德克薩斯大學(xué)的自然人類學(xué)家C.Kirk宣布自己發(fā)現(xiàn)了新的化石靈長類動物，并將其命名為Mescalerolemur horneri,，發(fā)現(xiàn)地點為西德克薩期州的“惡魔墓地”（Devil’s Graveyard）,。
Mescalerolemur horneri的上顎（左，中）和下顎（右）
梅斯卡勒羅狐猴（Mescalerolemur）生活于4300萬年前的始新世，與現(xiàn)代狐猴極其相似,。它是已滅絕靈長類兔猴型動物（Adapiforms）中的一種,，兔猴型動物在始新世的北半球地層中均有發(fā)現(xiàn)。與北美相比,，梅斯卡勒羅狐猴與歐亞大陸和非洲大陸的兔猴型動物親緣關(guān)系更近,。Krik說，梅斯卡勒羅狐猴與之前發(fā)現(xiàn)的始新世靈長類群體很不一樣,，梅斯卡勒羅狐猴與倭兔猴屬（Mghgarita）僅發(fā)現(xiàn)于德克薩斯的大拐彎地區(qū)（the Big Bend region）,，出現(xiàn)于廣布北美的兔猴型動物之后，它的發(fā)現(xiàn),，為中始新世北美與歐亞大陸之間動物交流提供了新的證據(jù),。
始新世末期，由于全球變冷,，北美的靈長類動物和其他熱帶屬種均逐漸消失,。Kirk的發(fā)現(xiàn)，顯示了北美靈長類的最后一次爆發(fā),。西德克薩斯州緯度相對較低,，氣候更為穩(wěn)定，為喜暖動物提供了最后的庇護(hù)所,。2005年M.Butcher在這里發(fā)現(xiàn)了一顆梅斯卡勒羅狐猴的牙齒化石,，之后，大量靈長類化石在比“惡魔墓地”還要早3至4百萬年的一個叫“紫灘”（Purple Bench）的地方被發(fā)現(xiàn),，“惡魔墓地”曾產(chǎn)出倭兔猴屬化石,。
Kirk曾以為發(fā)現(xiàn)的只是倭兔猴屬的一個新種，但是后來隨著化石材料的逐漸增多,，他開始意識到,，一個新屬已經(jīng)被發(fā)現(xiàn)。梅斯卡勒羅狐猴體型極小,，僅重370克左右,，與現(xiàn)代狐猴極為相似。不過,，梅斯卡勒羅狐猴的發(fā)現(xiàn)仍表明,，兔猴型動物與狐猴和叢猴的親緣關(guān)系較其與人類的親緣關(guān)系更近。比如,，梅斯卡勒羅狐猴下顎的左右部分是兩塊單獨的骨骼,，靠聯(lián)接帶連接起來。這是狐猴和叢猴的典型特征,，而兔猴型動物中的一種Mahgarita stevensi，則擁有與人類相似的融合下顎,。但是由于梅斯卡勒羅狐猴與兔猴型動物親緣極近,，融合下顎的特征出現(xiàn)在兔猴型動物與猴和猿類中應(yīng)該為互相獨立的演化過程,。（生物谷Bioon.com）
生物谷推薦原文：
Journal of Human Evolution DOI:10.1016/j.jhevol.2011.02.014
New adapiform primate of Old World affinities from the Devil’s Graveyard Formation of Texas
E. Christopher Kirka, , and Blythe A. Williams
Most adapiform primates from North America are members of an endemic radiation of notharctines. North American notharctines flourished during the Early and early Middle Eocene, with only two genera persisting into the late Middle Eocene. Here we describe a new genus of adapiform primate from the Devil’s Graveyard Formation of Texas. Mescalerolemur horneri, gen. et sp. nov., is known only from the late Middle Eocene (Uintan) Purple Bench locality. Phylogenetic analyses reveal that Mescalerolemur is more closely related to Eurasian and African adapiforms than to North American notharctines. In this respect, M. horneri is similar to its sister taxon Mahgarita stevensi from the late Duchesnean of the Devil’s Graveyard Formation. The presence of both genera in the Big Bend region of Texas after notharctines had become locally extinct provides further evidence of faunal interchange between North America and East Asia during the middle Eocene. The fact that Mescalerolemur and Mahgarita are both unknown outside of Texas also supports prior hypotheses that low-latitude faunal assemblages in North America demonstrate increased endemism by the late middle Eocene.
Keywords: Adapidae; Caenopithecinae; Cercamoniinae; Asiadapinae; Notharctinae; Eocene; Uintan; Mescalerolemur; Mahgarita
