉摩(mo)龍(long)(long)幾小時就(jiu)能(neng)吃(chi)光一片樹(shu)林。阿(a)拉摩(mo)龍(long)(long)每(mei)(mei)天都必(bi)須四處遷(qian)徙尋找(zhao)食物,因此,科學(xue)家(jia)推(tui)測雌性阿(a)拉摩(mo)龍(long)(long)從不(bu)筑巢生蛋(dan),而(er)是每(mei)(mei)次(ci)只(zhi)(zhi)下5,6只(zhi)(zhi)蛋(dan),從而(er)提(ti)高后(hou)代(dai)的(de)(de)存(cun)活率。通常情況(kuang)下,每(mei)(mei)3000枚蛋(dan)中,只(zhi)(zhi)有一個可以(yi)(yi)順利活到成年。
阿(a)拉(la)摩龍(long)(long)(long)有許多骨(gu)(gu)骼(ge)和散骨(gu)(gu)化石(shi)(shi)的(de)(de)發(fa)現,意味(wei)著阿(a)拉(la)摩龍(long)(long)(long)分(fen)布很(hen)廣,是一(yi)個成(cheng)功的(de)(de)物種。頭(tou)骨(gu)(gu)化石(shi)(shi)仍沒有發(fa)現。保存(cun)最完整的(de)(de)化石(shi)(shi)來(lai)自(zi)于亞成(cheng)年(nian)的(de)(de)阿(a)拉(la)摩龍(long)(long)(long),通過這些化石(shi)(shi)可以(yi)(yi)推(tui)算出成(cheng)年(nian)阿(a)拉(la)摩龍(long)(long)(long)的(de)(de)大(da)小。這些龐大(da)的(de)(de)植食恐(kong)龍(long)(long)(long)可能是以(yi)(yi)群體生活,以(yi)(yi)高大(da)樹木上(shang)的(de)(de)葉(xie)子(zi)為食,然后(hou)用胃里的(de)(de)胃石(shi)(shi)幫助消化。它們(men)和掠食性的(de)(de)暴龍(long)(long)(long)類(lei)恐(kong)龍(long)(long)(long)及其(qi)他獸腳類(lei)恐(kong)龍(long)(long)(long)生活在(zai)同(tong)一(yi)片土地(di)上(shang)很(hen)可能是最后(hou)滅(mie)亡(wang)的(de)(de)非(fei)鳥類(lei)恐(kong)龍(long)(long)(long)之(zhi)一(yi)。
成年阿(a)(a)拉摩(mo)(mo)龍體(ti)型巨(ju)大,沒有(you)(you)天敵(di),但(dan)霸王(wang)龍會攻擊(ji)(ji)小個(ge)(ge)體(ti)阿(a)(a)拉摩(mo)(mo)龍,一(yi)塊小個(ge)(ge)體(ti)的(de)阿(a)(a)拉摩(mo)(mo)龍頸(jing)骨化石(shi),因為上面(mian)還保存(cun)有(you)(you)霸王(wang)龍的(de)牙齒(chi)化石(shi),而在另(ling)一(yi)具小個(ge)(ge)體(ti)阿(a)(a)拉摩(mo)(mo)龍的(de)前肢化石(shi)上也(ye)發現過(guo)霸王(wang)龍的(de)咬痕。可以想象當(dang)時(shi)霸王(wang)龍襲擊(ji)(ji)阿(a)(a)拉摩(mo)(mo)龍時(shi)的(de)場景。