日前,,研究人員通過計算機(jī)虛擬拼湊最新發(fā)現(xiàn)的滅絕狐猴頭骨碎片,,現(xiàn)已成功地在計算機(jī)上呈現(xiàn)出這種巨型狐猴的完整頭骨模型。據(jù)悉,,巨型狐猴的學(xué)名叫做“Hadropithecus stenognathus”,,其體型與現(xiàn)今的雌性狒狒大小相當(dāng)。目前生活在馬達(dá)加斯加島的紅領(lǐng)狐猴重9磅,,而這種滅絕的巨型狐猴體重卻達(dá)到65磅,。
研究人員虛擬創(chuàng)建的完整巨型狐猴頭骨的相關(guān)詳細(xì)資料發(fā)表在本周出版的《美國國家科學(xué)院學(xué)報》上,據(jù)悉,,迄今為止科學(xué)家只發(fā)現(xiàn)了巨型狐猴的兩塊頭骨,。紐約美國國家歷史博物館伊恩 塔特薩爾說,“這是一種非常罕見特殊的狐猴,,之前我們對它的認(rèn)識十分有限,,僅掌握到成年體頭骨的特征,與目前我們創(chuàng)建的頭骨模型相差甚遠(yuǎn),。”據(jù)悉,,他在《美國國家科學(xué)院學(xué)報》上同期研究報告中發(fā)表了評論注解。
這項最新研究是基于1899年對巨型狐猴的頭骨發(fā)現(xiàn),,當(dāng)時動物化石收集專家弗朗茲·西科拉教授在馬達(dá)加斯加島安德拉霍馬那洞穴里發(fā)現(xiàn)這些頭骨化石的,;2003年,美國波蘭特大學(xué)人類學(xué)家納塔利·瓦塞利帶領(lǐng)一支研究小組重返安德拉霍馬那島進(jìn)行勘測,,他們挖掘出某種神秘物種的頭骨碎片和肢體骨骼,。
他們將這些骨骼化石帶回了波蘭特大學(xué)進(jìn)行分析,瓦塞利的同事蒂莫西·賴安和艾倫·沃爾克使用計算機(jī)X射線斷層掃描技術(shù)(CT)對新骨骼化石進(jìn)行了呈像,,除了對這些化石樣本進(jìn)行CT掃描之外,,研究小組還對巨型狐猴頭骨進(jìn)行了3D呈像,。圖像顯示巨型狐猴是原猴亞目物種中大腦與身體比例最大的物種。
巨型狐猴長著巨大的骨冠狀頭骨,,這非常類似于大猩猩,,它具有強(qiáng)勁的口腔咀嚼肌肉。研究人員稱,,這暗示著這種滅絕狐猴經(jīng)常食用堅硬的食物,,比如:種子和堅果等。
這項研究不僅揭示了這種罕見狐猴的特征,,同時也發(fā)現(xiàn)了一批馬達(dá)加斯加島狐猴物種,。塔特薩爾告訴美國生活科學(xué)網(wǎng)站說,“這項研究非常重要,,它對于理解研究狐猴物種的多樣性具有很大幫助?,F(xiàn)今當(dāng)你來到馬達(dá)加斯加島,你所看到的狐猴物種僅是冰山一角,,從某種程度上講,,該島的完整動物種群與人類到達(dá)之后有很大的差異。”
1.6億年前,,馬達(dá)加斯加島開始從岡瓦納超大陸分離,,在1.24億年前,該島已形成一個獨(dú)立成形的島嶼,,從地理結(jié)構(gòu)上與其他島嶼相分隔,,馬達(dá)加斯加島具有其獨(dú)特的植物群和動物群。狐猴的原始祖先出現(xiàn)于馬達(dá)加斯加島,,最終變化形成8個物種,,其中3個物種現(xiàn)已滅絕。當(dāng)人類在2300年前出現(xiàn)在馬達(dá)加斯加島上時,,幾種狐猴也從此消失了,。
塔特薩爾說,“狐猴物種在體型上有著較大的差異范圍,,像巨型狐猴這樣最大的狐猴在人類抵達(dá)馬達(dá)加斯加島之后便滅絕了,。我認(rèn)為它們滅絕的原因是太容易被捕殺,它們的移動速度很緩慢,,很容易被人類發(fā)現(xiàn)其蹤跡,。此外,由于它們具有較低的生殖率,,更易于遭受攻擊,。”
據(jù)美國國家歷史博物館統(tǒng)計,目前,現(xiàn)存的幾種狐猴物種仍處于瀕危滅絕,,其主要原因是森林過度采伐,,但同時也由于人類打獵和誘捕。(生物谷Bioon.com)
生物谷推薦原始出處:
PNAS published ahead of print July 28, 2008, doi:10.1073/pnas.0805195105
A reconstruction of the Vienna skull of Hadropithecus stenognathus
T. M. Ryan*, D. A. Burney†, L. R. Godfrey‡, U. B. Göhlich§, W. L. Jungers¶, N. Vasey‖, Ramilisonina**, A. Walker*,††, and G. W. Weber‡‡
Abstract
Franz Sikora found the first specimen and type of the recently extinct Hadropithecus stenognathus in Madagascar in 1899 and sent it to Ludwig Lorenz von Liburnau of the Austrian Imperial Academy of Sciences. Later, he sent several more specimens including a subadult skull that was described by Lorenz von Liburnau in 1902. In 2003, some of us excavated at the locality and found more specimens belonging to this species, including much of a subadult skeleton. Two frontal fragments were found, and these, together with most of the postcranial bones, belong to the skull. CT scans of the skull and other jaw fragments were made in Vienna and those of the frontal fragments at Penn State University. The two fragments have been reunited with the skull in silico, and broken parts from one side of the skull have been replaced virtually by mirror-imaged complete parts from the other side. The parts of the jaw of another individual of a slightly younger dental age have also been reconstructed virtually from CT scans with mirror imaging and by using the maxillary teeth and temporomandibular joints as a guide to finish the reconstruction. Apart from forming a virtual skull for biomechanical and systematic analysis, we were also able to make a virtual endocast. Missing anterior pieces were reconstructed by using part of an endocast of the related Archaeolemur majori. The volume is 115 ml. Hadropithecus and Archaeolemur seem to have had relatively large brains compared with the other large-bodied subfossil lemurs.