Sauropods are part of a larger group of dinosaurs called the sauropodomorphs, or sauropod-like dinosaurs.

蜥脚类恐龙是更大的恐龙群的一部分，称为蜥脚类恐龙或类蜥脚类恐龙。

Early dinosaur morphs, early theropods and early sauropodomorphs have been found in the late Triassic sediments all over the world.

在世界各地的晚三叠世沉积物中都发现了早期恐龙变种、早期兽脚类恐龙和早期蜥脚类动物。

Still, all of the similarities between sauropods and sauropodomorphs means that it's a little hard to tell exactly when sauropods themselves evolved.

尽管如此，蜥脚类动物和蜥脚类动物之间的所有相似之处意味着很难准确判断蜥脚类动物本身是何时进化的。

But the most common definition is that once sauropodomorphs had to stand on all four legs and stopped having grasping fingers, they were officially sauropods.

但最常见的定义是， 一旦蜥脚类动物必须四足站立并且不再有抓握的手指，它们就正式成为蜥脚类动物。

And it looked a lot like the sauropodomorphs that it coexisted with, having a somewhat shorter neck and generally smaller body size than later sauropods.

它看起来很像与之共存的蜥脚类动物，比后来的蜥脚类动物有更短的脖子和更小的体型。

But Vulcanodon had one subtle but important new feature: Unlike other sauropodomorphs, its front legs were about as long as its back legs, and it probably spent all of its time on all fours.

但 Vulcanodon 有一个微妙但重要的新特征：与其他蜥脚类动物不同，它的前腿和后腿差不多长，而且它可能所有时间都用四肢着地。