Paleontologists may have discovered when plant-eating dinosaurs evolved their long necks after a new species of sauropodomorph was found in Argentina.

古生物学家或许已经确定了食草恐龙在何时进化出了长颈，此前他们在阿根廷发现了一种新的蜥脚类恐龙物种。

The fossils of the new dinosaur species, named Huayracursor jaguensis, were found in the Santo Domingo Formation in the Andes of La Rioja province in northwestern Argentina, according to a paper Thursday in Nature.

根据周四发表在《自然》杂志上的一篇论文，这一新恐龙物种的化石在阿根廷西北部拉里奥哈省安第斯山脉的圣多明各地层被发现，被命名为胡伊拉库里奥斯。

H. jaguensis likely lived during the Late Triassic period, between 201 million and 237 million years ago.

胡伊拉库里奥斯可能生活在2.01亿至2.37亿年前的晚三叠世。

Its neck bones show signs of extensions that may have resulted in the evolution of long-necked sauropodomorphs that were found in the region in later periods, the researchers said.

其颈骨显示出一些可能导致了长颈蜥脚类恐龙进化的延伸特征，长颈蜥脚类恐龙在后期生存在这一地区， 研究人员说道。

Drastic ecosystem changes took place during the Late Triassic, which led to a rise in diversification in several animal groups, including dinosaurs, early mammal relatives and a group that includes crocodiles, according to the paper.

根据这篇论文，晚三叠世发生了剧烈的生态系统变化，导致一些动物种群多样化程度提高，其中包括恐龙、 早期哺乳动物亲属以及一个包含鳄鱼的种群。

Much of the evidence of early evolution in dinosaurs has been discovered in South America. Most of the key discoveries were made in Ischigualasto-Villa Union Basin in western Argentina and the Parana Basin in southern Brazil.

恐龙早期进化的大部分证据都是在南美洲发现的。 大部分关键发现都是在阿根廷西部的伊斯瓜拉斯托-维亚乌尼翁盆地和巴西南部的巴拉那盆地发现的。

"This new fauna is the first to be recovered from the newly identified Northern Precordillera Basin," the researchers wrote.

研究人员写道：“这是首次从新发现的北普雷科迪勒拉盆地发现的动物群。”

However, H. jaguensis was discovered in a "distinct" region -- in the Andes mountain range about 2 miles above sea level. Sauropodomorphs are herbivores known for their large size and long necks. The clade includes "brontosaurs," the well-known sauropod.

然而，胡伊拉库里奥斯发现于一个“独特的”地区——海拔约2英里（约3.2千米）的安第斯山脉。 蜥脚类恐龙是食草动物，以其巨大的体型和长颈而闻名。 这一进化枝包括著名的蜥脚类动物——“雷龙”。

H. jaguensis is estimated to have measured at nearly 5 feet long and weighed about 40 pounds. It had a shorter neck compared to later sauropodomorphs, but its cervical vertebra showed signs of elongation.

据估计，胡伊拉库里奥斯身长近5英尺（约1.5米），体重约40磅（约18公斤）。 与后来的蜥脚类恐龙相比，它的脖子较短，但其颈椎显示出伸长的迹象。

The finding of H. jaguensis expands what researchers know about the diversity and geographic range of early dinosaurs, the researchers said.

研究人员称，胡伊拉库里奥斯的发现拓展了研究人员对早期恐龙的多样性和地理范围的认知。