在阿根廷發(fā)現了小型汽車大小的古代犰狳

在阿根廷發(fā)現了小型汽車大小的古代犰狳

An extraordinary discovery has been made by a farmer in Argentina who was fortunate enough to stumble across the fossil remains of four enormous Glyptodon fossils in the Vallimanca stream channel while transporting cattle. A post from the Institute of Archaeological and Palaeontological Investigations of the Pampa Quaternary (Incuapa-Conicet) details how the specimens were revealed from the earth following a drought in the area that has sapped the stream, forcing the top of a shell into the open.

阿根廷一名農民在運送牛群時，在Vallimanca河流中偶然發(fā)現了四具巨大的雕齒獸化石。Pampa第四紀考古與古生物學研究所的一篇文章詳細介紹了這些標本是如何在干旱之后從地球上被發(fā)現的。

Farmer Juan de Dios Sota was taking his cows to graze when he spotted the unusual protrusion and didn’t recognize it to be the carcass of a horse or cow, which are common in the region. Upon spotting the shell, the farmer contacted the local authorities and a team of palaeontologists was sent out to recover the specimens and assess the four Glyptodons who it appears died together.

農民胡安·德·迪奧斯·索塔(Juan de Dios Sota)在帶著奶牛去吃草時，發(fā)現了這個不尋常的突出物，但他沒有認出這是馬或牛的尸體，這在該地區(qū)很常見。發(fā)現這只貝殼后，這位農民聯系了當地政府，派了一隊古生物學家去找回這些標本，并對這四只雕齒獸進行評估，它們似乎是一起死去的。

Incuapa, Faculty of Social Sciences of the University of the Center of the Province of Buenos Aires and Conicet, researchers work to free the fossil remains from the Salado stream, Bolívar (Incuapa-Conicet)

The unusual discovery will hopefully allow researchers to clarify if this species exhibited sexual dimorphism as the group is believed to be two adults and two juveniles of differing sexes. “These kind of cases, in which several individuals together who died in the same circumstances, are really exceptional and undoubtedly will give us a lot of information about these enigmatic animals and will allow us to test several hypotheses that we have been driving in recent years,” said Palaeontologist on-site Ricardo Bonini, in a statement.

這一不尋常的發(fā)現有望讓研究人員弄清楚，這一物種是否表現出兩性的二態(tài)性，因為該物種被認為是兩個不同性別的成年人和兩個未成年人。“幾個人在相同的情況下一起死亡，這是非常罕見的，毫無疑問，這將給我們提供很多關于這些神秘動物的信息，也將使我們能夠測試我們近年來一直在推動的幾個假設。”現場古生物學家里卡多·博尼尼在一份聲明中說。

Glyptodons roamed in South America for more than 20 million years, and its thought they may have eventually gone extinct at the hands of early man, who may have used the shells of the dead animals as shelter during bad weather. These enormous, heavily armored relatives of armadillos are a part of the mammalian superorder Xenarthra. Like other Xenarthrans, they were herbivorous animals and as such their anatomy was adapted for protection.

雕齒獸在南美洲游蕩了2000多萬年，人們認為它們可能最終在早期人類手中滅絕了，早期人類可能在惡劣的天氣里把死去動物的殼當作庇護所。這些巨大的、全副武裝的犰狳親戚是哺乳動物超目Xenarthra的一部分。像其他的Xenarthrans一樣，它們是食草動物，因此它們的解剖結構被保護著。

Complete glyptodon fossil at the Cleveland Museum of Natural History in Cleveland, Ohio. Tim Evanson/Flickr CC-BY-SA 2.0

They had immensely tough, tortoise-like shells that protected their body, and bony deposits on the skin called osteoderms to protect the parts that protruded from their armor. Despite being the size of modern cars, their arsenal of defense mechanisms implies they were preyed upon and their most likely assailant was a group known as the Terror Birds, a family of flightless carnivorous birds. Glyptodons were confirmed as relatives to modern-day armadillos, whose name in Spanish means “little armored one”, by DNA sequencing carried out in 2016.

它們有非常堅硬的，像烏龜一樣的外殼來保護它們的身體，皮膚上的骨沉積稱為骨皮，用來保護它們盔甲上突出的部分。盡管它們的體型和現代汽車一樣大，但它們強大的防御機制意味著它們曾被捕食，而它們最有可能的攻擊者是一群被稱為“恐怖鳥”的不會飛的食肉鳥類。2016年進行的DNA測序證實，雕齒獸與現代犰狳有親緣關系，犰狳在西班牙語中的意思是“小甲鎧”。