波塞(sai)東(dong)龍(long)(long)可(ke)能是已知(zhi)的(de)最(zui)高(gao)的(de)恐龍(long)(long)。在美國俄(e)克拉荷馬州(zhou)【oklahoma, usa】發現。波塞(sai)東(dong)龍(long)(long)是一種類(lei)似于腕龍(long)(long)的(de)恐龍(long)(long),但(dan)更大。波塞(sai)東(dong)龍(long)(long)大約有30米(mi)(mi)長,但(dan)可(ke)能高(gao)達18米(mi)(mi),比(bi)最(zui)大的(de)腕龍(long)(long)還高(gao)4-5米(mi)(mi),體重(zhong)達50-60噸(dun)。波塞(sai)東(dong)龍(long)(long)的(de)脖(bo)子(zi)可(ke)能比(bi)馬門溪龍(long)(long)的(de)還長,達到12米(mi)(mi)左右。他(ta)的(de)一截(jie)頸椎就(jiu)有1.5米(mi)(mi)長。
波塞(sai)(sai)東龍(long)的(de)(de)(de)(de)化石包含:四(si)個(ge)天(tian)然狀(zhuang)態(tai)的(de)(de)(de)(de)頸(jing)(jing)(jing)椎(中(zhong)間第(di)五到第(di)八個(ge))、以及(ji)頸(jing)(jing)(jing)部(bu)肋(lei)(lei)(lei)骨(gu)(gu)(gu)(gu)。波塞(sai)(sai)東龍(long)的(de)(de)(de)(de)脊椎骨(gu)(gu)(gu)(gu)非(fei)常地長(chang),最大的(de)(de)(de)(de)一個(ge)脊椎骨(gu)(gu)(gu)(gu)長(chang)度約1.4米,是紀錄中(zhong)最長(chang)的(de)(de)(de)(de)。對于(yu)這些骨(gu)(gu)(gu)(gu)頭的(de)(de)(de)(de)檢驗(yan),顯示出它們是由蜂窩狀(zhuang)骨(gu)(gu)(gu)(gu)細胞所構(gou)成,而且骨(gu)(gu)(gu)(gu)細胞非(fei)常細,類似雞或鴕鳥的(de)(de)(de)(de)骨(gu)(gu)(gu)(gu)細胞,使(shi)得波塞(sai)(sai)東龍(long)的(de)(de)(de)(de)頸(jing)(jing)(jing)部(bu)較(jiao)輕(qing),且較(jiao)容易(yi)舉起。波塞(sai)(sai)東龍(long)的(de)(de)(de)(de)頸(jing)(jing)(jing)部(bu)肋(lei)(lei)(lei)骨(gu)(gu)(gu)(gu)極長(chang),第(di)六(liu)節頸(jing)(jing)(jing)肋(lei)(lei)(lei)的(de)(de)(de)(de)長(chang)度為3.42米,比長(chang)頸(jing)(jing)(jing)巨龍(long)的(de)(de)(de)(de)最長(chang)頸(jing)(jing)(jing)肋(lei)(lei)(lei)長(chang)18%,也超越馬門溪龍(long)的(de)(de)(de)(de)頸(jing)(jing)(jing)肋(lei)(lei)(lei)。
波(bo)塞(sai)(sai)(sai)東龍(long)的(de)(de)(de)體型(xing)估計(ji),是根據波(bo)塞(sai)(sai)(sai)東龍(long)的(de)(de)(de)四個頸椎,與柏林亨波(bo)特博物館的(de)(de)(de)長頸巨龍(long)標(biao)本(編號HM SII)比較得來的(de)(de)(de)數據。編號HM SII標(biao)本是已知最完(wan)整的(de)(de)(de)腕龍(long)類(lei)化石,但該標(biao)本被認為(wei)由不同個體化石拼湊而成,因此數據可能不完(wan)全正確。波(bo)塞(sai)(sai)(sai)東龍(long)與其他(ta)腕龍(long)科近親的(de)(de)(de)比較是困難(nan)的(de)(de)(de),因為(wei)有限的(de)(de)(de)化石紀錄。
波塞(sai)東(dong)龍(long)的(de)的(de)頸(jing)部(bu)長度被(bei)估計為11.25到12米,而(er)編號(hao)HM SII的(de)腕龍(long)標本頸(jing)部(bu)長度為9米。這(zhe)個數據是(shi)假設波塞(sai)東(dong)龍(long)的(de)頸(jing)部(bu)其(qi)它(ta)部(bu)分比例與長頸(jing)巨龍(long)頸(jing)部(bu)比例是(shi)一樣(yang)的(de),這(zhe)是(shi)個非常合(he)理的(de)假設方式。
波(bo)塞(sai)(sai)東龍(long)(long)可能可以將頭部(bu)高(gao)舉過地(di)面(mian)達17米(mi)(mi),大(da)約是(shi)六層樓高(gao)。腕龍(long)(long)科恐龍(long)(long)的(de)長(chang)(chang)頸部(bu)與高(gao)肩膀,使得它(ta)們(men)是(shi)已知最高(gao)的(de)一(yi)群恐龍(long)(long)。在某些層面(mian),波(bo)塞(sai)(sai)東龍(long)(long)的(de)體格類似現代(dai)長(chang)(chang)頸鹿,它(ta)們(men)同樣擁有短身(shen)體與長(chang)(chang)頸部(bu)。相較而言,長(chang)(chang)頸巨龍(long)(long)可將頭部(bu)高(gao)舉到離地(di)面(mian)13.5米(mi)(mi)。波(bo)塞(sai)(sai)東龍(long)(long)的(de)肩膀可能有6或(huo)7米(mi)(mi)高(gao),而身(shen)長(chang)(chang)被估計約為(wei)30米(mi)(mi)或(huo)是(shi)34米(mi)(mi)長(chang)(chang)。
波(bo)塞東(dong)龍(long)(long)(long)的(de)(de)體重(zhong)被估(gu)計(ji)為50到(dao)(dao)(dao)60公(gong)噸(dun)之(zhi)間。波(bo)塞東(dong)龍(long)(long)(long)的(de)(de)脊椎(zhui)骨(gu)(gu)比長(chang)(chang)頸(jing)巨(ju)龍(long)(long)(long)的(de)(de)脊椎(zhui)骨(gu)(gu)還長(chang)(chang)約(yue)25%到(dao)(dao)(dao)33%,但直徑僅(jin)大了10%到(dao)(dao)(dao)15%。這些數(shu)據(ju)意味(wei)者波(bo)塞東(dong)龍(long)(long)(long)的(de)(de)身體可能比長(chang)(chang)頸(jing)巨(ju)龍(long)(long)(long)還巨(ju)大,但就比例而言頸(jing)部(bu)較小(xiao)。長(chang)(chang)頸(jing)巨(ju)龍(long)(long)(long)的(de)(de)體重(zhong)為40到(dao)(dao)(dao)44公(gong)噸(dun),這個數(shu)據(ju)是將不(bu)同測(ce)量的(de)(de)結(jie)果平均(jun)得到(dao)(dao)(dao)的(de)(de)數(shu)據(ju)。然而,任何估(gu)計(ji)都(dou)是某(mou)些科學家的(de)(de)一(yi)家之(zhi)言,就已經(jing)發現的(de)(de)恐龍(long)(long)(long)木(mu)乃伊就較其骨(gu)(gu)骼判斷要大1/4來(lai)分析,基于4節頸(jing)骨(gu)(gu)的(de)(de)波(bo)塞東(dong)龍(long)(long)(long)的(de)(de)最大估(gu)計(ji)值為肩高8.5米(mi),臀高6.75米(mi),頭部(bu)可以(yi)達(da)到(dao)(dao)(dao)18.3米(mi)高,體重(zhong)在55噸(dun)以(yi)上或達(da)到(dao)(dao)(dao)80噸(dun)。
然(ran)而,相較(jiao)于(yu)長頸(jing)巨龍(long),波(bo)(bo)塞東龍(long)擁(yong)有相對(dui)細(xi)(xi)長的頸(jing)部(bu)。如果波(bo)(bo)塞東龍(long)的身體(ti)(ti)也是(shi)較(jiao)為細(xi)(xi)長,那之(zhi)前所估計的數(shu)據將會過高。舉(ju)例而言(yan),體(ti)(ti)型(xing)較(jiao)粗(cu)壯的迷(mi)惑龍(long),體(ti)(ti)重(zhong)比身體(ti)(ti)較(jiao)長、但體(ti)(ti)型(xing)修長的梁龍(long)還重(zhong)。此(ci)外,波(bo)(bo)塞東龍(long)可(ke)(ke)能(neng)擁(yong)有氣囊系統,類似鳥(niao)類,氣囊系統可(ke)(ke)減低(di)蜥腳類恐(kong)龍(long)的體(ti)(ti)重(zhong)約20%以(yi)上(shang)。
波塞(sai)東(dong)龍(long)(long)(long)(long)可能是(shi)北美洲(zhou)最后(hou)的巨大蜥(xi)腳類恐(kong)龍(long)(long)(long)(long)。蜥(xi)腳類恐(kong)龍(long)(long)(long)(long)包含(han)陸地上出現過最大的動物,是(shi)群分布(bu)(bu)廣(guang)泛且成功的演(yan)化支。它們首次出現于早侏(zhu)(zhu)羅紀(ji),并且很(hen)快(kuai)地散(san)布(bu)(bu)到全世界。到了晚(wan)侏(zhu)(zhu)羅紀(ji),梁龍(long)(long)(long)(long)科(ke)與腕龍(long)(long)(long)(long)科(ke)恐(kong)龍(long)(long)(long)(long)在(zai)北美洲(zhou)與非洲(zhou)等地占(zhan)優(you)勢,到了晚(wan)白(bai)堊(e)紀(ji),泰坦巨龍(long)(long)(long)(long)科(ke)廣(guang)泛分布(bu)(bu)于南半球。在(zai)晚(wan)侏(zhu)(zhu)羅紀(ji)到晚(wan)白(bai)堊(e)紀(ji)期(qi)(qi)間,蜥(xi)腳類的化石紀(ji)錄很(hen)稀少。這(zhe)段期(qi)(qi)間的北美洲(zhou)很(hen)少發現標本(ben),所發現的標本(ben)也通常(chang)是(shi)破碎骨(gu)頭,或是(shi)幼年個(ge)體。而白(bai)堊(e)紀(ji)存活的蜥(xi)腳類恐(kong)龍(long)(long)(long)(long)在(zai)體型上縮減(jian)(身(shen)長減(jian)到15米左右,而體重為10到15公噸),因此波塞(sai)東(dong)龍(long)(long)(long)(long)的發現相當不尋(xun)常(chang)。
波塞(sai)東龍(long)生存于墨西(xi)哥灣的(de)海岸,墨西(xi)哥灣的(de)海岸在當時(shi)侵入到奧克拉荷馬州一(yi)帶,形成巨大的(de)三角洲,類似今(jin)日的(de)密西(xi)西(xi)比河(he)三角洲。這個地區在當時(shi)可能沒有(you)掠食動物可以(yi)(yi)攻擊完全成長的(de)波塞(sai)東龍(long)個體(ti),但肉(rou)食龍(long)下目的(de)高棘(ji)龍(long)(體(ti)型較(jiao)小于暴龍(long))與以(yi)(yi)群體(ti)行動的(de)恐爪龍(long)可能以(yi)(yi)幼(you)年波塞(sai)東龍(long)個體(ti)為獵物。
在2004年,德恩·奈許(xu)(Darren Naish)與(yu)他的同事敘述了一只巨大(da)腕(wan)龍(long)科恐(kong)(kong)龍(long),該(gai)恐(kong)(kong)龍(long)發(fa)現(xian)于早(zao)白堊(e)紀的英格蘭,并類似于波(bo)塞(sai)東(dong)龍(long)。該(gai)腕(wan)龍(long)科恐(kong)(kong)龍(long)僅(jin)發(fa)現(xian)兩個頸椎,在某些細節明顯(xian)地類似波(bo)塞(sai)東(dong)龍(long),而它們可能在體型(xing)上相似。該(gai)腕(wan)龍(long)科恐(kong)(kong)龍(long)的發(fa)現(xian)突顯(xian)了早(zao)白堊(e)紀時期北美(mei)洲與(yu)歐(ou)洲恐(kong)(kong)龍(long)的相似。