Both those features--myomeres and notochords--are found only in chordates.

这两种特征——肌节和脊索——仅存在于脊索动物中。

Forming a notochord like those still found in some of today's jawless fish.

形成像今天某些无颌鱼中仍然存在脊索。

Perhaps the chordate crowd, with their notochords, segmented muscles and big bony skeletons.

或许是脊索动物，有脊索，分节肌肉和干瘪大骨。

The answer then is The chordate.

是脊索动物。

And the rod down its back was a notochord, an early precursor of the vertebral column seen in vertebrates.

而它背部棒结构是脊索，这是脊椎动物中出现脊柱前身。

For one thing, the white lines found on some of those fossils go past the eyestalks where true notochord would end.

其中一个原因是，那些化石上白色线条延伸过了眼柄，而真正脊索应该在那里结束。

Most of the main groups of the animal kingdom—arthropods, brachiopods, coelenterates, echinoderms, molluscs and even chordates, the branch from which vertebrates went on to develop—are found in the fossil beds of the Cambrian.

人们在寒武纪群落里发现了动物王国主要动物集群，包括腕足、腔肠、棘皮、软体和脊索（脊椎动物进化分支）。

The major groups of animals we see around us today -- from sponges to arthropods to chordates -- all showed up in this little window of time in the Cambrian.

今天我们看到主要动物群体——从海绵到节肢动物再到脊索动物——都在寒武纪这个短暂时间窗口中出现了。

It's called a Pikaia and it's a little wormlike creature but it's thought that this is a chordate, and that is the branch of life that we're in, so it could that this is our earliest known ancestor.

它叫皮卡虫，确实和普通虫子差不多，不过人们认为它是一种脊索动物，也就是说，它和我们是同一类动物，所以这也许是我们最祖先了。

Simple as it was, this was one of the earliest chordates -- part of the family that would give rise to the vertebrates and includes us, making us cousins over 500 million years removed.

尽管结构简单， 这却是最脊索动物之一——属于一个最终演化出脊椎动物家族， 而我们人类也属于这个家族，因此我们在5亿多年后成为了远亲。