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

或许是脊索动，有脊索，分节肌肉和干瘪大骨架。

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.

我们今天我们周围看的主要动群——从海绵节肢动脊索动——都出现纪的这小时间窗口。

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.

人们纪群落里发现了动王国的主要动集群，包括腕足、腔肠、棘皮、软体和脊索（脊椎动进化的分支）。

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，也就是说，它和我们是同一类动，所以这也许是我们最早的祖先了。

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.

尽管很简单， 但这是最早的脊索动之一——属于脊椎动家族的一部分， 包括我们内，使我们相隔 5 亿年成为远亲。